A high-precision, sports-type, non-invasive portable cardiopulmonary function parameter measurement device

Abstract

The present invention belongs to the technical field of cardiopulmonary function detection, and specifically relates to a high-precision, sports-type, non-invasive portable cardiopulmonary function parameter measurement device, comprising a host computer and a slave computer, the slave computer comprising an electrocardiogram detection module, a chest impedance detection module, a microcontroller and a wireless communication module, the chest impedance detection module comprising a signal generator, a filter, a constant current source, an instrument amplifier, a common-mode filter, a detection circuit, a high-pass filter, a high-precision signal amplifier, a differential circuit and a voltage raising module; the slave computer also comprises an acceleration sensor, and the device ensures that electrocardiogram signals and chest impedance signals can be accurately detected even in a motion state, greatly reduces noise interference caused by motion, improves the recognition of data feature points by the host computer algorithm, makes the detection data more accurate, and fills the gap in the domestic non-invasive cardiopulmonary related equipment for exercise cardiopulmonary function.

Description

Technical Field

[0001] The present invention belongs to the technical field of cardiopulmonary function detection, and in particular relates to a high-precision, sports-type, non-invasive, portable cardiopulmonary function parameter measuring device. Background Art

[0002] Cardiopulmonary function parameters have been used clinically for many years. By monitoring these parameters, we can obtain valuable patient information, such as heart rate (HR), transthoracic fluid volume (TFC), velocity index (VI), stroke volume (SV), cardiac output (CO), and more. These parameters are of great clinical significance for both medical treatment and scientific research. With the advancement of biomedical engineering and clinical medicine, various methods for measuring cardiopulmonary function parameters have emerged, such as floating catheter technology using thermodilution and continuous cardiac output measurement with pulse indicators. However, these techniques require invasive data monitoring, which not only requires high technical skills from medical staff, but is also expensive and physically harmful to the patient. Therefore, invasive testing techniques have significant limitations. Meanwhile, non-invasive testing methods have gradually matured. They do not cause physiological harm to patients and are relatively inexpensive. Among them, ICG parameters measured by impedance cardiography have significant clinical significance. Not only are their accuracy, reproducibility, and sensitivity comparable to invasive techniques, but more importantly, impedance cardiography can be used in many specialized situations, particularly for mild to critically ill patients and those undergoing exercise. However, while a few non-invasive testing devices are currently available in China that can be used for mild to critically ill patients, none of them can measure cardiopulmonary function parameters during exercise, particularly for postoperative exercise rehabilitation testing of heart patients and continuous cardiopulmonary function testing of athletes. This product perfectly addresses these issues. Therefore, it is necessary to conduct further in-depth research on running cardiopulmonary function testing equipment to improve its detection accuracy and realize the widespread application of exercise cardiopulmonary function testing equipment. Summary of the Invention

[0003] Existing technologies are difficult to meet people's needs. In order to solve the above-mentioned problems, the present invention proposes a high-precision, sports-type, non-invasive portable cardiopulmonary function parameter measurement device, which integrates a large number of high-precision, low-power chips into a very small circuit board. It can accurately measure various current cardiopulmonary parameters of the human body, while increasing the portability of the device and greatly increasing the usage time of the device.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A high-precision, sports-type, non-invasive portable cardiopulmonary function parameter measurement device, including a host computer and a slave computer, including the host computer and the slave computer, the slave computer including an electrocardiogram detection module, a chest impedance detection module, a microcontroller and a wireless communication module, the chest impedance detection module including a signal generator, a filter, a constant current source, an instrument amplifier, a common-mode filter, a detection circuit, a high-pass filter, a high-precision signal amplifier, a differential circuit and a voltage boost module;

[0006] The lower computer also includes a motion state monitoring module, and the motion state monitoring module includes an acceleration sensor.

[0007] Compared with the prior art, the present invention has the following beneficial effects:

[0008] This device utilizes a high-precision current source, precision amplification circuitry, and an impedance calibration system to minimize impedance detection errors. It also prioritizes signal optimization during exercise. When the human body is in motion, the signal features are clearly visible, significantly enhancing the host computer's ability to reproduce exercise cardiopulmonary signals. The entire device boasts ultra-low power consumption, with the lithium battery providing sufficient operating power for the entire system, resulting in a battery life of up to five days.

[0009] The acceleration detection module can monitor the human body's motion status. The high-noise motion ECG signal detected by the ECG detection module is compensated by the accelerometer to stabilize it within a certain range. The motion ECG data is then used to calibrate the motion impedance data to achieve higher-precision motion analysis.

