Transmitter and receiver for medical applications

Abstract

The present disclosure proposes a transmitter and receiver for medical applications, wherein the transmitter comprises: an analog front end for receiving an analog signal of a neural electrode; a digital baseband processing module for digitizing and channel coding the analog signal to obtain a coded signal; a modulator for 16-QAM modulation of the coded signal to obtain a modulated signal; 16-QAM modulation is used to improve the scalable data rate; a plurality of target frequency signals are generated by a phase-locked frequency divider, and the target frequency signals are divided into a plurality of target sub-frequency signals; the phase of the modulated signal is adjusted based on the plurality of target sub-frequency signals to obtain a phase-adjusted signal, realizing multi-band data transmission within the transmitter; and finally a power amplifier amplifies the phase-adjusted signal, and the amplified phase-adjusted signal is transmitted to a transmitting unit so that the transmitting unit transmits a signal, realizing high-speed and low-power signal transmission.

Description

Technical Field

[0001] This disclosure relates to the field of information processing technology, and more specifically to a transmitter and receiver for medical applications. Background Technology

[0002] Medical and biological devices, especially implantable devices, are widely used for biosignal acquisition. Implantable devices require high-speed data transmission for applications such as neural signal acquisition and continuous physiological monitoring.

[0003] However, traditional wireless transmission technologies, while providing high transmission rates, increase the power consumption of implanted devices, leading to inaccurate signal acquisition. Therefore, there is an urgent need to develop a high-speed, low-power transmission device to solve these problems. Summary of the Invention

[0004] This disclosure proposes a transmitter and receiver for medical applications.

[0005] The first aspect of this disclosure provides a transmitter for medical applications, including an analog front-end, a digital baseband processing module, a modulator, a phase-locked divider, and a power amplifier. The analog front-end is used to receive analog signals from neural electrodes. The digital baseband processing module is used to digitize and channel-code the analog signals to obtain an encoded signal. The modulator is used to perform 16-QAM modulation on the encoded signal to obtain a modulated signal. The phase-locked divider is used to generate multiple target frequency signals and divide the target frequency signals into multiple target sub-frequency signals. The phase of the modulated signal is adjusted based on the multiple target sub-frequency signals to obtain a phase adjustment signal. The power amplifier is used to amplify the phase adjustment signal and transmit the amplified phase adjustment signal to a transmitting unit so that the transmitting unit can transmit signals.

[0006] In this embodiment of the disclosure, the transmitter further includes a frequency shaping filter for spectral shaping of the modulated signal.

[0007] In this embodiment of the disclosure, the transmitting unit is further configured to adjust the impedance matching between the power amplifier and the antenna.

[0008] In this embodiment of the disclosure, the digital baseband processing module includes a symbol mapper for mapping the encoded signal onto symbols on a 16-QAM constellation diagram.

[0009] A second aspect of this disclosure provides a receiver for medical applications, including an analog-to-digital converter (ADC) and a digital baseband processing module. The ADC is used to convert an analog signal received by a receiving unit into a digital signal, wherein the analog signal is a signal transmitted by the transmitter. The digital baseband processing module is used to demodulate and channel decode the digital signal to obtain a decoded signal.

[0010] In this embodiment of the disclosure, the receiver further includes a gain control module for adjusting the gain of the decoded signal.

[0011] In this embodiment of the disclosure, the receiver further includes: the frequency shaping filter, used to perform spectrum shaping on the digital signal.

[0012] In this embodiment of the disclosure, the receiver further includes a display device for displaying the decoded signal in real time.

[0013] In this embodiment of the disclosure, the receiving unit is further configured to optimize impedance matching between the antenna and the receiver.

