An at least partially implantable system for rehabilitation of a hearing disorder with at least one acoustic sensor (microphone) for picking up an acoustic sensor signal and converting the acoustic sensor signal into corresponding electrical signals, an electronic signal processing unit for audio signal processing and amplification, an electrical power supply unit which supplies individual components of the system with energy, and an output-side actuator stimulation arrangement, the actuator stimulation arrangement has a dual intracochlear arrangement in combination with a stimulator arrangement with at least one stimulator element for at least indirect mechanical stimulation of a damaged inner ear and one electrically acting stimulation electrode arrangement with at least one cochlear implant electrode for electrical stimulation of the inner ear.

1. Field of the Invention
This invention relates to an at least partially implantable system for rehabilitation of a hearing disorder which comprises at least one sensor (microphone) for picking up an acoustic signal and converting the acoustic signal into the corresponding electrical signals, an electronic signal processing unit for audio signal processing and amplification, an electrical power supply unit which supplies individual components of the system with current, and an output-side actoric stimulation arrangement.
2. Description of Related Art
The expression xe2x80x9chearing disorderxe2x80x9d is defined here as inner ear damage, combined inner ear and middle ear damage, and a temporary or permanent noise impression (tinnitus).
In recent years rehabilitation of sensorineural hearing disorders with partially implantable electronic systems has acquired major importance. In particular, this applies to the group of patients in which hearing has completely failed due to accident, illness or other effects or in which hearing is congenitally non-functional. If, in these cases, only the inner ear (cochlea), and not the neural auditory path which leads to the brain, is affected, the remaining auditory nerve can be stimulated with electrical stimulation signals. Thus, a hearing impression can be produced which can lead to speech comprehension. In these so-called cochlear implants (CI), an array of stimulation electrodes, which is controlled by an electronic system (electronic module) is inserted into the cochlea. This electronic module is encapsulated with a hermetical, biocompatible seal and is surgically embedded in the bony area behind the ear (mastoid). The electronic system contains essentially only decoder and driver circuits for the stimulation electrodes. Acoustic sound reception, conversion of this acoustic signal into electrical signals and their further processing, always takes place externally in a so-called speech processor which is worn outside on the body. The speech processor converts the preprocessed signals into a high frequency carrier signal which, via inductive coupling, is transmitted through the closed skin (transcutaneously) to the implant. The sound-receiving microphone is always located outside of the body and, in most applications, in a housing of a behind-the-ear hearing aid worn on the external ear. The microphone is connected to the speech processor by a cable. Such cochlear implant systems, their components, and the principles of transcutaneous signal transmission are described, by way of example, in published European Patent Application EP 0 200 321 A2 and in U.S. Pat. Nos. 5,070,535, 4,441,210, 5,626,629, 5,545,219, 5,578,084, 5,800,475, 5,957,958 and 6,038,484. Processes of speech processing and coding in cochlear implants are described for example in published European Patent Application EP 0 823 188 A1, in European Patent 0 190 836 A1 and in U.S. Pat. Nos. 5,597,380, 5,271,397, 5,095,904, 5,601,617 and 5,603,726.
In addition to rehabilitation of congenitally deaf persons and those who have lost their hearing using cochlear implants, for some time there have been approaches to offer better rehabilitation than with conventional hearing aids to patients with a sensorineural hearing disorder which cannot be surgically corrected by using partially or totally implantable hearing aids. The principle arises, in most embodiments, in stimulating an ossicle of the middle ear or, directly, the inner ear via mechanical or hydromechanical stimulation and not via the amplified acoustic signal of a conventional hearing aid in which the amplified acoustic signal is supplied to the external auditory canal. The actuator stimulus of these electromechanical systems is accomplished with different physical transducer principles such as, for example, by electromagnetic and piezoelectric systems. The advantage of these devices is seen mainly in the sound quality which is improved compared to conventional hearing aids, and, for totally implanted systems, in the fact that the hearing prosthesis is not visible.
Such partially and fully implantable electromechanical hearing aids are described, for example, by Yanigahara et al. xe2x80x9cImplantable Hearing Aidxe2x80x9d, Arch Otolaryngol Head Neck Surg-Vol 113, 1987, pp. 869-872; Suzuki et al. xe2x80x9cImplantation of Partially Implantable Middle Ear Implant and the Indicationxe2x80x9d, Advances in Audiology, Vol. 4, 160-166, Karger Basel, 1988; H. P. Zenner et al. xe2x80x9cFirst implantations of a totally implantable electronic hearing system for sensorineural hearing lossxe2x80x9d, in HNO Vol. 46, 1998, pp. 844-852; H. Leysieffer et al. xe2x80x9cA totally implantable hearing device for the treatment of sensorineural hearing loss: TICA LZ 3001xe2x80x9d, HNO Vol. 46, 1998, pp. 853-863; H. P. Zenner et al. xe2x80x9cActive electronic hearing implants for patients with conductive and sensorineural hearing lossxe2x80x94a new era of ear surgeryxe2x80x9d, HNO 45: 749-774; H. P. Zenner et al. xe2x80x9cTotally implantable hearing device for sensorineural hearing lossxe2x80x9d, The Lancet Vol. 352, No. 9142, page 1751; and are described in numerous patent documents among others in published European Patent Applications EP 0 263 254 A1, EP 0 400 630 A1, and EP 0 499 940 A1, and in U.S. Pat. Nos. 3,557,775, 3,712,962, 3,764,748, 5,411,467, 4,352,960, 4,988,333, 5,015,224, 5,015,225, 5,360,388, 5,772,575, 5,814,095, 5,951,601, 5,977,689 and 5,984,859. Here, the insertion of an electromechanical transducer through an opening in the promontory for direct fluid stimulation in the inner ear is described in U.S. Pat. Nos. 5,772,575, 5,951,601, 5,977,689 and 5,984,859.
Many patients with inner ear damage also suffer from temporary or permanent noise impressions (tinnitus) which cannot be surgically corrected and for which, to date, there are no approved drug treatments. Therefore, so-called tinnitus maskers (International Patent Application Publication WO-A 90/07251, published European Patent Application EP 0 537 385 A1, German Utility Model No. 296 16 956) are known. These devices are small, battery-driven devices which are worn like a hearing aid behind or in the ear and which, by means of artificial sounds which are emitted, for example, via a hearing aid speaker into the auditory canal, psychoacoustically mask the tinnitus and thus reduce the disturbing noise impression, if possible, to below the threshold of perception. The artificial sounds are often narrowband noise (for example, third-band noise). The spectral position and the loudness level of the noise can be adjusted via a programming device to enable adaptation to the individual tinnitus situation as optimally as possible. In addition, the so-called retraining method has been developed recently in which, by combination of a mental training program and presentation of broadband sound (noise) near the auditory threshold, the perceptibility of the tinnitus in quiet conditions is likewise supposed to be largely suppressed (H. Knoer xe2x80x9cTinnitus retraining therapy and hearing acousticsxe2x80x9d journal xe2x80x9cHoerakustikxe2x80x9d 2/97, pages 26 and 27). These devices are also called xe2x80x9cnoisersxe2x80x9d.
In the two aforementioned methods for hardware treatment of tinnitus, hearing aid-like, technical devices must be carried visibly outside on the body in the area of the ear; these devices stigmatize the wearer and, therefore, are not willingly worn.
U.S. Pat. No. 5,795,287 describes an implantable tinnitus masker with direct drive of the middle ear, for example, via an electromechanical transducer coupled to the ossicular chain. This directly coupled transducer can preferably be a so-called xe2x80x9cFloating Mass Transducerxe2x80x9d (FMT). This FMT corresponds to the transducer for implantable hearing aids which is described in U.S. Pat. No. 5,624,376.
In commonly owned co-pending U.S. patent applications Ser. Nos. 09/372,172 and 09/468,860, which are hereby incorporated by reference, implantable systems for treatment of tinnitus by masking and/or noiser functions are described, in which the signal-processing electronic path of a partially or totally implantable hearing system is supplemented by corresponding electronic modules such that the signals necessary for tinnitus masking or noiser functions can be fed into the signal processing path of the hearing aid function and the pertinent signal parameters can be individually adapted by further electronic measures to the pathological requirements. This adaptability can be accomplished by storing or programming the necessary setting data of the signal generation and feed electronics by using hardware and software in the same physical and logic data storage area of the implant system, and by controlling the feed of the masker or noiser signal into the audio path of the hearing implant via the corresponding electronic actuators.
Depending on the desired function, implantable rehabilitation devices of the aforementioned type consist of several functional units, especially: (1) a sensor (microphone) which converts the incident airborne sound into an electrical signal; (2) an electronic signal processing, amplification and implant control unit; (3) an implantable electromechanical or electroacoustic transducer which converts the amplified and preprocessed sensor signals into mechanical or acoustic vibrations and sends them via suitable coupling mechanisms to the damaged middle and/or inner ear, or, in the case of cochlear implants a cochlear stimulation electrode; and (4) an electric power supply system which supplies the aforementioned modules. Furthermore, there can be an external unit which makes available electrical recharging energy to the implant when the implant-side power supply unit contains a rechargeable (secondary) battery. Especially advantageous devices and processes for charging rechargeable implant batteries are described in commonly owned co-pending U.S. patent application Ser. No. 09/311,566 and in commonly owned U.S. Pat. No. 5,279,292, which are hereby incorporated by reference. Preferably, there can also be a telemetry unit with which patient-specific, audiological data can be wirelessly transmitted bidirectionally or programmed in the implant and thus permanently stored, as was described by Leysieffer et al. in HNO Vol. 46, 1998, pp. 853-863.
