Bioelectrical impedance tomography system and data acquisition method thereof

Abstract

The present invention discloses a bioelectrical impedance tomography system and its data acquisition method. The bioelectrical impedance tomography system includes a bioelectrical impedance tomography device and a host computer. The bioelectrical impedance tomography device includes: a data acquisition module; a PCIe module, which sends an interrupt instruction to the host computer to notify the host computer of the completion of data acquisition after waveform data acquisition and processing; a data integration module, which is used to cache the waveform data acquired in real time and, after arranging and reorganizing multiple segments of waveform data according to preset rules, store them in the memory of the PCIe module through direct memory access technology; a data preprocessing module, which calculates the real and imaginary parts of the waveform data through direct memory access technology and writes the real and imaginary parts of the waveform data into the memory of the PCIe module; and a host computer, which enables multi-channel direct memory access technology to read the processed waveform data. The present invention improves the real-time performance of the bioelectrical impedance tomography system.

Description

Technical Field

[0001] The present invention relates to the technical field of bioelectrical impedance tomography, and in particular to a bioelectrical impedance tomography system and a data acquisition method thereof. Background Art

[0002] Electrical Impedance Tomography (EIT) is a type of non-invasive medical imaging. Its basic principle is to apply a safe excitation current (voltage) signal to the surface of the target tissue being measured, while simultaneously measuring the voltage (current) signal on the target tissue surface. An image reconstruction algorithm is then used to obtain the impedance (or impedance change) image distribution within the measured tissue.

[0003] Due to its imaging algorithm, the EIT system has a long data sampling time. Consequently, it needs to buffer a large amount of data. If the buffered data is transmitted in bursts and the transmission bandwidth is insufficient, the transmission time will be very long, directly affecting the overall imaging speed of the EIT equipment and, in turn, the user experience.

[0004] Existing transmission interfaces, such as Gigabit network interfaces, do not meet transmission bandwidth requirements. While 10GbE network interfaces do meet bandwidth requirements, Arm-side chips supporting 10GbE networks are expensive, have limited models, and offer limited protocol flexibility. To address this technical issue, PCIe hard cores and DMA technologies have emerged.

[0005] PCIe (PCI Express) is a third-generation, high-performance I / O bus with advantages such as high speed, point-to-point serial transmission, exclusive bandwidth for devices at both ends, and flexible and convenient expansion. PCIe DMA data transmission technology effectively reduces processor resource usage by providing direct memory access to data, significantly improving system efficiency.

[0006] Direct Memory Access (DMA) is a memory access technology in computer science. It allows certain hardware subsystems within a computer to independently read and write to system memory without the intervention of the central processing unit (CPU). DMA is a fast data transfer method with the same processor load.

[0007] Taking the prior art with publication number CN111090221B as an example, this prior art discloses a PCIe DMA data transmission system and its transmission method for use in a direct-write lithography system. The transmission system includes a host computer, a PCIe hard core, an engine control module, a register read / write module, a C2H asynchronous buffer module, an H2C asynchronous buffer module, and a user interface module; the host computer and the PCIe hard core are interactively connected; and the PCIe hard core and the engine control module are interactively connected. The engine control module includes a register module, an interrupt module, an SGDMA engine, an SGDMA read buffer pool, and an SGDMA write buffer pool. The user interface module includes a USER register, a TX data transmission interface, an RX data reception interface, a dynamic synchronous memory DDR4, and an exposure processing module. Although this prior art applies PCIe-DMA technology, the technical solution is specifically implemented on the SGDMA engine, which results in a limited scope of application of the technical solution and cannot be applied to EIT systems.

[0008] Therefore, how to provide a bioelectrical impedance tomography system that can improve the stability and transmission bandwidth of the EIT system while reducing the CPU processing burden is a technical problem that needs to be solved urgently in the industry. Summary of the Invention

[0009] In order to solve the technical problems of insufficient stability and low transmission bandwidth of the EIT system in the prior art, the present invention proposes a bioelectrical impedance tomography system and a data acquisition method thereof.

[0010] The bioelectrical impedance tomography system proposed in the present invention includes a bioelectrical impedance tomography device and a host computer. The bioelectrical impedance tomography device includes:

[0011] A data acquisition module receives an acquisition command from the host computer and acquires real-time waveform data;

[0012] After waveform data acquisition and processing is completed, the PCIe module sends an interrupt command to the host computer to notify the completion of data acquisition;

[0013] The data integration module is used to cache the waveform data collected in real time, and after arranging and reorganizing multiple segments of waveform data according to preset rules, store them in the memory of the PCIe module through direct memory access technology; in a specific embodiment, the memory of the PCIe module is specifically DDR3.

