A method and an apparatus for quantifying the amount of fluid administered to a patient simulator during simulated medical surgery. A fluid administered to a manikin and delivered to a reservoir associated with the manikin. The quantity of fluid administered is determined based on the change of weight of the reservoir. A simulated response to the administered fluid can be computed, based on the determined quantity of fluid administered.

1. Field of the Invention
This invention relates to an integrated patient simulator and methods of using the same. In particular, this invention discloses an improved patient simulator capable of realistically simulating nerve stimulation, lung movement, lung volume measurement and lung breathing noise, administration, detection, identification and quantification of medicaments and fluids introduced during simulated surgery, bronchial resistance, computer controllable compliances and also possessing an improved computational configuration, an electric cardiac synchronization pulse, audible heart and lung sounds, simulation of continuous blood gases, pulmonary artery (PA) catheter inflation detection, difficult airway, spontaneous breathing and other anesthesiological indications, and gas exchange via a mass-flow controller.
2. Background of the Invention
Currently, a new resident in medicine will receive a very limited duration of didactic teaching about the principles of particular medical procedures, such as anesthesia, before delivering care to his/her first real patient. The resident is then faced with a new and unfamiliar environment while shouldering the tremendous responsibility of caring for an ill and sometimes anesthetized patient. Similarly, experienced physicians who require continuing medical education, refresher courses (e.g., handling of rare ailments and situations) or familiarization with newly introduced and/or technologically sophisticated equipment or procedures do not have the opportunity for hands-on practice in a realistic environment, without risk to a patient. Of course, these undesirable situations also apply to other disciplines such as allied health care and veterinary medicine, for instance.
The patient simulator disclosed in U.S. patent application Ser. No. 07/882,467 addresses the above-mentioned deficiencies in medical, allied health care and veterinary education. The improved self-regulating full-scale patient simulator technology described herein comprises further embodiments of a patient simulator.
The lung portion of the integrated patient simulator disclosed herein consumes and/or produces gases including oxygen, carbon dioxide, nitrogen, nitrous oxide and volatile anesthetics. Under the control of a mathematical model of human physiology implemented on a computer, uptake and delivery of the above mentioned gases is computed by the uptake and delivery module of the physiological model. The computed uptake and delivery is then physically created by gas substitution in the hardware module for simulating gas exchange in the lung simulator portion of the patient simulator. The lung will also simulate spontaneous inspiration with computer control of tidal volume (VT), respiratory rate (RR) and functional residual capacity (FRC) and will also allow the simulation of a cough. In addition, the lung will exhibit the desired lung mechanics and gas exchange when mechanically or manually ventilated.
The patient simulator system of this invention has several components including lung mechanics (software and hardware): gas exchange (software and hardware); a physiologic model (software); cardiovascular; uptake and distribution; neuromuscular system; pharmacokinetics/pharmacodynamics; physiologic control models; and a unique linking of the different subsystems of the patient simulator so that the patient responds realistically to inputs from the trainee/student.
A major improvement of the lung/patient simulator is that it allows realistic action/reaction interplay between the actions of the trainee, responses of the simulated patient, data shown on the monitors and subsequent actions by the trainee. Another significant improvement that distinguishes the lung/patient simulator from similar systems is that its software and hardware are self-regulating. The present hybrid (mechanical and mathematical) lung model regulates itself regardless of type of gas (air, anesthetics, hypoxic, etc.) inhaled, and, surprisingly, even the blunting of physiological control mechanisms (e.g., ventilatory response to carbon dioxide) is self-regulated.
The present patient simulator is an integrated, self-regulating system. For instance, in a non-self-regulating system, an awkward input situation would invariably lead to physiologically implausible behavior from the system or such stimuli would result in an inability of the system to handle the input at all. A self-regulating system is more robust in the accommodation and simulation of unplanned events because it will still provide an appropriate response. Thus, self-regulation is highly desirable, yet glaringly absent from the prior art.
For instance, if the trainee accidently ventilates the lung with a hypoxic (lacking oxygen) gas mixture (e.g. pure argon gas), a conventional system may not be able to react appropriately. However, the present invention provides an integration of relevant systems such that, through self-regulation, appropriate simulated manifestations of hypoxia would be produced in the various output devices of the patient simulator, e.g. increased breathing rate and heart rate.
As another example, those skilled in the art are aware that increased CO.sub.2 levels in the lung will cause hyperventilation. Hyperventilation results in lowering of CO.sub.2 levels in the lungs due to washing away of the carbon dioxide. In a non-self-regulating patient simulator, increased lung CO.sub.2 may or may not lead to increased ventilation. If no increase occurs, the reality of the simulation is decreased, thereby lessening the teaching value of the simulation.
Thus, it is clear that self-regulating systems hold clear advantages above non-self-regulating systems.
Furthermore, a means for adequately handling the injection of liquid anesthetic into the breathing circuit has been attempted by other researchers. The problems encountered in the prior art included (a) freezing of the location where the liquid anesthetic is introduced because of the heat of vaporization extracted from the surroundings as the liquid anesthetic evaporates, (b) pooling of the injected liquid through lack of heat to vaporize the liquid anesthetic and (c) uncontrolled evaporation of the anesthetic liquid from the syringe to the breathing circuit (i.e. the tubing or conduit assembly which physically connects the anesthesia machine or ventilator to the patient/manikin). The instant integrated patient simulator solves these problems by providing a means as usable not only in the simulation but in real life anesthesia applications.
A real life practitioner must be able to react to a patient who is undergoing a degree of bronchial restriction. Therefore, it is highly desirable for a patient simulator to be able to simulate bronchial resistance where the restriction of gas flow may be varied upon a continuum. Without manual intervention, such capability is lacking in the prior art systems.
In a full-scale patient simulator, it is necessary to be able to simulate changes in bronchial resistance. In a full-scale simulator using real gas flows, independent computer-controlled variable orifices (with maximum openings of 0.5" diameter) placed in the bronchi would allow simulation of changes in bronchial or airway resistance. No prior art devices (e.g., photographic camera iris diaphragms) were found which could simulate variable bronchial resistances in the relevant diameter range. Furthermore, a device capable of allowing a suction catheter to pass down the bronchus was preferable. Thus, the present invention could not use butterfly valves with an internal diameter of 0.5".
Another possible embodiment was a stepper motor actuated cam or lever that presses a flexible conduit closed. However, because the stepper motor would have needed to be overly large in order to provide the force necessary to maintain the flow area completely closed and capable of holding a pressure of 120 cm H.sub.2 O, one of the design specifications, it was highly desirable and necessary to design an alternative computer-controlled variable orifice device.
During simulation, it is preferable if the drugs and IV fluid administered by the trainee to the simulated patient are automatically sensed and input into the computer, rather than having to depend on the simulation instructor to recognize and manually enter the drug or IV fluid type, concentration and dose administered to the patient. Thus, in prior systems, the simulation instructor might be distracted and miss the administration of the drug or IV fluid by the student or might manually enter into the simulation controller the wrong type, concentration or dose of the drug or IV fluid.
In addition, the amount of drug and/or IV fluid administered by the student is a critical input to the physiological model of the patient because the response of the patient is dose- and volume-dependent. The amount of IV fluid dripped into the patient is also a parameter that needs to be quantified if the fluid balance of the simulated patient is to be correctly modelled. It does not appear that prior art systems have contemplated a means for quantification of drug administered. As in drug identification, a system that will allow quantification of the amount of drug or IV fluid injected via an intravenous (IV) line without the need for a human observer is highly desirable.
U.S. patent application Ser. No. 07/882,467 disclosed and claimed one embodiment of distributed processing network for implementing the computer portions of the current patient simulator: a ring-shaped array of single-board computers (i.e., DACS PAN- Data Acquisition and Control System).
It has been found that a star configuration for a network of single board computers is more preferable. The extent of computational power and parallel processing required for simulating a patient's different physiological subsystems is facilitated by a distributed processing network. For example, one computer takes modulates the mechanical lung while another controls the palpable pulses. The ring network is less robust than a star network configuration because if one of the single board computers becomes non-functional, the entire network ceases to operate. In the star network configuration, the network will still function even if one of the computers on the network fails.
The realism of a simulation would be marred if the different signs or variables dependent on the cardiac rhythm were at different frequencies (e.g., an ECG heart rate of 70 beats per minute (bpm) but a pulse rate from the pulse oximeter of 90 bpm). A mechanism that allows synchronization of all cardiac related events is, therefore, highly desirable and necessary for a realistic patient simulator.
The realism of a patient simulator would also be compromised if the simulator lacked audible heart, lung and breathing sounds emanating from the appropriate portions of the simulator. In addition, spontaneous breathing is highly desirable and adds to the realism of the patient simulator.
In addition, a realistic patient simulator should be able to simulate the monitoring of continuous blood gases. Simulation of continuous blood gases monitoring is highly desirable in light of recent technological advances implementing such technology in the everyday practice of specialists. Furthermore, it is highly desirable that a patient simulator have a means for detecting pulmonary artery (PA) catheter inflation.
Also, it is desirable to have a patient simulator capable of simulating a difficult airway. Difficult airway may be caused by a number of factors, such as an allergic reaction. In a difficult airway situation, the patient's trachea closes and prevents the flow of air in and out of the patient's lungs. Thus blocked, it is not possible to insert through the trachea an endotracheal tube (ETT) for securing the airway. It is highly desirable to provide a patient simulator capable of simulating this potential complication so that a trainee may be taught the proper response techniques such as a cricothyrotomy.
In addition, a difficult airway is a potentially lethal incident which anesthesiologists and other practitioners will likely encounter in actual patients. The American Society of Anesthesiologists has declared that is essential for any anesthesiologist to know how to handle such a situation as one of his or her practice parameters. Thus, the patient simulator provides a risk-free way to assess whether a trainee has successfully learned how to handle a difficult airway.
It is also desirable to provide a patient simulator capable of efficient and realistic gas exchange. Although a previous embodiment of the patient simulator contained a gas exchange module, the current module differs in important ways. Most importantly, the patient simulator disclosed herein uses mass flow controllers instead of frequency modulated valves as in the previous embodiment. Modulated valves provided inaccurate control over the flow rate of the different gases. In addition, maximum flow rate was limited in the prior embodiment in an unrealistic fashion which resulted in an unrealistically small difference between inhaled and exhaled oxygen levels. Finally, the frequency modulated valves resulted in inconsistent signals transmitted to the capnogram (depiction of CO.sub.2 level over time) which manifested themselves as ripples instead of straight lines, especially during plateau portions of the exhalation.
In addition, Instead of a "copper kettle" Vernitrol vaporizer being used to introduce vaporized volatile anesthetic into the lung bellows, a syringe pump with a novel copper device is used in the present invention. In copper kettle systems, a carrier gas (generally O.sub.2) is bubbled through a pool of liquid anesthetic contained in a solid copper vaporizer. The use of the syringe pump eliminates the necessity of using a carrier gas per se thus simplifying the behavior of the gas exchange subsystem in general.
Realistic simulation of gas exchange is necessary because it allows the use of real or modified medical gas analyzers such as those used in real operating rooms. Other simulators do not model gas exchange at all. Instead, other simulators in the art bleed CO.sub.2 at variable rates into the bellows representing the simulated lungs. Thus, the simulators are incapable of simulating even the most rudimentary gases being exchanged such as oxygen. Nor are those systems capable of simulating the consumption or excretion of the amount of volatile anesthetics.
In addition, when an oxygen analyzer is used to sample the flow of gases into and out of a real patient's lung, exhaled oxygen will be notably lower than inhaled oxygen due to consumption in the patient's lungs. Unlike other simulators, the patient simulator of this invention is capable of realistically portraying to external monitoring equipment the differential between inspired and expired oxygen concentration. When other simulators are linked to an oxygen analyzer, the insiparatory and expiratory oxygen levels will be identical either indicating grave health problems to the patient or a serious breakdown in the realism of the simulation. Thus, the accurate modeling of gas exchange, as accomplished by the instant invention is highly desirable.