Basically, in all these at least partially implantable systems, the (audio) signal processing or signal generation and the implant control modules, such as, for example, a controlled battery recharging system or a telemetry system for bidirectional transmission of, for example, variable, patient-specific parameters are accomplished on the implant-side by permanently fixed hardware units. This also applies when digital signal processors, microcontrollers or microprocessors are used for signal processing or generation or for implant management, regardless of whether the signal processors are built as so-called xe2x80x9chardwired logicxe2x80x9d, i.e., in xe2x80x9chardwiredxe2x80x9d logic architecture, or whether their operating programs are stored in the read-only memory areas (for example, ROM) of the corresponding processors. These programs, which are provided and are necessary for basic operation of the implant and for the intended functions, are hereinafter called the operating program or the operating software. In the known implant systems, this operating software is placed in the system during production, for example, by mask programming of processor storage areas and can no longer be changed after implantation.
In contrast thereto, patient-specific data such as, for example, audiological adaptation data or variable implant system parameters (for example, a variable in one of the software programs for control of battery recharging mentioned above) are herein called operating parameters. In known totally implantable implant systems, after implantation, these operating parameters can be transmitted transcutaneously, i.e., wirelessly through the closed skin, to the implant and thus can be changed.
The above described at least partially implantable hearing systems for rehabilitation of inner ear damage which are based on an output-side electromechanical transducer, differ from conventional hearing aids essentially only in that the output-side acoustic stimulus (i.e., an amplified acoustic signal in front of the eardrum) is replaced by an amplified mechanical stimulus of the middle ear or inner ear. The acoustic stimulus of a conventional hearing aid ultimately leads to vibratory, i.e., mechanical, stimulation of the inner ear, via mechanical stimulation of the eardrum and the subsequent middle ear. The requirements for effective audio signal preprocessing are fundamentally similar or the same. Furthermore, in both embodiments on the output side a localized vibratory stimulus is ultimately routed to the damaged inner ear (for example, an amplified mechanical vibration of the stapes in the oval window of the inner ear).
Basically, in this routinely used rehabilitation of inner ear damage by active hearing systems (regardless of whether the rehabilitation is by an external acoustic stimulus or by an implanted electromechanical stimulus), at present there is a major drawback which is described below in summary for understanding of this invention: most cases of sensorineural deafness are based on more or less pronounced damage of the outer hair cells in the inner ear. These outer hair cells, which in large number are located in the organ of Corti along the basilar membrane, form part of the so-called cochlear amplifier which, depending on local excitation of the basilar membrane as a result of traveling wave formation, actively mechanically de-attenuates this local stimulation range at low levels and thus small traveling wave amplitudes, which leads to an increase in sensitivity. This active amplification is based on a very complex, efferently controlled process which is not described here. It is furthermore assumed that at very high levels of inner ear stimulation as a result of the high loudness, this effect is reversed in its action and thus locally reduces and actively attenuates the traveling wave amplitude. These nonlinear characteristics of the cochlear amplifier, which is located along the organ or Corti in several hundred functional units with locally limited action, are of decisive importance for the function of the healthy inner ear. In partial or total failure of the outer hair cells, in addition to a loss of sensitivity which leads to a rise in the hearing threshold, other disadvantages arise: the described active de-attenuation of the basilar membrane leads to high Q-factors of the envelopes of the traveling waves (tuning curves) which are essentially responsible for the frequency differentiation capacity (tone pitch differences). If this high quality is lacking due to failure or partial damage of the outer hair cells, the affected individual can perceive tone pitch differences much more poorly. The rise of the hearing threshold leads, moreover, to a reduction of the dynamic range since the upper sensory boundary (discomfort threshold) in labyrinthine deafness does not rise at the same time. This reduction of dynamics results in an increased perception of loudness which is called positive recruitment. The described effects, which arc caused by damage or failure of the outer hair cells, lead, in the overall effect for the affected individual, to a reduction in speech comprehension, especially in a noisy environment (summary description in Zenner, H. P.: Hearing, Georg Thieme Verlag Stuttgart, New York, 1994, pages 20-23, 107 and 108, and LePage, E. W., Johnstone, M. B.: xe2x80x9cNon-linear mechanical behavior of the basilar membrane in the basal turn of the guinea pig cochlea.xe2x80x9d Hearing Research 2 (1980), pp. 183-189).
An important consequence of this described mechanism is that, as indicated above, both in conventional acoustic hearing aids and also in partially or fully implantable hearing systems, the important functions of the damaged outer hair cells and thus of the cochlear amplifier cannot be replaced or at least partially restored. U.S. Pat. No. 6,123,660 discloses a converter arrangement for partially or fully implantable hearing aids for direct mechanical excitation of the middle ear or inner ear, which is provided with a piezoelectric converter element and also with an electromagnetic converter which are accommodated in a common housing and the two can be coupled via the same coupling element to the middle ear ossicle or directly to the inner ear. Furthermore, implantable hearing systems are known (U.S. Pat. No. 5,997,466, 6,005,955) which work with two or more output-side electromechanical converters in one or locally separate arrangements. These embodiments are, however, uniquely described in that a system design with more than one converter enables a linear superposition of the deflection frequency responses of the individual converters which, as a result, allows an output-side excitation form of the cochlea which is adjustable or programmable depending specifically on frequency or spectrally optimized as much as possible and thus will lead to a spectrally balanced and sufficient loudness impression of the implant system. Rehabilitation of the cochlear amplifier with the aforementioned features is, however, not possible by these embodiments or described signal preprocessing methods.
In cochlear implants (CI), solely electrical stimulation signals are now used as the actuator stimuli. After implantation of a CI in completely deaf patients, training is generally necessary for rehabilitation of hearing, since the artificial stimuli must be learned, because the artificial stimuli do not fundamentally correspond to the biologically proper form of stimulation of the inner ear. Conversely, this rehabilitation phase is omitted after implantation of an electromechanical hearing system in those with hearing difficulties since the mechanical form of stimulation is biologically suitable, as described above, and since the mechanical form of stimulation ultimately largely corresponds with a hearing aid at least with respect to the basic function, i.e., the stimulation at the input of the inner ear is of a vibratory nature.
For the aforementioned reasons, implantable electromechanical systems cannot be employed for hearing disorders which approach deafness. Here, cochlear implants with purely electrical stimulation of the inner ear may be considered which of course do not promise sound quality which for example would enable acceptable music transmission, but which rather are primarily designed for acquiring or restoring sufficient speech comprehension, as much as possible without lip reading. As a result of the electrical stimulation, as described, hearing losses which extend to complete deafness are possible in a spectrally wide audiological range.
Recently it has become scientifically known from CI implantations that even for incomplete deafness cochlear implants (CIs) can be successfully used when sufficient speech discrimination can no longer be achieved with a conventional hearing aid. Interestingly it was demonstrated that the important inner ear structures which enable residual acoustic hearing capacity can be maintained in part or largely stably over time when a CI electrode is inserted into the cochlea (S. Ruh et al.: xe2x80x9cCochlear implant for patients with residual hearingxe2x80x9d, Laryngo-Rhino-Otol. 76 (1997) pp. 347-350; J. Mueller-Deile et al.: xe2x80x9cCochlear implant supply for non-deaf patients?xe2x80x9d Laryngo-Rhino-Otol. 77 (1998) pp. 136-143; E. Lehnhardt: xe2x80x9cIntracochlear placement of cochlear implant electrodes in soft surgery techniquexe2x80x9d, HNO 41 (1993), pp. 356-359). In the foreseeable future it certainly will be possible, in case of residual hearing capacity, to clinically place CI electrodes intracochlearly in a manner such that the remaining inner ear structures can be preserved over the long term and thus can continue to be stimulated in a biologically proper manner, i.e., vibrationally, and lead to a usable hearing impression.
The object of the invention is to devise an at least partially implantable system for rehabilitation of a hearing disorder which can be matched especially effectively and flexibly to the individual pathological and audiological situation of the respective patient.
This object is achieved in that, in an at least partially implantable system for rehabilitation of a hearing disorder which comprises at least one sensor (microphone) for picking up an acoustic signal and converting the acoustic signal into corresponding electrical signals, an electronic signal processing unit for audio signal processing and amplification, an electrical power supply unit which supplies individual components of the system with current, and an output-side actuator stimulation arrangement, as the actuator stimulation arrangement there is a dual intracochlear arrangement which in combination has a stimulator arrangement with at least one stimulator element for at least indirect mechanical stimulation of the inner ear and an electrically acting stimulation electrode arrangement with at least one cochlear implant electrode for electrical stimulation of the inner ear.
With the system both stimulation methods, i.e., the use of mechanical and electrical stimulation, can be used in a single implant system and can be applied patient-specifically depending on the individual audiological situation (xe2x80x9cdualxe2x80x9d hearing implant). Direct stimulation of the cochlea prevents or largely reduces the occurrence of feedback, i.e., coupling of the output signal into the sensor (microphone) because the ossicle chain and thus the eardrum are not excited to vibrations or at least are to a reduced degree. This is especially advantageous when an acoustic sensor (microphone function) is applied in the immediate vicinity of the eardrum, as is known from U.S. Pat. Nos. 5,814,095 and 5,999,632. Therefore, overall with this implant system the use of a combined xe2x80x9cdualxe2x80x9d output-side converter array circumvents or at least reduces the indicated drawbacks of a purely electromechanically acting hearing system and of a purely electrically acting implantable CI such that by the combined action of the two forms of stimulation and individually maximized parameter adjustment of the controlling electronic preprocessing system on the one hand an indication position as audiologically wide as possible and on the other hand in individual patients a result as optimum as possible with respect to speech discrimination, sufficient loudness in all relevant spectral ranges and high sound quality are achieved.