[0014] a data preprocessing module that checks and performs fast Fourier transform processing on the waveform data in the memory of the PCIe module through direct memory access technology, calculates the real part and imaginary part of the waveform data, and writes the real part and imaginary part of the waveform data into the memory of the PCIe module through direct memory access technology;

[0015] The host computer enables multiple channels to read the waveform data in the memory of the PCIe module through direct memory access technology.

[0016] Furthermore, the bioelectrical impedance tomography device also includes a register read and write module; the storage space of the PCIe module is divided into a data storage part and a control storage part, and the register read and write module updates the value stored in the control storage part of the PCIe module through direct memory access technology to control other modules to respond.

[0017] Furthermore, the PCIe module includes a User interface for communicating with a host computer through a preset communication protocol; the control command of the host computer is transmitted to the register read-write module through the User interface to update the value of the control storage part of the PCIe module; or after each module of the bioelectrical impedance tomography device executes the corresponding control command, the value of the corresponding control storage part is updated and transmitted to the host computer through the User interface to feedback the response result of the corresponding module executing the corresponding control command.

[0018] Furthermore, the register read / write module modifies the value of the corresponding register for storing the acquisition command in the control storage part through direct memory access technology to trigger the data acquisition module to start acquiring real-time waveform data or stop acquiring real-time waveform data.

[0019] Furthermore, the register read-write module modifies the value of the corresponding register in the control storage part for storing waveform data acquisition rounds through direct memory access technology, and triggers the PCIe module to send an interrupt instruction to the host computer when the value of the corresponding register reaches a preset maximum acquisition round.

[0020] Furthermore, the PCIe module includes an interrupt request unit, and the interrupt instruction is sent through the interrupt request unit.

[0021] Furthermore, the data integration module arranges and reorganizes multiple segments of waveform data according to preset rules, including: arranging each segment of waveform data in the order of acquisition, and cutting off the data before the Nth zero crossing of the sine wave of each segment of waveform data, and splicing and reorganizing the data after the Nth zero crossing of the sine wave of each segment of waveform data in the order of arrangement.

[0022] Furthermore, after the amount of the arranged and reorganized waveform data reaches a preset amount, the data integration module stores the arranged and reorganized waveform data into the PCIe module.

[0023] Furthermore, the data preprocessing module checks the waveform data stored in the PCIe module to verify the integrity of the waveform data.

[0024] The above technical solution includes a data acquisition method applied to a bioelectrical impedance tomography system having a register read / write module, including:

[0025] The host computer accesses the register read-write module through the PCIe module to send an acquisition command to control the data acquisition module to start running, and the data acquisition module outputs the waveform data measured in real time;

[0026] Cache multiple waveform data segments into the data integration module, which arranges and reorganizes the multiple waveform data segments according to preset rules, waiting to be stored in the data storage part of the PCIe module;

[0027] When the reorganized waveform data reaches a preset data amount and the data storage portion of the PCIe module allows writing, the reorganized waveform data is stored in the data storage portion of the PCIe module;

[0028] The data preprocessing module performs a data integrity check on the stored waveform data, performs a fast Fourier transform after the check is completed, calculates the real part and the imaginary part of the waveform data, and writes the real part and the imaginary part of the waveform data to the data storage part of the PCIe module when the data storage part of the PCIe module allows writing;

[0029] The PCIe module determines whether the data collection round has reached the preset maximum collection round. If so, it sends an interrupt command to the host computer to notify the host computer that the waveform data collection has been completed;

[0030] The host computer enables multiple channels to obtain data from the data storage part of the PCIe module in parallel.

[0031] The present invention improves the bandwidth of waveform data processed in the PCIe module to the host computer through PCIe modules and direct memory access technology. At the same time, the present invention also ensures the coordinated operation between the host computer and the various modules of the bioelectrical impedance tomography device through direct memory access technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention is described in detail below with reference to the embodiments and accompanying drawings, in which:

[0033] Figure 1 It is a structural block diagram of an embodiment of the present invention.

[0034] Figure 2 This is a collection flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] Thus, a feature indicated in this specification is intended to illustrate one of the features of one embodiment of the present invention, rather than to imply that every embodiment of the present invention must have the described feature. In addition, it should be noted that this specification describes many features. Although certain features can be combined together to illustrate possible system designs, these features can also be used in other, not explicitly described, combinations. Thus, unless otherwise noted, the described combinations are not intended to be limiting.