Apparatus and method for quantifying fluid delivered to a patient simulator

University of Florida Research Foundation


Systems and methods for detecting defective pixels in a video sequence having a plurality of frames, the method comprising determining one or more frames of a single scene and determining a plurality of buffers of each frame related to the single scene, detecting one or more candidate pixels for a first predefined number of frames, tracking the detected one or more candidate pixels for a second predetermined number of frames, validating the one or more candidate pixels for presence of defect and marking a candidate pixel from the one or more candidate pixels as a defective pixel based on one or more predefined conditions.

A number of digital imaging devices are in common use today for capturing images and videos including digital still cameras and digital video cameras. Such digital imaging devices are equipped with an image sensor designed to convert light received via lenses into electrical signals. A charge coupled device (CCD) sensor and a complementary metal oxide semiconductor (CMOS) sensor are a few examples of the image sensors included in an imaging device. The image sensor includes multiple photodiodes provided corresponding to multiple pixels constituting an image and arranged to output pixel data representing pixel values of the corresponding pixels. Further, Images/Videos are generally captured in RGB format. In capturing device, there are sensor arrays containing sensors for each pixel position. As the data is captured in RGB format, but the visible light contains other colours also, so filters are provided before these sensors to filter out unwanted colour frequencies. Now to capture R, G, B value at each pixel, one would require 3 filters as well as 3 sensors for each pixel. This is not an economic way to capture any image, so some colour filter arrays are employed to capture the image with 3 times less sensors. The colour filters filter the light by wavelength range, such that the separate filtered intensities include information about the specific colour of light. For example, the Bayer filter is used for separating the R,G,B color information in a way that each quartet of sensors contains two diagonally opposite sensors for Green, one for Red and one for Blue. The raw image data captured by the image sensor is then converted to a full-colour image (with intensities of all three primary colours represented at each pixel) by a demosaicing algorithm which is tailored for each type of colour filter.
The photodiodes in a digital imaging device may be aligned as an array of M×N pixels, with the incident illumination at location (i,j) denoted by I(i,j). Each photodiode location produces an output Y(i,j), which depends on the incident illumination I(i,j) according to a linear function Y(i,j)=m I(i,j)+b; where m is the sensitivity and b is the bias or offset of the defect. In an ideal scenario, the sensitivity m is unity and the bias b is zero, such that the output always directly reflects the input. Due to malfunction of the sensor the sensitivity may either be greater than 1 or may be 0 and the bias may be very high thus resulting in a pixel value higher or lower than the incident illumination. Malfunction of any of the photodiodes can result in certain discrepancy in the original pixel values, thus in an output image a higher or lower pixel value may be displayed. Depending upon the values of non-unity sensitivity and a non-zero bias, defective pixels can be of various types namely Dead Pixels, Stuck Pixels and Hot Pixels. Dead Pixels are produced by sensors with zero sensitivity and low or zero bias. Stuck Pixels are produced by sensors with zero sensitivity and high bias. Hot Pixels are produced by sensors with non-unity sensitivity and/or non-zero bias.
A number of techniques have been proposed for detecting any defective pixel caused by malfunction of image sensors among multiple pixels constituting a taken image or video frame. A prior art techniques disclose for example, detecting a white defect as a defective pixel in a single plate color video camera. The prior art techniques check the absence of a high-frequency component in a target pixel set as a processing object based on the frequency characteristics of peripheral pixels with different color filters from the color filter set on the target pixel, and identify the target pixel as a defective pixel in response to subsequent detection of the presence of the high frequency component in the target pixel. However, the existing techniques are either ineffective or inefficient in detecting defective pixels in a video sequence that comprises of a plurality of frames.
The erroneous sensors produce a pixel value that looks pretty much different from its actual value and the pixel values in the surrounding region. Although these erroneous sensors are detected at the time of manufacturing of capturing device and some error-correction mechanism is also provided for the same, still these problems in sensors can also occur in field working. The systems and methods described in the present disclosure deal with detection of such type of defective pixels present in a video in an efficient manner.


Apart from a semiconductor substrate and a photosensitive region in the semiconductor substrate, which comprises a space charge zone region for generating a diffusion current portion and a diffusion region for generating a diffusion current portion, a photodiode includes an insulation means in the semiconductor substrate for at least partially confining the diffusion region against an adjacent surrounding region of the semiconductor substrate. The reduction of the bandwidth of photodiodes by the smearing of the response of the photodiode by the diffusion current is alleviated by providing an insulation means in the semiconductor substrate, which confines the diffusion region against the surrounding semiconductor substrate and hereby on the one hand reduces the number of charge carriers contributing to the diffusion portion by reducing the diffusion region, in which the diffusing charge carriers are generated, and on the other hand by “sucking off” diffusing charge carriers generated in the shrunk diffusion region by the insulation means, which is why same do not contribute to the photocurrent.

1. Field of the Invention
The present invention relates to a photodiode and, in particular, to fast photodiodes as are, for example, utilized in optical memories and in optical communications.
2. Description of the Related Art
Photodiodes are applied in various fields. Photodiodes are, for example, employed in X-ray detectors, camera sensors, triangulation sensors, optocouplers, monitoring devices, optical memories and optical transmission systems. In particular in the last-mentioned fields of application, photodiodes enabling signal processing in the megahertz to gigahertz region are required.
A photodiode utilizes the electrical field of a pn junction to capture charge carriers generated by light or to separate electron/hole pairs. The resulting photocurrent is composed of a drift portion and a diffusion portion. The. drift portion is formed by charge carriers generated in the space-charge zone of the pn junction and thus detected directly via the photocurrent. The drift portion of the photocurrent generated in this way has a bandwidth in the gigahertz region.
The diffusion current is formed by charge carriers generated outside the space-charge zone. After being generated, the charge carriers diffuse through the substrate due to a lacking field impact without an electromotive force and are detected at a time interval, offset from the generation, depending on the diffusion length. The bandwidth of this diffusion portion is considerably smaller than that of the drift current portion, namely smaller than about 10 MHz.
The percentage of the drift portion compared to the entire photocurrent approaches zero for large wavelengths. With an increasing wavelength, the bandwidth of the photocurrent consequently corresponds to the bandwidth of the diffusion portion. In contrast, the sensitivity of photodiodes at first increases with an increasing wavelength. The reason for this is that the penetration depth of light on the one hand increases with an increasing wavelength and that the recombination of charge carriers at the surface on the other hand is higher than in charges generated in deeper regions. The result is an increase in sensitivity or responsivity of the photodiodes with an increasing wavelength Starting at a certain wavelength at about 650 nm, the sensitivity of the photodiode, however, decreases with further increasing wavelengths since, due to the still greater penetration depth of long-wave light, charge carriers are generated in even deeper regions and the charge carriers generated in even deeper regions and diffusing towards the space-charge zone of the photodiode can no longer reach the space-charge zone of the photodiode before recombining.
Up to now, ways of addressing the problem of a limited bandwidth in systems requiring a photodiode having a bandwidth of several megahertz have been to fall back on discrete photodiodes produced by means of expensive special processes. Apart from the expenses for the external devices, this causes further expenses for example due to additional casing pins, bond pads, high-area and high-current input/output interfaces and additional printed circuit board area.
An alternative solution allowing fast photodiodes without modifying a process is described by Cathleen Rooman et al in "Asynchronous 250-Mb/s Optical Receivers with Integrated Detector in Standard CMOS Technology for Optocopler Applications," IEEE Journal of Solid State Circuits, vol. 35, No. 7, July 2000. In order to optimize speed without modifying a process, half of the diode area is used to detect the diffusion current. Additional circuit blocks calculating the diffusion portion from the photocurrent comprising a diffusion and a drift current portion are provided for this. The disadvantage of this procedure is that about half of the light power is employed for detecting the diffusion current. Furthermore, there are several non-amplifying devices in the signal path, which in turn means a considerable deterioration of the noise features of the read-out. In particular in communications and optical memory systems, noise is a critical parameter so that the procedure used there can only be employed in such systems under certain circumstances.
Another disadvantage of prior-art photodiodes generated on the process level is that they exhibit, as has been described before, a sensitivity characteristic curve which depending on the wavelength is not constant. A linearization of the sensitivity could, for example, be desired for reasons of compatibility in optical memory systems in which data is read out from data carriers, which can be archived, in different devices by means of light sources having different wavelengths. Up to now, such a linearization has only been achieved on the side of signal processing by means of complex circuit blocks, such as, for example, digital signal processors.


