A liquid crystal display (LCD) device includes an LCD panel having a plurality of data lines and a plurality of gate lines crossing the data lines, a data driving circuit to generate a data voltage, a demultiplexer to apply the data voltage from the data driving circuit to the data lines using a plurality of switching devices, and a control signal generator to generate a plurality of control signals having a first polarity of voltage in order to turn on the switching devices and in order to add a second polarity of voltage to the control signals.

1. Field of the Invention
The present invention relates to a liquid crystal display (LCD), and more particularly, to a demultiplexer for an LCD and a driving method thereof.
2. Discussion of the Related Art
In general, an LCD controls light transmittance of liquid crystals in accordance with a video signal so that a picture corresponding to the video signal can be displayed on the LCD. The LCD includes an LCD panel having liquid crystal cells arranged in an active matrix type, and driving circuits for driving the LCD panel. In the LCD panel, a plurality of data lines and a plurality of gate lines are intersected, and pixel driving thin film transistors (TFTs) are provided at respective intersected portions. The driving circuits of the LCD include a data driving circuit for supplying a data to the data lines of the LCD panel, and a gate driving circuit for supplying a scanning pulse to the LCD panel. Further, the driving circuits may include a demultiplexer provided between the data driving circuit and the data lines to distribute outputs of the data driving circuit into the data lines. The demultiplexer reduces the number of the outputs of the data driving circuit to simplify the data driving circuit and reduce the number of data input terminals of the LCD panel.
FIG. 1 shows a related art active matrix LCD. As shown in FIG. 1, the related art active matrix LCD includes an LCD panel 13 having m data lines DL1-DLm and n gate lines GL1-GLn crossing each other and a pixel driving TFT 16 provided at each intersection, a demultiplexer 14 provided between a data driving circuit 11 and the data lines DL1-DLm, and a gate driving circuit 12 for sequentially supplying a scanning pulse to the gate lines GL1-GLn.
The pixel driving TFT 16 applies a data signal from each of the data lines DL1-DLm to a pixel electrode 15 of a liquid crystal cell in response to a scanning signal from each of the gate lines GL1-GLn. Herein, the pixel driving TFT 16 has a gate electrode connected to a corresponding one of the gate lines GL1-GLn, a source electrode connected to a corresponding one of the data lines DL1-DLm, and a drain electrode connected to the pixel electrode 15 of the liquid crystal cell.
The data driving circuit 11 converts digital video data into analog gamma voltages, and makes a data time division for one line to apply the voltages to m/3 source lines SL1-SLm/3. The mn/3 demultiplexers 14 are arranged parallel to each other between the data driving circuit 11 and the data lines DL1-DLm. Each of the demultiplexers 14 includes first through third TFTs (hereinafter referred to as "MUX TFT") MT1, MT2 and MT3. The first through third MUX TFTs MT1, MT2 and MT3 make a time division of data input over one signal line in response to different control signals Φ1, Φ2 and Φ3 to apply these control signals to three data lines. The gate driving circuit 12 sequentially applies scanning pulses to the gate lines GL1-GLn by using a shift register and a level shifter.
FIG. 2 shows control signals Φ1, Φ2 and Φ3 and scanning pulses SP of the demultiplexer 14. As shown in FIG. 2, the scanning pulse SP has a gate high voltage Vgh during approximately one horizontal period 1H while maintaining a gate low voltage Vgl during the remaining period. A duty ratio of the scanning pulse SP is approximately one by several hundreds because one frame interval includes hundreds of horizontal periods.
Each of the control signals Φ1, Φ2 and Φ3 has the gate high voltage Vgh during approximately ⅓ horizontal period every horizontal period. A duty ratio of each of the control signal Φ1, Φ2 and Φ3 is about ½ to 1 by several numbers because each control signal is generated every horizontal period. Herein, when a duty ratio of each control signal is ½, only two of the MUX TFTs are included in a single demultiplexer.
The MUX TFTs MT1, MT2 and MT3 and the pixel driving TFT 16 are directly and simultaneously provided on a glass substrate of the LCD panel 13, and have the same swing width between the gate high voltage Vgh and the gate low voltage Vgl. If the MUX TFTs MT1, MT2 and MT3 are supplied with gate voltages having the same polarity for a long time, that is, if they receive a positive gate bias stress or a negative gate bias stress, variation and deterioration of operation characteristics occur more easily. The variation and deterioration results from the MUX TFTs MT1, MT2 and MT3 having a longer gate voltage application time than the pixel driving TFT 16 as shown in FIG. 2. Particularly, if the MUX TFTs MT1, MT2 and MT3 are formed from amorphous silicon TFT, then the variation and deterioration of operation characteristics occur more easily against the positive gate bias stress or the negative gate bias stress because a semiconductor layer structure of the amorphous silicon TFT has more defects than those of polycrystalline silicon TFT (poly-Si TFT). The variation in operation characteristics of the MUX TFTs MT1, MT2 and MT3 can be seen from experimental results in FIGS. 3 and 4.
FIGS. 3 and 4 show experimental results indicating that a characteristic change of a sample hydride amorphous silicon (a-Si:H TFT) happened when a positive gate bias stress and a negative gate bias stress were applied to the sample a-Si:H TFT having a channel width/channel length W/L of 120 μm/6 μm, respectively. In FIGS. 3 and 4, the horizontal axis represents a gate voltage [V] of the sample a-Si:H TFT while the vertical axis represents a current [A] between the source terminal and the drain terminal of the sample a-Si:H TFT.
FIG. 3 shows a threshold voltage and a movement in a transfer characteristic curve of a TFT according to a voltage application time when a voltage of +30V is applied to a gate terminal of the sample a-Si:H TFT. In FIG. 3, as the time when a high positive voltage is applied to the gate terminal of the a-Si:H TFT becomes longer, the transfer characteristic curve of the TFT is moved more to the right side 31 and the threshold voltage of the a-Si:H TFT rises.
FIG. 4 shows a threshold voltage and a movement in a transfer characteristic curve of a TFT according to a voltage application time when a voltage of −30V is applied to the gate terminal of the sample a-Si:H TFT. In FIG. 4, as the time when a high negative voltage is applied to the gate terminal of the a-Si:H TFT becomes longer, the transfer characteristic curve of the TFT is moved more to the left side (41) and the threshold voltage of the a-Si:H TFT is lowered.
FIG. 5 shows an accumulation of gate voltage stresses undergone at each of the MUX TFTs MT1, MT2 and MT3. In FIG. 5, as the gate voltage stresses of the MUX TFTs MT1, MT2 and MT3 are accumulated whenever the same polarity of the control signals Φ1, Φ2 and Φ3 are applied thereto, a threshold voltage of each of the MUX TFTs MT1, MT2 and MT3 gradually rises or falls. As the threshold voltage of the MUX TFT rises or falls in this manner, an operation of the demultiplexer 14 becomes unstable, thereby causing difficulty to normally drive the LCD.

Liquid crystal display and driving method thereof


Methods and systems are provided for assisting financial services firms and their representatives in efficiently managing their businesses, and in developing and maintaining strong customer service and loyalty. An integrated, preferably web based browser operated system is provided that uses one or more central databases to store customer, account, accounting, compliance, and other relevant information. Interfaces and tools are also provided for accessing the one or more central databases in a manner that is consistent with and supports how a representative actually works.

The distribution model used by the financial services industry to move investment products often begins with the DTCC (Depository Trust Clearing Corporation—formerly NSCC). The DTCC clears a majority of the investment market's equity, debt and mutual fund trades. Additionally, the DTCC clears some industry insurance transactions. Financial services firms such as Broker Dealers, who transact business through the DTCC, must either be a Clearing Broker Dealer or a correspondent to a Clearing Broker Dealer. Clearing Broker Dealers generally have systems that facilitate trading with the DTCC.
There are various types of Broker Dealers, including for example, insurance based Broker Dealers, bank based Broker Dealers, independent Broker Dealers, specialty niche Broker Dealers, and others. Insurance-based Broker Dealers have evolved to support the distribution of variable life and annuity products. In some cases, the insurance based Broker Dealers have grown to be quite sophisticated in order to attract sales professionals to sell not only the insurer's products, but other investment products.
Changes in legislation have allowed bank-based Broker Dealers to grow and acquire similar entities. As such, bank based Broker Dealers have become more sophisticated over time. They continue to attract representatives from wire house firms (i.e., Merrill Lync®, Paine Webber®, etc.), and train their representatives to focus on cross-selling bank and bank-related financial services. The cross-selling nature of their business requires the focus of referral tracking (identifying who in the bank or division referred the customer to the representative).
Independent Broker Dealers have been formed over time to provide a vehicle for successful registered representatives who have built their businesses through the traditional wire house environment. These successful professionals are attracted to the independent Broker Dealers because of an enhanced payout schedule. They are, however, often disappointed by the technological solutions provided by the Independent Broker Dealers. Affiliate offices are typically tied to independent Broker Dealers.
Specialty niche Broker Dealers have been formed to support vertically aligned specialty firms such as accountancy corporations and consumer and mortgage loan providers. These professionals attempt to cross sell their primary customers additional investment products.
Over the past few decades, the development and use of computers and computer technology to help manage the business of the larger financial service firms has grown rapidly. Smaller Broker Dealers have been left behind, however, because the commercially available technology solutions are simply cost prohibitive. Also during this period, the number of products offered by the financial services firms have increased substantially. Many of the product offerings were added in an incremental fashion, over an extended period of time. Consistent therewith, the software products developed to support the various product offerings were also incrementally developed. The legacy of this environment is a group of rather expensive yet powerful software applications that operate and are accessible primarily independently of one other, resulting in multiple standards, redundant files, and often data errors and failed system cross-processing. In many cases, such systems have caused significant harm to customer relationships and firm reputations.
What would be desirable, therefore, is a more affordable integrated system that assists financial services firms such as Broker Dealers in efficiently managing their businesses, and developing and maintaining strong customer service and loyalty.

