Transmitter and receiver for medical applications

Abstract

The present disclosure proposes a transmitter and a receiver for medical applications, wherein the transmitter comprises: an analog front end for receiving an analog signal of a neural electrode; the digital baseband processing module is used for performing digitization and channel coding on the analog signal to obtain a coded signal; the modulator is used for carrying out 16-QAM (Quadrature Amplitude Modulation) modulation on the coded signal to obtain a modulated signal; 16-QAM modulation is adopted, so that the extensible data rate is improved; generating a plurality of target frequency signals through a phase-locked frequency divider, and dividing the target frequency signals into a plurality of target sub-frequency signals; and adjusting the phase of the modulation signal based on the plurality of target sub-frequency signals to obtain a phase adjustment signal, thereby realizing multiband data transmission in the transmitter, and finally amplifying the phase adjustment signal by a power amplifier, and transmitting the amplified phase adjustment signal to a transmitting unit, so that the transmitting unit transmits the signal. And high-speed and low-power-consumption signal emission is realized.

Description

Technical Field

[0001] The present disclosure relates to the field of information processing technology, and in particular to a transmitter and a receiver for medical applications. Background Art

[0002] Medical biological devices, especially implantable devices, are widely used in biological signal acquisition. However, implantable devices require higher data rates for data transmission in the fields of neural signal acquisition and continuous physiological monitoring.

[0003] However, traditional wireless transmission technology, while providing a high transmission rate, will increase the power consumption of the implanted device, which will lead to inaccurate signals collected. Therefore, it is urgent to propose a high-speed and low-power transmission device to solve the above problems. Summary of the invention

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

[0005] The first aspect of the present disclosure proposes 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 encode the analog signals to obtain encoded signals; the modulator is used to perform 16-QAM modulation on the encoded signals to obtain modulated signals; 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 transmits a signal.

[0006] In the embodiment of the present disclosure, the transmitter further includes: a frequency shaping filter, configured to perform spectrum shaping on the modulated signal.

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

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

[0009] The second aspect embodiment of the present disclosure proposes a receiver for medical applications, including an analog-to-digital converter and a digital baseband processing module, wherein the analog-to-digital converter 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; and the digital baseband processing module is used to demodulate and channel-decode the digital signal to obtain a decoded signal.

[0010] In the embodiment of the present disclosure, the receiver further includes: a gain control module, configured to adjust the gain of the decoded signal.

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

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

[0013] In the embodiment of the present disclosure, the receiving unit is also used to optimize the impedance matching between the antenna and the receiver.

[0014] The technical solution provided in the embodiments of the present disclosure has 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 is used to receive analog signals from neural electrodes; the digital baseband processing module is used to digitize and channel encode the analog signals to obtain coded signals; the modulator is used to perform 16-QAM modulation on the coded signals to obtain modulated signals; the scalable data rate is improved by using 16-QAM modulation; multiple target frequency signals are generated by the phase-locked divider, and the target frequency signals are divided 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, thereby realizing multi-band data transmission in the transmitter; finally, the power amplifier amplifies the phase adjustment signal and transmits the amplified phase adjustment signal to the transmitting unit so that the transmitting unit transmits the signal, thereby realizing high-speed and low-power signal transmission.

[0016] Additional aspects and advantages of the present disclosure will be given in part in the following description and in part will become apparent from the following description or be learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiment and are not considered to be limitations of the present disclosure. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings.

[0018] In the attached picture:

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

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

[0021] Figure 3a Another schematic diagram of a transmitter for medical applications provided by an embodiment of the present disclosure is shown;

[0022] Figure 3b Another schematic diagram of a receiver for medical applications provided by an embodiment of the present disclosure is shown;

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

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

[0025] Figure 5a-5c A schematic diagram of a result provided by an embodiment of the present disclosure is shown;

[0026] Figure 6a-6d The eye diagram measurement result of the transmitter provided by an embodiment of the present disclosure is shown.

[0027] Figure 7a-7d A schematic diagram of constellation evolution provided by an embodiment of the present disclosure is shown;

[0028] Figure 8a-8b A schematic diagram of data changes corresponding to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0029] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0030] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the present disclosure should have the common meanings understood by those skilled in the art to which the present disclosure belongs.

[0031] Biomedical devices, especially implantable devices, are widely used in various 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 common, especially in medical and biomedical applications. The related technology combines 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 wide availability and relatively low power consumption. However, its limited throughput cannot meet the transmission of high-rate data, especially for applications that require high data rates, such as neural signal transmission or continuous physiological monitoring. Although Wi-Fi offers higher throughput, its high power consumption and resulting temperature increase make it unsuitable for implantable medical devices in thermally constrained situations such as implantable medical devices. Therefore, neither Bluetooth nor Wi-Fi can fully meet the requirements of high data rate transmission and low power consumption. This highlights the need for 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 strict energy and performance constraint environments.