Provided is a fiber reinforced cement based mixed material having high tensile strength and high toughness, the mixed material comprising a cementitious composition with fast development of early strength; a small hydration heat temperature; and a small shrinkage during curing. The fiber reinforced cement based mixed material contains 100 wt. parts of cement, 5-30 wt. parts of silica fume, 30-80 wt. parts of at least one pozzolanic material excluding the silica fume, 5-25 wt. parts of limestone powder, at least one chemical admixture, water, 70-150 wt. parts of aggregate having a largest aggregate diameter of 1.2-3.5 mm, and fibers, wherein at least some of the fibers comprise a fiber having asperities formed in the surface, the fiber having asperities being formed such that a ratio (h/H) of a depth h of each of recessed portions among the asperities to a smallest cross-sectional diameter H thereof is 0.05-0.8.

Conventional concrete ranges from normal concrete for use in civil engineering and architectural constructions to high-fluidity concrete, high-strength concrete, mass concrete, underwater concrete, etc. depending upon the intended use, and is basically a material intended to be reinforced with reinforcing steel bars. Nowadays, however, there is a trend to employ so-called fiber reinforced concrete (FRC) in which short fibers are incorporated into the conventional concrete for the purpose of supplementing steel bar reinforcement, preventing corner defects of members, and preventing cracking due to drying shrinkage.
The aggregates blended in these concretes are composed of a fine aggregate and a coarse aggregate. In conventional concrete, a unit weight of aggregate contained in a unit volume of concrete is generally greater than a unit weight of powder (=unit weight of cement+unit weight of mineral admixture). For example, the ratio of the unit weight of aggregate to the unit weight of powder is given by 400 to 700% for the most commonly used type of concrete. It is about 250 to 300% even for powder-type high-fluidity concrete containing a large amount of powder.
Moreover, the largest particle diameter of coarse aggregate used in conventional concrete is limited most often to 20 mm or 25 mm in case of applying to general structures, and limited to 40 mm or 80 mm in case of applying to dams and the like. Thus, in conventional fiber reinforced concrete, the bonding mechanism between the fibers and concrete does not rely on mechanical bond through the aggregate mixed in concrete but relies on chemical adhesion and frictional force between cement hydrates (cement paste) and the fibers.
On the other hand, ultra-high-strength fiber reinforced concrete has been known which is obtained by mixing reinforcing fibers such as metallic fibers or organic fibers into a cementitious matrix that is obtained by mixing cement and pozzolanic reaction particles (pozzolanic material) into aggregate having a largest aggregate particle diameter of 1 to 2 mm (see Patent Documents 5 and 6, etc).
Ultra-high-strength fiber reinforced concrete as described above has such a characteristic that it can secure a certain level of tensile strength and toughness even after development of a crack, by combining fibers having high tensile strength with a cementitious matrix being dense and having ultra high strength. Specifically, this has been considered to be due to the exertion of a so-called bridging effect which allows the fibers to cover tensile force for the cementitious matrix when a crack is developed in the cementitious matrix as a result of tensile stress.
For this reason, unlike conventional reinforced concrete, ultra-high-strength fiber reinforced concrete as described above does not require reinforcement with reinforcing steel bars. Moreover, concrete structures built using ultra-high-strength fiber reinforced concrete as described above can achieve reduction in the thickness and the weight of its components.
Moreover, ultra-high-strength fiber reinforced concrete as described above can achieve significant improvement in durability because ultra-high-strength fiber reinforced concrete is often subjected to heat curing (steam curing), and denser hydrated cement particles are developed in a short time through a hydration process compared with normal moist curing. Further, after heat curing, ultra-high-strength fiber reinforced concrete has such characteristics that drying shrinkage becomes almost zero, and a creep coefficient is significantly decreased.
The cementitious compositions disclosed in Patent Document 1 and Patent Document 2 have almost the same mix proportion except the type of cement. These Patent Documents are different in that the type of cement in the cementitious composition is ordinary Portland cement, high-early-strength Portland cement, or moderate-heat Portland cement in Patent Document 1, while it is low-heat Portland cement in Patent Document 2. The cementitious compositions of Patent Documents 1 and 2 are characterized in that the effects of improvement in fluidity, shortening of setting time, improvement in mixing properties, etc. are obtained by blending limestone powder having a specific grading distribution. According to Patent Documents 1 and 2, the improvement in fluidity or mixing properties cannot be achieved only by the adjustment of the fineness (Blaine specific surface area) of limestone powder, but it is indispensable that limestone powder should have a specific grading distribution.
However, the cementitious compositions disclosed in Patent Documents 1 and 2 are cementitious compositions for forming conventional concrete materials, and are not targeted for an ultra-high-strength cementitious matrix of ultra-high-strength fiber reinforced concrete which does not contain coarse aggregate as mentioned above. For this reason, although these cementitious compositions contain Portland cement, silica fume, and limestone powder, the effects of the limestone powder under conditions where a mineral admixture such as a pozzolanic material is blended are neither described nor suggested.
Both Patent Document 3 and Patent Document 4 are the documents on ultra-high-strength fiber reinforced concrete. Fibers contained in the latent hydraulicity composition of Patent Document 3 are organic fibers and carbon fibers, while fibers in Patent Document 4 are metallic fibers. Thus, these Patent Documents are different in terms of fibers, but are common in the cementitious matrix. The cementitious matrices disclosed in these documents are each composed of cement, fine particles, and two kinds of inorganic particles, in which a specific surface area and mix proportions by weight are specified to each of the materials.
Moreover, Patent Documents 3 and 4 each disclose a latent hydraulicity composition developed for the purpose of improving fluidity and segregation resistance, and improving mechanical properties such as compressive strength after curing. With respect to these disclosures, the literatures do not show the improvement in performance based on chemical reaction of materials blended, but describe the performance improvement in fluidity and segregation resistance by paying attention to the grading distribution or Blaine specific surface area of materials. Further, improvement in compressive strength after curing is also described by paying attention to the fact that the constituent materials are mixed by densest packing. These Patent Documents neither describe nor suggest the effects of the cementitious matrix obtained by mixing cement, silica fume, at least one pozzolanic material, and limestone powder on early strength, low shrinkage, low heat of hydration, high fluidity, high tensile strength, high toughness, and etc.
Moreover, Patent Documents 5 to 8 each disclose a composition of a cementitious matrix composed of cement and particles which undergo pozzolanic reaction. Further, metallic fibers, organic fibers, composite fibers obtained by combining organic fibers with metallic fibers, or the like are contained as fibers for reinforcing these cementitious matrices. The ultra-high-strength fiber reinforced concretes disclosed in these documents are characterized in that they allow improvement in fluidity, improvement in segregation resistance, improvement in durability by densifying a cementitious matrix, and improvement in mechanical characteristics after curing. Mixing of pozzolanic reaction particles leads to a state where pozzolanic reaction caused by the presence of cement can be expected, which allows improvement in mechanical properties after curing to be achieved. Moreover, a pozzolanic material also achieves the grading adjustment function of the components of a cementitious matrix composition. Accordingly, improvement in fluidity, improvement in segregation resistance, and densification of a cementitious matrix can be achieved. However, these Patent Documents neither describe nor suggest the effects generated by mixing limestone powder in addition to pozzolanic reaction particles and the achievement of high tensile strength and high toughness by improving the bonding performance between reinforcing fibers and a cementitious matrix.

Fiber reinforced cement based mixed material


An exemplary intermediate frequency (IF) signal loss compensation circuit for an outdoor unit of a communication system includes a sending circuit, a detection circuit, a receiving circuit, and a control circuit. The detection circuit detects in substantially real-time the loss of signal transmitted via a cable from the indoor to the outdoor unit, and transmits loss signal to the control circuit. The control circuit compares the loss signal with a pre-stored signal to determine the loss and then, the control circuit gives loss signals of the sending circuit a variable gain compensation according to the loss. The control circuit also gives loss signals of the receiving circuit a variable gain compensation in advance. The IF signal loss compensation circuit can detect the IF signal loss in substantially real-time, giving the IF signal a variable gain compensation for the loss.