Methods and systems for assisting financial services firms and their representatives


Embodiments are described for a pattern-based control system that learns and applies device usage patterns for identifying and disabling devices exhibiting abnormal usage patterns. The system can learn a user's normal usage pattern or can learn abnormal usage patterns, such as a typical usage pattern for a stolen device. This learning can include human or algorithmic identification of particular sets of usage conditions (e.g., locations, changes in settings, personal data access events, application events, IMU data, etc.) or training a machine learning model to identify usage condition combinations or sequences. Constraints (e.g., particular times or locations) can specify circumstances where abnormal pattern matching is enabled or disabled. Upon identifying an abnormal usage pattern, the system can disable the device, e.g., by permanently destroying a physical component, semi-permanently disabling a component, or through a software lock or data encryption.

It is estimated that over 70 million mobile devices are stolen each year, and less than 7% of these are recovered. In addition, devices are becoming ever more valuable, often costing thousands of dollars to replace. However, the cost of a stolen device often goes far beyond the monetary value of the device itself. The theft of personal information, financial information, credentials to other systems, etc. can far outweigh the cost of replacing stolen hardware.
There are numerous systems aimed at combating device theft. For example, many devices employ encryption technologies, authentication procedures, and biometrics to protect device data. However, the high value of devices and recoverable data available to device thieves results in the number of stolen devices rising each year.
The techniques introduced here may be better understood by referring to the following Detailed Description in conjunction with the accompanying drawings, in which like reference numerals indicate identical or functionally similar elements.

Device deactivation based on behavior patterns


In a speech encoder, a gain codebook switching circuit is supplied with short-term prediction gains from a short-term prediction gain calculator circuit and with mode information through an input terminal and compares the short-term prediction gains with a predetermined threshold value when the mode information indicates a predetermined mode. As a result of comparison, the gain codebook switching circuit produces gain codebook switching information which is delivered to a gain quantizer circuit. The gain codebook quantizer circuit is supplied with adaptive code vectors, excitation code vectors, impulse response information, and the gain codebook switching information, and gain code vectors from a particular gain codebook connected to one of a plurality of input terminals that is selected by the gain codebook switching information. For the excitation code vectors being selected, the gain quantizer circuit selects combinations of the excitation code vectors and the gain code vectors in the gain codebook selected by the gain codebook switching information.

This invention relates to a speech encoder operable with a short processing delay and, in particular, to a speech encoder for encoding a speech or voice signal with a high quality at a short frame period or length of 5 ms to 10 ms or shorter.
A conventional speech encoding system is disclosed, for example, in a paper contributed by K. Ozawa et al to the IEICE Trans. Commun. Vol. E77-B, No. 9 (September 1994), pages 1114-1121, under the title of "M-LCELP Speech Coding at 4 kb/s with Multi-Mode and Multi-Codebook" (Reference 1).
According to the above-referenced conventional system, a speech signal is encoded in a transmitting side as follows. By the use of linear predictive coding (LPC), spectral parameters representative of spectral characteristics are extracted from the speech signal at every frame having a frame length of, for example, 40 ms. Calculation is made of feature quantities for signal frames or weighted signal frames obtained by perceptually weighting the signal frames. The feature quantities are used in deciding modes (for example, vowel and consonant segments) to produce mode decision results. With reference to the mode decision results, algorithm or codebooks are switched.
In an encoding part, each frame is subdivided into speech subframes having a subframe length of, for example, 8 ms long. Adaptive parameters (delay parameters corresponding to pitch periods and gain parameters) are extracted from an adaptive codebook for each speech subframe with reference to a previous excitation signal. By the use of the adaptive codebook, pitch prediction is carried out for the speech subframes. For a residual signal obtained by the pitch prediction, an optimal excitation code vector is selected from an excitation codebook (vector quantization codebook) composed of noise signals of a predetermined kind. Excitation signals are quantized by calculating an optimal gain.
The excitation code vector is selected so as to minimize an error power between the residual signal and a signal composed of a selected noise signal. A multi-plexer is used to produce a transmission signal composed of a combination of indexes indicative of the kind of the excitation code vector thus selected, gains, the spectral parameters, and the adaptive parameters of the adaptive codebook.
However, the conventional speech encoding system is disadvantageous in that a sufficient speech quality can not be obtained because of a restricted codebook size.

Speech encoder capable of substantially increasing a codebook size without increasing the number of transmitted bits


A heart stimulating device has pulse generators which can operate in either a first mode wherein the stimulation pulse energy is adjusted to a capture threshold of a patient's heart, or a second mode wherein the stimulation pulse energy is fixed. An evoked response detector senses IEGM signals to detect capture or non-capture subsequent to an emitted stimulation pulse. A noise detector detects as noise IEGM signals having predetermined signal characteristics. The noise detector, after having detected noise, sets the pulse generators to operate in the second mode. A lead arrangement connects the pulse generators, the evoked response detector, and the noise detector to a patient's heart.

1. Field of the Invention
The present invention relates to a heart stimulating device having a capability to adapt its stimulation energy to the current capture threshold value in a patient's heart.
2. Description of the Prior Art
The invention concerns solutions to problems arising in sensing the activity of the heart when myopotential noise, external electromagnetic noise, or other noise is present.
Particularly, noise may severely affect sensing carried out with a unipolar lead connecting the heart and the stimulating device. For unipolar electrode systems the noise level is typically an order of magnitude higher than the noise level of bipolar electrode systems. Aggravating polarization problems may thus arise when stimulation and sensing employ the same polarity configuration, e.g., unipolar configuration.
Pacemakers may employ a unipolar or bipolar lead, i.e., a cardiac electrode arrangement plus a single or dual insulated wires or conductors connected to the pacemaker's connection terminal, for stimulating and sensing the activity of a patient's heart. A bipolar lead may be operated in bipolar or unipolar mode, but a unipolar lead can be operated only in unipolar mode.
Stimulation and sensing carried out on a common unipolar lead would be generally desirable provided that safety can be maintained. Two advantages of unipolar systems are the greater possibilities of using an already-implanted lead when the pacemaker needs to be replaced, and a lower number of components which may fail.
Some terminology used in this disclosure is explained below.
IEGM
An abbreviation for intracardiac electrogram. IEGM signals are emitted by active cardiac tissue and sensed through electrodes placed on or within the heart.
QRS or QRS complex
The ventricular depolarization as seen on the electrocardiogram or in the IEGM signals.
Intrinsic
Inherent or belonging to the heart itself. An intrinsic beat is a naturally occurring heartbeat.
Evoked response
The electrical activation of the myocardium caused by a pacemaker output pulse. The ability of heart cells to respond to a pacemaker output pulse depends on the extent to which the cells are in a refractory state.
Escape interval, basic interval, or basic escape interval
The period, typically of the order of 1000 milliseconds, between a sensed intrinsic cardiac event or a stimulation pulse output and the next pacemaker output pulse.
Lead
The insulated wire plus electrode(s) and terminal pin used to connect the pulse generator to cardiac tissue. The lead carries the stimulus from the pulse generator to the heart and, in demand modes, relays intrinsic cardiac signals back to the sense amplifier of the pulse generator. A single-chamber pulse generator requires one lead, while a dual-chamber pulse generator usually requires two (one for the atrium, another for the ventricle)
Bipolar lead
A pacing lead with two electrical poles that are external from the pulse generator. The negative pole or cathode is located at the extreme distal tip of the pacing lead, while the positive pole or anode is formed of an annular electrode located at a distance in the range of 10 millimeters from the cathode. The cathode is the electrode through which the stimulating pulse is delivered. Bipolar leads are characterized by relatively small spikes on the paced ECG.
Unipolar lead
A pacing lead with a single electrical pole at the distal tip of the pacing lead (negative pole). The anode (positive pole) is the pulse generator case. The cathode is the electrode through which the stimulating pulse is delivered. Unipolar stimulation or sensing via a unipolar lead is of course bipolar in the sense that, e.g., a conductive casing of the pacemaker constitutes a second pole.
Stimulation, capture, or pacing threshold
The minimum electric output from the pacemaker which consistently elicits a cardiac depolarization and contraction.
Stimulation energy
The energy of the electric output from the pacemaker. The energy is used herein to quantitatively describe the stimulation effectiveness of a stimulation pulse. Alternatively, it could be expressed in terms of voltage, current, width, shape, and/or charge of the pulse.
IEGM signal amplitude
The amplitude can be defined in two different ways: the peak value, i.e., the maximum distance (positive and/or negative) from the signal baseline, or the peak-to-peak value, i.e., the distance between the maximum positive and negative deflections of the IEGM signal. An implantable heart stimulating device usually senses the peak-to-peak value. Thus, a threshold for sensing could refer to either of these definitions.
In U.S. Pat. No. 4,969,460 a pacemaker is described having a spontaneous event and noise detector for sensing inter alia noise. When noise is detected a noise flag is set and capture detection and automatic output regulation is suspended (see e.g. col.24, lines 26-48). Instead pacing takes place with a comparatively large output. Criteria for setting the noise flag are not discussed.
The Pacesetter.RTM. REGENCY.TM. pacemaker with AUTOCAPTURE.TM., described in Pacesetter.RTM. User Manual, ordering no. 63 46 493 E500E, published in 1995, uses a bipolar arrangement connecting the pacemaker to the heart when operating in a mode wherein the stimulation pulse energy is adjusted in relation to the patient's changing capture threshold. In that AUTOCAPTURE mode, only one pole of the lead is used for delivering stimulation pulses, while both poles are used for sensing IEGM signals that are indicative of the heart's stimulation response and natural activity. In other modes of operation the pacemaker may be programmed to deliver stimulation pulses and sense heart activity in either bipolar or unipolar mode. The pacemaker may always completely inhibit a pulse, in order to favor natural heartbeats. In that way a long life of the battery-powered heart stimulating device may be achieved.
The adaptive function is advantageous, but to ensure correct evoked response (ER) detection, bipolar sensing is deemed absolutely necessary. In the described pacemaker, unipolar sensing could endanger correct ER detection, since that sensing is more sensitive to noise, especially myopotential, influence than bipolar sensing, as mentioned above. Depending on the sign and magnitude of the noise, ER sensing could erroneously indicate capture or non-capture, which could lead to an inappropriate reaction by the pacemaker.
Also, when sensing and stimulation are carried out with the same polarity, the sensing can be complicated due to polarization at the electrode(s) caused by the stimulation pulse, however, that is a problem not specifically related to the occurrence of noise.
If sensing and pulse adjustment based thereon could be performed reliably with a unipolar lead instead of a bipolar lead, one would also benefit from the advantages of a less complicated conductive means for transferring both the stimulation and sensing signals.
The general operation of a prior art pacemaker of the type initially described will now be described in greater detail.
Such a pacemaker operates in a sensing mode that incorporates a refractory period. Immediately following a pacemaker output or a sensed intrinsic event, the pacemaker ceases to be responsive to detectable signals for a predetermined period of time. This prevents the pulse generator from detecting the terminal portion of the depolarization signal and, in some circumstances, the repolarization signal which might result in timing errors.
In atrial applications, longer refractory periods should be employed to prevent detection of terminal portions of the QRS complex which, if detected, would reset the pulse generator timing, resulting in a lower pacing rate than the programmed rate.
The refractory period (=total refractory period) consists of a programmable absolute refractory period during which detection of all signals is blocked, and a non-programmable relative refractory (or noise-sampling) period (100 ms) during which detected signals cause a restart of the relative refractory period. Continuous detection of signals at a frequency of 10 Hz or more causes the pulse generator to revert to asynchronous operation at the programmed basic rate as long as noise is present. During periods of noise detection, the pulse generator stimulates at the programmed pulse amplitude and pulse width if the adjustment mode (AUTOCAPTURE.TM.) is "OFF". If the adjustment mode is programmed "ON", the algorithm is interrupted and the output set to 4.5 V/0.49 ms to ensure pacing. High stimulation energy is necessary when the adjustment mode is "ON" because the noise will probably give false ER detections. As soon as the noise is absent, the pulse generator reverts to the normal inhibited mode with the same amplitude and pulse width as before the noise mode was entered, when operating in the adjustment mode. In this pacemaker, the noise is detected by the same circuit, with the same amplitude threshold, as used to sense heartbeats.
The programmable refractory periods, including the relative refractory period of 100 ms, range from 250 ms to 550 ms in steps of 50 ms.
Signals which occur at a frequency of 10 Hz or more are interpreted as noise and will cause the pacemaker to revert to asynchronous operation at the programmed rate while continuing to monitor for the presence of noise. This protects the patient by preventing the pacemaker from being totally inhibited by external interference.
Signals which occur at a frequency below 10 Hz have no effect upon pulse generator timing, unless the signal is detected during the normal sensing (or alert) period following the noise sampling period. Should this occur, pulse generator output either will be inhibited or triggered depending on the operating mode.