The stimulator arrangement can advantageously have at least one intracochlear electromechanical converter for direct mechanical stimulation of the inner ear and/or at least one intracochlear hair cell stimulating electrode for indirect mechanical stimulation of the inner ear by electrical stimulation of the outer hair cells. Preferably there is an intracochlear array with several stimulator elements for direct and/or indirect mechanical stimulation of the inner ear which can be implanted directly into the fluid-filled space of the inner ear (scala tympani or scala vestibuli) just like a cochlear implant electrode array which is provided preferably with a plurality of cochlear implant electrodes.
The hair cell stimulation electrodes intended for indirect mechanical stimulation of the inner ear are preferably made such that in the implanted state the hair cell stimulation electrodes come to rest in the immediate vicinity of the outer hair cells. Here the circumstance is used that the outer hair cells react mechanically with changes in length when the outer hair cells are artificially stimulated by electricity. These dynamic elongations are synchronous with the electrical stimulation signal up to very high frequencies which can extend to above the audiological range to be supplied. In this way, similarly to when using intracochlear electromechanical converters, electrical stimulation forms achieved on the output side for example by means of cochlear implant electrodes can be combined with mechanical cochlear stimulations because the outer hair cells are directly operated as xe2x80x9celectromechanical convertersxe2x80x9d as takes place in a healthy, undamaged inner ear biologically by neural efferent triggering. This application is especially suitable for pathological cases in which only the outer hair cells are damaged for example by ototoxic medications, i.e., the outer hair cells can no longer perform their neural transmitter function or can only do so to a limited degree, the stereocilia which xe2x80x9cmechanicallyxe2x80x9d join the hair cells to the tectorial membrane are however undamaged or intact to such an extent that there is reliable mechanical coupling to the tectorial membrane stable over the long term.
The cochlear implant electrode(s) intended for direct electrical stimulation of the inner ear is (are), as is known in the prior art for cochlear implants, feasibly embedded in the carrier or fixed or on the carrier such that in the implanted state a portion of the surface of each stimulation electrode is in direct galvanic contact with the lymphatic fluid of the inner ear or directly with one of the neural structures to be stimulated.
There can be a common carrier for the cochlear implant electrode(s) and the electromechanical converter(s), the electromechanical converter(s) and the cochlear implant electrode(s) being arranged advantageously along the carrier alternating in one another. In this way mechanical wave propagation within the carrier between adjacent electromechanical converter elements can be damped and locally concentrated mechanical stimulation per converter can be achieved.
However, there can also be separate carriers for the cochlear implant electrode(s) and the electromechanical converter(s). In this case, the carrier for the cochlear implant electrode(s) is arranged such that in the implanted state the carrier is oriented to the inside with reference to the cochlea, in order to lie as near as possible to the neural structure (modiolus) to be stimulated.
The dual intracochlear arrangement preferably has a total diameter in the range of 0.4 mm (apical area) to 2.0 mm (basal area) and a total length between 5 mm and 50 mm. The carrier or carriers advantageously comprise a biocompatible material which is biostable in the inner ear, preferably a polymer, especially a silicone. The individual electromechanical converters can be embedded in the carrier for reasons of biocompatibility such that the individual electromechanical converters are completely surrounded by a thin layer of the carrier material.
In order to minimize mechanical wave propagation from a converter within the carrier to adjacent converters, in another embodiment of the invention between the individual output-side electromechanical converters mechanical attenuation elements are embedded in the carrier, the material of the attenuation elements for a similar cross sectional geometry to that of the carrier being preferably chosen such that to achieve high attenuation values there is a high mechanical impedance difference compared to the carrier material. As already mentioned, optionally the cochlear implant electrodes can moreover be used as attenuation elements.
The electromechanical converter(s) is (are) preferably made hermetically sealed and the electromechanical converter(s) can work fundamentally according to any known electromechanical converter principle, and can be made especially as electromagnetic, electrodynamic, piezoelectric, magnetostrictive or dielectric (capacitive) converters. When using the piezoelectric converter principle the electromechanical converter(s) is (are) advantageously made using PZT ceramic (lead zirconate titanate) or PVDF (polyvinylidene fluoride), preferably using geometrical shape transformations, especially the bimorph principle, the unimorph principle or the heteromorph principle with passive material partners such that at a given converter voltage the electromechanical converter(s) produce maximum deflection with minimum electric power consumption.
In another embodiment of the invention, several stimulator elements for at least indirect mechanical stimulation of the inner ear are arranged distributed equidistantly or at logarithmic distances according to the tonotopic frequency-location assignment along the basilar membrane of the inner ear, and in the case of a tonotopic arrangement of stimulator elements for mechanical stimulation of the inner ear 20 to 24 stimulator elements or groups of stimulator elements can lead to especially favorable results according to psychoacoustic critical bands.
The electromechanical converter(s) feasibly has (have) a transmission range from roughly 100 Hz to roughly 10 kHz and electromechanical converter(s) is (are) preferably highly tuned, i.e., the first mechanical resonant frequency is at the upper end of the desired transmission frequency range, especially at roughly 8 kHz to roughly 10 kHz. This results in that the deflection frequency response of the converters in the transmission range is largely free of resonances and for voltage impression and the use of piezoelectric converters is flat regardless of frequency. Thus there is no ripple in the transmission range.
The cochlear implant electrode(s) and/or the hair cell stimulation electrode(s) can comprise all known biocompatible metals, especially pure platinum, preferably platinum-iridium alloys (preferably 90% Pt, 10% Ir), pure gold, gold alloys, tantalum, tantalum alloys, niobium, niobium alloys and high quality steels.
The signal processing unit feasibly has a preprocessing arrangement for pre-amplification and/or filtering and for analog-digital (A/D) conversion of the acoustic sensor signals. The signal processing unit can in particular comprise anti-aliasing filters. In the presence of several acoustic sensors preferably each of the acoustic sensors is upstream of its own analog-digital converter.
In another embodiment of the invention, the signal processing unit can contain software modules which parallel to operation of the hearing aid enables masking of tinnitus. With this multichannel hearing implant system, tinnitus which can be at least peripherally localized can be masked more effectively than with known conventional tinnitus maskers.
The signal processing unit advantageously has a digital signal processor for processing the A/D-converted acoustic sensor signals which have been optionally preprocessed by means of the preprocessing arrangement and/or for generation of digital signals for tinnitus masking, at least one analog-digital converter being assigned to the actuator stimulation arrangement and preferably upstream of the stimulator element(s) for at least indirect mechanical stimulation of the inner ear and the cochlear implant electrode(s) for electrical stimulation of the inner ear its own digital-analog converter being located.
In another embodiment of the invention, the signal processing electronics contains software modules which trigger the stimulator element(s) for at least indirect mechanical stimulation of the inner ear, therefore especially the intracochlear electromechanical converters which directly mechanically excite the inner ear and/or the hair cell stimulation electrodes which mechanically excite the inner ear in interaction with the outer hair cells, such that the spectral, time, amplitude- and phase-referenced properties of the signals which trigger the stimulator elements are dimensioned such that a traveling wave is produced on the basilar membrane of the damaged inner ear which is as near as possible to that of healthy hearing.
The software modules can be designed to be static such that as a result of scientific findings the software modules are filed once in the program storage of the digital signal processor and remain unchanged. But then if later for example due to more recent scientific findings improved algorithms for speech signal processing are available and these improved algorithms are to be used, the entire implant or implant module which contains the corresponding signal processing unit must be replaced by a new unit with the altered operating software by invasive surgery on the patient. This surgery entails renewed medical risks for the patient and is very complex.
This problem can be solved in that, in another embodiment of the invention, a wireless, preferably PC-based telemetry means is provided for transmission of data between the implanted part of the system and an external unit, especially an external programming system, a rewritable implantable storage arrangement is assigned to the signal processor for accommodating and reproducing the operating program and at least parts of the operating program can be replaced or changed by data transmitted from the external unit via the telemetry means. In this way, after implantation of the implantable system the operating software as such can be changed or completely replaced, as is explained for otherwise known systems for rehabilitation of hearing disorders in U.S. Pat. No. 6,198,971.
In addition, the design of totally implantable systems preferably is such that, in a manner known per se, after implantation also operating parameters, i.e., patient-specific data, for example audiological adaptation data, or variable implant system parameters (for example, a variable in a software program for control of battery recharging), can be transmitted transcutaneously, i.e., wirelessly through the closed skin, to the implant and can thus be changed. In such a case the software modules are designed to be preferably dynamic, or in other words, adaptive, in order to rehabilitate the hearing disorder as optimally as possible. In particular the software modules can be designed to be adaptive, and parameter matching can be accomplished by training by the implant wearer and using other aids.