1. Field of the Invention
Embodiments of the present disclosure relate to an intermediate frequency (IF) signal loss compensation circuit, and particularly to an IF signal loss compensation circuit in an outdoor unit of a communication system.
2. Description of Related Art
Communication systems comprises transmitting signals between a transmitter and a receiver. The signals may be transmitted wirelessly or through a cable. However, there may be IF signal loss between the transmitter and the receiver when transmitting a signal via the cable.
Referring to FIG. 2, one such communication system includes an outdoor unit 20 and an indoor unit 60. The outdoor unit 20 is connected to the indoor unit 60 via a cable 40, and to an antenna 10. The cable 40 transmits IF signals and control signals between the outdoor unit 20 and the indoor unit 60. Due to loss during IF signals transmitted via the cable 40 or other devices, IF signals are attenuated, and as a result, there is a need to compensate for the IF signals loss in the cable.
Referring to FIG. 3, one such IF signal loss compensation circuit in the outdoor unit 20 includes an up converter 22, a sending amplifier 24, a down converter 26, a receiving amplifier 28, and an IF splitter 30. When the indoor unit 60 receives signals from the outdoor unit 20, radio frequency (RF) signals received from the antenna 10 are sent to the down converter 26 and is converted into IF signals, wherein the IF signals are amplified by the receiving amplifier 28 and is sent to the indoor unit 60 via the IF splitter 30. While the indoor unit 60 sends signals to the outdoor unit 20, the IF signals from the indoor unit 60 are sent to the sending amplifier 24 via the IF splitter 30 to be amplified, and then are sent to the up converter 22 and converted into RF signals. The RF signals are sent to the antenna 10. In this communication system, the sending amplifier 24 and the receiving amplifier 28 are fixed gain amplifiers and can only give IF signals loss a fixed gain compensation. Moreover, the fixed gain amplifiers cannot detect the IF signals loss in substantially real-time, consequently giving IF signals loss a variable gain compensation according to the loss.
What is needed, therefore, is an compensation circuit to remedy the above mentioned deficiencies.

Wireless communication system and intermediate frequency signal loss compensation circuit thereof


There is provided a method for processing broken glass particles subject to moisture, to which residues of stickers adhere. The method comprises receiving the broken glass particles continuously at a delivery point of a drum, transporting the broken glass particles as a stream of broken glass particles in the drum to a discharge point, wherein the stream of broken glass particles is removed from the drum, rotating the drum such that circulation and mutual friction of the stream of broken glass particles occurs, and applying a gas stream to the stream of broken glass particles and guiding the gas stream over the stream of broken glass particles to remove the residues of stickers, wherein the transporting of the stream of broken glass particles is decelerated in a bulge of the drum.

Waste glass is collected in Germany in publicly situated barrels in particular. A preselection is made in that waste glass of a specific color is only to be thrown into a specific barrel in each case. The public complies with this to a greater or lesser extent. A strict separation according to color of the glass is not achievable in this way, of course.
Waste glass consists of bottles in particular, but also can-shaped glass articles. In any case, the waste glass is afflicted with strong contamination. This includes residues of container contents, metal parts such as bottle caps, and plastic parts. Stickers such as labels are particularly unpleasant.
All of these contaminants must be removed in the course of the processing (recycling) of waste glass. The invention is concerned therewith.
The process for processing waste glass or broken glass of any type includes numerous method steps. These include, inter alia, the crushing of the glass thrown into the barrels into shards or particles. These may be the size of the palm of a hand, for example.
A further decisive method step is the separation of the glass particles into the various color fractions. The glass particles and their color are detected in the traps by optical sensors, and the measurement result controls blowing nozzles connected downstream, which in turn react selectively to the individual colors and reject incorrect colors.
Residues of stickers such as labels which adhere to the glass shards interfere in this case. Therefore, a corresponding method step for removing the stickers is connected upstream from the mentioned separation according to color. The invention is directed to this method step.
Facilities for removing the residues of stickers are known. A trough is filled with particles of waste glass. The trough contains stirrers, which revolve in the mass of the particles. The revolving results in mutual friction of the individual particles, the residues of stickers also being detached more or less well from the particles, so that they may be removed in a following step. It is known that the removal of the stickers functions better if the glass shards are as damp as possible. However, the known method is inadequate under various aspects. The stirrers are subject to a high degree of wear. The separation of the residues of the stickers from the glass particles is only incomplete.

Method and device for preparing broken glass


A sun visor monorail system, which includes a monorail mounted adjacent a window in a car or airplane cockpit and a sun visor which is selectively positionable along the monorail and selectively stowable away from the window or deployable next to the window, is provided with a gripping system for selectively releasing the sun visor from, and locking the sun visor onto, the monorail. The gripping system includes a first gripping member having a surface for contacting the monorail, a second gripping member having a surface opposed to the first member's surface for contacting the monorail and holding the monorail between the two surfaces, a mounting mechanism supporting the members, and a locking mechanism coupled to the members. The locking mechanism includes a cam mechanism for transforming a rotational force, applied by hand to the locking mechanism, into a gripping force applied to the monorail through the gripping members. The sun visor system is also provided with a rail stop mountable on the monorail, providing detented rotational positions allowing the sun visor to either be flipped up and away from the window or deployed in front of the window.

The present invention relates generally to sun visors installed in cars or airplane cockpits for filtering or blocking sunlight coming in through the car or cockpit windows. More particularly, it concerns such a sun visor mounted on a monorail with a locking carriage assembly that allows a user to move the sun visor along the monorail, to lock the sun visor in any selected position, and to move the sun visor to an end of the monorail where it may be flipped to a detented, upper position away from the windows.
Applicant is the inventor of the sun visor system described in U.S. Pat. No. 5,056,854, which is a monorail-mounted sun visor system. The monorail is installed in a car or airplane cockpit, preferably just above the windows. The sun visor includes a mounting structure for mounting the sun visor on the monorail. The mounting structure includes jaws contacting the monorail and a panel is connected to the mounting structure. The mounting structure may be selectively locked onto or released from the monorail by operating a knob which turns a screw that tightens or loosens the jaws. This sun visor system provides a convenient, adjustable sunvisor but, it has drawbacks as well. The screw-tightened jaws are prone to loosening inadvertently in the highly vibratory environment of the car or airplane. Although the knob is quite large, giving the user a strong mechanical advantage for tightening the screw, loosening is still a problem and extreme tightening of the screw may make it difficult for the next user of the sun visor to adjust the sun visor position. Furthermore, the mechanical advantage of the knob and screw is only obtained at the cost of requiring the user to turn the knob several times around to adjust between the tightened and loosened positions.
Another drawback is encountered when the visor is flipped up to a fixed, stowed position, as desirable at times in cars and as required in airplane cockpits by the FAA for takeoffs and landings: The sun visor is moved from a deployed position to the stowed position, in a two-handed operation that involves loosening the jaws, flipping the visor up and then tightening the jaws. However, when the visor is flipped up, the knob for tightening the jaws is adjacent the car ceiling or cockpit bulkhead on a side of the jaws facing away from the user, increasing the difficulty of tightening the knob.
What would be preferable is a sun visor mounted on a monorail, providing the maximum flexibility in positioning, that can be locked in place at any selected position on the monorail by a simple, locking handle. The handle would be operable in a simple motion, like a light switch or door knob, but would provide for a positive lock of the sun visor on the monorail. The switch would preferably also provide a total of three positions: (1) a locked position in which the sun visor is substantially fixed in an axial position by a brake along the monorail but, with a leverage advantage obtained by gripping an edge of the visor panel opposite the monorail, the sun visor is also rotatable about the monorail; (2) an intermediate, partially-released position in which the sun visor may be easily moved along or rotated about the monorail while the brake remains in frictional contact with the monorail; and (3) a fully-released position in which the brake is withdrawn from the monorail completely. The monorail is preferably made of a simple, ungated, unitary structure. Another desirable feature in a sun visor would be a structure that provided for flipping the visor up to a detent-fixed, stowed position where the visor may be easily locked in place.
The sun visor of the present invention provides all of these advantages and more. The monorail structure for mounting the sun visor is constructed of an elongate, rigid structure, such as a steel rod having mounting tabs welded thereon for attaching the monorail to the car ceiling or airplane cockpit bulkhead. The monorail is installed around at least the front and sides of the car or cockpit. The sunvisor includes a mounting structure which is coupled to two gripping members with opposed surfaces. The gripping members are mountable on the monorail. A panel frame is coupled to the mounting structure and a visor panel, made of a deeply tinted plastic or glass or an opaque material, is held by the panel frame so that, when the gripping members are mounted on the monorail, the visor panel nominally hangs down adjacent the car or cockpit windows. The visor panel thus advantageously provides a filter or block that can be positioned anywhere sunlight interferes with the driver's or pilot's vision.
The mounting structure includes a mounting mechanism supporting the gripping members and a locking mechanism coupled to the gripping members. Each of the gripping members is supported separately by the mounting mechanism so that each may move independently of the other, although, preferably, the locking mechanism is designed to move the gripping members simultaneously in opposite directions to grip or to release the monorail. The locking mechanism includes a rotatable handle, operable by the user to move the gripping members between the three positions: locked, intermediate, and fully withdrawn. The handle is coupled to a cam mechanism which transforms the rotation of the handle into a translational braking force on the gripping members. The cam mechanism includes front, middle, and rear wheels coaxially coupled by a shaft. The front wheel is welded to the handle. A first dowel pin extends perpendicularly between the front and middle wheels, parallel to, but offset from, the shaft. A second dowel pin extends perpendicularly between the middle and rear wheels, also parallel to, but offset from, the shaft. The dowel pins are positioned and coupled to the gripping members so that, when the handle is turned, one dowel pin moves up and the other dowel pin moves down, causing the gripping members to move in opposite directions.
In the fully withdrawn position, the dowel pins are side by side, on opposite sides of the shaft, lying in a plane roughly parallel to the monorail, and the gripping members are fully retracted from the monorail. As the handle is turned toward the intermediate position, which is approximately 45.degree. from the fully withdrawn position, the dowel pin coupled to the lower gripping member moves up and the dowel pin coupled to the upper gripping member moves down, causing the gripping members to grip the monorail. A spring biases the gripping members to the intermediate position.
Moving the handle to the locked position, which is about 90.degree. from the fully withdrawn position, causes the gripping members to tighten their grip on the monorail. As the grip tightens, the gripping members and monorail press together, producing a force reactive to the braking or gripping force which tends to force the gripping members apart. Prior to the handle reaching the locked position, the reactive force also tends to oppose the rotation of the handle. However, when the handle reaches the locked position, about 90.degree. from the fully withdrawn position, with the dowel pins lying in a plane perpendicular to the monorail, the reactive force is perpendicular to the tangent of the rotational force and so the reactive force no longer has a component opposing the rotational force. As the handle is rotated slightly further, past the 90.degree. position, the reactive force has a component that actually increases the rotational force, ensuring that the handle and gripping members will remain in the locked position.
At one end of the monorail, a rail stop is installed including a fixed member adapted to be rigidly mounted on the monorail and a rotatable member pivotally coupled to the fixed member. The stop includes a detent mechanism interposing the fixed and rotatable members that fixes the rotatable member in place at any of two or more selectable positions relative to the fixed member. The rotatable member also includes a coupling member for engaging the mounting mechanism of the sun visor to control rotation of the sun visor about the monorail.
A significant advantage of the sun visor of the present invention is that the user may quickly and easily rotate the handle just a quarter turn from the fully-released position to the locked position to secure the visor in place. Another advantage is that in the locked position, the gripping members will not release their grip on the monorail despite vibration that would cause a hand-tightened screw to back out.
Another appreciable advantage of the invention is that the user may slide the sun visor into the coupling member of the rail stop and flip the visor panel up to a detented, stowed position and back down to a deployed position. With the sun visor at the rail stop, but down in the deployed position, the user may position the handle to the locked position and then flip the sun visor up to the stowed position. The locked position of the handle prevents axial movement of the sun visor along the monorail, so, the sun visor remains engaged by the coupling member of the rail stop and the rail stop prevents rotational movement of the sun visor about the monorail unless the detent is overcome.
A further advantage of the present invention is that, with the handle in the spring-loaded intermediate position, a user may freely slide the sun visor around the car or cockpit. This position is adequate to hold frictionally the sun visor in place on the rail under most transient conditions. For higher g-forces, the sun visor may be locked in place with just a one-eighth turn of the handle.
These and additional objects and advantages of the present invention will be more readily understood after a consideration of the drawings and the detailed description of the preferred embodiment.