Heart stimulating device with stimulation energy responsive to detected noise


Methods and systems for thinning the output of an array antenna are disclosed. The thinning can be applied in response to determining that the performance of a multiple element antenna array with respect to a desired signal has been compromised by the presence of one or more interfering signals. The application of a thinning pattern has the effect of turning off selected antenna elements within the array. The effect of applying a particular thinning pattern on the realized performance of the antenna system can be determined. An alternate thinning pattern can be applied if the previous thinning pattern did not result in an improvement, or a sufficient improvement, in the performance of the antenna system.

Array antennas, including but not limited to phased array antennas, are used in a wide variety of applications. In operation, the individual elements of the antenna are controlled to produce a desired beam pattern. For example, it is often desirable to produce a beam pattern having a main beam aligned in a direction of interest, while at the same time attenuating the sidelobes or beams in directions that are not of interest. This general configuration can increase the signal to noise ratio of the overall signal received by the antenna for a signal source aligned with the main beam.
Phased array antennas can be controlled to lower sidelobe levels or to place a null in the direction of jammers or other interfering signals. Almost all antenna array adaptive nulling algorithms require digital beamforming or a receiver at every element of the array in order to form a covariance matrix for calculating the adaptive weights. Digital beamforming is impractical for large arrays due to the cost of the required hardware and software systems. In addition, while there is some ability to attenuate the gain of an array antenna in areas outside of the main beam, sidelobes of various amplitudes will generally be present at various angles relative to the main beam. Therefore, selecting a beam pattern that produces nulls in areas of the beam pattern corresponding to interfering signal sources can be difficult.

Dynamic thinning of a phased array aperture


A method for unambiguous determination of a range to and/or of a relative velocity of an object with respect to a motor vehicle is disclosed. An unambiguity area (RUn) for the range and/or an unambiguity area (VUn) for the relative velocity may be determined by means of a frequency-modulation continuous-wave radar in the motor vehicle, with a predetermined sequence of frequency-modulated signal pulses being transmitted by the frequency-modulation continuous-wave radar in a measurement cycle. Mutually different unambiguity areas (RUn) for the range and/or mutually different unambiguity areas (VUn) for the relative velocity are defined for at least two successive measurement cycles, and the range and/or the relative velocity are/is determined on the basis of, in each case, at least one measured value for the range and/or for the relative velocity from each measurement cycle.

The invention relates to a method for unambiguous determination of a range to and/or of a relative velocity of an object with respect to a motor vehicle by means of a frequency-modulation continuous-wave radar in the motor vehicle. The frequency-modulation continuous-wave radar transmits a predetermined sequence of frequency-modulated signal pulses (Chirps) in an individual measurement cycle. An unambiguity area for the determination of the range and/or an unambiguity area for the determination of the relative velocity are/is determined by the sequence of frequency-modulated signal pulses. The invention also relates to a driver assistance device and to a vehicle having a driver assistance device such as this.
The present interest therefore relates to a frequency-modulation continuous-wave radar (frequency modulated continuous wave radar). This is referred to in the following text as an FMCW radar, or simply as a radar. A radar such as this operates as follows: the radar transmits a predetermined number of frequency-modulated signal pulses (also referred to by the term "Chirps") as a transmitted signal in a measurement cycle. The radar then receives a received signal, which is the transmitted signal reflected by an object. The transmitted signal is compared with the received signal. Two major measurement variables of the radar are the range and the relative velocity. The range is determined by the delay time of the transmitted signal; the relative velocity is determined by the change in the frequency of the transmitted signal, resulting from the Doppler effect.
The use of radars such as these in motor vehicles is already known from the prior art. The document DE 10 2005 048 209 A1 describes a motor vehicle having an FMCW radar such as this. This method is distinguished in that only the range but not the relative velocity is determined in predetermined time periods within a measurement cycle, for objects in at least one subarea of the area around the motor vehicle. A sequence of 16 to 64 frequency-modulated signal pulses, each having a time duration of about 250 μs, is transmitted by the radar in one measurement cycle and per radar lobe (per beam); the received signal for the entire sequence of signal pulses is then evaluated coherently. This allows a relatively high Doppler-frequency resolution and a relatively high signal-to-noise ratio (SNR), while at the same time making good use of the available measurement time. The parameters of the transmitted signal and the system parameters were chosen such that good measurement results could be achieved using the existing components, specifically in particular on the basis of the chosen time duration of the individual signal pulse of 250 μs, and on the basis of a sampling rate of an analogue-digital converter for the received signal. In this case, the sampling rate is 1 MHz.
In reality, the measurement of the two variables—the range and the relative velocity—is subject to limitations: the resolution and the unambiguity of the measurement are restricted. In principle, a radar can process a plurality of targets at the same time. The resolution capability of the radar indicates how far the targets must be apart from one another in order to allow the radar to detect them as two separate targets. Both range and velocity resolution are possible for targets using the radar according to document DE 2005 048 209 A1. By way of example, a range resolution of 1 m means that the range from the radar to two targets must differ by at least one 1 m in order to allow them to be resolved by the radar.
As already stated, the range measurement and the relative velocity measurement may be ambiguous. In general, this results from sampling effects. The ambiguity problem is illustrated by the following example: by way of example, a radar can detect targets up to a maximum range of 300 m. The range unambiguity (the unambiguity area) may, however, for example be 100 m, and therefore significantly below the maximum range of the radar. In this case, a measured value for the range of about 10 m means that the target may be at a range of 10 m, 110 m or 210 m away from the radar.
The choice of the parameters for the transmitted signal, as well as the system parameters, influences the unambiguity area for the determination of the range and the unambiguity area for the determination of the velocity. As stated above, in the case of the parameters mentioned, the unambiguity area for the range is about 100 m, and the unambiguity area for the determination of the velocity is about 80 km/h. However, in practice, the radar can also detect targets which are at a range of considerably more than 100 m away from the radar. In practice, in particular on motorways, relative velocities may additionally occur between −200 km/h and +200 km/h. There is therefore a major requirement to increase the unambiguity areas for the range and the velocity overall.
In order to increase the unambiguity area for determination of the range, in principle it will be possible to increase the sampling rate of the analogue/digital converter in the receiver. However, this solution is not optimal. Increasing the sampling rate of the analogue-digital converter increases the costs for this component. On the other hand, the unambiguity area for determination of the velocity could be increased by reducing the time duration of an individual frequency-modulated signal pulse. However, in this case, the sampling rate of the analogue/digital converter would then have to be correspondingly increased in order to keep the range resolution constant; in addition, correspondingly more signal pulses would have to be transmitted for the same Doppler-frequency resolution. This once again results in the problem of increased hardware costs.