[0014] The technical solutions provided in this disclosure have at least the following technical effects or advantages:

[0015] The transmitter for medical applications includes an analog front-end, a digital baseband processing module, a modulator, a phase-locked divider, and a power amplifier. The analog front-end receives analog signals from neural electrodes; the digital baseband processing module digitizes and channels the analog signals to obtain coded signals; the modulator performs 16-QAM modulation on the coded signals to obtain modulated signals; the use of 16-QAM modulation improves scalable data rates; the phase-locked divider generates multiple target frequency signals and divides them into multiple target sub-frequency signals; the phase of the modulated signals is adjusted based on the multiple target sub-frequency signals to obtain a phase-adjusted signal, enabling multi-band data transmission within the transmitter; finally, the power amplifier amplifies the phase-adjusted signal and transmits it to the transmitting unit for signal transmission, achieving high-speed, low-power signal transmission.

[0016] Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of this disclosure. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this disclosure. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0018] In the attached diagram:

[0019] Figure 1 A schematic diagram of a transmitter for medical applications provided according to an embodiment of the present disclosure is shown;

[0020] Figure 2 A schematic diagram of a receiver for medical applications provided according to an embodiment of the present disclosure is shown;

[0021] Figure 3a A further schematic diagram of a transmitter for medical applications provided according to an embodiment of the present disclosure is shown;

[0022] Figure 3b A further schematic diagram of a receiver for medical applications provided according to an embodiment of the present disclosure is shown;

[0023] Figure 4a A schematic diagram of data processing for a receiver and transmitter for medical applications provided in an embodiment of this disclosure is shown;

[0024] Figure 4b A schematic diagram of automatic gain control provided in an embodiment of the present disclosure is shown;

[0025] Figures 5a-5c A schematic diagram illustrating the results provided by an embodiment of this disclosure is shown;

[0026] Figures 6a-6d The eye diagram measurement results of a transmitter provided in an embodiment of this disclosure are shown.

[0027] Figures 7a-7d A schematic diagram of constellation evolution provided in an embodiment of this disclosure is shown;

[0028] Figures 8a-8b A schematic diagram showing the data changes corresponding to an embodiment of this disclosure is shown. Detailed Implementation

[0029] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0030] It should be noted that, unless otherwise stated, the technical or scientific terms used in this disclosure shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure pertains.

[0031] Biomedical devices, especially implantable devices, are widely used in a variety of applications, including blood monitoring, functional stimulation for bowel control, insulin pumps, neural electrode recording, and certain diseases.

[0032] In recent years, wireless communication solutions have become increasingly prevalent, particularly in medical and biomedical applications. Related technologies combine independent analog front-end (AFE) designs with commercial wireless controllers such as Bluetooth and Wi-Fi. Bluetooth has become a common choice due to its widespread availability and relatively low power consumption. However, its limited throughput cannot meet the demands of high-rate data transmission, especially for applications requiring high data rates, such as neural signal transmission or continuous physiological monitoring. While Wi-Fi offers higher throughput, its high power consumption and subsequent temperature rise make it unsuitable for implantable medical devices in thermally constrained environments. Therefore, neither Bluetooth nor Wi-Fi can fully satisfy the requirements of high data rate transmission and low power consumption. This highlights the necessity of a new wireless communication solution that must balance low power consumption and high data rate capabilities, especially for medical implants and other devices operating in environments with stringent energy and performance constraints.

[0033] Based on the above, a 3-10 Mbps transceiver integrated circuit operating at 400 MHz has been developed in related technologies; however, this system only provides a moderate data rate, insufficient to support data communication across more than one hundred channels. Transmitting raw neural data, especially when the data rate of a single neuron reaches 20 KS / s, requires significantly higher capacity to accommodate neural interfaces with hundreds of channels. To meet these demands, the data rate must be increased, but this must be balanced with stringent low-power requirements, which are crucial for the lifespan and efficiency of medical implantable devices. A low-power 400 MHz transmitter has also been designed in related technologies, achieving a data rate of 10 Mbps. While this design optimizes energy efficiency, it is insufficient when the task involves transmitting data from approximately 100 effective electrodes. Bandwidth limitations pose a challenge to ensuring reliable, real-time transmission of neural signals, highlighting the need for advancements in data rate capacity and power efficiency for biomedical applications.

