CN86202153U - Single passage induction man-made cochlea device - Google Patents

Abstract

A device that transmits sound information to electrodes implanted in the patient's body by electromagnetic induction, and reconstructs hearing in patients with total sensory nerve deafness through electrical stimulation. It is composed of a sound processor that realizes the conversion of sound and electricity, an information transmitter that transmits the above-mentioned signals, and an electric stimulator that stimulates the auditory nerve to stimulate the sense of sound. The utility model provides a cochlear artificial device with low price and low power consumption. The transmitter adopts a common base capacitor three-point oscillation circuit and a fully complementary power amplifier circuit.

Description

The utility model is a device that transmits sound information to electrodes implanted in the patient's body in the form of electromagnetic induction, and reconstructs the hearing of the sensorineural total deafness patient through electric stimulation.

The fundamental basis for the realization of cochlear implants in the prior art is that electrical stimulation of the auditory nerve can induce sound perception. The difficulty in implementing a cochlear implant lies in the fact that the range of electrical stimulation signals that the auditory nerve can accept cannot adapt to changes in external sounds, both in terms of strength and bandwidth. A general cochlear implant is composed of a sound processor that realizes acoustic-electric conversion, a transmission system that transmits the above-mentioned electrical signals, and an electrical stimulator that stimulates the auditory nerve to stimulate the sense of sound. US Patent International Patent Classification No. Int, CL ³ (A61N1/18) U.S. Patent Classification No. US, CL128/419R; 128/784, 179/107R; Patent No. 4,419,995, named "Single-channel Auditory Stimulation System ", the structure of the sound processor is complex and consumes a lot of power; the AM transmitter requires high voltage and is parallel resonance.

The purpose of this utility model is to propose a low-cost, low-power-consumption single-channel cochlear implant device, which sends the sound information of the voice band to the auditory nerve, simplifies the structure of the inductive cochlear implant, makes it more practical, and expands information. The permissible error in the relative positions of the transmitting and receiving parts of a transmission system. The effect of the utility model is: the patient can hear the environmental sound, and the sense of security is improved. After training, it can understand simple daily language, improve the patient's lip-reading ability, and improve the patient's pronunciation ability through auditory feedback.

The utility model comprises a sound processor, an information transmitter and a receiving stimulator implanted in a patient's body. The sound processor consists of a microphone, preamplifier, bandpass filter and adjustable threshold comparator. The passband of its bandpass filter is from 100Hz to 3KHz. Its adjustable threshold comparator can adjust the sound sensitivity in the range of 50~60dBSPL. Its information transmitter is composed of a switching oscillator or a switching modulator, a power amplifier, a transmitting coil and a receiving coil. Its oscillator adopts a three-point oscillation circuit with fixed inductance and common base capacitance, and its start-up is controlled by a voltage level. There is a resistor between the collector of the transistor of the oscillator and the resonant circuit, and there is also a resistor between the collector and the base of the transistor. These two resistors stabilize the output amplitude and make the circuit easy to start oscillation. The transmitting coil of the information transmitter adopts the form of series resonance, and the receiving coil adopts the form of parallel resonance. The resonant capacitor is connected close to the transmitting coil to reduce the influence of the distributed capacitance of the leads. The power amplifier adopts a voltage series negative feedback circuit, the pre-stage bias current of the power amplifier circuit is 0.5-1.5mA, and a series current negative feedback is introduced.

Embodiment of the utility model is described below in conjunction with accompanying drawing

Figure 1 is a block diagram of a single-channel cochlear implant device

Figure 2 is a schematic circuit diagram of a single-channel cochlear implant

Figure 3 is a circuit diagram of signal transmission and implantation

Figure 4 is a circuit diagram of a switching modulator

In the figure: (1) and (14) are microphones, (2) are preamplifiers, (3) are bandpass filters, (4) are adjustable threshold comparators, and (5) are switching oscillators or switches (6) is a power amplifier, (7) is a transmitting coil, (8) is a skin, (9) is a receiving coil, (10) is a receiving stimulator, (11) is an electrode, (12), ( 16), (17), (18), (20), (23), (25), (28), (30), (32), (33), (39), (43), (44) , (47), (51), (53), (55), (56), (57), (59), (62), (63), (66), (67), (68), ( 71), (84), (88), and (90) are resistors. (24), (52) are potentiometers, (15), (21), (26), (27), (31), (34), (36), (40), (41), (46) , (48), (49), (50), (54), (60), (61), (72), (80), (81), (83), (85) are capacitors. (19), (29), (35), and (37) are integrated circuit blocks. (45), (58), (64), (65), (69), (70) are transistors. (42) is the inductance coil. (13), (22), (73) are plug holes. (76), (77) are plugs. (82) is a diode. (38) are light-emitting diodes. (74) is the positive pole of the power supply, (75) is the ground, (86) is the transformer, and (87), (91) are field effect tubes. (78), (79) are low-frequency shielded wires.