Sun visor monorail system with locking carriage assembly


An RF test connector plug (30) for securing an opening (32) to access an RF test connector (33) for testing an electrical connection of an antenna (26) of a radio communication device (20) that allows testing of an antenna connection and prevents removal by a user. First and second leg members (40, 46) of the RF test connector plug (30) extend upward from a lower portion (38) shaped to conform to a curvature of an outer surface of the radio communication device. First and second tabs (52, 54) are positioned at the opening (32) to secure and to position the first leg member (40) and the second leg member (46), respectively, along the antenna (26) to prevent rotation of the RF test connector plug (30) within the opening (32).

The present invention generally relates to a radio communication device, and more particularly to a plug assembly for controlling access to an RF test connector of a radio communication device.
A radio communication device includes an antenna that is electrically connected to circuitry located in a housing portion of the radio communication device. In order to test whether the antenna is operating properly during manufacture of the radio communication device, an RF test connector is positioned on the radio communication device that enables test equipment to be directly coupled to test the connection of the antenna. Since it is desirable for the antenna connection be tested in the factory, while the radio communication device is in a filly assembled, closed state, the RF test connector must be accessible from outside the radio communication device. For example, radio communication devices are known that include a coaxial type RF test connector, located either along the upper back portion of the radio device or the bottom portion of the radio device, to enable the antenna connection to be tested with the radio communication device in the fully assembled, closed state.
In addition, radio communication devices are also known in which the RF test connector is made available from the outside by being positioned so as to be accessible via an opening located along the outer surface of the radio device. Such radio communication devices include an RF test connector plug, such as a plastic plug shaped to fill the opening, or a common rubber plug, that is inserted within the opening during periods when the antenna connection is not being tested. The RF test connector plug is used to both cosmetically improve the overall appearance of the radio communication device and to prevent debris from entering the opening and corrupting operation of the antenna. However, these RF test connector plugs can be easily removed by a user, enabling the user to access the RF test connector and increasing the likelihood for debris to accumulate within the opening.
Accordingly, what is needed is an RF test connector plug that, in addition to enabling a radio communication device to be tested in a closed condition during the manufacture of the radio communication device, prevents the RF test connector from being accessed by a user after the manufacturing process.


An inner bag is adhered by an adhesive to the substantially entire region of a pouring spout attaching panel of a carton blank, and to substantially half regions of panels bordering the pouring spout attaching panel, which are on the side of a pouring spout. The inner bag is adhered to the carton at a part which is remotest from the pouring spout and is normal to a direction of movement made by the inner bag when air is drawn. The inner bag is adhered to the carton blank at the substantially entire region of the pouring spout attached panel, and four corners on the side of the panel, which enables the inner bag to be set up into a square shaft with high precision upon the setting-up of the carton blank.

The present invention relates to a bag-in-carton with an inner bag adhered to an inside surface thereof, a method for forming the bag-in-carton, and a carton blank body. Bag-in-cartons (BICS) having inner bags adhered to inside surfaces thereof have been used as liquid packaging containers. The carton of a BIC is usually in the shape of a rectangular parallelopiped having a flat bottom surface and a flat top surface, and four flat side surfaces disposed between the bottom and the top surfaces. An inner bag is adhered to the inside surfaces of the four side surfaces. Such BICs are used in packaging liquids of low viscosities, such as juices, liquors, etc. When contents of such BICs are discharged through the pouring spouts, the inner bags are deformed inside the cartons as the contents are discharged.
A BIC includes an inner bag adhered to the inside surface of the carton. Depending on the position where the inner bag is adhered to the inside surface, in some cases, the inner bag cannot be well formed when the BIC is set up, or a material to be contained in the inner bag cannot be filled in the inner bag.
Depending on a position where the inner bag is adhered to the inside surface of the carton, when a content of the inner bag is discharged, the content sometimes resides in the inner bag.

Bag-in-carton, method for forming the bag-in-carton and carton blank body


An adjustable unitary roof bracket device having left and right secondary housings that can be extended or retracted with respect to the main housing or base. The secondary housings are adjustable in order to vary the overall length of the device which serves as extended planking while in its secured state.

