A cochlear implant system based on neural feedback closed-loop control

Abstract

The present invention discloses a cochlear implant system based on neural feedback closed-loop control, comprising an external part and an implant part. The external part comprises a mobile power supply, an external signal processing unit and a transmission coil, and the implant part comprises a receiving coil, an implant processing unit and a stimulation sampling electrode. The external signal processing unit comprises an acoustic-electric and feedback control module, a power module, a hardware acceleration module, a sensor module, a radio frequency modulation module and a storage module. The acoustic-electric and feedback processing module comprises a sound processing module, an acoustic-electric mapping module, a stimulus input encoding module and a feedback output decoding module. The implant processing unit comprises a radio frequency demodulation module, an auditory nerve signal processing module and an interface module. The interface module comprises a stimulation trigger module and a neural telemetry module. The present invention simulates the control mechanism of the auditory system, controls the stimulus input part through the neural feedback output part, and forms a complete closed-loop control to protect and enhance the hearing experience in a noisy environment.

Description

Technical Field

[0001] The present invention belongs to the field of medical devices, and in particular relates to a cochlear implant system based on neural feedback closed-loop control. Background Art

[0002] The neural conduction of the auditory nerve system of the cochlea includes afferent and efferent. The afferent part starts from the action of the hair cells in the cochlea, passes through the spiral ganglion in the cochlea and its extended axons to the brain, and produces hearing. For patients with sensorineural hearing loss, some of their hair cells are diseased or damaged, resulting in blockage of the afferent pathway, resulting in hearing loss. At present, the only means of treating patients with severe sensorineural hearing loss is cochlear implants, which directly stimulate the hair cells and the remaining auditory nerves to rebuild the afferent pathway and restore the patient's hearing. However, the feedback mechanism of the auditory nerve system, that is, the efferent pathway, cannot be rebuilt. Its function is to transmit the brain's active regulatory signals and control the sensitivity of the hair cells to sound. This feedback mechanism has been proven to have multiple functions, one of the more important of which is that it can suppress the human ear's perception of noise in a noisy environment, allowing relatively clear hearing of the target sound. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to control the stimulation signal sent by the cochlea by collecting the feedback signal of the auditory nerve system, thereby forming a complete closed-loop control system, that is, compensating for the regulatory mechanism of the auditory nerve that is missing in the deaf, and protecting and enhancing the user's hearing experience in a noisy environment.

[0004] In order to achieve the above-mentioned purpose, the technical solution of the present invention is as follows: A cochlear implant system based on neural feedback closed-loop control includes an external part and an implant part, wherein the external part includes a mobile power supply, an external signal processing unit and a transmission coil, and the implant part includes a receiving coil, an implant processing unit and a stimulation sampling electrode, wherein:

[0005] The external signal processing unit includes an acoustic, electrical and feedback processing module, a power module, a hardware acceleration module, a sensor module, a radio frequency modulation module and a storage module, wherein the acoustic, electrical and feedback processing module includes a sound processing module, an acoustic and electrical mapping module, a stimulus input encoding module and a feedback output decoding module; the implant processing unit includes a radio frequency demodulation module, an auditory nerve signal processing module and an interface module, wherein the interface module includes a stimulus triggering module and a neural telemetry module;

[0006] The mobile power supply is connected to the power module, and the power module adjusts the power of the mobile power supply to supply power at different voltages according to the requirements of the extracorporeal signal processing unit;

[0007] The transmitting coil is connected to the radio frequency modulation module, and the transmitting coil sends the stimulation code output by the radio frequency modulation module. The receiving coil and the transmitting coil are both provided with magnets at their centers, and are attracted to each other by the magnets to form a centroidal connection.

[0008] The sensor module collects ambient sound around the system and sends the collected audio signal to the hardware acceleration module;

[0009] The hardware acceleration module pre-processes the audio signal collected by the sensor, converts the audio signal from the time domain to the frequency domain, and then sends the processed sound frequency domain signal to the sound processing module;

[0010] The storage module provides a storage unit for the sound and feedback processing module;

[0011] The sound processing module processes the sound frequency domain signal, ie, the audio signal, from the hardware acceleration module, and sends the processed audio signal to the acoustic-electrical mapping module.