Furthermore, the signal processing electronics can contain a software module which achieves simulation of a xe2x80x9chealthyxe2x80x9d cochlear amplifier as optimum as possible based on an adaptive neural network. Training of this neural network can take place again by the implant wearer and/or using other external aids. Especially in the neural network for simulation of a xe2x80x9chealthyxe2x80x9d cochlear amplifier the principle of time-reversed acoustics (TRA) can be implemented, and triggering of the output-side electromechanical converters can take place by TRA such that locally limited areas of the cochlea are mechanically stimulated.
The storage arrangement for storage of operating parameters and the storage arrangement for holding and reproducing the operating program can be implemented as storages independent of one another; however there can also be a single storage in which both the operating parameters and also operating programs can be filed.
The storage arrangement for storage of operating parameters and the storage arrangement for storage and retrieval of the operating program can be implemented as storages independent of one another; however there can also be a single storage in which both the operating parameters and also operating programs can be filed.
This approach allows matching of the system to circumstances which can be detected only after implantation of the implantable system. Thus, for example, in an at least partially implantable hearing system for rehabilitation of a monaural or binaural inner ear disorder and of a tinnitus by mechanical stimulation of the inner ear, the sensoric (acoustic sensor or microphone) and actoric (output stimulator) biological interfaces are always dependent on anatomic, biological and neurophysiological circumstances, for example on the interindividual healing process. These interface parameters can also be individual, also especially time-variant. Thus, for example the transmission behavior of an implanted microphone can vary interindividually and individually as a result of being covered by tissue, and the transmission behavior of an electromechanical transducer which is coupled to the inner ear can vary in view of on different coupling qualities. These differences of interface parameters which cannot be eliminated or reduced in the devices known from the prior art even by replacing the implant can now be optimized by changing or improving the signal processing of the implant.
In an at least partially implantable hearing system, it can be advisable or become necessary to implement signal processing algorithms which have been improved after implantation. Especially the following should be mentioned here:
speech analysis processes (for example, optimization of a fast Fourier transform (FFT))
static or adaptive noise detection processes
static or adaptive noise suppression processes
processes for optimization of the signal to noise ratio within the system
optimized signal processing strategies in progressive hearing disorder
output level-limiting processes for protection of the patient in case of implant malfunctions or external faulty programming
processes of preprocessing of several sensor (microphone) signals, especially for binaural positioning of the sensors
processes for binaural processing of two or more sensor signals in binaural sensor positioning, for example optimization of spacial hearing or spacial orientation
phase or group delay time optimization in binaural signal processing
processes for optimized driving of the output stimulators, especially for binaural positioning of the stimulators.
Among others, the following signal processing algorithms can be implemented with this system even after implantation:
processes for feedback suppression or reduction
processes for optimization of the operating behavior of the output transducer(s) (for example, optimization of the frequency response and phase response, improvement of the impulse response)
speech signal compression processes for sensorineural hearing loss
signal processing methods for recruitment compensation in sensorineural hearing loss.
Furthermore, in implant systems with a secondary power supply unit, i.e., a rechargeable battery system, but also in systems with primary battery supply it can be assumed that these electrical power storages will enable longer and longer service lives and thus increasing residence times in the patients as technology advances. It can be assumed that fundamental and applied research for signal processing algorithms will make rapid progress. The necessity or the patent desire for operating software adaptation and modification will therefore presumably take place before the service life of the implanted power source expires. The system described here allows this adaptation of the operating programs of the implant even when the implant has already been implanted.
Preferably, there can furthermore be provided a buffer storage arrangement in which data transmitted from the external unit via the telemetry means can be buffered before being relayed to the signal processor. In this way the transmission process from the external unit to the implanted system can be terminated before the data transmitted via the telemetry means are relayed to the signal processor.
Furthermore, there can be provided checking logic which checks the data stored in the buffer storage arrangement before relaying the data to the signal processor. There can be provided a microprocessor module, especially a microcontroller, for control of the A/D-converters and/or the D/A converters and/or the signal processor within the implant via a data bus, preferably the checking logic and the buffer storage arrangement being implemented in the microprocessor module, and wherein also program parts or entire software modules can be transferred via the data bus and the telemetry means between the outside world, the microprocessor module and the signal processor.
An implantable storage arrangement for storing the working program for the microprocessor module is preferably assigned to the microprocessor module, and at least parts of the working program for the microprocessor module can be changed or replaced by data transmitted from the external unit via the telemetry means.
In another embodiment of the invention, at least two storage areas for storage and retrieval of at least the operating program of the signal processor may be provided. This contributes to the reliability of the system, in that due to the multiple presence of a storage area which contains the operating program(s), for example, after transmission from the exterior or when the implant is turned on, checking for the absence of faults in the software can be done.
Analogously to the above, the buffer storage arrangement can also comprise at least two storage areas for storage and retrieval of data transferred from the external unit via the telemetry means, so that after data transmission from the external unit still in the area of the buffer storage the absence of errors in the transferred data can be checked. The storage areas can be designed for example for complementary filing of the data transferred from the external unit. At least one of the storage areas of the buffer storage arrangement however can also be designed to store only part of the data transferred from the external unit, wherein in this case the absence of errors in the transferred data is checked in sections.
Furthermore, to ensure that in case of transmission errors, a new transmission process can be started, a preprogrammed read-only memory area which cannot be overwritten can be assigned to the signal processor, in which ROM area the instructions and parameters necessary for xe2x80x9cminimum operationxe2x80x9d of the system are stored, for example, instructions which after a xe2x80x9csystem crashxe2x80x9d ensure at least error-free operation of the telemetry means for receiving an operating program and instructions for its storage in the control logic.
As already mentioned, the telemetry means is advantageously designed not only for reception of operating programs from the external unit but also for transfer of operating parameters between the implantable part of the system and the external unit such that on the one hand such parameters (for example the volume) can be adjusted by a physician, a hearing aid acoustics specialist or the wearer of the system himself, and on the other hand the system can also transfer the parameters to the external unit, for example to check the status of the system.
A totally implantable hearing system of the aforementioned type can have on the implant side in addition to the actoric stimulation arrangement and the signal processing unit at least one implantable acoustic sensor and a rechargeable electrical storage element, and in this case a wireless transcutaneous charging device can be provided for charging of the storage element. For a power supply there can also be provided a primary cell or another power supply unit which does not require transcutaneous recharging. This applies especially when it is considered that in the near future mainly by continuing development of processor technology a major reduction in power consumption for electronic signal processing can be expected so that for implantable hearing systems new forms of power supply will become usable in practice, for example power supply which uses the Seebeck effect, as is described in U.S. Pat. No. 6,131,581. Preferably, there is also provided a wireless remote control for control of the implant functions by the implant wearer.
In case of a partially implantable hearing system, at least one acoustic sensor, an electronic signal processing arrangement, a power supply unit and a modulator/transmitter unit are contained in an external module which can be worn outside on the body, especially on the head over the implant. The implant comprises the output-side electromechanical transducer and the intracochlear stimulation electrode array, but is passive in terms of energy and receives its operating energy and transducer control data via the modulator/transmitter unit in the external module.
The described system can be designed to be monaural or binaural for the fully implantable design as well as for the partially implantable design. A binaural system for rehabilitation of a hearing disorder of both ears has two system units which each are assigned to one of the two ears. In doing so the two system units can be essentially identical to one another. However, one of the system units can also be designed as a master unit and the other system unit as a slave unit which is controlled by the master unit. The signal processing modules of the two system units can communicate with one another in any way, especially via a wired implantable line connection or via a wireless connection, preferably a bidirectional high frequency path, a ultrasonic path coupled by bone conduction, or a data transmission path which uses the electrical conductivity of the tissue of the implant wearer such that in both system units optimized binaural signal processing and transducer array control are achieved.
These and further objects, features and advantages of the present invention will become apparent from the following description when taken in connection with the accompanying drawings which, for purposes of illustration only, shows several embodiments in accordance with the present invention.