Method for unambiguously determining a range and/or a relative speed of an object, driver assistance device and motor vehicle


According to one embodiment, for each GOP, frames from an I frame present at a leading position of GOP to an I frame contained in a succeeding GOP and B frames referencing the I frame contained in the succeeding GOP are managed as a new GOP. For each new GOP, video frames from a leading I frame to a last I frame are subjected to a decoding process in order of increasing PTS value. For each new GOP with the last I frame of the video frames discarded, the video frames are subjected to video display in order of decreasing PTS value.

1. Field
One embodiment of the invention relates to a video reproduction apparatus, a video reproduction method, and a video reproduction process program which are used to reproduce digital video signals subjected to a efficient compression coding process using an inter-frame prediction coding technique, from an information recording medium, and in particular, to improvements in a video reproduction apparatus, a video reproduction method, and a video reproduction process program which perform forward and reverse variable-speed reproductions.
2. Description of the Related Art
As is well-known, efforts have been made to reduce the amount of information in video signals to be digitally recorded on an information recording medium, for example, a hard disk, by subjecting the video signals to an efficient compression coding process. As an efficient compression coding process of this kind, the Moving Picture Experts Group (MPEG) scheme is currently commonly adopted.
The MPEG scheme specifies three types of video frames: intra (I) frames, predictive (P) frames, and bidirectionally predictive (B) frames. Of the three types of frames, the I frames correspond to intra-frame coded videos coded using only intra-frame information. Video signals for one frame can be restored using only the I frames.
The P frames correspond to inter-frame forward prediction coded videos predicted on the basis of past frames. The P frames may involve inter-frame reverse prediction coding that predicts videos on the basis of future frames. The B frames correspond to inter-frame bidirectional prediction coded videos predicted on the basis of both past and future frames.
The MPEG scheme records and reproduces video signals on and from the information recording medium in group-of-picture (GOP) units; a GOP contains the three types of frames having respective predetermined numbers of frames. This enables random accesses to allow performance of various special reproduction operations such as reproduction from any position, forward and reverse variable-speed reproductions, and still reproduction.
Among the special reproduction operations, the forward and reverse variable-speed reproductions are generally achieved by searching for the I frames present in GOP read from the information recording medium, subjecting the I frames to a decoding process, and displaying the decoded video frames forward or in reverse along a time sequence.
However, one GOP is ordinarily often composed of 15 frames, one I frame, four P frames, and 10 B frames and thus contains an amount of information corresponding to a video display time of about 0.5 seconds. Thus, the simple technique of decoding and displaying only the I frames in each GOP fails to display videos with smooth motions particularly during the reverse variable-speed reproduction.
Jpn. Pat. Appln. KOKAI Publication No. 2003-244641 discloses a technique of enabling smooth reverse reproduction by, during forward data reproduction, storing stream data obtained by decoding coded data, in a buffer area, and during reverse data reproduction, reading the decoded stream data stored in the buffer area for display.

Video reproduction apparatus, video reproduction method, and video reproduction process program


Embodiments of the present invention disclose a frame transmission method for a wireless local area network and a wireless local area network apparatus, and relate to the field of communications technologies. According to the present invention, in a frame transmission process in a WLAN, a frame sent by a wireless local area network WLAN apparatus is received, and the frame of a particular standard is recognized by detecting a user common signal field included in the frame, so that backward compatibility of a WLAN apparatus is implemented, and hybrid networking of WLAN apparatuses of different standards can be supported, thereby improving flexibility of network deployment, and reducing complexity of networking.

The 802.11 protocol suite specified by the Institute of Electrical and Electronics Engineers (Institute of Electrical and Electronics Engineers, IEEE) is a standard for a wireless local area network (Wireless local Access Network, WLAN), and existing WLAN standards based on the orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing, OFDM) technology include evolving standards such as 802.11a, 802.11n, and 802.11ac, and are still continuously evolving. With the development and gradual popularization of the WLAN, a case in which WLAN apparatuses supporting different standards coexist will exist in a long term. To implement backward compatibility, an access point (Access Point, AP) and a station (Station, STA) with a new-generation standard need to support earlier standards.
Frame formats used by multiple existing WLAN standards and future WLAN standards are different. Therefore, a WLAN apparatus employing a new-generation standard needs to have a capability of recognizing a frame of a particular WLAN standard, and the frame of the particular WLAN standard does not affect receiving of a frame of another standard.

This patent is subject to a terminal disclaimer.

Frame transmission method for wireless local area network and wireless local area network apparatus


A position detecting element that enables a position to be detected at high speed and high precision, and a range sensor using the same. The position detecting element is provided with a PIN photodiode array 1 having n segments and a parallel arithmetic processing portion 2 that calculates the segment having maximum intensity by comparing n outputs from the segments of the PIN photodiode array 1. The range sensor includes a light source by which the object to be measured is irradiated by optical beam, a lens that gathers rays of the reflected light from the surface of the object to be measured and the position detecting element mentioned above that detects the position of the light gathered by the lens.

A range sensor using a conventional position detecting element is, for example, disclosed in JP62-28610. FIG. 7 shows the optical system that is the basic component of this range sensor.
FIG. 7 includes a light source 101 using an emitting element such as a light-emitting diode, a semiconductor laser and the like, a first lens 102, a second lens 103 whose focal length is f and a position detecting element 104 using PSD or CCD. The optical system in FIG. 7 is structured in order to fulfill the Scheimpflug condition. That is, the following equation (Equation 1) shows the relations of (1) the angle .theta. formed by the optical axis of the light source 101 and the optical axis of the second lens 103, (2) the angle .beta. formed by the principal plane of the second lens 103 and the detecting plane of the position detecting element 104, (3) the distance L from the intersection O of the optical axis of the light source 101 and the optical axis of the second lens 103 to the second lens 103, and (4) the distance d between the intersection of the optical axis of the light source 101 and the principal plane of the second lens 103 and the principal point of the second lens 103. EQU .beta.=tan.sup.- (f0/d), Equation 1
where f0=f.multidot.L/(L-f). In Equation 1, f indicates the focal length of the second lens 103. When the Scheimpflug condition is fulfilled, the optical beam reflected by the object to be measured through the first lens 102 after exiting from the light source 101 forms images on the position detecting element 104 by the second lens 103 in case where the object to be measured Ob is located not only at the intersection O of the optical axis of the light source 101 and the optical axis of the second lens 103 but also at the position O' deviated from the intersection O on the optical axis as shown by the broken line.
The principle of measuring distance by using this kind of range sensor is explained as follows. The part of the light reflected from the object to be measured Ob forms images at the point A on the position detecting element 104 by the second lens 103, when the object to be measured Ob is located at the position O. The part of the light reflected from the object to be measured Ob forms images at the point B on the position detecting element 104 as shown by the broken line in FIG. 7, when the object to be measured Ob has moved to the position O'. Thus, the position on the optical axis of the light source 101 is converted into the position of the image-formation on the position detecting element 104. Consequently, the shift, unevenness and the like of the object to be measured can be determined by measuring the shift of the position of the image-formation on the position detecting element 104.
However, the position detecting element mentioned above has the following problems. When PSD is used as a position detecting element and the position is detected by the sampling rate of more than 10 MHz, a resolution (normalized by the length of PSD) is on the order of 1/100, which is not enough. On the other hand, when CCD, which is for example a line sensor of 5000 pixels, is used as a position detecting element, the resolution (normalized by the length of CCD) reaches 1/5000. However, the scan rate of CCD is only on the order of several KHz and it is difficult to realize the high speed scan like at the scan rate of 10 MHz. Thus, it was difficult to detect a position at high speed (more than 10 MHz) and high precision (high resolution) using the conventional position detecting elements. As a result, it was difficult to have both the high speed performance of more than 10 MHz and the distance measurement of the high precision in the range sensor using this kind of position detecting elements.

Position detecting element and range sensor

Matsushita Electric Industrial Co., Ltd.


A device displays images such that a driver can easily recognize an obstacle. The device includes a measurement for measuring a distance and direction to an obstacle, a comparison section for comparing the measured distance with a threshold value, a viewpoint determination section for determining a first viewpoint when the measured distance is larger than the threshold value and a second viewpoint based on the measured direction when the measured distance is not larger than the threshold value, an image generating section for generating an image representing an environment as seen from the first viewpoint when the first viewpoint is set and an image of a particular spot representing a view of the vehicle and the obstacle as seen from an area of the second viewpoint when the second viewpoint is set, and a display section for displaying the bird's eye image or the image of the particular spot.

Conventionally, a vehicle surrounding display device as described above (hereinafter, referred to as a conventional display device) includes a plurality of imaging devices, a plurality of laser range finders, a solid virtual section, an image converting section, and an image display section.
The plurality of imaging devices are mounted on a vehicle 1 and these imaging devices image an environment in the vicinity of the vehicle 1. The plurality of laser range finders measure distances to objects within view fields (subjects of the imaging device) from the laser range finders. One imaging device and one laser range finder are disposed in the vicinity of each other.
The solid virtual section is operable to obtain a distance image (see an upper left image of FIG. 18) within the view field based on distance information from the laser range finder, and to recognize objects within the view field based on an original image (see an upper right image of FIG. 18) imaged by the aforementioned imaging device. Based on the two pieces of image information which are the original image and the distance image, and the information about the recognized objects, a three-dimensional field of view is reproduced by simulating an invisible portion of the objects, which cannot be captured by the imaging device.
The three-dimensional information reproduced by solid virtual means is sent to the image converting section. As shown in a lower image of FIG. 18, based on the received three-dimensional information, the image converting section generates a bird's eye view which appears to be imaged by a virtual camera which is set to be virtually mounted above the vehicle. The bird's eye view represents a view of the vehicle and its surroundings seen from an appropriate viewpoint at the side of the vehicle, and is displayed by the image display section.
Alternatively, viewpoints for the bird's eye view are set at two points diagonal to the upper right and the upper left of the vehicle, respectively. The bird's eye view imaged from either viewpoint is selectively displayed. In this case, the viewpoints for the bird's eye view are switched to each other in accordance with a steering angle of the vehicle.
[Patent document 1] Japanese Laid-Open Patent Publication 7-17328

Matsushita Electric Industrial Co., Ltd.