[0012] The acoustic-electrical mapping module converts the audio signal into an electrical signal for neural stimulation and outputs it to the stimulation afferent encoding module;

[0013] The stimulus input encoding module encodes the data according to a preset communication protocol format to form 16-bit stimulus input data. The stimulus input data is then transmitted and encoded to generate a carrier wave, which is then sent to the radio frequency modulation module.

[0014] The feedback outgoing decoding module decodes the neural feedback signal detected by the radio frequency modulation module according to a preset protocol, extracts the frequency and amplitude information for analysis, and determines the processing parameters in the sound processing module. The frequency information represents the frequency band corresponding to the audio processing, and the amplitude determines the size of the signal gain.

[0015] The radio frequency modulation module modulates the coded signal and transmits the modulated signal through the transmission coil; at the same time, the transmission coil detects feedback information from the receiving coil during the transmission process, and the feedback information includes a digital signal fed back from the auditory nerve signal processing module;

[0016] The transmitting coil is connected to the receiving coil to transmit signals and energy;

[0017] The receiving coil transmits the received modulated signal to the radio frequency demodulation module by coupling with the transmitting coil, and simultaneously receives the neural feedback information from the auditory nerve signal processing module;

[0018] The radio frequency demodulation module demodulates the signal into stimulation code, extracts the data and sends it to the auditory nerve signal processing module;

[0019] The auditory nerve signal processing module decodes the stimulation code and configures the corresponding parameters of the stimulation trigger module in the interface module according to the decoded information. The parameters include stimulation electrodes, stimulation amplitude, and stimulation time. The auditory nerve signal processing module also receives the neural feedback digital signal detected by the neural telemetry module in the interface module and analyzes and compares the signal. If it is a control signal from the auditory nerve feedback, it generates a digital neural feedback signal and sends it to the receiving coil.

[0020] The stimulation trigger module sends electrical stimulation through the stimulation sampling electrode according to the parameter configuration. The electrical stimulation is achieved by the cooperation of the current source and the switch. The electrical stimulation amplitude is achieved by adjusting the current of the current source. The stimulation time is achieved by controlling the opening and closing intervals of the switch. The electrode selection is achieved by controlling the electrode switch.

[0021] The neural telemetry module monitors the response of the auditory nerve through a preset scanning method according to the parameter configuration and sends it to the auditory nerve signal processing module;

[0022] The stimulation sampling electrodes include at least two groups, each group consisting of 16-60 electrode contacts made of biocompatible materials arranged linearly. The position of each electrode contact corresponds to the cochlea's perception of frequency at that location. The two groups of stimulation sampling electrodes are respectively set in the left ear and the right ear, with no order restriction. One group is used to send stimulation and the other group is used to collect neural feedback.

[0023] Preferably, the magnet arranged at the center of the transmission coil can adjust its magnetism.

[0024] Preferably, the sensor module comprises several microphones.

[0025] Preferably, the sound processing module processes the sound frequency domain signal from the hardware acceleration module, wherein if there is no information sent by the feedback outgoing decoding module, the audio signal is processed according to a preset default method; if there is a feedback signal sent from the feedback outgoing decoding module, the feedback signal is decoded, and the feedback frequency band is suppressed according to the information decoded from the signal, and its basic amplitude is determined according to the mean of the minimum amplitude in the signal amplitude spectrum multiplied by the signal gain. The greater the gain, the stronger the suppression effect.

[0026] Preferably, the acoustic-electrical mapping module converts the audio signal into a corresponding electrical stimulation signal according to the spectrum of the signal, and then sends the mapped electrical stimulation information to the stimulation input encoding module. The electrical stimulation information includes the stimulation electrode, stimulation time, and stimulation amplitude. The stimulation electrode corresponds to the signal frequency band and is related to the number of stimulation electrodes. The frequency range of the audio signal is 0-8000Hz, and each stimulation electrode represents a frequency band. The stimulation amplitude and the average spectrum energy corresponding to the frequency band are piecewise linearly mapped. The higher the energy, the greater the stimulation energy.

[0027] Preferably, the radio frequency modulation module modulates the carrier through a 16 MHz modulation signal.