The present invention relates to roofing brackets and, more particularly, to an improved, safe, and unitary roofing bracket that eliminates the need for wooden planking commonly placed between separate, single steel roofing brackets.
Roofing brackets have been found to be a necessity in construction, and the roofing industry in particular. Defined by law, such as safety standards set forth by O.S.H.A., any roof area comprising more than a {fraction (5/12)} pitch (i.e., a five inch incline for one foot of linear run) is required to be scaffolded at the edge of the roof. The roof area itself must be bracketed and planked, with supporting roofing brackets spaced no more than four feet apart, the planks being laid securely between brackets. In building a home, for example, a framer will use this bracket and planking system to support himself or herself while sheeting over exposed roof rafters. A roofer often uses this same bracket and planking system to support himself or herself safely upon an area of roof while he or she applies tar paper and shingle.
Commercial roofing brackets, such as ones manufactured by AJC Tools and other manufacturers, are nailed securely onto a roof surface, thereby allowing for the placement of a chosen planking. Standard sized, 2 by 4""s, 2 by 6""s, and even 2 by 10""s (dimensions given in width and depth of above wooden plankings) are commonly used and placed within direct contact with previously secured roof brackets. Lengths of wooden planking can vary from a scant few feet up to and exceeding twelve feet in length. With the roofing brackets and their planking now in place, a roofer can now use the bracket and planking system to keep oneself upright, and in a relative safe position with respect to the chosen area of workspace along the roof.
This conventional system of planking is presumed safe, so long as the wooden plankings themselves do not split or weaken, or even break entirely. The roofing brackets themselves, made of steel, are quite durable, but their success as a safety feature depends entirely on the strength and durability of the wooden planking that the afore-mentioned brackets support, as well as secure nailing. Through use, weathering and age, the bracket and planking system now in use can be crippled, or even fail entirely if any of the wooden planks placed within the holds of these brackets break or snap apart, or through the fault of its user, fail to secure each bracket securely. Only one bracket need fail for a planking to slip out of a secure position and cause its user to stumble or even fall from his or her perch. It is an opinion of many of its users, that this standard design practice can be improved upon.
The present invention is based on the discovery that it would be advantageous and safer to provide a complete, one unit roofing bracket system, so that the brackets and the user""s safety are not solely dependent upon fallible wooden plankings.
The present invention features an adjustable roofing bracket wherein separate, secondary housings can be retracted or extended out from a center main housing, thus varying the overall length of the apparatus. Once a given length has been established, nailing tabs secure the apparatus upon the chosen, desired work surface.
In U.S. Pat. No. 4,884,775 issued to Karl Fischer on Dec. 5, 1989 for ADJUSTABLE ROOF BRACKET, an adjustable roof bracket constitutes three main parts: a main body part and two smaller arms, which together create a pivot point, thereby allowing the roofing bracket""s angle in relation to its inclined work-space to be altered, creating a more receptive and comfortable angle for the addition of wood planking.
The present invention features an adjustable, unitary roofing bracket apparatus. The bracket comprises a main housing, into or out or which separate, secondary housings retract or extend from the main housing. Each secondary housing has a bearing track upon which it glides, retreating or extending itself a chosen distance in relation to the main housing. A nailing tab, the section of the bracket assembly used to secure the apparatus upon an inclined surface, is permanently affixed to each outward end of both secondary housings and extends or retracts along with the secondary housing, unless secured. A stationary nailing tab is permanently affixed to the center of the main housing as well.
Choosing a desired, extended length of the apparatus by extending or retracting both secondary housings, the location and position of the apparatus is secured by use of all three nailing tabs. Each nailing tab consists of a main body, comprising a flat, thin metal strip which extends away from the bottom end and rear of each section of housing it is attached to. An upper shoe plate, permanently attached to, and a part of the nailing tab assembly, is fitted with two slots, narrowed at their upper ends, receptive to the given size of a standard, #16 common nail.
It is common nails that secure the entire roofing aparatus bracketing device upon the inclined surface. By placing the shoe plate into its lowest position, closest to the base of its housing, after lightly securing the common nails, the narrowed slot of the shoe plate catches and secures the nails, thus securing the position of the nailing tab to its respective housing and thus to the entire roofing bracketing device. For added safety, a safety pin can then be placed in its receptive slot, thus preventing any accidental and undesired disturbance of the location of the nailing tab in relation to the area to which it is secured. By extending the secondary housings and securing each nailing tab to its respective surface area, the roofing bracket device in now ready to be utilized.
Another safety feature incorporated into this roofing bracket device is a locking pin, located within the top side of each secondary housing and approximately one inch from its inner end. If over-extended, the locking pin catches its mated hole at the top of the main housing and protrudes upward, thus preventing further extension of the secondary housing. To further advise the user, red-marked safe lines are drawn onto the exterior of the secondary housing, further warning the user to halt extension if safe lines become visible. The locking pins are spring loaded and can retreat back into the main housing body, thus allowing for the location of the secondary housing to be repositioned.
In its extended and secured position the roofing bracket system can now be utilized for its intended purpose, supporting an individual, and tools and material, so he or she can perform required tasks. In its envisioned and present form, metal alloy construction of this invention in its entirety has eliminated the need for wooden planking between each roofing brackets, since the main housing and both secondary housings replace the standard wooden plank.
It is an object of this invention to provide a more secure, safe and improved roofing bracket.
It is another object of this invention to provide an entirely self-contained roofing bracket system, thus eliminating the need for standard wooden plank or plankings.
It is another object of this invention to provide a roofing bracket that is adjustable in length in order to more adequately accommodate its user and not restrict the user to a predefined or fixed length of the equipment in use.


An exposure apparatus sequentially performs exposure in each of a plurality of underlying shot regions formed on a substrate and includes a controller. The controller is configured to judge, for each of the plurality of shot regions, whether to perform one-shot exposure without dividing the shot region or divided exposure, based on information of respective shapes of the plurality of shot regions, determine a shape of each partial region in the shot region in which the divided exposure is to be performed, and control the exposure so as to perform the one-shot exposure or the divided exposure in each of the plurality of shot regions based on a result of the judgment and the determined shape of each partial region.

Field of the Invention
The present invention relates to exposure apparatuses, exposure methods, and device manufacturing methods.
Description of the Related Art
Conventionally, alignment in a semiconductor exposure apparatus (a so-called "stepper" or the like) measures positions or positional error related to several shot regions set in advance on a substrate such as a semiconductor wafer, and a shot arrangement is then determined for the respective shot regions based thereon. What is known as "global alignment" is employed, where the respective shot regions are aligned in order on the wafer in positions corresponding to a master plate such as a reticle using the determined shot arrangement.
In addition to global alignment, magnification components and rotation components of the shot regions themselves are being corrected, with the aim of correcting distortion in the shapes of the shot regions caused by increased complexity in the manufacturing process, complexity that is a result of finer sizes, higher levels of integration, and higher angles of view being established in semiconductors. Such a technique is disclosed in Japanese Patent Laid-Open No. 2003-92252. A process of cutting a wafer thin, a process of laminating a thinned wafer to a support substrate under pressure, and so on are known as processes that produce distortion in the shapes of the shot regions. Meanwhile, Japanese Patent Laid-Open No. 2005-3965 proposes divided exposure, which divides a wafer into several exposure regions in accordance with positional deviation and exposes those regions rather than exposing the entirety of a single exposure region on the wafer, with the aim of further improving the precision of alignment.
However, wafers processed in a step-and-repeat semiconductor exposure apparatus have a large number of shot regions, and thus it is often the case that measuring alignment marks necessary for correcting distortion in the shapes of the shot regions takes time. There has thus been a problem in that correcting distortion in the shapes of the shot regions greatly reduces the throughput. There is an additional problem in that divided exposure makes it necessary to calculate the shapes of the regions obtained through the division, position deviation amounts, and so on, which reduces the throughput even further.

Exposure apparatus, exposure method, and device manufacturing method


Fibroblast cells are treated with a chemical inhibitor of protein kinase C such as staurosporine, in conjunction with functionally hypoxic micromass culture so as to be induced into chondrogenic differentiation. Such fibroblast-derived, chondrocyte-like cells may be seeded onto three-dimensional polymer scaffolds for use in the repair of articular cartilage lesions, and thus can obviate the need for invasive techniques to harvest autologous chondrocytes from a limited supply of existing articular cartilage, or to avoid the need for obtaining allogeneic chondrocytes from non-biocompatible donor tissues.

The present invention generally relates to tissue engineering applications, and more particularly for repair of cartilage and treatment of bony defects by uses of chondrocyte-like cells prepared from fibroblasts.
Annually, over one million procedures involving cartilage replacement are performed in the United States. Many are as a result of debilitating ailments affecting articular cartilage. Articular cartilage is a thin layer of soft connective tissue (0.5-5 mm thick) that covers the articulating surfaces of long bones in synovial joints. The principal function of articular cartilage is to redistribute applied loads and to provide a low friction-bearing surface to facilitate movement within these joints. The most common of the pathological conditions affecting articular cartilage is osteoarthritis (OA), a degenerative joint disease that afflicts between 32-38 million Americans. OA is characterized by a progressive loss of cartilage tissue due to excessive mechanical trauma or to continual loading overtime, resulting in joint pain and stiffness. Unlike other connective tissues, cartilage has a limited reparative ability because it lacks a reservoir of undifferentiated mesenchymal cells that can be recruited to a defect in aid in wound repair (whereas bone possesses marrow and periosteum-derived precursor cells on the inner and outer portions of the tissue, respectively). In addition, cartilage is an avascular tissue, and therefore, cannot rely upon the circulatory system to transport nutrients and cells to sites of damage. Thus, one approach that has been used has been to expose damaged cartilage tissue to stimuli by drilling or scraping through the cartilage into the subchondral bone to cause bleeding. However, when repair does occur, it often results in the formation of fibrocartilage which lacks the structural components and organization to withstand the mechanical demands of the natural tissue. As such, there is a need to develop effective replacement therapies for articular cartilage to restore its biological function.
Current surgical procedures to correct cartilage tissue defects involve primarily the use of autogenous or allogeneic tissue grafts. Autogenous grafts are biocompatible, but their use is limited due to a lack of tissue supply, and because of pain and morbidity which often develop at the donor site. Furthermore, the mechanical integrity of the tissue at the donor site may be compromised, rendering the remaining cartilage more susceptible to damage in the future. Allograft tissue, on the other hand, is more readily available, but the risk of disease transmission and immune responses to alloantigens present difficulties.
Recent advances in the fields of cell and molecular biology, biotechnology, and biomaterials have led to the emergence of tissue engineering, an exciting new discipline applying both engineering and life science principles to the formation of biological substrates capable of regenerating functional mammalian tissues both in vitro and iii vivo. Present attempts to engineer articular cartilage involve the isolation of primary, differentiated cells (i.e. chondrocytes) from biopsies of existing cartilage tissue and seeding these cells onto three-dimensional carrier materials. A major limitation of these techniques is that the cells are often procured from an autologous source. As such, the problem of limited donor tissue supply is not circumvented as the cellular component of the implant is harvested from host cartilage tissue. In addition, invasive surgical procedures are required to obtain the necessary quantity of cells. Alternatively, the procurement of cells from cadavers carries the inherent risk of transfer of pathogens, and the undue expense of screening for the presence of harmful pathological agents. The drawback to both of these approaches stems from the source of cellular material.
It is known that connective-tissue cells, including fibroblasts, cartilage cells, and bone cells, can undergo radical changes of character. Thus, as explained by Alberts et al., Molecular Biology of the Cell, (2nd Ed., 1989, pp. 987-988), a preparation of bone matrix may be implanted in the dermal layer of the skin and some of the cells there converted into cartilage cells and later others into bone cells. Cultured cartilage cells, or chondrocytes, can be converted so as to acquire characteristics of fibroblasts and stop producing type II collagen (characteristic of cartilage), but instead start producing type I collagen (characteristic of fibroblasts).
Hunziker, U.S. Pat. No. 5,368,858, issued November 29, 1994, describes matrix compositions for the treatment or repair of cartilage including a transforming growth factor associated with a delivery system contained within the matrix. The transforming growth factor is described as TGF-xcex2 said to be capable of inducing conversion of repair cells into chondrocytes. Shorts, U.S. Pat. No. 5,632,745, issued May 27, 1997, describes a cartilage repair unit with a matrix in which xe2x80x9crepair factorsxe2x80x9d such as fibroblast growth factor and xe2x80x9cTGF-xcex2xe2x80x9d are included. Thus, a chondrogenic growth-supporting matrix is said to permit vascular invasion and cellular migration between healthy cancellous bone and the damaged articular cartilage area.
A great variety of materials said to be useful as scaffolds, or matrices, are known and proposed for cartilage implants. For example, materials such as collagen gels, poly(D,L-lactide-co-glycolide (PLGA) fiber matrices, polyglactin fibers, calcium alginate gels, polyglycolic acid (PGA) meshes, and other polyesters such as poly-(L-lactic acid) (PLLA) and polyanhydrides are among those suggested and are in varying degrees of development and use. However, osteoinductive cells, such as improved chondrocyte-like cells for tissue engineering applications, without the problems of invasive surgery for the recipient from other regions of the body or cells without risk of disease transmission from others, remain desirable for uses such as seeding the synthetic matrices.
In one aspect of the present invention, fibroblasts are first converted to chondrocyte-like cells by treating with a combination of agents. One agent is an hypoxia mimicking agent and the second agent is a chemical inhibitor of protein kinase C (PKC). These converted chondrocyte-like cells display at least one cartilage phenotype.
Typical cartilage phenotypes are the cellular morphology, the production of cartilage matrix components, the expression of the aggrecan and type II collagen MRNA, and the down-regulation of type I collagen mRNA. Thus, the converted chondrocyte-like cells of the invention will typically show an increase in aggrecan and in type II collagen mRNA expressions and a decrease in type I collagen MRNA. Such a display of cartilage phenotype is illustrated, for example, by FIG. 5.
The initial conversion of chondrocyte-like cells is preferably where the cells are cultured in a high density micromass with conversion occurring in a period occurring from about 12 hours up to about 36 hours. The high density micromass culture is preferably achieved on a biocompatible (preferably biodegradable) scaffold. Such a scaffold assists in creating the high density micromass and can subsequently serve as a template for cartilage repair. The so-converted cells, when attached to a scaffold, can thereafter be maintained with the chondrocyte phenotype for about one to two weeks prior to implantation by maintaining them in a chemically defined, serum-free media.
The inventive cells are useful in a variety of reparative applications, including the repair of articular cartilage in synovial joints, of tracheal and esophageal cartilage, and for cosmetic purposes including modification of nasoseptal and ear cartilage. Other applications include intervertebral disc repair as an alternative to spinal fusion following disc herniation, oral and maxillofacial surgery including temporomandibularjoint disc replacement, and treatment of osteochondral and bony defects.
Chondrocyte-like cells of the invention are preferably used in reparative applications by being placed in a suitable matrix in the desired site for repair. The matrix is preferably partly or entirely formed by scaffold on which the cells were preferably seeded and converted. Preferred matrices are biodegradable, and can direct cellular remodeling through mechanical influences such as fine fibers and surface treatments to enhance cell attachment and alignment.