[0034] In view of this, embodiments of the present disclosure provide transmitters and receivers for medical applications, such as... Figure 1The transmitter shown is an embodiment of the present disclosure. The transmitter includes an analog front-end 101, a digital baseband processing module 102, a modulator 103, a phase-locked divider 104, and a power amplifier 105. The analog front-end 101 receives analog signals from neural electrodes; the digital baseband processing module 102 digitizes and channel-codes the analog signals to obtain coded signals; the modulator 103 modulates the coded signals using 16-QAM to obtain modulated signals; the phase-locked divider 104 generates multiple target frequency signals and divides the target frequency signals into multiple target sub-frequency signals; it adjusts the phase of the modulated signals based on the multiple target sub-frequency signals to obtain phase-adjusted signals; and the power amplifier 105 amplifies the phase-adjusted signals and transmits the amplified phase-adjusted signals to the transmitting unit for signal transmission.

[0035] The transmitter also includes a frequency shaping filter for spectral shaping of the modulated signal. A transmitting unit is also included for adjusting the impedance matching between the power amplifier 105 and the antenna. The digital baseband processing module 102 includes a symbol mapper for mapping the coded signal onto symbols on a 16-QAM constellation diagram.

[0036] In this embodiment, the transmitter employs 16-QAM modulation to achieve scalable data rates up to 96 Mbps. Furthermore, 16-QAM effectively balances the trade-off between data rate and robustness, as higher-order QAM schemes are more sensitive to noise and require a higher signal-to-noise ratio for accurate transmission.

[0037] like Figure 2 As shown, this is a receiver disclosed in an embodiment of the present disclosure, including an analog-to-digital converter 201 and a digital baseband processing module 202. The analog-to-digital converter 201 is used to convert an analog signal received by the receiving unit into a digital signal, wherein the analog signal is a signal transmitted by the transmitter; the digital baseband processing module 202 is used to demodulate and channel decode the digital signal to obtain a decoded signal.

[0038] The receiver further includes a frequency shaping filter for spectral shaping of the digital signal. The receiver also includes a display device for real-time display of the decoded signal. The receiving unit is further configured to optimize impedance matching between the antenna and the receiver.

[0039] like Figure 3a and Figure 3bThe diagram illustrates the main structure of the communication process between the transmitter and receiver in this embodiment. The transmitter primarily consists of a phase-locked frequency divider, a power amplifier, and a band-shaping modulator. The signal generated by the phase-locked frequency divider is in the range of 1.6 to 1.8 GHz, which is then divided by 4 to modulate the data to 400 MHz. The phase-locked frequency divider structure can generate different frequency signals in different frequency bands, facilitating multi-band data transmission within the system. An embedded phase multiplexer and amplitude control are implemented in the power amplifier, which is driven by four different phase signals. 16-QAM modulation is achieved by combining current from the corresponding phases with varying amplitudes, thereby achieving efficient modulation and precise signal processing.

[0040] The 16-QAM constellation points used in this system are derived from the set {-3,1,1,3}, representing the in-phase component (I) and quadrature component (Q), respectively. The preamble symbol is selected as the two points with the largest spacing on the diagonal of the constellation diagram, optimizing signal distinguishability and improving synchronization accuracy.

[0041] The preamble consists of 14 symbols and is encapsulated along with the transmitted signal. To improve transmission efficiency and reduce the impact of noise interference, all received data is oversampled by a factor of 10. This oversampling increases the resolution of the received signal, enabling more accurate reconstruction of the transmitted data. However, to maintain low power consumption, the transmitter's sampling factor is limited to 6. This careful balance between receiver-side oversampling and transmitter-side low sampling ensures power efficiency and robust signal processing in noisy environments.