[0028] Preferably, the auditory nerve signal processing module includes an analog-to-digital conversion circuit, and the parameters configured in the auditory nerve signal processing module include sampling accuracy, sampling rate, gain and scanning mode. The sampling accuracy is 12bit, 10bit or 8bit; the sampling rate is 2us, 4us, 8us or 16us; the gain is 400 times, 800 times or 1600 times; the scanning mode is continuous scanning, interval scanning or advanced scanning.

[0029] The beneficial effects of the present invention are:

[0030] This system addresses the shortcomings of conventional cochlear implants, which lack closed-loop feedback control methods. The human auditory system has a feedback function. After the brain perceives sound, it transmits feedback signals to the auditory nerve in the cochlea through a neural feedback pathway, controlling the sensitivity of the sensorineural nerve. For example, in a noisy environment, this can suppress the response of the auditory nerve to noise-sensitive frequency bands, thereby improving a person's ability to communicate in noisy environments. Currently popular electronic cochlear implants only have a forward stimulation pathway, and neural telemetry is only used intraoperatively to detect whether the auditory nerve responds to electrical stimulation. Therefore, they lack this feedback control mechanism. The present invention extracts and analyzes the feedback neural signals to identify the noise frequency bands that the brain wants to suppress, suppressing the noise, thereby improving the user's ability to communicate in noisy environments. If the extracted neural feedback signals increase the sensitivity of the sensorineural nerve, the sound signal is amplified. This system also provides a risk control measure for abnormal stimulation of the cochlear system. Once abnormal sounds caused by cochlear stimulation are detected, such as loud noises, they can be immediately controlled after being transmitted back through the brain, preventing the user from untimely or inappropriate treatment and causing further harm. In summary, the present invention can improve the speech communication ability of cochlear implant users in noisy environments, enhance their ability to perceive small sounds, and reduce the damage caused to users by abnormal noises generated by abnormal stimulation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a structural block diagram of a cochlear implant system based on neural feedback closed-loop control according to a specific embodiment of the present invention;

[0032] Figure 2 This is a block diagram of the external structure of a cochlear implant system based on neural feedback closed-loop control according to a specific embodiment of the present invention;

[0033] Figure 3 This is a structural block diagram of the implant portion of a cochlear implant system based on neural feedback closed-loop control according to a specific embodiment of the present invention; DETAILED DESCRIPTION

[0034] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0035] See also Figure 1-Figure 3 , is a block diagram of the structure of a cochlear implant system based on neural feedback closed-loop control, including the external and implantable parts. The external part consists of an external signal processing unit 12, a mobile power supply 11, and a transmission coil 13. The implantable part consists of a signal receiving coil 21, an implant processing unit 22, and a stimulation sampling electrode 23. The external signal processing unit 12 consists of an acoustic, electrical, and feedback processing module 123, a power module 126, a hardware acceleration module 125, a sensor module 124, a radio frequency modulation module 121, and a storage module 122. The acoustic, electrical, and feedback processing module 123 consists of a sound processing module 1234, an acoustic, electrical mapping module 1232, an incoming stimulus encoding module 1231, and an outgoing feedback decoding module 1233. The implant processing unit 22 consists of an radio frequency demodulation module 221, an auditory nerve signal processing module 222, and an interface module 223. The interface module 223 consists of a stimulation triggering module 2231 and a neural telemetry module 2232.

[0036] The transmitting coil 13 is connected to the RF modulation module 121 to transmit the stimulation code. Both the receiving coil 21 and the transmitting coil 13 have magnets at their centers, forming a centrifugal connection through magnet attraction. The magnets in the transmitting coil 13 can be adjusted by changing the model.

[0037] The mobile power supply 11 is connected to the power module 126 to provide external power to the entire system. The power module 126 adjusts the power of the mobile power supply 11 and supplies power at different voltages according to the needs of other modules in the extracorporeal signal processing unit 12.

[0038] The sensor module 124 is responsible for collecting ambient sound and then sending the audio signal to the hardware acceleration module 125. The sensor is generally composed of a microphone or a microphone array.