[0033] Based on the above situation, a 3-10 Mbps transceiver integrated circuit operating at 400 MHz has also been developed in the related art; however, the system only provides a moderate data rate, which is insufficient to support data communication of more than one hundred channels. Transmitting raw neural data, especially when the data rate of a single neuron reaches 20KS / s, requires higher capacity to accommodate neural interfaces with hundreds of channels. To meet these needs, the data rate must be increased, but this must be balanced with strict low power requirements, which is critical to the service life and efficiency of medical implantable devices. A low-power 400 MHz transmitter has also been designed in the related art to achieve a data rate of 10 Mbps. Although this design optimizes energy efficiency, it is insufficient when the task is to transmit data from about 100 active electrodes. Bandwidth limitations pose a challenge to ensuring reliable and real-time transmission of neural signals, emphasizing 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 a transmitter and a receiver for medical applications, such as Figure 1The transmitter disclosed in the embodiment of the present disclosure is shown, and the transmitter includes an analog front end 101, a digital baseband processing module 102, a modulator 103, a phase-locked frequency divider 104, and a power amplifier 105. The analog front end 101 is used to receive the analog signal of the neural electrode; the digital baseband processing module 102 is used to digitize and channel encode the analog signal to obtain a coded signal; the modulator 103 is used to perform 16-QAM modulation on the coded signal to obtain a modulated signal; the phase-locked frequency divider 104 is used to generate a plurality of target frequency signals and divide the target frequency signal 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 adjustment signal; the power amplifier 105 is used to amplify the phase adjustment signal and transmit the amplified phase adjustment signal to the transmitting unit so that the transmitting unit transmits the signal.

[0035] The transmitter further includes: a frequency shaping filter for performing spectrum shaping on the modulated signal. A transmitting unit is further used to adjust 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 to symbols on a 16-QAM constellation diagram.

[0036] The transmitter in the disclosed embodiment adopts 16-QAM modulation to achieve a scalable data rate of up to 96 Mbps. In addition, 16-QAM effectively balances the trade-off between data rate and robustness, because high-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, the receiver disclosed in the embodiment of the present disclosure includes 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 a receiving unit into a digital signal, and 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 performing spectrum shaping on the digital signal. The receiver further includes a display device for displaying the decoded signal in real time. The receiving unit is further used to optimize the impedance matching between the antenna and the receiver.

[0039] like Figure 3a and Figure 3bAs shown, the main structure of the communication process between the transmitter and the receiver of the embodiment of the present disclosure is shown. The transmitter is mainly composed 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, and then divided by 4 to modulate the data to 400 MHz. The phase-locked frequency divider structure can generate different frequency signals on different frequency bands, which facilitates multi-band data transmission within the system. An embedded phase multiplexer and amplitude control are implemented in the merit amplifier, where the amplifier is driven by four different phase signals. 16-QAM modulation is achieved by combining the current from the corresponding phase with the varying amplitude, thereby achieving efficient modulation and precise signal processing.

[0040] The 16-QAM constellation points used by the system are derived from the set {-3, 1, 1, 3}, which represent the in-phase component (I) and the quadrature component (Q). The leading symbol is selected as the two points with the largest spacing on the diagonal of the constellation diagram, which optimizes the signal distinguishability and improves the synchronization accuracy.

[0041] The preamble consists of 14 symbols and is packaged with the transmitted signal. To improve transmission efficiency and reduce the effects of noise interference, all received data is oversampled by a factor of 10. This oversampling increases the resolution of the received signal, allowing for more accurate recovery of the transmitted data. However, to keep power consumption low, the sampling factor of the transmitter is limited to 6. This careful balance between oversampling on the receiver side and undersampling on the transmitter side ensures power efficiency and robust signal processing in noisy environments.

[0042] In order to reduce inter-symbol interference, an SRRC (square root raised cosine) filter is applied. The frequency response of the SRRC in the embodiment of the present disclosure is as follows: Figure 4b As shown. In the receiver, the power trigger is used to calculate the power of the input data, thereby realizing the monitoring of the signal strength. In order to enhance the robustness of the system to interference, a moving average filter is integrated to smooth the signal fluctuations and reduce the noise, thereby improving the stability of the signal. Automatic gain control (AGC) is used to ensure that the power of the input signal remains within the optimal range, thereby stabilizing the signal and improving the reception accuracy. The AGC part is shown in Figure 4b Shown is the basic feedback structure implementation of a 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 data set, ensuring high accuracy and reliability of the received signal, especially in the presence of noise and interference. Figure 5bThe down-sampled results obtained by processing the data through an automatic gain control (AGC) system are shown. These results show the signal quality after gain adjustment, demonstrating the effectiveness of the AGC in maintaining a consistent signal strength before further processing.