[0037] The technical solution of the present invention is mainly used in EIT products. The monitor needs to wear an electrode belt with electrodes. By applying a safe excitation current (voltage) signal on the surface of the target tissue to be measured, the voltage (current) signal on the surface of the target tissue is measured at the same time, and the electrical impedance information carried by the corresponding position is analyzed and calculated, and this is used as the basis for bioelectrical impedance imaging.

[0038] like Figure 1 As shown, the present invention proposes a bioelectrical impedance tomography system, which includes a bioelectrical impedance tomography device and a host computer. The bioelectrical impedance tomography device is used to collect real-time waveform data and transmit it to the host computer through a PCI interface.

[0039] In one embodiment, the bioelectrical impedance tomography device of the present invention includes a data acquisition module, a PCIe module, a data integration module, and a data preprocessing module.

[0040] The data acquisition module acquires real-time waveform data when the bioelectrical impedance tomography device receives an acquisition command from the host computer.

[0041] After waveform data acquisition and processing are completed, the PCIe module sends an interrupt command to the host computer to notify the completion of data acquisition.

[0042] The data integration module is used to cache waveform data collected in real time, and after arranging and reorganizing multiple segments of waveform data according to preset rules, it is stored in the memory of the PCIe module through direct memory access technology. In one embodiment, the data integration module arranges each segment of waveform data in the order of acquisition, removes the data before the Nth zero crossing of the sine wave of each segment of waveform data, and splices and reorganizes the data after the Nth zero crossing of the sine wave of each segment of waveform data according to the arrangement order. For example, based on empirical values, the data integration module removes the data before the third zero crossing of the sine wave of each segment of waveform data, and only retains the data after the third zero crossing of the sine wave, thereby avoiding errors or influences caused by unstable signals in the early stage of the waveform data acquisition process, and obtaining stable waveform data.

[0043] The data preprocessing module uses direct memory access technology to inspect and perform fast Fourier transform (FFT) processing on the waveform data in the PCIe module's memory, calculating the real and imaginary parts of the waveform data. These data are then written to the PCIe module's memory using direct memory access technology. This allows the bioelectrical impedance tomography device to collect real-time waveform data while also performing corresponding special processing on the waveform data. Fourier analysis converts a signal from the time domain to the frequency domain, or vice versa. The FFT quickly calculates this transformation by decomposing the DFT matrix into the product of sparse (mostly zero) factors. Using the FFT, we can convert the time domain waveform to the frequency domain for analysis. In one embodiment, the data integration module stores the reorganized waveform data in the PCIe module after the amount of reorganized waveform data reaches a preset amount, thereby avoiding excessively frequent accesses to the PCIe module's memory. The data preprocessing module herein checks the waveform data stored in the PCIe module, specifically verifying the integrity of the waveform data, for example, using a CRC check.

[0044] After waveform data acquisition and processing is complete, the host computer receives an interrupt command and uses multiple channels to concurrently read waveform data from the PCIe module's memory. The C2H (Card to Host) channel between the host computer and the PCIe module handles DMA transfers from the card to the host. The H2C (Host to Card) channel handles DMA transfers from the host to the card.

[0045] The above technical solution implements multi-channel data transmission between the host computer and the bioelectrical impedance tomography device via PCIe, which provides better transmission bandwidth between the host computer and the bioelectrical impedance tomography device and improves the real-time performance of the waveform data received by the host computer. At the same time, the above technical solution implements rapid response of data acquisition within the bioelectrical impedance tomography device through direct memory access technology (DMA technology), further improving the real-time performance of waveform data acquisition. At the same time, the above technical solution implements special processing of the collected data within the bioelectrical impedance tomography device through direct memory access technology (DMA technology), which not only improves real-time performance but also reduces the burden on the host computer's CPU.

[0046] In a further embodiment, the bioelectrical impedance tomography device further includes a register reading and writing module.

[0047] The PCIe module's storage space is divided into a data storage section and a control storage section. The data storage section is used to store waveform data and its real and imaginary parts. The control storage section is used to store control logic. The register read / write module uses direct memory access technology to update the values ​​stored in the PCIe module's control storage section to control the responses of other modules. In other words, by changing the corresponding register values ​​to change the corresponding control logic, and then adding direct memory access technology, the bioelectrical impedance tomography device no longer needs to include additional control components such as a CPU, and can control each module within the bioelectrical impedance tomography device or trigger corresponding responses.