[0039] The hardware acceleration module 125 pre-processes the ambient sound collected by the sensor, converts the signal from the time domain to the frequency domain, and then sends the processed sound data to the sound processing module 1234.

[0040] The storage module 122 provides a storage unit.

[0041] The acoustic, electrical and feedback processing module 123 is composed of a sound processing module 1234 , an acoustic, electrical mapping module 1232 , a stimulus input encoding module 1231 and a feedback output decoding module 1233 .

[0042] The acoustic-electrical mapping module 1232 is responsible for converting audio signals into electrical signals for nerve stimulation. The module first converts the sound information into the information required for the corresponding electrical stimulation based on the spectrum of the signal, and then sends the mapped electrical stimulation information to the stimulation input coding module 1231. This information includes information about the stimulation electrode, stimulation time, and stimulation amplitude. The stimulation electrode corresponds to the frequency band of the signal and is related to the number of stimulation electrodes. The frequency range of the signal is from 0 to 8000 Hz, corresponding to different stimulation electrodes from high to low, and each electrode represents a frequency band. The amplitude of the stimulation and the average spectral energy corresponding to the frequency band are piecewise linearly mapped. The higher the energy, the greater the energy of the stimulation.

[0043] The stimulus incoming coding module 1231 encodes the data according to the format of the set communication protocol to form a total of 16 bits of stimulus incoming data. After transmission coding, the stimulus incoming data generates a carrier and is sent to the RF modulation module 121.

[0044] The RF modulation module 121 modulates the carrier wave with a 16 MHz modulation signal and transmits the signal through the transmission coil 13 .

[0045] The outgoing feedback decoding module 1233 decodes the neural feedback signal detected by the RF modulation module 121 according to a preset protocol, extracting information such as frequency and amplitude for analysis, and determining the parameters of the corresponding processing method in the sound processing module 1234. The frequency information represents the frequency band corresponding to the audio processing, and the amplitude determines the signal gain.

[0046] The sound processing module 1234 is responsible for processing the audio data from the hardware acceleration module 125. If no information is fed back to the decoding module 1233, the audio is processed according to the system's inherent method. If there is a feedback signal from the decoding module 1233, the feedback frequency band is suppressed based on the information decoded from the signal. The basic amplitude is determined by multiplying the mean of the minimum amplitude in the signal amplitude spectrum by the signal gain. The greater the gain, the stronger the suppression effect. The processed audio is then sent to the acoustic-electrical mapping module 1232.

[0047] The RF modulation module 121 modulates the code and transmits the modulated signal through the transmission coil 13 ; at the same time, the transmission coil 13 detects the feedback from the receiving coil 21 during the transmission process, which includes the digital signal fed back from the auditory nerve signal processing module 222 .

[0048] The transmitting coil 13 is connected to the receiving coil 21 of the implanted part and is responsible for the transmission of the modulation signal and the transmission of energy.

[0049] The receiving coil 21 sends the received modulated signal to the RF demodulation module 221 through coupling with the transmitting coil 13 , and simultaneously receives the neural feedback data from the auditory nerve signal processing module 222 .

[0050] The radio frequency demodulation module 221 demodulates the signal into stimulation code, extracts the data and sends it to the auditory nerve signal processing module 222 .

[0051] The auditory nerve signal processing module 222 has two tasks: one is to decode the stimulation code and configure the corresponding parameters of the stimulation trigger module 2231 in the interface module 223 according to the content. These parameters include the stimulation electrode, amplitude and time, etc. The other is to receive the effective neural feedback digital signal detected by the neural telemetry module 2232 in the interface module 223, and analyze and compare the signal. If it is a control signal from the auditory nerve feedback, a digital neural feedback signal is generated and sent to the receiving coil 21.

[0052] Stimulation trigger module 2231 delivers stimulation via the stimulation electrodes based on parameter configuration. Stimulation is achieved through the coordination of a current source and a switch. The amplitude of the stimulation is achieved by adjusting the current of the current source; the duration of the stimulation is achieved by controlling the opening and closing of the switch; and electrode selection is achieved by controlling the corresponding electrode switch.