[0010] This device utilizes advanced, high-precision, low-noise exercise cardiopulmonary measurement circuitry, ensuring accurate detection of ECG and thoracic impedance signals even during exercise. This significantly reduces noise interference caused by exercise and enhances the host computer algorithm's ability to identify data feature points, resulting in higher accuracy. This device addresses the current lack of noninvasive cardiopulmonary equipment for exercise cardiopulmonary function in China and has significant clinical and scientific significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 An overall schematic diagram provided for the present invention;

[0012] Figure 2 A schematic diagram of the principle block diagram provided by the present invention;

[0013] Explanation of the numbers in the figure: 1-signal generator, 2-filter, 3-constant current source, 4-instrumentation amplifier, 5-common mode filter, 6-detection circuit, 7-high-pass filter, 8-high-precision signal amplification circuit, 9-differentiation circuit, 10-voltage boost module, 11-acceleration sensor, 12-ECG sensor, 13-power frequency filter, 14-microcontroller, 15-Bluetooth module, 16-host computer, 17-slave computer. DETAILED DESCRIPTION

[0014] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below with reference to specific illustrations.

[0015] It should be noted that, in the present invention, when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0017] Example 1

[0018] See also Figure 1-2A high-precision, sports-type, non-invasive portable cardiopulmonary function parameter measurement device includes a host computer 16 and a slave computer 17, including a host computer 16 and a slave computer 17, the slave computer 17 includes an electrocardiogram detection module, a chest impedance detection module, a microcontroller 14 and a wireless communication module, the chest impedance detection module includes a signal generator 1, a filter 2, a constant current source 3, an instrument amplifier 4, a common mode filter 5, a detection circuit 6, a high-pass filter 7, a high-precision signal amplifier 8, a differential circuit 9 and a voltage raising module 10, the microcontroller 14 controls the signal generator 1 to generate a sine wave, the sine wave passes through the filter 2 and is input to the constant current source 3, and the sine wave constant current excitation signal is applied to the human body by driving the shielded lead wire, the instrument amplifier 4 detects the signal changes on the human body, and the instrument The meter amplifier 4 converts it into a single-ended signal, and the common-mode filter 5 filters out the ECG interference signal from the single-ended signal, leaving a pure ICG signal that enters the detection circuit 6. The signal output by the detection circuit 6 is the basic impedance Z0 of the human body, and is output to the microcontroller 14. After the signal output by the detection circuit 6 passes through the high-pass filter 7 and the high-precision signal amplifier 8 in sequence, the signal output by the high-precision signal amplifier 8 is an impedance change signal △Z, and the high-precision signal amplifier 8 outputs the impedance change signal △Z to the microcontroller 14. The impedance change signal △Z then passes through the differential circuit 9 and the voltage raising module 10 in sequence. The output signal of the voltage raising module 10 is an impedance differential signal dz, and the voltage raising module 10 outputs the impedance differential signal dz to the microcontroller 14;

[0019] The lower computer 17 further includes a motion state monitoring module, and the motion state monitoring module includes an acceleration sensor 11 .

[0020] A chest impedance measurement circuit uses a new type of DDS chip as a signal generator to emit a high-frequency sine wave signal. After passing through a filtering circuit and a constant current source circuit, the signal is applied to the body part to be measured. The signal is then sampled by an instrument amplifier, detected, amplified, and filtered before being sent to a microcontroller. The microcontroller performs a simple calculation on the calibration value of a precision resistor to obtain a real-time impedance change value.

[0021] This ECG detection circuit, with motion artifact cancellation, is used to detect ECG signals during patient movement. It incorporates a built-in two-pole low-pass filter with a cutoff frequency of 37Hz and a two-pole high-pass filter with a cutoff frequency of 0.3Hz. The total signal gain within the passband is 400. This circuit fully conditions the weak ECG signals collected from the human body before feeding them into the microcontroller module.

[0022] A motion state monitoring circuit can further reduce the noise generated by the patient's motion by monitoring the accelerometer signal; at the same time, the microcontroller can use the currently monitored motion information to determine the patient's current motion state and make corresponding mode changes.

[0023] Furthermore, the lower computer is also provided with an LED display module, which includes a red LED, a green LED, a blue LED, a white LED and a yellow LED. The red LED represents the charging status, the green LED represents the battery full status, the blue LED represents the heart beating status, the white LED represents that the system is running, and the yellow LED represents what mode the system is currently in.

[0024] Furthermore, the ECG detection circuit detects ECG signals on the human body through the three-lead ECG wire. The ECG signals fully conditioned by the ECG detection circuit flow to the microcontroller 14 after passing through the power frequency filter circuit 13 .

[0025] Furthermore, the chest impedance detection module detects uV-level human electrical signals from the human body, and after passing through the instrument amplifier circuit and the high-precision signal amplification circuit, its amplitude is increased to V level. The microcontroller collects this signal and sends it to the host computer for analysis.

[0026] Furthermore, a buzzer is provided in the lower computer 17 , and the buzzer is electrically connected to the microcontroller 14 .

[0027] When the battery is too low or an abnormal human condition is detected, the buzzer will sound an alarm.

[0028] Furthermore, the wireless communication module adopts a Bluetooth module 15 for transmission, and a data storage module is also provided in the wireless communication module, and the data storage module is connected to the microcontroller 14 .