The utility model is composed of a microphone (1), a preamplifier (2), a bandpass filter (3), an adjustable threshold comparator (4), an oscillator (5), a power amplifier (6), and a transmitting coil (7) ) is made into a pocket-sized device, which is carried by the patient. The receiving coil (9), the receiving stimulator (10) and the electrodes (11) are encapsulated with corrosion-resistant, non-toxic, waterproof and insulating polymer materials and then implanted into the patient's body. The bare metal part at the front end of the electrode (11) is placed in the cochlea, and the microphone (1), preamplifier (2), band-pass filter (3) and adjustable threshold comparator (4) constitute the sound processor. The preamplifier (2) linearly amplifies the sound signal to improve the signal-to-noise ratio. The function of the band-pass filter (3) is to pass the main components in the speech and filter out the secondary components and interference noise in the speech. The passband of the band-pass filter (3) is 100Hz-3KHz, which is wider than the customary voice range of 300Hz-3KHz, because 100Hz-300Hz is a frequency band with a better effect of receiving electrical stimulation on the auditory nerve.

The carrier wave oscillator of the utility model connects its input terminal to the resistance (47) and places it at high level or low level respectively, so as to realize the radio frequency modulation of the audio frequency square wave. As a radio frequency oscillator working in a switching state, its start-up characteristics and working characteristics during step-down are a more important index. The existing radio frequency oscillator is unsatisfactory in this respect, based on the typical capacitor three-point oscillator, the following improvements are made: a resistor (43) is connected in series between the oscillation tube (45) and the resonant circuit, and the oscillation A resistor (44) is connected between the collector and the base of the tube (45), and the operating point of the oscillator tube is set appropriately so that the current is about 0.4 ~ 0.6mA, so that the oscillation characteristics and step-down characteristics of the oscillator are greatly improved. Improvement, while its working stability and waveform are also improved. Its characteristic is that the parallel negative feedback of the DC voltage makes the circuit self-stabilizing and adjusting for each DC. For the radio frequency oscillation signal, the self-supply bias effect of the circuit is greatly enhanced, and the oscillation characteristics and voltage reduction characteristics are improved.

The oscillator is connected with the output terminal with high and low level square wave pulses, and has the advantages of novelty, simple circuit and low power consumption.

The fully complementary power amplifier of the utility model includes two parts, namely the preamplifier stage composed of transistors (58) and other components, and the preamplifier stage composed of transistors (64), (65), (69), (70) and other components. Two-stage complementary push-pull circuit. The present invention provides a fully complementary amplifier. At the maximum output level, its actual efficiency can be close to the ideal efficiency value, and its no-load current and crossover distortion are far smaller than typical complementary circuits, and the requirements for the consistency of the tubes are also significantly reduced. Since the two pairs of complementary amplifier tubes in this circuit adopt common emitter amplification, and a closed-circuit negative feedback composed of resistance branches is introduced between the two pairs of complementary stages, not only the two-stage complementary amplifiers have a high forward magnification, but also the feedback The branch circuit provides a deep voltage series negative feedback. The power amplifier can reduce distortion and no-load current, reduce the consistency requirements for complementary tubes, and has a significant improvement over typical power amplifiers, so that the closed-loop voltage amplification of the complementary stage is 2-8 times, and the output signal of the pre-stage The voltage can be reduced to 1/2 - 1/8, so that it changes from the large-signal working state to the small-signal working state, which can greatly reduce the bias current of the preamplifier tube and improve the distortion. The various distortions caused by the complementary stage are greatly reduced, which can reduce the various DC biases of the complementary stage, make it consume less quiescent current, and the quiescent current of the final stage is close to zero, which improves the working characteristics under low power supply voltage and the maximum efficiency actually achieved.

The plug hole (22) is set up for the patient to listen to the radio receiver.

The receiving stimulator (10) is a half-wave demodulation circuit, which is encapsulated with a corrosion-resistant, non-toxic, waterproof and insulating polymer material and implanted behind the ear. The front end of the electrode (11) is exposed so as to generate a stimulating electric field near the auditory nerve. The resonant capacitor (80) is connected close to the transmitting coil (7) to form a series resonant circuit, the impedance is very low near the resonant frequency, and the influence of the distributed capacitance of the leads is negligible. Therefore a low frequency metal isolated wire (78) can be used. The plug (76) is connected with the power amplifier (6) through the plug hole (73).

The present invention is successful through 8 examples of tests, and the optimal scheme has been selected. The cost is much lower than similar foreign products.

Claims (3)

1, a kind of induction single channel artificial cochlea device, be that acoustic information is sent to heeling-in at the intravital electrode of patient, make the sensory nerve anacusia patient rebuild the device of audition by electricity irritation, form by microphone, speech processor, amplitude modulation transmitter, transmission coil, receiving coil, stimulator and electrode.The speech processor that is characterised in that of the present utility model has adopted preamplifier, band filter and adjustable threshold comparator.Information carrying is by switching regulator agitator or switching regulator manipulator, power amplifier, and transmitting coil and receiving coil are formed.Transmitting coil is a serial-resonant, and receiving coil is the parallel resonance formula.Resonant capacitance is connected and installed near transmitting coil.Agitator adopts the common base Colpitts oscillation circuit of fixed inductance, and power amplifier is the two-stage complementary power amplification circuit of the direct manifold type of emitting stage altogether.

2, according to claim 1 single channel artificial cochlea device, it is characterized in that string one resistance (43) between oscillating circuit and transistor (45), be connected to resistance (44) between the colelctor electrode of transistor (45) and the base stage, its frequency of oscillation is a radio frequency.

3, according to the single channel artificial cochlea device of claim 1, it is characterized in that the complementary amplifying circuit of two-stage common emitter that power amplifier is made up of inverter stage transistor (58) and transistor (64) (65) (69) (70), and resistance (62).

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