[0042] To mitigate inter-symbol interference, an SRRC (square root raised cosine) filter is applied. The frequency response of the SRRC in this embodiment is as follows: Figure 4b As shown in the diagram. In the receiver, a power trigger is used to calculate the power of the input data, thereby monitoring the signal strength. To enhance the system's robustness against interference, a moving average filter is integrated to smooth signal fluctuations, reduce noise, and thus improve signal stability. Automatic gain control (AGC) is employed to ensure that the power of the input signal remains within the optimal range, thereby stabilizing the signal and improving reception accuracy. The AGC section is as follows... Figure 4b The diagram shows the implementation of the basic feedback structure for digital AGC.

[0043] like Figure 5a As shown, the received signal is scaled to the optimal power range. A matched filter is applied to accurately identify the correct downsampled dataset, ensuring high accuracy and reliability of the received signal, especially in the presence of noise and interference. Figure 5bThe downsampling results obtained from data processed by an automatic gain control (AGC) system are presented. These results show the signal quality after gain adjustment and demonstrate the efficiency of AGC in maintaining a consistent signal strength before further processing.

[0044] In order to accurately map the received signals to their respective constellation points, according to Figure 4b The constellation diagram portion uses a precise rounding algorithm. i Imap represents the in-phase portion of all valid frequency modulation data. i This method represents the mapped coordinates. It ensures accurate approximation of the received coordinate values, mitigates the impact of noise, and improves the accuracy of symbol detection. By aligning the received data with the nearest constellation point, this method can also serve as a demodulation solution for the system.

[0045] Frequency offset is eliminated using a Costas loop, such as Figure 4b As shown. The phase difference of the input data is detected by a phase detector and then passed through a loop filter. The loop filter is used to eliminate high-frequency noise and unwanted components generated during transmission. The filtered error signal represents the low-frequency component required for phase correction. A VCO is used for real-time phase adjustment to ensure that the phase difference between the input signal and the reference signal is minimized.

[0046] The phase deviation between the initial preamble and the received preamble is recorded as the initial frequency adjustment value, allowing for faster frequency correction and improved overall synchronization speed. A decision-oriented algorithm is used to synchronize the phase offset to ensure proper demodulation and minimize the impact of frequency offset. The frequency difference between the desired frequency and the received frequency is calculated using the following formula as the basis for frequency adjustment.

[0047]

[0048] The result after frequency correction is as follows Figure 5c As shown, the data points are accurately aligned with the standard 16-QAM constellation diagram.

[0049] The transmitter and receiver described above are further verified using a specific embodiment. The transmitter is manufactured using a 40nm CMOS process with an effective area of ​​0.76 mm². It achieves a scaling data rate of up to 96 Mbps and consumes 5.8 mW at -5 dBm, and is specifically designed for transmitting large amounts of neural signal data in medical applications.

[0050] Figures 6a-6dThe eye diagram measurement results for the transmitter using 16QAM modulation are shown. With the carrier frequency set to 436.5 MHz, the measured EVM (Error Vector Magnitude) was 5.98%. Successful reception of 16-QAM modulated data with a bit error rate (BER) of 0 indicates that there were no errors during transmission and reception. This demonstrates the robustness and reliability of the system in maintaining signal integrity throughout the communication process, even under conditions of potential noise or interference.

[0051] Figures 7a-7d The evolution constellation of the received data frequency modulation module is shown. Figure 7b The frequency variations throughout the adjustment process are described, highlighting the trade-off between adjustment speed and frequency correction accuracy. Red dots correspond to the introductory sequence, as described in Section III-B. Figure 7c After rotating to the correct position, the constellation is displayed and aligned according to the preamble position to ensure the accuracy of demodulation and the integrity of the signal. The received data EVM is 0.08, and the bit error rate remains at 0. Figure 7d The effect of a preprocessing filter applied to received data is demonstrated. This filter effectively reduces noise, thereby improving signal clarity and enhancing overall data integrity in subsequent processing stages.

[0052] Figure 8a and Figure 8b The variation of the error vector magnitude (EVM) of the received data as a function of signal-to-noise ratio (SNR) and samples per symbol (SPS) is shown. The bit error rate (BER) remains at 0, and the EVM fluctuates between 0.8% and 10%. As expected, the higher SNR and SPS result in a lower EVM value, indicating good signal quality. Furthermore, the system exhibits robust performance over a frequency offset range of -50kHz to 50kHz, where the BER remains at 0 and the EVM stabilizes at around 10%, confirming effective frequency tolerance.