At least partially implantable system for rehabilitation of hearing disorder


Disclosed is a method for welding wear-resisting hard metals directly to iron base members which are slide or wear members of machinery. Hard metals comprising a tungsten carbide and a binder consisting of 15 to 30% by weight of Ni and/or Co is employed as said hard metals. A Ni alloy metal containing no Cr is used as a filler metal.

The present invention relates to a method for welding hard metals directly to wear members in order to enhance their resistance to wear, the wear members being in general made of iron base metals an being for instance the inner surfaces of the outer shells of centrifugal separators, the screw blades in the inner shells of centrifugal separators, the wear members of construction machines such as wear parts of concrete pump shutoff valves, side guides of rolling mill stands and so on.
It has been long considered that it is impracticable to weld hard metals to iron base metals such as cast iron, ordinary steels and stainless steels, mainly because of the resultant thermal cracking of the hard metals, the resultant formation of structurally defective layers in the weld and the extreme decrease in strength due to the structurally defective layers. Therefore, the methods for mechanically joining hard metals to the wear members with pins, for silver brazing hard metals to the wear members or for indirectly welding hard metals to the wear members through the backing plates have been mainly employed.
For instance, in order to join hard metal segments to the screw blades in the inner shells of centrifugal separators, there have been proposed (1) the method disclosed in U.S. patent application Ser. No. 533,198 filed Dec. 16, 1974 and now U.S. Pat. No. 3,977,515 wherein a segment is inserted into a dovetail groove of a screw blade and is joined at one end to the blade with a pin and (2) the method disclosed in U.S. Pat. No. 3,764,062 wherein a hard metal segment is securely joined, by silver brazing, to a backing plate and then the backing plate is welded to the screw blade. The former is unsatisfactory in practice with respect to workability and setting strength. The latter has been widely appreciated to be useful because of easiness in operation. However, a further improvement has been desired wherein a hard metal is directly welded to wear members without the resultant thermal cracking, by selected combination of hard metal and filler metal.
An object of the present invention is therefore to provide a method for directly welding hard metals to iron base metals, the method having been so far considered impossible.
Another object of the present invention is to provide a method for easily and positively welding hard metals to wear members of for example centrifugal separators, construction machines and rolling mill stands in order to ensure long service life of machinery.
A further object of the present invention is to provide a method for welding hard metals to wear members which facilitates the replacement operation of hard metal members when such members are worn out or suddenly broken.
The present invention will become more apparent from the following description of a preferred embodiment thereof taken in conjunction with the accompanying drawings.

Ishikawajima-Harima Jukogyo Kabushiki Kaisha


Disclosed is a method for operating a transistor as a rectifier element, and a circuit arrangement including a control circuit and a transistor.

A switched mode power supply comprises an input stage for generating an alternating voltage having a varying amplitude and/or frequency from an input voltage, and an output stage for rectifying the alternating voltage and thereby providing a DC voltage to a load. The input stage may comprise a switch that is driven by a pulse width-modulated control signal and that generates a pulse width-modulated alternating voltage. By varying the duty cycle of the control signal voltage regulation of the output voltage can be achieved.
Instead of using a diode rectifier a so-called "synchronous" rectifier (SR) can be used in the output stage. The synchronous rectifier comprises a transistor, e.g., a MOSFET, in particular a power MOSFET, and a control circuit for switching the transistor on and off in a way as to allow a current to flow through the transistor in only one direction. As compared to a diode a MOSFET that is in on state has lower power losses, thus resulting in an increased efficiency of the rectifier circuit.
A power MOSFET has a MOS channel that conducts dependent on a control signal applied to the MOSFET's gate terminal, and has an integrated body diode that conducts, independent of the control signal, when the MOSFET is reverse biased. In conventional switched mode power supplies that comprise a MOSET as a rectifier element the MOSFET is connected such that it is reverse biased in those time periods in which it is expected to conduct for rectifying purposes. In transition periods, i.e., when the transistor is in transition between the forward biased and the reverse biased operating state, and when the MOS channel is not yet conducting the body diode takes over the current through the MOSFET. In general the duration of the time periods when the body diode conducts should be as short as possible in order to minimize power losses.
Switched mode power supplies can be operated in so-called discontinuous current mode (DCM). In DCM there is a time period in each switching cycle of operation when the current through the rectifier circuit is zero before the begin of a following switching cycle. In DCM switched mode power supplies that comprise a synchronous rectifier it is desired to switch the rectifier transistor off when the current through the transistor reaches zero (zero current switching). This requires measuring the current through the transistor, where such current measurement can be performed by measuring a voltage across the transistor. However, when the current approaches zero the voltage also approaches zero, which complicates the voltage measurement during those time periods that are of particular interest. Further, propagation delays in the transistor control circuit make zero current switching difficult. If there is a delay between a time when the transistor control signal assumes a switch-off level and the time when the transistor really switches off, then the switch-off level has to be generated before the current reaches zero, i.e., the switch-off level has to be generated when the current (or the measurement voltage) falls below a switch-off threshold larger than zero. Since propagation delays may be dependent on the temperature adjusting the switch-off threshold is difficult.


The present invention relates to a polyurethane prepared from a mixture comprising: (a) at least one polyethylene glycol; (b) at least one di-isocyanate; (c) at least one polydialkyl siloxane diol; and (d) at least one diol of formula (I) wherein n is an integer from 1 to 25; wherein the polyethylene glycol, di-isocyanate, polydialkyl siloxane diol and diol are reacted under substantially anhydrous conditions. Further aspects of the invention relate to a process for preparing a polyurethane. The invention also relates to a process for preparing a polyurethane xerogel in the form of a molded article, said process comprising the steps of: (i) preparing a reaction mixture comprising at least one polyethylene glycol, at least one di-isocyanate, at least one polydialkyl siloxane diol and at least one diol of formula I as described above; (ii) reacting the reaction mixture formed in step (i) under substantially anhydrous conditions to form a polyurethane xerogel; and (iii) injection molding the polyurethane xerogel to form a molded article.

Soft contact lenses offer a viable alternative to spectacles for the correction of visual defects such as myopia, hypermetropia and astigmatism. Early lenses were manufactured from polymers based on 2-hydroxyethyl methacrylate, (HEMA). Although these lenses provided some comfort but did not provide sufficient oxygen permeability to prevent problems associated with corneal hypoxia. Attempts to address this problem included copolymerising HEMA with hydrophilic monomers such as methacrylic acid and N-vinyl pyrrolidone. Although these polymers increased the level of oxygen permeability, the incorporation of these comonomers also leads to problems such as protein and lipid deposition, corneal desiccation, staining and lens dehydration.
More recently, a new generation of polymers has been developed to further increase the level of oxygen. These materials are based on the copolymerisation of silicone methacylates with hydrophilic comonomers. The lenses produced from these materials were originally designed for extended wear. Though daily wear products also exist now. Although successful in further increasing DK, these new materials still suffer from limitations such as lipid binding and dryness, all of which decrease lens on eye comfort.
There is therefore still a need for new contact lens polymers, which offer sufficient oxygen levels for normal corneal metabolism during daily wear, and which provide a high level of comfort throughout the day.
One class of polymers which holds considerable promise for novel contact lens materials are PEG based polyurethanes.
Urethane chemistries have also been widely investigated in the field of biomedical devices. For example, U.S. Pat. No. 3,786,034 discloses hard, hydrophilic polyurethane materials formed from reacting a specific polyol with a polyfunctional isocyanate. U.S. Pat. No. 3,821,186 teaches similar such materials. Likewise, U.S. Pat. No. 4,136,250 teaches a polymer formed by reacting a high molecular weight polydimethyl siloxane diol with 2 mole equivalents of isophorone di-isocyanate and then reacting with excess hydroxyl-containing monomers. Further urethane copolymers are disclosed in U.S. Pat. No. 4,454,309 and U.S. Pat. No. 4,359,553.
U.S. Pat. No. 6,930,196 discloses polyurethane hydrogel contact lenses prepared from prepolymers made by reacting (a) at least one multifunctional compound; (b) at least one di-isocyanate; and (c) at least one diol. The prepolymers so formed are then reacted with excess water to form a hydrogel polymer suitable for use as a contact lens.
U.S. Pat. No. 4,644,033 discloses a polyurethane hydrogel formed from the reaction of a polyoxyethylene and a polyfunctional isocyanate in a non-aqueous solvent. The materials can be molded into contact lenses.
U.S. Pat. No. 5,932,200 discloses a polyurethane formed from reacting a diol component and an organic di-isocyanate with critical selection of the amount of water in the reaction mixture and the diol component. The polyurethane is in the form of a gel that has applications in burn/wound care dressings and as surgical implants.
U.S. Pat. No. 4,885,966 and U.S. Pat. No. 5,175,229 disclose hydrophilic polymeric soft contact lenses prepared from prepolymers that are isocyanate-capped oxyethylene-based diols or polyols having a molecular weight of about 7000 to 30,000, wherein essentially all of the OH groups are capped with polyisocyanate. The prepolymers are hydrated to form polyurea-polyurethane polymers that are characterised by having a non-ionic surface which is resistant to non-specific protein adsorption.
U.S. Pat. No. 4,989,710 discloses linear polymers comprising polyurethane/urea polyethylene glycol combined with units of polypropylene glycol. The presence of polypropylene glycol leads to a higher modulus and tensile strength.
U.S. Pat. No. 5,563,233 discloses a hydrophilic polyether polyurethane polymer which is the reaction product of a polyoxyalkylene glycol, a glycol and an organic di-isocyanate. Similarly, U.S. Pat. No. 5,932,200 and U.S. Pat. No. 5,120,816 discloses contact lenses made from hydrogels derived from the reaction product of polyethylene glycols and di-isocyanates. Urea groups are introduced into the backbone by incorporating qualitatively measured amounts of water into the reaction mixture. In each case, the presence of water leads to the formation of urea groups in the backbone chain which in turn gives rise to increased modulus values that are undesirable in the contact lens industry.
The use of silicone-containing polymers has led to contact lenses exhibiting much higher oxygen permeabilities. However, the incorporation of silicone can lead to other adverse performance characteristics, such as surface wettability problems.
Silicone-containing materials suitable for contact lens technology are described in U.S. Pat. No. 6,312,706, which discloses a hydrogel material that is the polymerisation product of a comonomer mixture comprising (a) a polysiloxane-containing urethane prepolymer end-capped with polymerizable ethylenically unsaturated organic radicals, (b) tris-(trimethylsiloxy)silyl propyl methacrylate and (c) a hydrophilic comonomer.
U.S. Pat. No. 4,136,250 teaches polymers formed from mono-olefinic monomers cross-linked with a major amount of a di- or tri-olefinic polysiloxane based macromer having a molecular weight between about 400 and about 800.
U.S. Pat. No. 4,962,178 discloses siloxane-urethane polymers suitable for use as oxygen permeable membranes or ophthalmic devices, having based on total urethane groups 50-80% of —C—NH—COO—C— groups and 50-20% of —C—NH—COO—Si— groups, which consists essentially of the polymerisation product of (a) 80-95% weight of a poly-isocyanate capped, linear or branched polysiloxane prepolymer and (b) 20-50% by weight of a linear polydialkyl or polydiphenyl-siloxane disilanol having terminal siloxanol groups.
U.S. Pat. No. 4,983,702 discloses a cross-linked siloxane-urethane polymer in the form of an ophthalmic device, which consists essentially of the reaction product of (a) a di- or poly-hydroxyalkyl substituted alkyl polysiloxane and (b) an aliphatic, cycloaliphatic or atomatic di- or tri-isocyanate, wherein the total number of hydroxyol groups in component (a) is stoichiometrically equivalent to the total number of isocyanate groups in component (b), and with the proviso that an effective cross-linking amount of (a) or (b) is present and possesses a functionality of greater than two.
U.S. Pat. No. 4,711,943 discloses a non-fibrous polymeric contact lens material having improved oxygen permeability and stability, said material comprising a monomer having a first portion for increasing wettability which is hydrophilic and includes a side chain functionality selected from —CO—N— or —O—CO—N— (such as an acrylamide), and a second portion for increasing oxygen permeability, said second portion including a siloxane.
The present invention seeks to provide new silicone-containing polyurethane-based materials that are suitable for use in the contact lens industry. The silicone-containing polyurethane-based materials of the invention are thermoplastic copolymers that exhibit exemplary physical properties, for example, in terms of modulus, oxygen permeability, light transmissibility, surface wettability and wearer comfort over extended periods. Advantageously, the thermoplastic materials described herein are suitable for use in conventional injection molding apparatus, thereby enabling high throughput production of contact lenses.