[0048] In one embodiment, the PCIe module includes a user interface for communicating with a host computer via a preset communication protocol. The preset communication protocol is mainly a communication protocol for control commands to implement control commands and corresponding interactions between the host computer and the PCIe module.

[0049] Control commands from the host computer are transmitted to the register read / write module via the user interface, thereby updating the values ​​in the control storage section of the PCIe module, that is, updating the values ​​in the corresponding registers. Alternatively, after each module of the bioelectrical impedance tomography device executes a corresponding control command, it updates the values ​​in the corresponding control storage section and transmits the updated values ​​to the host computer via the user interface to provide feedback on the corresponding module's response to the control command. In other words, the response results of each module of the bioelectrical impedance tomography device executing the corresponding control command are also achieved by updating the values ​​in the corresponding control storage section.

[0050] In a specific application embodiment, the register read / write module modifies the value of the corresponding register for storing the acquisition command in the control storage part through direct memory access technology to trigger the data acquisition module to start or stop acquiring real-time waveform data.

[0051] In another specific application embodiment, the register read-write module modifies the value of the corresponding register in the control storage part for storing the waveform data acquisition round through direct memory access technology. When the value of the corresponding register reaches the preset maximum acquisition round, it will automatically trigger the PCIe module to send an interrupt instruction to the host computer to notify the host computer that the waveform data acquisition of this round is completed, so that the host computer can obtain data from the PCIe module through multiple channels as soon as possible.

[0052] Specifically, the PCIe module includes an interrupt request unit (IRQ), and an interrupt instruction is sent through the interrupt request unit.

[0053] In addition, the PCIe module also includes a data dynamic access arbitration module, which is used to manage the collaborative relationship between the data acquisition module and the data storage part of the PCIe module's memory. When the data dynamic access arbitration module determines that the data storage part of the PCIe module is idle, the data storage part of the PCIe module is allowed to be written.

[0054] The above embodiments may also be combined into a preferred embodiment, which also falls within the protection scope of the present invention.

[0055] In the above embodiment, when the embodiment includes a register reading and writing module, the data acquisition method of the bioelectrical impedance tomography system of the present invention includes the following steps.

[0056] like Figure 2 As shown, the host computer first accesses the register read-write module through the PCIe module to send an acquisition command. In one embodiment, the register read-write module is accessed through the User interface of the PCIe module, thereby modifying the value stored in the corresponding register in the memory of the PCIe module to trigger the data acquisition module to start running. At the same time, the data acquisition module outputs real-time measured waveform data. For example, when the value stored in the corresponding register in the memory of the PCIe module is modified to the value corresponding to the start of acquisition, a corresponding high-level or low-level signal can be generated, thereby triggering the data acquisition module to start acquiring real-time waveform data.

[0057] Then, multiple segments of waveform data are cached in the data integration module one after another. The data integration module arranges and reorganizes the multiple segments of waveform data according to preset rules, waiting to be stored in the data storage part of the PCIe module.

[0058] To improve efficiency, the data integration module stores the reorganized waveform data in the PCIe module's data storage only after the reorganized waveform data reaches the specified data volume. Therefore, when the reorganized waveform data reaches the preset data volume and the PCIe module's data storage allows writing, the reorganized waveform data is stored in the PCIe module's data storage.

[0059] The data preprocessing module performs a data integrity check on the stored waveform data, performs fast Fourier transform processing after the check is completed, calculates the real and imaginary parts of the waveform data, and writes the real and imaginary parts of the waveform data to the data storage part of the PCIe module when the data storage part of the PCIe module allows writing.

[0060] The PCIe module determines whether the data acquisition round has reached the preset maximum acquisition round. If so, it sends an interrupt command to the host computer to notify the host computer that the waveform data acquisition has been completed. The host computer can enable multi-channel parallel acquisition of data from the data storage part of the PCIe module. The current round of acquisition task is completed and waits for the next host computer to initiate a new acquisition command again, and then repeat the above steps.