[0053] A 16-QAM modulation communication system with an operating rate of 96 Mbps and supporting 400 MHz data transmission across 128 neural electrode channels was successfully implemented. The received data was correctly processed and demodulated, achieving a bit error rate (BER) of 0 with noise in the transmission mode, demonstrating the system's robustness and reliability.

[0054] A first clock domain 101, a second clock domain 102, and a memory 103 are connected. The first clock domain 101 is connected to the second clock domain 102, and the second clock domain 102 is connected to the memory 103. The sampling frequency of the first clock domain 101 is lower than the sampling frequency of the second clock domain 102. The first clock domain 101 is used to acquire the neural signals of the subject through acquisition electrodes. The second clock domain 102 is used to acquire the neural signals of the first clock domain 101 and store the neural signals in the memory 103.

[0055] The first clock domain 101 and the second clock are combined to realize multi-channel low-power high-speed neural signal sampling. In this embodiment, 128-channel neural signal sampling is realized.

[0056] It should be noted that:

[0057] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of this disclosure may be practiced without these specific details. In some instances, well-known structures and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0058] Similarly, it should be understood that, in order to simplify this disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of this disclosure, various features of this disclosure are sometimes grouped together in a single embodiment, figure, or description thereof. However, this approach to disclosure should not be construed as reflecting a schematic diagram in which the claimed disclosure requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of this disclosure.

[0059] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this disclosure and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0060] The above description is merely a preferred embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A transmitter for medical applications, characterized in that, Includes analog front-end, digital baseband processing module, modulator, phase-locked divider, and power amplifier. Analog front end, used to receive analog signals from neural electrodes; A digital baseband processing module is used to digitize and channel-code the analog signal to obtain a coded signal; A modulator is used to perform 16-QAM modulation on the encoded signal to obtain a modulated signal; A phase-locked frequency divider is used to generate multiple target frequency signals in the range of 1.6-1.8 GHz, and divide the target frequency signals into multiple target sub-frequency signals in a 400 MHz frequency band by dividing by 4; the phase of the modulation signal is adjusted based on the multiple target sub-frequency signals to obtain a phase adjustment signal; A power amplifier is used to amplify the phase adjustment signal and transmit the amplified phase adjustment signal to the transmitting unit so that the transmitting unit can transmit the signal; wherein the power amplifier adopts an embedded phase multiplexer and amplitude control structure and is driven by four different phase signals.

2. The transmitter according to claim 1, characterized in that, The transmitter further includes a frequency shaping filter for spectral shaping of the modulated signal.

3. The transmitter according to claim 1, characterized in that, The transmitting unit is also used to adjust the impedance matching between the power amplifier and the antenna.

4. The transmitter according to claim 1, characterized in that, The digital baseband processing module includes a symbol mapper for mapping the encoded signal onto symbols on a 16-QAM constellation diagram.

5. A receiver for medical applications, characterized in that, Includes analog-to-digital converters and digital baseband processing modules. The analog-to-digital converter is used to convert the analog signal received by the receiving unit into a digital signal, wherein the analog signal is the signal transmitted by the transmitter according to any one of claims 1-4; The digital baseband processing module is used to demodulate and channel decode the digital signal to obtain a decoded signal.

6. The receiver according to claim 5, characterized in that, The receiver also includes a gain control module for adjusting the gain of the decoded signal.

7. The receiver according to claim 5, characterized in that, The receiver further includes a frequency shaping filter for performing spectral shaping on the digital signal.

8. The receiver according to claim 5, characterized in that, The receiver also includes a display device for displaying the decoded signal in real time.

9. The receiver according to claim 5, characterized in that, The receiving unit is also used to optimize impedance matching between the antenna and the receiver.

Images