The invention concerns API proxy based adaptive security. The invention implements adaptive security for API servers, while avoiding data bottlenecks and maintaining client experience. The invention provides methods and configurations for API security that may be employed at proxies for implementing routing decisions involving client messages received at said proxies. The invention also involves generating or collecting at proxies, log information that captures data corresponding to received client messages and responses from API servers—which log information correlates communications between clients, proxies and backend API servers, and includes data relevant for purposes generating API metrics and identifying anomalies and/or indicators of compromise. The invention yet further provides security server clusters configured for generating API metrics and/or identify anomalies or indicators of compromise—which may be used by proxies to terminate existing connections and block subsequent requests or messages from clients associated with the identified anomalies or indicators of compromise.

API based web applications, distributed applications and client server applications may use one or more proxy nodes (including servers, virtual machines and linux containers) interposed between clients and servers for routing, load balancing and security at the API layer. Proxy nodes of the above type distribute incoming client requests or messages among multiple servers to ensure one or more of targeted routing, balanced server utilization, minimized server overloads, and high availability.
Proxies of router or load balancer type receive client requests or messages, select an appropriate server(s) for processing the requests or messages and transmit the requests or messages to the selected server(s).
FIG. 1 illustrates a network architecture 100 comprising a proxy 104 disposed as a network intermediate between clients 102 (i.e. clients 102a, 102b and 102c) and servers 106 (106a, 106b and 106c).
Based on information retrieved from a DNS server or other name server, requests or messages from client 102 for services from server backend 106 are directed to proxy 104. Proxy 104 transmits the received requests or messages to an appropriate server (106a to 106c) within server backend 106. Depending on the configuration of proxy 104, responses from servers 106a to 106c may first be received at proxy 104 and thereafter redirected to requesting client 102.
In implementing proxy functionality (for example, routing or load balancing), a proxy receives data packets addressed to a target service or server. The proxy transmits the data packets to an appropriate server based on predefined policies and techniques (e.g. routing or load balancing policies and techniques). In prior art proxies, such switching decisions typically rely on information associated with Layers 2 to 4 of the Open System Interconnection ("OSI") model, or Transmission Control Protocol/Internet Protocol ("TCP/IP").
FIG. 2 illustrates protocol layers of the OSI model 200 and the corresponding TCP/IP model. In the OSI model, each network device modularly implements the various OSI layers. Beginning with Layer 7 and progressing downward, each layer communicates with the layer immediately below and immediately above. As devices move to lower layers, the information is increasingly packaged for the specific hardware associated with the device/network—concluding in Layer 1, which is the physical communication channel. Under TCP/IP, Layers 1 to 2 are implemented as a subnet (or MAC) stack, Layer 3 as the Internet (or IP) stack, Layer 4 as the transport (or TCP/UDP) stack, and Layers 5 to 7 as the Application stack. Data generated by a first network device is processed down the protocol stacks, from Layer 7 to Layer 1, into a packet, with each stack adding a header to the packet. The packet is then transmitted over a physical channel to a second network device, which processes the packet up the stacks starting from Layer 1, and unwraps the respective headers after terminating them at their associated stacks. At Layer 7, the application data of the first device is retrieved for interaction with the application of the second device.
FIG. 3 illustrates various headers of an IP packet 300. Each IP packet consists of a data portion for carrying a data payload and a header portion for carrying overhead information. The header portion is partitioned into layer or protocol dependent headers. By way of example, a Layer 2 or MAC header includes a destination MAC address and a source MAC address that specify the destination and source hardware addresses of a node within a subnet. A Layer 3 or IP header includes a source IP address and a destination IP address that respectively specify the IP addresses of the source and destination nodes on the Internet. A Layer 4 or TCP header includes a source TCP port and a destination TCP port that respectively specify the port numbers used by the source node and the destination node.
The payload/data portion of the IP packet contains Layer 7 information which includes data generated by the application. This data may include HTTP headers—which is regarded as application data and is therefore located in the payload portion of the IP packet. The HTTP header may comprise a URL field for specifying a URL that the data packet is requesting, and may also include a cookie field for the application to communicate environmental information.
Implementing data analytics or security solutions at an individual server level has certain associated limitations, inasmuch that the pool of analyzed data is limited to data received at the individual server—which limits the reliability and accuracy of the results of such analysis.
Additionally, implementing first level security analysis at the server level is a less than optimal solution, for the reason that a server necessarily requires to receive a client request or message before it can determine whether such request or message comprises a security threat. The fact that a security threat necessarily has to be received at a server (thereby subjecting the server to the likelihood of damage) before the security threat can be identified or assessed, presents challenges of its own to server security.
Existing API security solutions also face challenges in terms of big data characteristics of velocity (increasing bandwidth and increasing processing powers of devices resulting in increasing demand for web services and APIs), volume (increasing number of API requests from increasing number of users having increasing number of devices), variety (increasing number of available web services and APIs) and veracity (identifying source and security or authentication related parameters of web service access data and/or API access data).
There is accordingly a need for efficient data analytics and security solutions that protect a server backend from security threats. Additionally, the security solutions need to be tailored for addressing the specific security requirements associated with big data capture, streaming and processing for protecting APIs at the edge of (i.e. at entry points of) cloud and data centers using aggregated information from various endpoints.

Methods and systems for API proxy based adaptive security


An infant pacifying apparatus which includes: sound system includes a sound generator and associated power source; an auditory output device associated with the sound system; a receiving portion is configured to: be located on a hand or an arm of an adult cradling an infant; and house or be connected to a housing for containing: the auditory output device; or the sound system and auditory output device.

Devices which make use of white noise to induce sleep in adults and to soothe and pacify infants are well known and a few representative examples include:                GB 1,165,541 Titled: Sleep Inducing Device.        This specification discloses a sine wave oscillator inside a pillow which can generate white noise.        U.S. Pat. No. 4,681,096 Titled: Method and Apparatus for Therapeutic Motion and Sound Treatment of Infants        This specification discloses an apparatus which imparts a rhythmic cyclic motion to a support surface as well as generate a sound at 60-80 decibels within a frequency range of 200 Hz and 4000 Hz.        U.S. Pat. No. 4,819,616 Titled: Baby Calmer        This specification details a sound source which generates a random noise over an audio frequency range to at least 10 kHz.        U.S. Pat. No. 4,825,471 Titled: Garment Useful for listening to Audio Signals        This specification discloses a garment to be worn on the upper torso of a human.
However, conventional infant calming devices employing white noise such as those outlined above suffer from one or more of the following drawbacks:                being bulky and not easily carried such as pillow;        being affixed to a support surface such as a cot;        needing to be worn by the infant which can be uncomfortable, impractical or dangerous in some situations or unsightly;        being designed for use within a cot or bassinet and not being readily portable;        producing a sound that is dangerously loud if the infants ear is positioned too close to the device;        not producing a sound in a region substantially adjacent an infant's ear;        producing a sound which is audible to adults in the vicinity of the device;        not permitting the adult holding the device in use to safely or confidently hold the infant at the same time, or to maintain tactile contact with the infant while in use        not being readily adaptable to a variety of different situations in which an infant may need to be calmed.
It is desirable for the present invention to address the foregoing problems or at least to provide the public with a useful choice.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.
All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.
Throughout this specification, the word "comprise", or variations thereof such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.