[0029] When there is no matching Bluetooth signal, the MCU will store the detected data in the data storage module. After the Bluetooth communication is restored, the saved data will be uploaded to the host computer to achieve the effect of uninterrupted detection.

[0030] Furthermore, the amplification factor of the instrument amplifier circuit is adjustable within the range of 1, 2, 5, and 10. The microcontroller can automatically adjust the amplification factor according to the current motion impedance signal to ensure that the signal is not cut off due to being too large.

[0031] Furthermore, the signal generator model is AD9833, the filter model is AD8626, the constant current source model is AD8625, the instrument amplifier model is AD8250, the common mode filter model is AD8627, the high pass filter model is AD8625, the high precision signal amplification circuit model is AD620, the differential circuit model is AD8625, the acceleration sensor model is MPU6050, the electrocardiogram sensor model is AD8232, the microcontroller model is STM32,

[0032] Note that AD8625, AD8626, and AD8627 are the same type of op amps, namely AD8250 op amp, AD8626 op amp, and AD9833 op amp.

[0033] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-precision, sports-type, non-invasive, portable cardiopulmonary function parameter measurement device, comprising a host computer and a slave computer, characterized in that: The lower computer includes an electrocardiogram detection module, a chest impedance detection module, a microcontroller, and a wireless communication module. The chest impedance detection module includes a signal generator, a filter, a high-precision constant current source, an instrument amplifier, a common-mode filter, a detection circuit, a high-pass filter, a high-precision signal amplifier, a differential circuit, and a voltage boost module. The lower computer also includes a motion state monitoring module, which includes an acceleration sensor. The acceleration sensor signal is connected to the microcontroller; The motion state monitoring circuit monitors the accelerometer signal to further reduce the noise generated by the patient's motion. At the same time, the microcontroller can use the currently monitored motion information to determine the patient's current motion state and make corresponding mode changes. The microcontroller controls the signal generator to generate a sine wave, which is input into a high-precision constant current source after passing through a filter, and the sine wave constant current excitation signal is applied to the human body by driving a shielded lead wire. The instrument amplifier detects the signal changing on the human body, and the instrument amplifier converts it into a single-ended signal. The common-mode filter filters out the electrocardiogram interference signal from the single-ended signal, and the remaining pure ICG signal enters the detection circuit. The signal output by the detection circuit is the basic impedance Z0 of the human body and is output to the microcontroller. After the signal output by the detection circuit passes through a high-pass filter and a high-precision signal amplifier in sequence, the signal output by the high-precision signal amplifier is an impedance change signal △Z. The high-precision signal amplifier outputs the impedance change signal △Z to the microcontroller. The impedance change signal △Z then passes through a differential circuit and a voltage raising module in sequence. The output signal of the voltage raising module is an impedance differential signal dz, and the voltage raising module outputs the impedance differential signal dz to the microcontroller. The common-mode filter can switch the signal output channel. A precision resistor is provided in the common-mode filter, and the common-mode filter outputs the signal to the precision resistor. The microcontroller collects the signal after passing through the precision resistor, and the microcontroller calibrates the current impedance data. The ECG detection module and the chest impedance detection module collect weak signals of the human body's ECG and chest impedance, and transmit them to the microcontroller for processing. The wireless communication module sends the signals processed by the microcontroller to the host computer for reception. The software in the host computer performs real-time analysis and calculation of the data and signal filtering, synchronously displays the waveforms of the ECG, cardiac impedance, and impedance differential, and uses an algorithm to extract the characteristic points of the waveforms to calculate cardiac output (CO), stroke volume (SV), and cardiac function index (CI).

2. The high-precision, sports-type, non-invasive, portable cardiopulmonary function parameter measurement device according to claim 1 is characterized by: The wireless communication module adopts Bluetooth transmission, and a data storage module is also provided in the wireless communication module, and the data storage module is connected to the microcontroller.

3. The high-precision, sports-type, non-invasive, portable cardiopulmonary function parameter measurement device according to claim 1 is characterized by: The amplification factor of the instrument amplifier circuit is adjustable within the range of 1, 2, 5, and 10. The microcontroller can automatically adjust the amplification factor according to the current motion impedance signal.

4. The high-precision, sports-type, non-invasive, portable cardiopulmonary function parameter measurement device according to claim 1 is characterized by: The lower computer is also provided with an LED display module, which includes a red LED, a green LED, a blue LED, a white LED and a yellow LED. The red LED represents the charging status, the green LED represents the battery full status, the blue LED represents the heart beating status, the white LED represents that the system is running, and the yellow LED represents what mode the system is currently in.

5. The high-precision, sports-type, non-invasive, portable cardiopulmonary function parameter measurement device according to claim 1 is characterized by: The lower computer also includes a power supply module, which is powered by a lithium battery. The lithium battery is electrically connected to the microcontroller.

6. The high-precision, sports-type, non-invasive, portable cardiopulmonary function parameter measurement device according to claim 1 is characterized by: A buzzer is provided in the lower computer, and the buzzer is electrically connected to the microcontroller.

Images