[0053] Based on the configured parameters, the neural telemetry module 2232 monitors the auditory nerve's response using a pre-set scanning method and transmits the data to the auditory nerve signal processing module 222. This module primarily consists of an ADC analog-to-digital conversion circuit. Configurable parameters include sampling rate, gain, and scanning method. Sampling accuracy can be 12-bit, 10-bit, or 8-bit; sampling rate can be 2µs, 4µs, 8µs, or 16µs; gain can be 400x, 800x, or 1600x; and scanning methods include continuous scanning, interval scanning, and advanced scanning.

[0054] The stimulation and sampling electrodes 23 consist of at least two groups, each consisting of 16-60 linearly arranged electrode contacts made of fully biocompatible materials. The position of each electrode corresponds to the cochlear frequency perception at that location. The two groups of electrodes are implanted in the patient's left and right ears (in no particular order), one for delivering stimulation and one for collecting neural feedback. Separate implantation exploits the symmetry and crossover of the left and right auditory nerve pathways, allowing feedback signals to act on both ears simultaneously; this also prevents interference of the stimulation signal with the neural feedback signal. The stimulation and sampling electrodes are designed as universal, interchangeable modules. The position of each electrode corresponds to the cochlear frequency perception at that location. Sampling is performed using a scanning method with a 1-second cycle. Scanning can be categorized as continuous scanning, interval scanning, or advanced scanning. Continuous scanning involves sampling each electrode contact sequentially in the order of the electrodes, with traversal of all electrodes comprising a single cycle. Interval scanning involves cyclic scanning with intervals of n electrodes, until all electrodes have been traversed, representing a single cycle. Interval scanning involves cyclic scanning with intervals of n electrodes, where n can be any integer from 1 to 6. Advanced scanning increases the number of scans for the electrodes corresponding to the primary frequency while reducing the number of scans for the electrodes corresponding to the secondary frequency. The primary frequency band is concentrated in the mapping of 50-3500Hz.

[0055] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A cochlear implant system based on neural feedback closed-loop control, characterized in that: It includes an external part and an implanted part, wherein the external part includes a mobile power supply, an external signal processing unit and a transmission coil, and the implanted part includes a receiving coil, an implant processing unit and a stimulation sampling electrode, wherein, The external signal processing unit includes an acoustic, electrical and feedback processing module, a power module, a hardware acceleration module, a sensor module, a radio frequency modulation module and a storage module, wherein the acoustic, electrical and feedback processing module includes a sound processing module, an acoustic and electrical mapping module, a stimulus input encoding module and a feedback output decoding module; the implant processing unit includes a radio frequency demodulation module, an auditory nerve signal processing module and an interface module, wherein the interface module includes a stimulus triggering module and a neural telemetry module; The mobile power supply is connected to the power module, and the power module adjusts the power of the mobile power supply to supply power at different voltages according to the requirements of the extracorporeal signal processing unit; The transmitting coil is connected to the radio frequency modulation module, and the transmitting coil sends the stimulation code output by the radio frequency modulation module. The receiving coil and the transmitting coil are both provided with magnets at their centers, and are attracted to each other by the magnets to form a centroidal connection. The sensor module collects ambient sound around the system and sends the collected audio signal to the hardware acceleration module; The hardware acceleration module pre-processes the audio signal collected by the sensor, converts the audio signal from the time domain to the frequency domain, and then sends the processed sound frequency domain signal to the sound processing module; The storage module provides a storage unit for the sound and feedback processing module; The sound processing module processes the sound frequency domain signal, i.e., the audio signal, from the hardware acceleration module, and sends the processed audio signal to the acoustic-electrical mapping module; The acoustic-electrical mapping module converts the audio signal into an electrical signal for neural stimulation and outputs it to the stimulation afferent encoding module; The stimulus input encoding module encodes the data according to a preset communication protocol format to form 16-bit stimulus input data. The stimulus input data is then transmitted and encoded to generate a carrier wave, which is then sent to the radio frequency modulation module. The feedback outgoing decoding module decodes the neural feedback signal detected by the radio frequency modulation module according to a preset protocol, extracts the frequency and amplitude information for analysis, and determines the processing parameters in the sound processing module. The frequency information represents the frequency band corresponding to the audio processing, and the amplitude determines the size of the signal gain. The radio frequency modulation module modulates the coded signal and transmits the modulated signal through the transmission coil; at the same time, the transmission coil detects feedback information from the receiving coil during the transmission process, and the feedback information includes a digital signal fed back from the auditory nerve signal processing module; The transmitting coil is connected to the receiving coil to transmit signals and energy; The receiving coil transmits the received modulated signal to the radio frequency demodulation module by coupling with the transmitting coil, and simultaneously receives the neural feedback information from the auditory nerve signal processing module; The radio frequency demodulation module demodulates the signal into stimulation code, extracts the data and sends it to the auditory nerve signal processing module; The auditory nerve signal processing module decodes the stimulation code and configures the corresponding parameters of the stimulation trigger module in the interface module according to the decoded information. The parameters include stimulation electrodes, stimulation amplitude, and stimulation time. The auditory nerve signal processing module also receives the neural feedback digital signal detected by the neural telemetry module in the interface module and analyzes and compares the signal. If it is a control signal from the auditory nerve feedback, it generates a digital neural feedback signal and sends it to the receiving coil. The stimulation trigger module sends electrical stimulation through the stimulation sampling electrode according to the parameter configuration. The electrical stimulation is achieved by the cooperation of the current source and the switch. The electrical stimulation amplitude is achieved by adjusting the current of the current source. The stimulation time is achieved by controlling the opening and closing intervals of the switch. The electrode selection is achieved by controlling the electrode switch. The neural telemetry module monitors the response of the auditory nerve through a preset scanning method according to the parameter configuration and sends it to the auditory nerve signal processing module; The stimulation sampling electrodes include at least two groups, each group consisting of 16-60 electrode contacts made of biocompatible materials arranged linearly. The position of each electrode contact corresponds to the cochlea's perception of frequency at that location. The two groups of stimulation sampling electrodes are respectively set in the left ear and the right ear, with no order restriction. One group is used to send stimulation and the other group is used to collect neural feedback.