Disclosed is a novel process for the preparation of tabular silver halide grains having parallel twinning planes which comprises the steps of:. 1) supplying an aqueous solution of a water-soluble silver salt, an aqueous solution of a water-soluble halide and an aqueous solution of a protective colloid into a mixing machine provided external to a reaction vessel where they are mixed to form nuclear grains; and PA1 2) introducing the nuclear grains into a ripening vessel comprising a pipe where they are ripened at an elevated temperature.

In the prior art process which has heretofore been commonly used to prepare tabular AgX grains, nucleation, ripening and growth are effected in one tank (a so-called batch process). This process has two disadvantages.
First, in order to prepare tabular grains having narrowly distributed sizes, the duration of nucleation is preferably short. However, when the duration of nucleation is shortened, the amount of added solutes is reduced, reducing the yield of an AgX emulsion. If the rate of addition is raised in an attempt to make up for the reduction in the amount of added solutes, high concentration solute solutions must be added at a great flow rate. This creates the problem that agitation and mixing speed cannot keep up with the flow rate, particularly in mass production.
Second, in the nucleation and ripening procedures, nuclear grains which have been formed early and grains which have been formed later are mixed with each other, causing physical ripening therebetween and resulting in a wider size distribution. Further, in the nucleation procedure, nuclei which have been formed early undergo physical ripening and grain growth, while those formed later undergo less physical ripening and grain growth. This also widens the size distribution of tabular AgX grains.
In order to eliminate these disadvantages, various improvements have been attempted in the tank process. However, none of these attempts has been successful. For example, JP-A-2-838 (the term "JP-A" as used herein means an "unexamined published Japanese patent application") discloses in its example a nucleation duration of 5 seconds to 10 minutes at a temperature of 30.degree. C. EP 0,362,69A2 discloses the addition of a silver salt solution to the system in 2 seconds to form nuclei. However, such a technique is infeasible in mass production as mentioned above. The aforementioned problems cannot be solved at the same time in the batch process. As a process other than the batch process, European Patent 0408752A1 discloses a process which comprises continuously supplying to a high temperature reaction vessel finely divided grains formed in a mixing vessel provided external to the reaction vessel, and then immediately causing ripening reaction to effect nucleation reaction. However, since nuclei which have been introduced early into the reaction vessel and those which have been introduced later have different histories, and since both these grains are ripened at the same time, uniformity is reduced.
U.S. Pat. No. 5,104,786 discloses adding a silver salt solution to an aqueous solution containing a halide and passing a protective colloid through a pipe to effect nucleation. In this process, it is true that nuclear grains thus formed advantageously have the same history. However, since the aqueous solution of silver salt and the aqueous solution of halide are mixed in a fine pipe, turbulence needs to occur in the pipe, requiring a large amount of liquid to flow in the fine pipe. The mixing in a pipe attains a lower mixing efficiency than that obtained by general agitators. Therefore, the concentration of the solution to be added must be minimized to a relatively low value. This inevitably means that the yield of the emulsion will be reduced. Further, this patent provides no improvement in the uniformity of the history of various grains in the ripening procedure, and the ripening procedure is still batch-wise.

Process for the preparation of silver halide grains


The hydrophilicity of porous separation membranes is maintained by bonding the membranes to thermoplastic fiber substrates at least on their peripheries before the membrane peripheries are sealed in a thermoplastic resin. The membranes are capable of being integrity tested.

A filtration unit having hydrophilic, porous polymeric membranes and which is capable of being tested for integrity finds application in areas with high demands for filtration reliability, i.e., in the pharmaceutical and food industries, in medicine, in laboratory work and in biotechnology. Porous membranes are rendered hydrophilic either by virtue of their structural morphology or by the addition of a hydrophilic wetting agent or other hydrophilic additive. Such filters are normally used in the form of modules or cartridges.
Filtration reliability is understood in the art to mean that the filtration unit must show sufficiently high mechanical and chemical stability to last a reasonable period of time and must be capable of being tested for integrity. Filtration capacity relates to the volume flow of filtrate per unit of time, which is typically expressed as flux.
A frequently employed integrity test for filtration units having hydrophilic, porous membranes is that constituting fluid impingement on one side of the membrane, the pores of which are filled with a fluid such as water or by a gas such as air under a test pressure. From the measurement of the duration of the pressure loss at the membrane side pressurized with test gas, or by the quantity of the test gas which penetrates through the membrane, conclusions can be drawn as to the integrity of the membrane within the filtration unit. Exemplary tests include burst tests, bubble-point tests and diffusion tests. All known integrity tests for hydrophilic membranes require a thorough wetting of both the membrane filtration surface and its peripheral sealed surfaces.
In general, the use of hydrophilic, porous membranes in filtration units is expensive, if one wishes to maintain a relatively small inventory of filtration units that are not integrity testable. A current method of incorporating such membranes into hydrophilic filtration modules comprises potting such membranes at their peripheries in thermoplastic resin end caps or anchoring elements so as to achieve a fluid-tight seal between the membrane and the module at both ends of the module. The chief drawback of this known method is that the heat from the melt of the thermoplastic resin tends to denature the hydrophilic, porous membranes in the area of contact with the membranes and in areas adjacent thereto, often rendering the membranes hydrophobic in those areas. As a consequence, these hydrophobic-rendered peripheral areas can no longer be wetted with water, which in turn causes the integrity test gas to pass without hindrance through the pores in these areas, thereby simulating a failed membrane.
In addition, such hydrophilic membranes tend to be brittle, and so can be only lightly stressed by mechanical loading, and are susceptible to tearing and tend toward progressive fissuring. Thus, in the treatment of these membranes, for instance where cutting, stamping or pleating are concerned, or even in the act of incorporation into a module, defects can be introduced. This already fragile mechanical stability of the membrane may be further impaired by the action of the hot melt of the thermoplastic resin during the potting, often leading to breaks in the membrane, with the result that the filtration modules are no longer testable for integrity. In biological fluid filtration applications, this is unacceptable because of the risk of contaminants bypassing the membrane filter and, for example, entering the blood stream of a patient:.
One way to cure such problems is disclosed in PCT Application No. 96/14913 wherein the resulting peripheral hydrophobic areas are post-treated with a hydrophilic agent. Several suggestions for overcoming the hydrophobic periphery problem are disclosed in European Patent No. 0 096 306. One proposal is to seal the edges of the hydrophilic membrane with non-porous polyester film, which on one side, is provided with a solvent-free polyethylene coating serving as a fusion adhesive. In the same patent, the reduction of the porosity of the hydrophilic membrane along the membrane edges was also proposed by the use of a casting dope which yielded a smaller pore size than that of the main surface of the membrane. A third method was to mechanically compress the membrane along its edges so as to collapse its pores in the compressed areas.
European Patent No. 0 036 315 also discloses a mechanical procedure, whereby the sensitive peripheral area of the hydrophilic membranes is treated by applying an adhesive thereto. The disadvantage of this treatment lies in the unsatisfactory temperature stability of the membrane areas which have been so treated, when they are exposed to a plurality of steam cycles at 134.degree. C. Commonly assigned U.S. Pat. No. 4,969,997 describes a method of imparting fluid impermeability to the edges of porous membranes by forming a film over the surface of the membrane edges, the film formation being accomplished by contacting the membrane edges with a hot gas to liquify the membrane in the edge area, then allowing the same to cool so as to seal the pores and form a film.
German Patent No. 43 39 810 discloses impregnation of the peripheral areas of the membranes with a hydrophilic-rendering agent to thereby saturate the membranes in those areas. The so-treated membranes are subsequently washed and dried. Theoretically, these membranes should possess, in their impregnated areas, at least double the hydrophilicity as the untreated areas. The result of this is that following potting of the membranes, because of the great surplus of hydrophilic agent in the peripheral areas of the membranes, no edge hydrophobic characteristics appear.
All of the above proposed solutions possess at least one of the following disadvantages:
they are technologically expensive in money and time, PA1 they introduce foreign agents which may be flushed out during filtration, PA1 the active filtration surface is diminished by film deposition or by coating with a non-porous film, thereby reducing flux, and PA1 the peripheral areas of the membrane suffer from mechanical injury.
Thus, the purpose of the present invention is to create a hydrophilic membrane filter unit capable of being tested for integrity, which, in the periphery of the membrane, is sealed with the thermoplastic resin-of a module without compromising the hydrophilicity in the peripheral or edge areas of the membrane and which has improved filtration reliability and capacity.

Integrity testable filtration unit using supported hydrophilic porous membranes


A method for managing a temperature of a device includes determining a temperature of a circuit or a package including the circuit, and selectively operating a thermoelectric semiconductor based on the determined temperature to adjust the temperature of the circuit or the package.

The inventive concept relates to semiconductor and, more particularly, to thermoelectric cooling packages including a thermoelectric cooler and thermal management methods thereof.
Electronic devices have been increasingly smaller and lighter with development of the semiconductor industry and through the requirement of users, and semiconductor packages used as components of the electronic devices have also been increasingly smaller and lighter. To satisfy the above demands, a plurality of semiconductor chips or semiconductor chips of various kinds which are stacked to realize a single package have been developed. However, heat radiated from the semiconductor package including the stacked semiconductor chips during operation thereof may increase to cause thermal stress.