A suspension for a HGA includes a base plate, a flexure having a suspension tongue for holding a slider, a load beam, and a hinge that are assembled together; wherein a strengthening plate is formed on the suspension tongue to increase stiffness of the suspension tongue. So the invention enable the use of the suspension with lower pitch and roll stiffness while preventing the suspension deformation. This ensures the slider mounted on the suspension have a good flying performance. The invention also discloses a HGA with such a suspension and a disk drive unit having such an HGA.

Disk drives are information storage devices that use magnetic media to store data. Consumers are constantly desiring greater storage capacity for such disk drive devices, as well as faster and more accurate reading and writing operations. Thus, disk drive manufacturers have continued to develop higher capacity disk drives by, for example, increasing the density of the information tracks on the disks by using a narrower track width and/or a narrower track pitch. However, each increase in track density requires that the disk drive device have a corresponding increase in the positional control of the read/write head in order to enable quick and accurate reading and writing operations using for the higher density disks. As track density increases, it becomes more and more difficult using known technology to quickly and accurately position the read/write head over the desired information tracks on the storage media. Thus, disk drive manufacturers are constantly seeking ways to improve the positional control of the read/write head in order to take advantage of the continual increases in track density.
As a way to improve the positional control of the read/write head, Various dual-stage actuator systems have been developed in the past for the purpose of increasing the speed and fine tuning the position of the read/write head over the desired tracks on high density storage media. Such dual-stage actuator systems typically include a primary voice-coil motor (VCM) actuator and a secondary micro-actuator, such as a PZT micro-actuator. The VCM actuator is controlled by a servo control system that rotates the actuator arm that supports the read/write head to position the read/write head over the desired information track on the storage media. The PZT micro-actuator is used in conjunction with the VCM actuator for the purpose of increasing the positioning speed and fine tuning the exact position of the read/write head over the desired track. Thus, the VCM actuator makes larger adjustments to the position of the read/write head, while the PZT micro-actuator makes smaller adjustments that fine tune the position of the read/write head relative to the storage media. In conjunction, the VCM actuator and the PZT micro-actuator enable information to be efficiently and accurately written to and read from high density storage media.
FIG. 1 a illustrates a portion of a conventional disk drive unit and shows a magnetic disk 101 mounted on a spindle motor 102 for spinning the disk 101. A voice coil motor arm 104 carries a HGA 100 that includes a slider 103, incorporating a read/write head. A voice-coil motor (VCM) (not shown) is provided for controlling the motion of the motor arm 104 and, in turn, controlling the slider 103 to move from track to track across the surface of the disk 101, thereby enabling the read/write head to read data from or write data to the disk 101. In operation, a lift force is generated by the aerodynamic interaction between the slider 103 and the spinning magnetic disk 101. The lift force is opposed by equal and opposite spring forces applied by a suspension of the HGA such that a predetermined flying height above the surface of the spinning disk 101 is maintained over a full radial stroke of the motor arm 104.
FIG. 1b illustrates the HGA 100 of the conventional disk drive device of FIG. 1a. FIG. 1c is an enlarged, partial side perspective view of the HGA 100 of FIG. 1b. The HGA 100 includes the slider 103, a PZT micro-actuator 105, and a suspension 110 to support the slider 103 and the PZT micro-actuator 105. The suspension 110 comprises a base plate 113, a hinge 112, a load beam 115, and a flexure 114. The flexure 114 provides a suspension tongue 328 for supporting the slider 103 and the PZT micro-actuator 105 on the suspension 110. The load beam 115 has a dimple 329 formed thereon to support the suspension tongue 328. The PZT micro-actuator 105, as described above, is provided in order to improve the positional control of the slider 103. More particularly, the PZT micro-actuator 105 corrects the displacement of the slider 103 on a much smaller scale, as compared to the VCM, in order to compensate for the resonance tolerance of the VCM and the head suspension assembly. The PZT micro-actuator 105 enables, for example, the use of a smaller recording track pitch, and can increase the "tracks-per-inch" (TPI) value by 50% for the disk drive unit, as well as provides an advantageous reduction in the head seeking and settling time. Thus, the PZT micro-actuator 105 enables the disk drive device to have a significant increase in the surface recording density of the information storage disks used therein.
With reference to FIGS. 1b to 1d, the PZT micro-actuator 105 includes a ceramic U-shaped frame which has a bottom arm 137 and two ceramic beams or side arms 107 that hold the slider 103 there-between. Each ceramic beam 107 has a PZT element 208 thereon. The PZT micro-actuator 105 is physically coupled to the flexure 114. Three electrical connection balls 109 (gold ball bonding or solder ball bonding, GBB or SBB) are provided to couple the micro-actuator 105 to suspension inner traces 910 located at the side of each of the ceramic beams 107 of the micro-actuator 105. In addition, there are four metal balls 108 (GBB or SBB) for coupling the slider 103 to suspension outer traces 190 located at the side of each of the ceramic beams 107 of the micro-actuator 105. The slider 103 is partially bonded with the two ceramic beams 107 at two predetermined positions 106 by epoxy 112. This bonding makes the movement of the slider 103 dependent on the movement of the ceramic beams 107 of the micro-actuator 105. When power is supplied through the suspension traces 910, the PZT elements 208 expand or contract to cause the two ceramic beams 107 of the U-shape micro-actuator frame to deform, thereby making the slider 103 move on the track of the disk in order to fine tune the position of the read/write head. In this manner, controlled displacement of the slider 103 can be achieved for fine positional tuning. Also, a parallel gap 398 is formed between the micro-actuator 105 and the suspension tongue 328 in order to ensure free movement of the slider 103.
As is known to all, with the quickly increasing of the HDD capability, the actual HDD selling prices becomes lower and lower. The manufacturer are continue to develop methods to cut down the material cost in order to meet the market. A typically example is make the head slider smaller and smaller, etc. from 100% slider to 50% slider. The current is 30% slider and everyone is focusing on 20% slider now. Since reduction of the slider size results in reduction of the size of the air bearing surface (ABS) side of the slider, while a big capacity HDD must have a lower and lower slider flying height, so it is a big challenge on the design for ABS pattern of the slider and the static parameter of the suspension, for example, the stiffness of the suspension. Due to limitation in ABS design, a lower and lower stiffness is required for the suspension, for instance, the pitch stiffness of the suspension is less than 0.75 μN/mm and the roll stiffness of the suspension is less than 0.6 μN/mm. To achieve such a low stiffness, the flexure of the suspension has reduced its thickness from traditional 25 μm to 22 μm or thinner.
However, the thickness reduction of the flexure may cause a problem on slider dynamic performance, for example, the suspension tongue may be deformed, such a problem may become serious especially under circumstance when a micro-actuator is applied. FIG. 1e is a diagrammatic view showing the deformation of the suspension tongue 328 under the support of the dimple 329 of the load beam 115. As shown in FIG. 1e, the free end of the suspension tongue 328 is bent toward the micro-actuator 105, which will reduce the gap 398 between the micro-actuator 105 and the suspension tongue 328, even cause an interference between the micro-actuator 105 and the suspension tongue 328, which further deteriorates the dynamic performance of the slider 103, such as position adjustment performance.
Hence, it is desired to provide a lower stiffness suspension, a head gimbal assembly (HGA), and a disk drive unit with such suspension that are suitable for small size slider and micro-actuator to solve the above-mentioned problems.

Suspension with strengthening plate, head gimbal assembly, and disk drive unit with the same


A gas amount measuring device including a vacuum container, a first pipe, an air release valve being attached to the first pipe, a second pipe, a calibration gas generator being attached to the first pipe, a third pipe, a vacuum gauge, a first valve, a leak valve, a second valve, a turbomolecular pump, a third valve, and a roughing pump being attached to the third pipe in order from a vacuum container side, a first bypass pipe connecting the third pipe between the vacuum container and the first valve to the third pipe between the leak valve and the second valve, a fourth valve being attached to the first bypass pipe, and a second bypass pipe connecting the third pipe between the leak valve and the second valve to the third pipe between the third valve and the roughing pump, a fifth valve being attached to the second bypass pipe.

1. Field of the Invention
The present invention relates to a gas amount measurement device. More specifically, the present invention relates to a gas amount measurement device for measuring an entire amount of gas contained in molten metal or an amount of gas attached to an inclusion.
2. Description of the Related Art
Conventionally, a specific metal or alloy is used for a component such as a vehicle engine. Meanwhile, it is generally known that an amount of impurity gas per unit weight after refining a component is smaller than that before refining. This is because the impurity gas contained in a sample, that is, the component vaporizes during refining. In such a case, the refined component is molten again so as to reduce the amount of impurity gas in the component as much as possible. However, the melting of the refined component again undesirably causes a cost hike.
Furthermore, recycling has recently become popular for used metal products from the viewpoint of effective use of resources. However, if an aluminum product, for example, is melted, various types of gases such as hydrogen gas, carbon dioxide gas, oxygen gas, and nitrogen gas are released. Due to this, if the used aluminum product is cast in a mold, bubbles disadvantageously remain in an obtained product and pinholes or the like undesirably occur in the obtained product.
To solve these problems, it is proposed to measure a gas amount in molten metal. A measurement device including a chamber containing the molten metal, a pump setting an internal pressure of the chamber to a predetermined pressure, and a measuring unit measuring the internal pressure of the chamber, and measuring a gas amount from a pressure rise due to gas released from the molten metal is disclosed in, for example, Jpn. Pat. Appln. KOKAI Publication No. 2003-83865.
However, with the technique disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2003-83865, the measurement device can only measure the total amount of all the gases present, but not individual gases.