Chondrocyte-like cells useful for tissue engineering and methods

The Regents of the University of California


Membrane-based assays using surface detector array devices suitable for use with a biosensor are disclosed. The device is formed of a substrate having a surface defining a plurality of distinct bilayer-compatible surface regions separated by one or more bilayer barrier regions. The bilayer-compatible surface regions carry on them, separated by an aqueous film, supported fluid bilayers. The bilayers may contain selected receptors or biomolecules. A bulk aqueous phase covers the bilayers on the substrate surface. Arrays may be engineered to display natural membrane materials in a native fluid bilayer configuration, permitting high-throughput discovery of drugs that target and affect membrane components. The membrane-based assays detect binding events by monitoring binding-induced changes in one or more physical properties of fluid bilayers.

Over the last several years, a number of high-throughput screening methods have been developed to facilitate the screening of thousands, if not millions, of compounds for a desired activity or activities. Such methods typically are based on detecting the binding of a potentially effective compound to a receptor. While these binding assays are effective at constraining the universe of compounds which may have the desired activity, they typically are not well-suited for evaluating this activity with any degree of detail.
The biological activity of potentially active compounds typically is evaluated using less efficient but more informative "secondary screens" or assays that typically require a substantial input of time by a trained technician or scientist. For evaluation of candidate compounds affecting integral membrane proteins such as receptors and ion channels, the amount of time required per compound may be several hours or days if the assay includes effects on electrophysiological activity. Evaluation of candidate compounds affecting lipid bilayer properties also may be time consuming. Accordingly, there is a need for a more efficient "secondary screen" of compounds affecting the activity of membrane proteins, other lipid bilayer-associated and integral components, including the lipids in the bilayer themselves to identify those few compounds that justify further detailed analysis.


A system and method are provided for collection and testing of a biologic sample in a self-diagnostic test. The system and method comprise collecting by a user of a testing device a biologic sample for use with the testing device, assigning correlative values as test results, and receiving the test results at a server disposed on a network. Some aspects include a mobile application operating on a mobile device with which the user interacts. These aspects allow advertisements and other messages to be presented to the user through the mobile application. Some aspects present different messages to the user based on the type of self-diagnostic test the user is conducting.

When using a mobile application to conduct self-diagnostic testing on biologic materials, a user may have opportunities to view messages within the mobile application. Therefore, what is desirable is a system and method for delivering messages and advertisements to a user through a mobile application.
SUMMARY
In one aspect thereof, a system and method are provided for collection and testing of a biologic sample in a self-diagnostic test. The system and method comprise collecting by a user of a testing device a biologic sample for use with the testing device, assigning correlative values as test results, and receiving the test results at a server disposed on a network. Some aspects include a mobile application operating on a mobile device with which the user interacts. These aspects allow advertisements and other messages to be presented to the user through the mobile application. Some aspects present different messages to the user based on the type of self-diagnostic test the user is conducting.

This patent is subject to a terminal disclaimer.

System and method for advertising in response to diagnostic test


A force sensing cantilever for use in a scanning probe microscope has both a top side and a bottom side. From the bottom side extends a probe tip. The bottom side is coated with a thin film of a first material and the top side is coated with a thin film of a second material. The first and second materials may be the same or they may be different. The materials and thicknesses of the respective films are selected so as to create opposing forces to counter the tendency of such cantilevers to bend when a thin film is applied to only one side thereof.