Thermoelectric cooling packages and thermal management methods thereof


The disclosure provides a touch sensor layer and a display device. The display device includes a display module and a touch sensor layer. The display module includes a substrate. The touch sensor layer is disposed on the substrate and includes a plurality of touch sensor units defined by a plurality of first non-continuous conducting lines and a plurality of second non-continuous conducting lines cross over each other. A sensor electrode is defined by some of the plurality of touch sensor units connected together.

Many types of input devices are presently available for performing operations in a computing system, such as buttons, keys, touch sensor panels, and the like. Touch sensor panels, in particular, are becoming increasingly popular because of their ease and versatility of operation as well as their declining price.
Behind the touch sensor panel, a display module can have red, green and blue sub-pixels and black mask patterned in horizontal and vertical directions, parallel to drive lines and sense lines of the touch sensor panel. The pattern formed by the drive lines and the sense lines can have a periodicity different from that of the sub-pixels of the display module and black mask. Because the drive lines and sensor lines may not be entirely clear, the superposition of the touch sensor panel and the display module can cause aliasing effects. As a result, visually unappealing Moire patterns can appear as alternating brighter and darker regions or bands. FIG. 1 illustrates exemplary Moire patterns that can appear when two sets of lines with slightly different pitches are superimposed.


A fixing mechanism fixing a storage device to a bracket includes a fastening member. The fastening member is fixed to the storage device, and has a first connecting hook and a second connecting hook. A first latching portion and a second latching portion are formed on the bracket. The first latching portion defines an engaging groove. The first connecting hook is elastic and engaged in the engaging groove of the first latching portion. The second connecting hook engages the second latching portion.

1. Technical Field
The present disclosure relates to fixing mechanisms, and particularly, to a fixing mechanism for an electronic device with a storage device.
2. Description of Related Art
Electronic devices, such as a desktop computer, or a server, usually include storage devices, such as hard disk drives, read/write digital video disc (DVD) drives, etc. These storage devices are commonly added to increase the functionality of the electronic device as desired.
A storage device may be mounted on an electronic device by a fixing mechanism. The fixing mechanism includes a storage device holder and associated fixing bracket and fasteners. Because installing and uninstalling the storage device from the electronic device is done in the housing of the electronic device, these processes can be tedious and troublesome. Further, with development in the electronics industry, many electronic devices are required to have a relatively thin profile. Therefore, the risk of damaging other working elements of the electronic device during the installing and uninstalling the storage device increases.
Therefore, there is room for improvement within the art.

Hong Fu Jin Precision Industry (ShenZhen) Co., Ltd.


In a shadow process mode, a scanner reads out an original with a first exposure lamp in a first scanning operation. The readout image data is stored in an image memory via an I/O control unit. In the second scanning operation, the scanner reads out the original with a second exposure lamp having an illumination direction different from that of the first exposure lamp. The image data read out in the second scanning operation and the data stored in the image memory are subtracted for each pixel by a subtractor. The difference thereof is compared with a predetermined value in a comparator. The compared result is output to a selector, whereby a desired image data is provided to a printer processing unit via the I/O control unit.

1. Field of the Invention
The present invention relates to image forming apparatuses, and more particularly, to an image forming apparatus receiving reflected light from an illuminated original for obtaining image data.
2. Description of the Related Art
Because an apparatus that reads out an original electrically has random noise superimposed on the readout data, only data of low reliability can be obtained with just one readout operation. An apparatus is known that reads out an image of the same original simultaneously by two CCDs, whereby an average of the readout two image data is adapted as the true image data.
If image data obtained by scanning a book or a cut-and-pasted original is directly output as a hard copy, the frame of the book or the edges of the cut-and-pasted original will appear as shadow regions in the image. It is necessary to eliminate image data of such shadow region to obtain a satisfactory image.
A device erasing such shadow region data is well known as follows. Edge data of a shadow region in a specified region is detected and determination is made that all the area between the edge data is a shadow region, whereby that region is completely erased.
In the above-described first conventional case, random noise can be removed to a certain level, but the picture quality of the image is not satisfactory since there is only one light source that illuminates the original.
In the above-described second conventional case, the usability is not satisfactory since it merely detects a shadow region in a specified area.

Image forming apparatus having illumination direction altered for every plurality of readout operations with respect to one original


Apparatus and methods provide for a non-linear scarf joint and a method for joining two components utilizing a non-linear scarf joint. A non-linear scarf joint includes multi-planar surfaces on connection ends of two components being joined to create a structure. Each multi-planar surface includes a first faying surface, a second faying surface, and a transition faying surface joining the first and second faying surfaces. A transition scarf angle associated with the transition faying surface is different than scarf angles associated with the first and second faying surfaces.

Components are often joined together end-to-end using adhesively bonded joints. Scarf joints are one example of an adhesively bonded joint. Scarf joints provide benefits over lap joints or various other types of adhesively bonded joints due to their increased control of shear peaking. Shear peaking occurs when a load applied to the joint is not uniformly transmitted along the length of the joint. Shear peaking typically occurs at the ends of the joint where the bond terminates. Conventional scarf joints provide angled surfaces at the ends of the components being joined, creating two flat planes that meet at an angle relative to the axis through the components.
The strength of a scarf joint is dependent upon the length-to-thickness ratio (LTR) of the joint. Low LTRs in which the length of the scarf joint is relatively short and the thickness of the components at the scarf joint is relatively thick, provide weak bonds. Conversely, high LTRs in which the length of the scarf joint is relatively long and the thickness of the components at the scarf joint is relatively thin, provide stronger bonds. A problem arises, however, in implementations in which the geometric constraints of the components being joined do not allow for optimum LTRs.
It is with respect to these considerations and others that the disclosure made herein is presented.


A method and system control approach for contemporaneous transfer of designated replacement pages from a main store to an associated memory having a write cycle 10.times. longer than a read cycle thereof (e.g. nonvolatile semiconductor memory). Each designated data page includes an associated home address within the nonvolatile semiconductor memory. The approach includes designating at least two data pages of the main store for transfer to the nonvolatile semiconductor memory; and upon occurrence of a predetermined condition, contemporaneously transferring the designated data pages from the main store to the nonvolatile semiconductor memory for writing into the nonvolatile semiconductor memory at their associated addresses. Preferably, the designated data pages are simultaneously written in the nonvolatile semiconductor memory subsequent to a simultaneous erase of their associated home addresses.

The advantages associated with organizing data processing memory into a hierarchical structure are well recognized in the art. By way of example, a processing system's internal memory may be organized as CPU registers, cache, backing (or bulk, auxiliary or secondary) memory and external memory. Today, external memory is most often implemented as a magnetic storage device, such as a magnetic direct access storage device (DASD). Magnetic disc storage typically comprises random access storage (i.e., direct access storage) in which any location designated by address can be accessed (data searched) within the same access time irrespective of a preceding access address. The drawback to magnetic storage is that higher power rates are necessary to operate the device, which is particularly significant today in view of the trend towards portability in the computer industry.
Nonvolatile semiconductor storage and other technologies such as optical storage require less power and have several orders of magnitude significantly better read access times (e.g., nanoseconds) compared with read access time for magnetic disc storage (e.g., milliseconds). In addition, projections indicate that the cost effectiveness of nonvolatile semiconductor storage will one day overtake that of magnetic storage DASD.
Although nonvolatile semiconductor read access cycle time is on the order of 100 ns, write access cycle times are still at least several orders of magnitude greater. Nominal values of 1 ms -1 sec for a write operation are common. As a specific example, consider a memory hierarchy including a cache, backing storage and a memory in which the write cycle is at least 10.times. (an order of magnitude) longer than the read cycle (e.g. nonvolatile semiconductor memory). In a well mannered system, a cache hit ratio of 99% might be obtained, along with a backing store hit ratio of 95%. Given these numbers and employing a 20 MHz processor, one process cycle in 2,000 can be expected to initiate a replacement page transfer from backing store to nonvolatile semiconductor memory. However, not all page transfers require a write operation into the direct access storage device.
Continuing with the example (and assuming that one-third of the transfer replacement pages need to actually be rewritten in the nonvolatile semiconductor memory), it can be shown that a write operation in the nonvolatile semiconductor memory proceeds at a slower rate than the frequency of page transfer operations (generated by the CPU) moving replacement pages from the backing store to the nonvolatile semiconductor memory. Thus, a significant data blockage can occur in a relatively short period of time, and the superior access time of the nonvolatile semiconductor memory would rarely be realized since almost all access to this memory will encounter a write cycle already in progress.
Therefore, a genuine need exists in the data processing art for a control technique for managing the transfer of data between certain memories of a hierarchical memory structure (including main store and long-write-cycle memory) in order to reduce the possibility of multiple write operations effectively blocking executing read operations between the main store and nonvolatile semiconductor memory. The present invention addresses this need; and, thereby, significantly enhances the capability of a system designer to provide a practical data processing system implementation employing nonvolatile semiconductor storage.

Hierarchical data storage system employing contemporaneous transfer of designated data pages to long write and short read cycle memory

International Business Machines Corporation