New ultrasound contrast agents that comprise microbubbles encapsulating a gas within a shell made from a blend of bipolar compounds having mixed carbon chain length. The compounds have hydrophobic groups selected from the group consisting of straight-chained alkyls, alkylethers, alkylthiolethers, alkyldisulfides, polyfluoroalkyls, and polyfluoroalkylethers having a carbon chain length greater than or equal to 16 and less than or equal to 32. The polar groups are connected to the hydrophobic groups by means of a linker. The polar head groups are selected from the group consisting of CO2-M+, SO3−M+, SO4−M+, PO3−M+, PO4−M+2, N(R)4+, a pyridinium or substituted pyridinium group, and a zwitterionic group; R is selected from the group consisting of —H, —CH3, alkyl, cycloalkyl, substituted cycloalkyls containing one or more heteroatoms, and benzyl and can be the same or different; and Z′ is a nonionic and M is a cation.

Ultrasound contrast is a very useful and widely used medical diagnostic technique. The technique takes advantage of the fact that the various fluids and tissues in the body reflect sound waves differently. This results in a contrast between reflected waves that can be detected and used to form an image of the tissue. Ultrasound is used for many different diagnostic purposes, e.g., prenatal imaging or to image bloodflow in the heart and arteries and observe blockages in blood circulation.
It has been discovered that an ultrasound image can be greatly enhanced by the presence of ultrasound contrast agents. By placing such contrast agents within the tissue to be imaged, a greater difference in the reflectance of the sound waves between the tissue to be imaged and the surrounding tissue occurs. This allows much sharper delineation of tissue boundaries and perfusion to be observed.
Such contrast agents are based on the acoustic impedance mismatch between a gas and a liquid. These agents are typically micron-sized bubbles containing various gases encapsulated in polymers, surfactants, proteins, polyaminoacids and their derivatives, liposomes, or inorganic shells. The bubbles, often called "microbubbles", are typically smaller than 10 micrometers so that they will pass through small vessels such as the capillary bed of the lung and reach the heart. They are commonly filled with a gas because it has been found that these gas-filled microbubbles provide very efficient ultrasound contrast, much better than that observed using liquid or solid contrast particles of equivalent size.
Although non-encapsulated gas microbubbles may be used for some purposes, they tend to change size very rapidly. The larger non-encapsulated gas microbubbles grow while the smaller microbubbles continue to diminish in size. Those that are small enough to pass through the lungs are effectively to small and dilute to provide useful contrast upon reaching the heart and are thus not practical for imaging the left side of the heart. The rate at which microbubbles undergo this type of change depends upon the actual gas used. Less soluble and diffusive types of gas will form non-encapsulated microbubbles that may be usable for imaging the left side of the heart.
Several encapsulated contrast agents have already been developed and are widely used. U.S. Pat. No. 5,614,169 describes microbubbles comprising carbohydrates and amphiphilic C22-50 organic acids. The organic acids were described as preferably containing at least one carboxyl group and could be, e.g., straight chain fatty acids. U.S. Pat. No. 5,352,436 describes microbubbles which are stabilized by the presence of two different surfactants. The first surfactant tends to be substantially soluble and nonionic, examples being polyoxyethylene fatty acid esters, such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan nonostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate and mixtures thereof. These esters include TWEEN 20, TWEEN 40, TWEEN 60, TWEEN 65 and TWEEN 80. The second surfactant is preferably insoluble and nonionic. These include sorbitan fatty acid esters, such as sorbitan monostearate, sorbitan monopalmitate and mixtures thereof. Such mixtures include SPAN 40 and SPAN 60, which comprise palmitic acid, myristic acid and pentadecanoic acid, and stearic acid, palmitic acid and myristic acid, respectively. Published PCT patent application WO 96/39197 describes stabilized ultrasound compositions comprising fluorinated amphiphilic compounds wherein these compounds can comprise short to long chain alkyls or fluoroalkyls.
Other patents have also described the use of sugars in ultrasound contrast agents. These include U.S. Pat. Nos. 4,681,119, 4,442,843 and 4,657,756 which disclose the use of particulate solids having a plurality of gas-filled voids and preferably also a plurality of nuclei for microbubble formation. EP-A-0123235 and EP-A-0122624 suggest ultrasound contrast agents consisting of surfactant-coated or surfactant-containing gas-containing microparticles which may include a variety of sugars. DE-A-3834705 suggests the use of suspensions containing microparticles of mixtures of at least one C10-20 fatty acid with at least one non-surface active substance, including sugars such as cyclodextrins, monosaccharides, disaccharides or trisaccharides, as well as other polyols and inorganic and organic salts.
Microbubbles have also been encapsulated in gelatin and albumen. ALBUNEX® Contrast Agent is a suspension of stable microencapsulated air bubbles which are encapsulated in human serum albumin. OPTISON® Contrast Agent is a suspension of stable microencapsulated octafluoropropane bubbles which are encapsulated in human serum albumin. Both are prepared by sonicating dilute human albumin at a temperature slightly below denaturing. ALBUNEX is prepared by sonicating in the presence of air; OPTISON® in the presence of octafluoropropane. Both are composed of gas-filled microbubbles with a mean diameter in the range of 3-5 microns and stabilized by a thin albumin shell.
U.S. Pat. No. 4,684,479 discloses surfactant mixtures for the production of stable gas-in-liquid emulsions comprising: (a) a glycerol monoester of saturated carboxylic acids containing from about 10 to about 18 carbon atoms or aliphatic alcohols containing from about 10 to about 18 carbon atoms; (b) a sterol-aromatic acid ester; and (c) a sterol, terpene, bile acid or alkali metal salt of a bile acid.
U.S. Pat. No. 4,466,442 discloses a solution for the production of gas microbubbles which contains a solution of at least one tenside and at least one viscosity-raising compound. Examples of suitable non-ionic tensides include polyoxyethylene fatty acid esters, and polyoxyethylated sorbitan fatty acid esters. Examples of viscosity-raising compounds include mono- or polysaccharides, dextrans, cyclodextrins, hydroxyethyl amylose, polyols, proteins, proteinaceous materials, amino acids, and blood surrogates.
U.S. Pat. No. 5,573,751 teaches the advantage of using any of a variety of gases in microbubbles which gases are longer lasting than other gases such as air. U.S. Pat. No. 5,352,436 teaches one process for preparing stabilized gas microbubbles with mean diameter less than 10 micrometers. U.S. Pat. No. 5,656,211 also teaches methods for preparing gas-filled microbubbles.
European Patent Application 0231091 discloses emulsions of oil in water containing highly fluorinated organic compounds as contrast agents. U.S. Pat. No. 4,900,540 describes the use of phospholipid-based liposomes containing a gas or gas precursor as a contrast-enhancing agent.
Ultrasound contrast agents have also been used for purposes other than tissue imaging, e.g., measuring pressure in a system or measuring fluid flow rates. U.S. Pat. No. 4,265,251 teaches a method of determining the pressure within a liquid containing vessel by (1) adding a solid precursor for at least one bubble the liquid, (2) retaining the precursor in the liquid for a sufficient time to form at least one bubble and to generate a sonic signal, (3) measuring a characteristic of the sonic signal which is representative of the pressure in the liquid, and (4) determining the pressure in the liquid from the measured characteristic. U.S. Pat. No. 4,483,345 teaches a method of non-destructively measuring the pressure of a desired region within a substance, from outside, by a process wherein ultrasonic waves are applied to the desired region within a substance, to generate bubbles within the liquid existing in the region during the negative pressure cycle of the ultrasonic waves and, thereafter, the generation of bubbles is detected by harmonic or subharmonic ultrasonic waves which accompany such bubbles and/or by the echo of other ultrasonic waves of higher frequency applied to the region. U.S. Pat. No. 4,316,391 teaches a method of measuring fluid flow rate in a system having a conduit through which a fluid flows. The method comprises adding a substance which provides a plurality of bubbles of a known quantity and size to the system upstream of the conduit. A sonic pulse is generated from a position opposite and spaced from the conduit as the bubbles pass through the conduit. Reflected sonic images are measured, which images are created by reflection of the pulse from the wall of the conduit distal from the position. Additionally, other reflections are measured from the bubbles themselves flowing between the two walls. The fluid flow rate is then determined from the sonic images.
A variety of methods are used to make microbubbles. Several of these are outlined in published PCT application WO 96/39197. This same application also describes many of the gases which may be included within the microbubbles.
These known agents are satisfactory for some applications but have limitations that prevent them from being useful for many purposes. They are often not stable when subjected to sterilization procedures and have relatively short half-lives after formulation or reconstitution. Also, the physical properties of the microbubbles at effective concentrations limit the depth in the tissue where a diagnostic image can be obtained. Often useful images can only be acquired for tissue a few centimeters from the ultrasound transmitter/receiver thus limiting the "penetration" of the procedure and the depth in the body from which images can be obtained. The amount of signal loss accountable to a variety of scattering processes is known as attenuation. Further, the physical properties of the microbubbles cause relatively high attenuation that limits the usefulness of the agent to obtain certain types of images, e.g. myocardial perfusion and images that must be obtained immediately after injection.
Additionally, known agents have not proven useful for measuring blood pressure in the body, particularly for measuring pressure within the cardiovascular system.
To illustrate these limitations, consider how an ultrasound image is obtained. An ultrasound image is obtained when an emitted sound wave strikes a microbubble and is reflected back to and detected by a receiver. Attenuation processes occur along the path transversed by the sound wave as it is returning to the receiver. Attenuation increases with the number and size of the microbubbles to which the transmitted signal interacts. Therefore, at some concentration for a given agent, image resolution and contrast is lost. Thus, the image detail deteriorates since many reflected signals no longer reach the receiver at the frequency of imaging. The depth of penetration by the signal is thus limited.
In addition, known ultrasound contrast agents are often administered to a patient by quickly injecting a large volume of the agent into the patient, i.e. a "bolus" injection. Ultrasound measurements are started immediately and taken over the next several seconds or minutes. However, the image obtained from the ultrasound measurement occurs in three stages. The measurement initially produces an image of relatively low diagnostic value as the microbubbles first enter the system. Next, as the concentration of the microbubbles increases, image contrast is lost due to the effects of attenuation. At this stage the image appears to "darken" to a point where virtually no image can be obtained. This shadowing is principally due to attenuation of the ultrasound signal caused by the high concentration of the contrast agent. The numerous microbubbles scatter or translate the reflected signal and prevent it from reaching the receiver. Then, in the third stage, the faded image returns as attenuation abates with a decline in the concentration of the contrast agent due to dilution, destruction, and uptake processes in the imaged organism. Diagnostic imaging is usually carried out in this often brief third stage.
The problem is that in the second stage regions which contain a large number of microbubbles obscure adjacent farfield locations of key medical interest. These adjacent locales often contain relatively much less contrast agent at peak dose. As the overall concentration declines and the image returns, the amount of contrast remaining in these areas of interest is insufficient or sub-optimal for giving good contrast or flow information. For example, myocardial perfusion tests using known contrast agents give poor results, if at all. The high concentration of contrast agent in the heart chambers following a bolus injection initially attenuates the signal obscuring the image of the perfusion of the heart muscle. As the concentration of contrast agent in the blood declines, the attenuation diminishes but little or no contrast enhancement of the heart muscle remains. Similarly, when measuring heart muscle function in a stress test, the patient is "stressed" and the ultrasound image is taken immediately before the patent's heart rate declines. Known ultrasound contrast agents are of limited use during a stress test because the imaging is carried out when these agents are in the second or "attenuated" stage. By the time the image returns, the heart rate is off peak and the image is no longer diagnostic.
Therefore, there is a need for ultrasound contrast agents that are more stable generally than known agents, that permit greater signal penetration than known agents by lowering attenuation, and that are useful in procedures where known agents have limited applicability. Such agents must be highly efficient. They must be very reflective yet minimally attenuating so that imaging procedures can produce better and more consistent ultrasound images, particularly for imaging heart perfusion, measuring blood pressure, and similar procedures.