[0044] In order to accurately map the received signals to their respective constellation points, Figure 4b In the constellation diagram part, the exact rounding algorithm is used. i Indicates the in-phase part of all valid FM data, Imap i Indicates its mapping coordinates. This method ensures the correct 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 be used as a demodulation solution for the system.

[0045] The Costas loop is used to eliminate the frequency offset, such as Figure 4b As shown. The phase difference of the input data is detected by the phase detector and then passes through the loop filter. The loop filter is used to eliminate high-frequency noise and unwanted components generated during the transmission process. The filtered error signal represents the low-frequency component required for phase correction. The 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 faster frequency correction and improving overall synchronization speed. A decision-directed algorithm is used to synchronize the phase offset to ensure proper demodulation and minimize the impact of frequency deviation. 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] Next, a specific embodiment is used to further verify the above transmitter and receiver. The transmitter is manufactured using a 40nm CMOS process with an effective area of ​​0.76 mm^2. It achieves a scaled data rate of up to 96Mbps and a power consumption of 5.8mW at -5dBm, and is specifically designed for transmitting large amounts of neural signal data in medical applications.

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

[0051] Figure 7a-7d The evolving constellation of the received data modulation module is shown. Figure 7b The frequency variation throughout the tuning process is depicted, highlighting the trade-off between tuning speed and frequency correction accuracy. The red dots correspond to the preamble sequence, as described in Section III-B. Figure 7c In the display, the constellation is rotated to the correct position and aligned according to the position of the leading edge to ensure the accuracy of demodulation and the integrity of the signal. The EVM of the received data is 0.08 and the bit error rate remains 0. Figure 7d Demonstrating the effect of a pre-processing filter applied to received data. The filter effectively reduces noise, thereby improving signal clarity and enhancing overall data integrity in subsequent processing stages.

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

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

[0054] A first clock domain 101, a second clock domain 102 and a memory 103, wherein 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 less than the sampling frequency of the second clock domain 102, and the first clock domain 101 is used to obtain neural signals of the object under test through acquisition electrodes; and the second clock domain 102 is used to obtain neural signals of the first clock domain 101 and store the neural signals in the memory 103.

[0055] The first clock domain 101 is combined with the second clock to achieve multi-channel low-power and high-rate neural signal sampling. In the embodiment of the present disclosure, 128 channels of neural signal sampling are achieved.

[0056] It should be noted that:

[0057] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present disclosure can be practiced without these specific details. In some instances, well-known structures and technologies are not shown in detail so as not to obscure the understanding of this description.

[0058] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of the exemplary embodiments of the present disclosure, the various features of the present disclosure are sometimes grouped together into a single embodiment, figure, or description thereof. However, the disclosed method should not be interpreted as reflecting the following schematic diagram: the claimed disclosure requires more features than the features explicitly recited in each claim. More specifically, as reflected in the claims below, the inventive aspects lie in less than all the features of the single embodiment disclosed above. Therefore, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, with each claim itself serving as a separate embodiment of the present disclosure.

[0059] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of this disclosure and form different embodiments. For example, in the claims below, any one of the claimed embodiments may be used in any combination.

[0060] The above is only a preferred specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present disclosure should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A transmitter for medical applications, characterized in that Including analog front end, digital baseband processing module, modulator, phase-locked divider, power amplifier, An analog front end for receiving analog signals from neural electrodes; A digital baseband processing module, used for digitizing and channel encoding the analog signal to obtain a coded signal; A modulator, used for performing 16-QAM modulation on the coded signal to obtain a modulated signal; A phase-locked frequency divider is used to generate a plurality of target frequency signals and divide the target frequency signals into a plurality of target sub-frequency signals; and adjust the phase of the modulation signal based on the plurality of 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 the transmitting unit so that the transmitting unit transmits the signal.

2. The transmitter according to claim 1, characterized in that The transmitter further includes: a frequency shaping filter, configured to perform spectrum shaping on 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 coded signal to symbols on a 16-QAM constellation diagram.

5. A receiver for medical applications, characterized in that Including analog-to-digital converter, digital baseband processing module, 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; 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 further includes: a gain control module, which is used to adjust the gain of the decoded signal.

7. The receiver according to claim 5, characterized in that The receiver further comprises: a frequency shaping filter, configured to perform spectrum 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 the impedance matching between the antenna and the receiver.

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