[0061] During the execution of the current round of acquisition tasks, when the reorganized waveform data is first stored in the data storage section of the PCIe module, the data storage section of the PCIe module is in an idle state and therefore allows writing. After the first set of reorganized waveform data is stored in the PCIe module, the waveform data is processed accordingly, so the PCIe memory is busy at this time. If the waveform data to be stored in the data storage section of the PCIe module for the second time is already prepared, since the data storage section of the PCIe module is busy at this time, the waveform data to be stored in the data storage section of the PCIe module for the second time will need to wait until the data dynamic storage arbitration module determines that the data storage section of the PCIe module is idle, and only then will the waveform data to be stored in the data storage section of the PCIe module for the second time be allowed to be stored in the PCIe module. This is the same for the third and mth waveform data, until the last waveform data acquisition and transmission is completed.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A bioelectrical impedance tomography system, comprising a bioelectrical impedance tomography device and a host computer, characterized in that: The bioelectrical impedance tomography device comprises: A data acquisition module receives an acquisition command from the host computer and acquires real-time waveform data; The PCIe module sends an interrupt command to the host computer after waveform data acquisition and processing is completed to notify the host computer of the completion of data acquisition; the data integration module is used to cache the waveform data acquired in real time, and after arranging and reorganizing multiple segments of waveform data according to preset rules, store them in the memory of the PCIe module through direct memory access technology; the storage space of the PCIe module is divided into a data storage part and a control storage part; a data preprocessing module that checks and performs fast Fourier transform processing on the waveform data in the memory of the PCIe module through direct memory access technology, calculates the real part and imaginary part of the waveform data, and writes the real part and imaginary part of the waveform data into the memory of the PCIe module through direct memory access technology; The host computer enables multiple channels to read the waveform data in the memory of the PCIe module through direct memory access technology; A register read / write module, which updates the value stored in the control storage part of the PCIe module through direct memory access technology to control other modules to respond; the register read / write module modifies the value of the corresponding register in the control storage part for storing acquisition commands through direct memory access technology to trigger the data acquisition module to start or stop acquiring real-time waveform data; the register read / write module modifies the value of the corresponding register in the control storage part for storing waveform data acquisition rounds through direct memory access technology, and when the value of the corresponding register reaches a preset maximum acquisition round, triggers the PCIe module to send an interrupt instruction to the host computer.

2. The bioelectrical impedance tomography system according to claim 1, wherein: The PCIe module includes a User interface for communicating with the host computer via a preset communication protocol; The control command of the host computer is transmitted to the register read-write module through the User interface to update the value of the control storage part of the PCIe module; Alternatively, after each module of the bioelectrical impedance tomography device executes the corresponding control command, the value of the corresponding control storage part is updated and transmitted to the host computer through the User interface to feedback the response result of the corresponding module executing the corresponding control command.

3. The bioelectrical impedance tomography system according to claim 1, wherein: The PCIe module includes an interrupt request unit, and the interrupt instruction is sent through the interrupt request unit.

4. The bioelectrical impedance tomography system according to claim 1, wherein: The data integration module arranges and reorganizes multiple segments of waveform data according to preset rules, including: arranging each segment of waveform data in the order of acquisition, and cutting off the data before the Nth zero crossing of the sine wave of each segment of waveform data, and splicing and reorganizing the data after the Nth zero crossing of the sine wave of each segment of waveform data in the order of arrangement.

5. The bioelectrical impedance tomography system according to claim 1, wherein: After the amount of the reorganized waveform data reaches a preset amount, the data integration module stores the reorganized waveform data into the PCIe module.

6. The bioelectrical impedance tomography system according to claim 1, wherein: The data preprocessing module checks the waveform data stored in the PCIe module to verify the integrity of the waveform data.

7. A data acquisition method for a bioelectrical impedance tomography system according to any one of claims 1 to 6, characterized in that: include: The host computer accesses the register read-write module through the PCIe module to send an acquisition command to control the data acquisition module to start running, and the data acquisition module outputs the waveform data measured in real time; Cache multiple waveform data segments into the data integration module, which arranges and reorganizes the multiple waveform data segments according to preset rules, waiting to be stored in the data storage part of the PCIe module; When the reorganized waveform data reaches a preset data amount and the data storage portion of the PCIe module allows writing, the reorganized waveform data is stored in the data storage portion of the PCIe module; The data preprocessing module performs a data integrity check on the stored waveform data, performs a fast Fourier transform after the check is completed, calculates the real part and the imaginary part of the waveform data, and writes the real part and the imaginary part of the waveform data to the data storage part of the PCIe module when the data storage part of the PCIe module allows writing; The PCIe module determines whether the data collection round has reached the preset maximum collection round. If so, it sends an interrupt command to the host computer to notify the host computer that the waveform data collection has been completed; The host computer enables multiple channels to obtain data from the data storage part of the PCIe module in parallel.

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