An external screw member includes a head, a shank, a parallel threaded portion, a tapered threaded portion, a screw thread, a convex portion and a screw driving side end face of the convex portion. The convex portion protruding more radially outward than the crest of the screw thread is formed in at least one of the parallel threaded portion and the tapered threaded portion over the tapered threaded portion and the parallel threaded portion. The screw driving side end face of the convex portion is configured to form an inclined plane which gradually rises from a root position of the end face at the side of the crest of the screw thread toward a crest of the convex portion in a direction opposite to a screw driving direction of the screw thread to reach the crest of the convex portion.

Self-tapping screws do not require tapping in a prepared hole in advance and hence are widely used, but require that screw driving torque at the time of forming a prepared hole be as low as possible. As a self-tapping screw for which screw driving torque is made low, there has been known an external screw in which a contact area between a screw thread and a prepared hole is made small, as illustrated in Patent Literature 1, for example.
The external screw described in this Patent Literature 1 has a first zone screw thread portion at the side of a screw head portion, and a second zone screw thread portion at the side of a screw tip end portion, wherein a self-tapping threaded portion with a thread height increased from a leading end of a thread at a root to a trailing end thereof at a crest is formed in the second zone screw thread portion, so that the generation of cutting chips is suppressed by changing the height of the screw thread on the circumference of the threaded portion.
However, when the length of an internal screw is long, the number of screw threads to be formed increases, and hence, there has been a problem that in a space of the self-tapping threaded portion in the second zone screw thread portion, cutting chips are not discharged well, but accumulate in the internal screw, as a result of which a screw driving torque increases abruptly.
In addition, Patent Literature 2 discloses a self-tapping screw which includes a machining screw portion for machining an internal screw thread, and a standard screw portion having a standard screw thread, wherein a screw thread continuously extending from the machining screw portion to the standard screw portion, and the machining screw portion is formed with a plurality of machining screw threads whose outside diameters and effective diameters are larger than those of the standard screw thread. A plurality of escape screw threads, whose outside diameters and effective diameters are smaller than those of the standard screw thread, are formed on the circumference of the machining screw portion between a plurality of machining screw threads, and the machining screw threads and the escape screw threads are formed into a continuously changing cross sectional shape, so that the generation of cutting chips at the time of machining is reduced, and an increase in the operation torque (driving torque) at the time of machining by the machining screw portion is suppressed.
However, in this Patent Literature 2, the machining screw portion is configured to machine the internal screw by means of the machining screw threads of a constant or fixed outside diameter from a tip end side. With such a configuration, the existence of the escape screw threads serves to suppress the increase of an operation torque, but a driving torque will be rapidly applied to the self-tapping screw from an early stage of machining, and so, operability of the self-tapping screw is bad. In addition, cutting chips are prone to accumulate in the spaces or gaps of the escape screw threads, thus posing a problem that the driving torque is increased due to the accumulation of the chips, as in the case of Patent Literature 1. Moreover, because the machining screw threads and the escape screw threads are configured to continuously change, a tool shape of a screw forming mold is complicated, and further, the screw threads of the internal screw once formed may be caused to further deform by the plurality of machining screw threads, thus giving rise to a fear that the shape of the screw threads of the internal screw may become imperfect or insufficient. As a result, it is difficult to carry out stable tightening or fastening.
On the other hand, it is considered that the self-tapping screw as described in Patent Literature 1 or Patent Literature 2 is used for an internal screw (a nut, etc.) to which foreign matter such as a paint film, etc., has been adhered, wherein the self-tapping screw is screwed into the internal screw, while removing the foreign matter by means of the tapping portion.
However, in the case of the external screw described in Patent Literature 1, the spaces or gaps between the second zone screw threads of the self-tapping screw portion are narrow, so that foreign matter can not be discharged well, thus causing jamming or biting of the foreign matter.
In addition, in the case of the self-tapping screw described in Patent Literature 2, too, exfoliated foreign matter can not be discharged well, so that the escape screw threads are clogged and jammed.
On the other hand, as a bolt which can be screwed into an internal screw (a nut, etc.) with foreign matter such as a paint film or the like adhered thereto, while removing the foreign matter, there has been developed a bolt as described in Patent Literature 3, for example. This bolt is partially provided, on at least a pressure side flank of each screw thread thereof, with a convex portion which exfoliates the paint film at the side of the internal screw, and the bolt is configured to be capable of being screwed into the internal screw, while exfoliating the paint film by the convex portion.
However, this bolt is not a self-tapping screw which is screwed into a prepared hole, while forming an internal screw in the prepared hole, and when the bolt is used as a self-tapping screw as it is, a lot of cutting chips will be produced, and hence, a driving torque will also become large.


A new mixing drill with speed sensing with multiple preset speeds for providing a display of drill motor speed while mixing for indicating the viscosity of drywall joint compound and plaster mixtures and providing a quick and easy method of mixing drywall compound to a specific consistency. The inventive device includes an electric drill, an on off switch, a detachable drill bit with vanes, a drill chuck with a magnetic marker, a magnetic sensor attached to the drill body, a drill speed counter, a motor controller, a keypad, a micro controller and a digital LCD display for displaying drill target speed setting and alternatively displaying the actual speed to target speed ratio for indicating viscosity of a mixture. After the mixing drill with speed sensing is has a target speed setting and the drill is started mixing, the mixing drill with speed sensing operates according to a control program such that pressing a keystroke initiates a control subroutine such that when the motor moves the vaned drill bit in a viscous mixture of materials and the viscosity of the mixture reduces with increased mixing time and motor speed increases with increased mixing time the motor will continue to mix until the sensed motor speed reaches the target speed at which time the motor controller serially connected to the on off switch and the drill motor stops the motor and mixing is finished.

1. Field of the Invention
The present invention relates to motor speed monitoring and control systems and more particularly pertains to a new mixing drill with speed sensingwith multiple preset speeds for providing a display of drill motor speed while mixing for indicating the viscosity of drywall joint compound and plaster mixtures and providing a quick and easy method of mixing drywall compound to a specific consistency.
2. Description of the Prior Art
The use of motor speed monitoring and control systems is known in the prior art. More specifically, motor speed monitoring and control systems heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art motor speed monitoring and control systems include U.S. Pat. No. 4,771,223 Armstrong et al; U.S. Pat. No. 4,901,587 Deremo et al; and monitoring of speed of rotation in well drilling U.S. Pat. No. 5,305,836 Hollbrook et al. Elements used in a novel combination in the mixing drill with speed sensing with multiple preset speeds are known prior art magnetic speed sensors in bicycle speedometer/odometers seen in U.S. Pat. No. 4,352,063 Jones et al and U.S. Pat. No. 3,898,563 Erisman; prior art actuation of a drill under control of a microcomputer seen in U.S. Pat. No. 5,181,808 Griggs et al; and prior art transmitting information from the head of a drill rod in mining operations in U.S. Pat. No. 5,268,683 Stolarczyk.
While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not disclose a new mixing drill with speed sensing with multiple preset speeds. The inventive device includes an electric drill, an on off switch, a detachable drill bit with vanes, a drill chuck with a magnetic marker, a magnetic sensor attached to the drill body, a drill speed counter, a motor controller, a keypad, a microcontroller and a digital LCD display for displaying drill target speed setting and alternatively displaying the actual speed to target speed ratio for indicating the viscosity of a mixture.
In these respects, the mixing drill with speed sensing with multiple preset speeds according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of providing a display of drill motor speed while mixing for indicating the viscosity of drywall joint compound and plaster mixtures and providing a quick and easy method of mixing drywall compound to a specific consistency.