1. Field of the Invention
This invention relates to scanning probe microscopy, and in particular to the preparation of force-sensing cantilevers for use in scanning probe microscopy and atomic force microscopy.
2. The Prior Art
In a conventional atomic force microscope or AFM, the deflection of a flexible cantilever is used to monitor the interaction between a probe tip disposed on an end of the cantilever and a surface under study. As the probe tip is brought close to the surface, it deflects in response to interactions with the surface under study. These deflections are used to control the distance of the tip from the surface and to measure details of the surface as explained, for example, in "Atomic Force Microscope", G. Binnig, C. F. Quate and C. Gerber, Physical Review Letters, Vol. 56, No. 9, pp. 930-933 (1986).
It is often desirable to operate an atomic force microscope in an oscillating mode--this is referred to in the art as the "AC mode". In the AC mode, the cantilever is vibrated at a high frequency (typically somewhere in the range of about 1 kHz to about 100 kHz), and the change in amplitude of the physical oscillations of the cantilever or phase of those oscillations with respect to the driving signal as the cantilever approaches a surface under study is used to control the microscope as explained, for example, in "Frequency Modulation Detection Using High-Q Cantilevers for Enhanced Force Microscopy Sensitivity", T. R. Albrecht, P. Gruitter, D. Horne and D. Rugar, Journal of Applied Physics, Vol. 69, pp. 668-673 (1991). One reason for using the AC mode to vibrate the cantilever is that by doing this, when oscillated at high amplitude, the probe tip is less likely to stick to the surface under study if it should come into contact with it. This is explained, for example, in "Fractured Polymer/Silica Fibre Surface Studied by Tapping Mode Atomic Force Microscopy", Q. Zhong, D. Inniss, K. Kjoller and V. B. Elings, Surface Science Letters, Vol. 290, pp. L688-L692 (1993). However, the AC mode of operation is also intrinsically more sensitive than other known methods of operating an atomic force microscope. AC detection shifts the signal to be detected to sidebands on a carrier signal, avoiding the low frequency noise that DC signals suffer from. In addition, the mechanical "Q" of a cantilever resonance can be used to enhance the overall signal to noise ratio of a microscope operated in this fashion as explained in "Frequency Modulation Detection Using High-Q Cantilevers for Enhanced Force Microscopy Sensitivity", T. R. Albrecht, P. Grutter, D. Horne and D. Rugar, Journal of Applied Physics, Vol. 69, pp. 668-673 (1991).
One version of an AC mode operated atomic force microscope, where contact between the probe tip and the surface under study is actually sought out, is described in U.S. Pat. No. 5,412,980 to V. Elings and J. Gurley entitled "Tapping Atomic Force Microscope" and in U.S. Pat. No. 5,519,212 to V. Elings and J. Gurley entitled "Tapping Force Microscope with Phase or Frequency Detection". In this version, where the oscillatory mode of operation is referred to as the "tapping mode" for the fact that it actually repeatedly taps at the surface under study, the oscillation is used mainly as a means of avoiding the effects of adhesion between the probe tip and the surface being "tapped". It has also been discovered that such adhesion may easily be overcome by chemical means. For example, the microscope may be operated in a fluid which minimizes adhesion. Alternatively (or additionally) a tip material may be chosen so as to minimize its adhesion to the surface under study. Where such techniques are used to reduce adhesive forces, there is no longer any reason to operate the atomic force microscope at a large oscillation amplitudes.
The usual method of exciting motion in the cantilever of an atomic force microscope is to drive it with an acoustic excitation. This method works well in air or gas and has been made to work with the tip submerged in water. See, for example, "Tapping Mode Atomic Force Microscopy in Liquids", P. K. Hansma, J. P. Cleveland, M. Radmacher, D. A. Walters, P. E. Hilner, M. Bezanilla, M. Fritz, D. Vie, H. G. Hansma, C. B. Prater, J. Massie, L. Fukunaga, J. Gurley and V. B. Elings, Applied Physics Letters, Vol. 64, pp. 1738-1740 (1994) and "Tapping Mode Atomic Force Microscopy in Liquid", C. A. J. Putman, K. 0. V. d. Werf, B. G. deGrooth, N. F. V. Hulst and J. Greve, Applied Physics Letters, Vol. 64, pp. 2454-2456 (1994). However, in a fluid, the motions of the cantilever become viscously damped, so that substantial acoustic amplitude is required to drive and sustain the desired oscillatory motion of the cantilever. Furthermore, the fluid acts as a coupling medium between the source of acoustic excitation and parts of the microscope other than the cantilever. The result of this undesired coupling is that parts of the microscope other than the cantilever get excited into motion by the acoustic signal used to vibrate the cantilever. If such motion leads to a signal in the detector, a background signal is generated which is spurious and not sensitive to the interaction between the tip and surface as explained in "Atomic Force Microscope with Magnetic Force Modulation", E. L. Florin, M. Radmacher, B. Fleck and H. E. Gaub, Review of Scientific Instruments, Vol. 65, pp. 639-643 (1993). S. M. Lindsay and co-workers have described a scheme for exciting the cantilever directly while avoiding unwanted mechanical coupling of an oscillatory signal into the larger structure of the atomic force microscope. This is described at, for example, "Scanning Tunneling Microscopy and Atomic Force Microscopy Studies of Biomaterials at a Liquid--Solid Interface", S. M. Lindsay, Y. L. Lyubchenko, N. J. Tao, Y. Q. Li, P. I. Oden, J. A. DeRode and J. Pan, Journal of Vacuum Science Technology A, Vol. 11, pp. 808-815 (July/August 1993). In this approach, a magnetic particle or film is attached to the cantilever and a solenoid near the cantilever is used to generate a controlled magnetic force on the cantilever. This arrangement gives extreme sensitivity to surface forces as discussed in "Atomic Force Microscopy of Local Compliance at Solid--Liquid Interfaces", S. J. O'Shea, M. E. Welland and J. B. Pethica, Chemical Physical Letters, Vol. 223, pp. 336-340 (1994), presumably because of a lack of the background spurious signals that would normally be present in an acoustically-excited atomic force microscope. It is the basis of a novel form of AC-AFM in which the cantilever is excited by magnetic means (see, for example, U.S. Pat. No. 5,515,719 entitled "Controlled Force Microscope for Operation in Liquids" to S. M. Lindsay and U.S. Pat. No. 5,513,518 entitled "Magnetic Modulation of Force Sensor for AC Detection in an Atomic Force Microscope" to S. M. Lindsay).
Magnetic cantilevers are required in order to operate such a microscope. Three approaches have been used. First, Lindsay et al. described a method for fixing a magnetic particle onto the cantilever ("Scanning Tunneling Microscopy and Atomic Force Microscopy Studies of Biomaterials at a Liquid--Solid Interface", S. M. Lindsay, Y. L. Lyubchenko, N. J. Tao, Y. Q. Li, P. I. Oden, J. A. DeRode and J. Pan, Journal of Vacuum Science Technology, Vol. 11, pp. 808-815 (1993)). This method, however, does not readily permit fabrication of suitable cantilevers in quantity. Second, O'Shea et al. ("Atomic Force Microscopy of Local Compliance at Solid--Liquid Interfaces", S. J. O'Shea, M. E. Welland and J. B. Pethica, Chemical Physical Letters, Vol. 223, pp. 336-340 (1994)) describe a method for evaporating a magnet coating onto the cantilever. In order to avoid bending the cantilever due to the interfacial stress introduced by the evaporated film, they place a mask over most of the cantilever so that the magnetic film is deposited only onto the tip of the force-sensing cantilever. This approach requires precision alignment of a mechanical mask and it is not conducive to simple fabrication of suitable coated cantilevers. Third, in an earlier invention by one of the present inventors (S. M. Lindsay, U.S. patent application Ser. No. 08/553,111 entitled "Formation of a Magnetic Film on an Atomic Force Microscope Cantilever") methods for coating cantilevers with magnetic films and for calibrating the properties of the films were described. However, while suited for its intended purposes, the yield of cantilevers produced by this process was not as high as desired as some of the cantilevers coated on one side only were manufactured with unacceptable bends or deformations.
Magnetic cantilevers have also been manufactured for the purpose of magnetic force microscopy, an imaging process which is used to sense local magnetization in materials such as magnetic recording media and recording heads. Grutter et al. (P. Grutter, D. Rugar, H. J. Mamin, G. Castillo, S. E. Lambert, C. J. Lin, R. M. Valletta, O. Wolter, T. Bayer and J. Greschner, "Batch Fabricated Sensors for Magnetic Force Microscopy", Applied Physics Letters, Vol. 57, No. 17, pp. 1820-1822, 22 Oct. 1990) describe a method for coating silicon cantilever probe tips with thin (15 nm) films of Cobalt, Cobalt alloys (Co/Pt/Cr) and Permalloy (Ni/Fe). These devices are typically 500 .mu.m long, 11.5 .mu.m wide, 5-7 .mu.m thick with a spring constant on the order of 1 N/m and resonant frequencies of about 35 kHz. Babcock et al. (K. Babcock, V. Elings, M. Dugas and S. Loper, "Optimization of Thin-Film Tips for Magnetic Force Microscopy", I.E.E.E. Transactions on Magnetics, Vol. 30, No. 6, pp. 4503-4505, November, 1994) describe sputtering thin films (500 .ANG.) of Cobalt alloy (Co/Cr) onto the probe tips of silicon cantilevers having lengths of 225 .mu.m widths of 27 .mu.m, thickness of 3 .mu.m, resonant frequencies of 92.4 kHz and spring constants of about 5 N/m . In each case, only the probe tip side of the cantilever was coated with the thin film. While suited for the task of Magnetic Force Microscopy, silicon cantilevers are expensive to fabricate and the yield is substantially lower than the yield for silicon nitride cantilevers. Silicon cantilevers are also generally much stiffer than silicon nitride cantilevers (with corresponding spring constants of about 50 N/m for silicon and less than 1 N/m for silicon nitride) and these "softer" cantilevers are desirable for imaging soft samples such as biological samples and the like. Silicon nitride cantilevers, however, suffer from the drawback that, because they are soft, they are easily bent upon being coated with a sputtered film.
Accordingly, it would be desirable to provide a magnetic cantilever and method for fabricating the same which results in higher yields and more ready manufacturability than heretofore available while inducing minimum bending and without requiring precision masks to cover parts of the cantilevers during deposition of a magnetic film.

Cantilevers for a magnetically driven atomic force microscope

Molecular Imaging Corporation Arizona Board of Regents


An electric circuit for controlling a magnetic head is mounted on a flexible printed circuit (hereinafter referred to as "FPC"), and the FPC is arranged in a folded state within an enclosure. The FPC has an electronic circuit disposed on one side surface thereof, the one side surface being formed when the FPC is extended in a plane. Connectors are arranged on one end portion of the FPC for connecting to the magnetic head and external equipment. A support member is bonded to the surface of the FPC opposite to the surface mounting the electronic circuit, and by this supporting member the FPC is secured in a state folded in at least two within the housing of the magnetic disk apparatus.

The present invention relates to a magnetic disk apparatus, and more particularly relates to a magnetic disk apparatus having an improved flexible printed circuit board incorporated into the housing thereof.
In magnetic disk apparatuses, reduction in size of the whole construction, and increase in storage capacity thereof have been rapidly achieved. A representative attempt to reduce magnetic disk apparatuses in size is disclosed in Japanese patent unexamined publication No. 62-283465, in which a flexible printed circuit board is mounted to a head arm, and a pre-amplifier is arranged on the flexible printed circuit board to be received in a recess in the head arm.
In magnetic disk apparatuses, an increase in storage capacity raises a problem in that the control of positioning of the magnetic head and mounting of the pre-amplifier become harder. An increase in storage capacity can be usually achieved by increasing the number of magnetic disks, but the increase of the number of magnetic disks in turn results in increases in number of both the magnetic heads and pre-amplifiers which amplify signals read by the magnetic heads. Particularly, conventional large scale integrated pre-amplifiers limit the number of magnetic heads, which perform signal processing, to six, for example. Accordingly, the number of pre-amplifiers must be increased as the number of magnetic disks and that of magnetic heads increase.
In the attempt of Japanese unexamined patent publication 62(1987)-283465, pre-amplifiers are mounted on head arms, and hence an increase in number of pre-amplifiers enlarges the moment of inertia of the head arms, so that the magnetic heads are deteriorated in accuracy of positioning. When the whole apparatus is reduced in size by down sizing the magnetic disks from 5 inches to 3.5 inches, the head arms also becomes small sized, and thus it becomes very difficult to mount pre-amplifiers to head arms.