2. The cochlear implant system based on neural feedback closed-loop control according to claim 1, characterized in that: The magnet arranged at the center of the transmission coil can adjust the magnetism.

3. The cochlear implant system based on neural feedback closed-loop control according to claim 1, characterized in that: The sensor module includes several microphones.

4. The cochlear implant system based on neural feedback closed-loop control according to claim 1, characterized in that: The sound processing module processes the sound frequency domain signal from the hardware acceleration module. If there is no information sent by the feedback outgoing decoding module, the audio signal is processed according to a preset default method. If there is a feedback signal sent from the feedback outgoing decoding module, the feedback signal is decoded and, based on the information decoded from the signal, the feedback frequency band is suppressed. The basic amplitude is determined by multiplying the mean of the minimum amplitude in the signal amplitude spectrum by the signal gain. The greater the gain, the stronger the suppression effect.

5. The cochlear implant system based on neural feedback closed-loop control according to claim 1, characterized in that: The acoustic-electrical mapping module converts the audio signal into a corresponding electrical stimulation signal based on the signal's spectrum, and then sends the mapped electrical stimulation information to the stimulation input encoding module. The electrical stimulation information includes the stimulation electrode, stimulation time, and stimulation amplitude. The stimulation electrode corresponds to the signal frequency band and is related to the number of stimulation electrodes. The frequency range of the audio signal is 0-8000Hz, and each stimulation electrode represents a frequency band. The stimulation amplitude and the average spectrum energy corresponding to the frequency band are piecewise linearly mapped. The higher the energy, the greater the stimulation energy.

6. The cochlear implant system based on neural feedback closed-loop control according to claim 1, characterized in that: The radio frequency modulation module modulates the carrier wave using a 16 MHz modulation signal.

7. The cochlear implant system based on neural feedback closed-loop control according to claim 1, characterized in that: The auditory nerve signal processing module includes an analog-to-digital conversion circuit. The parameters configured in the auditory nerve signal processing module include sampling accuracy, sampling rate, gain and scanning mode. The sampling accuracy is 12bit, 10bit or 8bit; the sampling rate is 2us, 4us, 8us or 16us; the gain is 400 times, 800 times or 1600 times; and the scanning mode is continuous scanning, interval scanning or advanced scanning.

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