Mixing drill with speed sensing with multiple preset speeds


A video signal encoder uses an encoding system such as that developed by the Moving Picture Experts Group (MPEG). A key component of this encoding system increases the quantization step size of image data, thus decreasing its quantization resolution, to reduce the number of bits used to encode the data. Apparatus according to the present invention, monitors the color information being encoded and inhibits or reduces any increase in quantization step size for the luminance component and the color component of the image when signals representing saturated or nearly saturated red image components are being encoded.

Significant reduction in video bandwidth for storage and transmission purposes is desirable in various applications such as compact disc video and high-definition television. One type of video compression system which has received considerable attention lately is that proposed by the Moving Pictures Expert Group (MPEG), a committee within the International Standards Organization (ISO). The MPEG system is described in a paper entitled, "MPEG Video Simulation Model 3 (SM3)" by the Simulation Model Editorial Group, available from ISO as ISO-IEC/JTC1/SC2/WG11/N0010 MPEG 90/041, 1990 which is hereby incorporated by reference for its teachings on the MPEG video signal encoding method. This system is related to the conditional Motion Compensated Interpolation (CMCI) video encoding system described in U.S. Pat. No. 4,999,705 entitled THREE DIMENSIONAL MOTION COMPENSATED VIDEO CODING, which is hereby incorporated by reference for its teachings on video encoding techniques.
The MPEG system integrates a number of well-known data compression techniques into a single system. These include motion-compensated predictive coding, discrete cosine transformation (DCT), adaptive quantization and variable-length coding (VLC). In these systems, the adaptive quantization step is performed on the coefficient values produced by the discrete cosine transform operation for blocks of 64 pixels derived from the input image.
The DCT coefficients are quantized with varying resolution as a function of the amount of data generated by the encoding operation. If an individual image frame produces a relatively large amount of encoded data, the quantization step sizes applied to successive frames may need to be increased to reduce the amount of encoded data used to represent those frames, so that the average level of data produced over several frame intervals is able to be transmitted through a fixed-bandwidth channel.
If, when the quantizer is applying coarse quantization to the DCT coefficients, an image is encoded which includes an object having relatively few contours, the reproduced image of this object may have undesirable quantization distortion. This distortion would appear as an exaggeration of the contours in the object. In addition, if the object contains color areas which are saturated or close to being saturated, the quantization distortion in the reproduced image may cause undesirably large steps in saturation, causing the object to appear cartoon-like. This is especially true if these saturated or close-to-saturated colors are in the range of red to orange, since the human eye is more sensitive to detail in this color range than in other color ranges.
It is well known that the human eye is most sensitive to detail in color hues defined by the in-phase or I chrominance vector, as defined by the National Television Standards Committee (NTSC). In actual images, however, quantization distortion is more likely to be noticed in red objects than in objects having hues defined by the I chrominance vector, since in actual images, red objects will be more prevalent, have more highly saturated colors and have fewer contours than objects having reddish-orange hues defined by the I chrominance vector. Although I hues, such as flesh tones, are prevalent in many video images, they are generally present only at relatively low levels of saturation.

High-definition video encoding system having color-sensitive quantization

Matsushita Electric Corporation of America


Devices and methods for sternal retraction that reduces bleeding from the cut edges of a sternum and reduces fracturing of the sternum during retraction. The devices and methods involve the use of sternal retractor blades having a certain geometry and inserts placed inside the sternal retractor blades during retraction of the sternotomy incision. The blades and inserts act to tamponade the blood flow from the cut sternal edge and reduce fracturing of the sternum during retraction.

The present invention relates generally to medical devices, and more specifically to a sternal retractor that minimizes blood loss and fractures of the sternum during use of the sternal retractor.
Approximately 1,000,000 cardiac surgical procedures are performed worldwide each year. In the vast majority (>95%) of these procedures, access to the heart is achieved by dividing the sternum, a procedure known as a sternotomy. The sternum is the "breast bone", a flat bone approximately 15 to 25 cm in length, 2 to 3 cm in width, and 8 to 16 mm in thickness. In fact, it consists of three bones connected by fused "joints": the manubrium is 3 to 6 cm long and is located at the cephalad end, the sternum proper is 12 to 15 cm long, while the xiphoid is 1 to 4 cm long and located at the caudal end. The manubrium and sternum are composed of thin (1 to 2 mm) outer and inner tables of cortical bone and a wafer-like, spongiform center of cancellous bone in which the bone marrow resides. Within this bone marrow are numerous venous sinusoids.
Bleeding from the cut sternal edges during a sternotomy can be profuse and prolonged, lasting the duration of the operation, which may be 4 to 8 hours. Cardiac surgical patients are usually given a powerful intravenous anticoagulant, heparin, which prevents the formation of clots during the operation. Total blood loss from the sternal marrow frequently exceeds one liter during a cardiac operation. In conventional operations performed with the use of the heart-lung machine, this shed blood is suctioned up into the venous reservoir of the heart-lung machine and then re-infused into the arterial system of the patient. Fat droplets and other particulate matter is copious within blood shed from bone marrow and these "impurities" are also re-infused into the patient, where they have been implicated as a cause of neurocognitive decline (brain injury), respiratory insufficiency, and renal failure after heart surgery. Recent reports in the literature have advocated discarding this shed blood, yet the sheer volume of blood shed from the sternal bone marrow makes this impractical in most cases. Alternatively, this shed blood may be "washed" in a centrifugal cell scavenge system prior to re-infusing the red blood cell portion. Unfortunately, all other blood components (platelets, coagulation proteins, serum proteins, etc.) are wasted in this system and derangements in the normal clotting ability of the patient often result. In either case, the volume of blood routinely shed from the sternum during cardiac surgery is a major cause of blood transfusion during and after cardiac surgery.
Transfusion associated with cardiac surgery is the single largest civilian demand for blood transfusion worldwide. Within the US, cardiac surgery consumes 10 to 15% of all blood provided by the Red Cross. Thus, there is a clear and immediate need for a way to safely reduce the volume of blood shed from sternal bone marrow during surgical procedures performed via sternotomy.
When the surgeon performs a sternotomy to access the heart or other mediastinal structures, the cut edges of the sternum are typically pried apart with a mechanical device known as a sternal retractor. This device is typically made of stainless steel and includes left and right arms and a rack and pinion mechanism to move the arms apart or together. The arms have blades attached thereto, which actually contact or grip the cut edges of the sternum to apply the opening pressure exerted by the rack and pinion. While these blades are currently available in different shapes and sizes to accommodate the numerous different available retractor systems, none are designed to reduce or prevent bleeding from the edges of the sternum.
Another issue with presently used sternal retractors is the issue of sternal fractures. Presently available blades only contact the central or middle region of the sternal edge. This applies a large amount of pressure against a relatively small surface area of the sternum, which leads to frequent fractures of the sternal edges. These fractures contribute to increased sternal bleeding and are associated with delayed or incomplete healing and increased risk of sternal wound infection.
Accordingly, there is a need for a sternal retractor that reduces bleeding from the cut sternal edge and that reduces fracture of the sternum.


Provided is a high resolution distance ranging apparatus using an ultra-wideband (UWB) communication. The apparatus includes: a first spectrum analyzer for extracting a frequency component corresponding to multipath time delay from a reception signal; a second spectrum analyzer for acquiring a noise subspace of the extracted frequency component and extracting a frequency component where maximum power is located from a frequency spectrum based on the noise subspace; a time of arrival (TOA) extractor for extracting TOA based on the frequency component where maximum power is located.

FIG. 1 is a block diagram showing a structure of a conventional distance ranging apparatus using an ultra-wideband (UWB) communication. The apparatus shown in FIG. 1 shows a structure of the distance ranging apparatus for a UWB radio.
A transmitted signal goes through a UWB antenna 101 and a band-pass filter 102 filters an output a signal form the UBW antenna 101 and outputs a filtered signal. Subsequently, a UWB signal receiver 103 such as a UWB coherent receiver and a UWB noncoherent receiver demodulates a signal modulated in a transmitting part from an output signal of the band-pass filter 102 and an analog to digital converter (ADC) 104 converts the demodulated signal into a digital signal. When the digital signal is acquired by the ADC 104, sampling information on a frame defining a section where data are physically transmitted is acquired. A frame adder 105 adds the sampled data through many frames, thereby reducing noise components.
When the frame adder 105 adds many frames, a time of arrival (TOA) estimator 106 calculates energy of the signal accumulating the frames and detects a maximum value of the calculated energy through first and second image signal processes. The TOA estimator 106 ranges a distance by detecting TOA when the maximum value of the energy is detected.
As described above, the conventional distance ranging apparatus is a system for applying diverse techniques to find a proper threshold in a time area. Therefore, there is a problem that resolution in distance ranging is largely changed according to the threshold set up to find a point at which the transmitted signal starts.
Since the conventional distance ranging apparatus is based on a time area signal process, noise or interference can affect on the distance ranging.

High resolution ranging apparatus and method using UWB

Electronics and Telecommunications Research Institute