A fingertip biological signal acquisition device, acquisition system and portable device

Abstract

The present application provides a fingertip biological signal acquisition device, an acquisition system and a portable device. The fingertip biological signal acquisition device includes a pulse wave sensor, an impedance measurement module and a control module. The impedance measurement module includes a first metal electrode and a second metal electrode that do not contact each other and are symmetric to each other. The pulse wave sensor is installed between the first metal electrode and the second metal electrode. The pulse wave sensor constructs a pulse wave detection area attached to the fingertip pulp, and the first metal electrode and the second metal electrode construct an impedance detection area surrounding the periphery of the pulse wave detection area. The control module is electrically connected to the pulse wave sensor and the impedance measurement module, and is used to send the electrical signals of the pulse wave sensor and / or the impedance measurement module to the outside. The fingertip biological signal acquisition device of the present application is small in size and easy to carry, and can complete the measurement of skin impedance and pulse wave with one finger, which is convenient to be integrated into other measurement devices.

Description

Technical Field

[0001] This application relates to the technical field of biological information collection, and in particular, to a fingertip biological signal collection device, a collection system, and a portable device. Background Art

[0002] Human body impedance and heart rate are two relatively common and important human biological signals. Human body impedance is usually measured by sending a tiny alternating current or voltage to the detection object through an electrode system placed on the body surface, detecting the corresponding impedance and its changes, and then obtaining relevant physiological and pathological information according to different application purposes. Human heart rate and heart rate variability are closely related to the human health status, can directly reflect or predict many diseases such as cardiovascular diseases, and are also related to the human fatigue state.

[0003] There are many devices and various methods for measuring human body impedance and heart rate. In the prior art, the measurement of human body impedance and heart rate is carried out separately, and different devices are required respectively. In particular, the measurement device for human body impedance is relatively large in size, which is not conducive to carrying and also not conducive to measuring at any time. In addition, limited by the size and measurement method of the human body impedance and heart rate measurement devices, they cannot be well integrated into other biological information collection systems.

[0004] Therefore, how to design a biological signal collection device that is easy to carry, easy to measure at any time, and easy to integrate into other measurement devices has become a relatively popular research point. Summary of the Invention

[0005] An object of an embodiment of this application is to provide a fingertip biological signal collection device, which is small in size, easy to carry, and can complete the measurement of skin impedance and pulse wave with one finger, and is easy to integrate into other measurement devices.

[0006] A second object of an embodiment of this application is further to provide a biological signal collection system using the above fingertip biological signal collection device.

[0007] A third object of an embodiment of this application is further to provide a portable device using the above fingertip biological signal collection device.

[0008] In a first aspect, a fingertip biological signal acquisition device is provided, which includes a pulse wave sensor, an impedance measurement module, and a control module. The impedance measurement module includes a first metal electrode and a second metal electrode that do not contact each other and are symmetric to each other. The pulse wave sensor is installed between the first metal electrode and the second metal electrode. The pulse wave sensor constructs a pulse wave detection area attached to the fingertip pulp, and the first metal electrode and the second metal electrode construct an impedance detection area surrounding the periphery of the pulse wave detection area. The control module is electrically connected to the pulse wave sensor and the impedance measurement module, and is used to send the electrical signals of the pulse wave sensor and / or the impedance measurement module to the outside world.

[0009] In an implementable solution, a gap is reserved between the first metal electrode and the second metal electrode, and the gap is greater than or equal to 1 mm.

[0010] In an implementable solution, notches are provided on the sides of the first metal electrode and the second metal electrode that are close to each other, and the notches on the first metal electrode and the second metal electrode form an opening larger than the outer shape of the pulse wave sensor.

[0011] In an implementable solution, the control module includes a wireless communication module, and the wireless communication module is used to send the electrical signals of the pulse wave sensor and the impedance measurement module to the outside world.

[0012] In an implementable solution, both the first metal electrode and the second metal electrode are arc-shaped metal sheets that are concave downward.

[0013] In an implementable solution, a support structure is further included. The support structure includes a base, a vertical plate, and springs. The vertical plate and the base enclose a first cavity, a second cavity, and a central cavity. The central cavity is located in the middle of the base. The first cavity and the second cavity are adjacent to the central cavity and are symmetrically distributed. A plurality of springs are respectively installed on the base in the first cavity and the second cavity; the back side of the first metal electrode is installed on the spring in the first cavity, the back side of the second metal electrode is installed on the spring in the second cavity, the height of the first metal electrode and the second metal electrode is greater than or equal to the height of the vertical plate, and the pulse wave sensor is installed in the central cavity.

[0014] In an implementable solution, the upper end of the vertical plate is an arc-shaped structure that is concave downward and is adapted to the outer shapes of the first metal electrode and the second metal electrode, both of which are arc-shaped metal sheets.

[0015] In an implementable solution, the wireless communication module is provided with a pluggable electronic plug, and an electronic jack adapted to the electronic plug is provided on one side of the base.

[0016] According to a second aspect of the present application, a biological signal acquisition system is further provided, which includes a host computer and the fingertip biological signal acquisition device in the above solution. The control module of the fingertip biological signal acquisition device is communicatively connected to the host computer.

[0017] According to the third aspect of the present application, a portable device is further provided, including the fingertip biological signal acquisition device in the above solution.

[0018] Compared with the prior art, the beneficial effects of the present application are as follows:

[0019] 1. In the technical solution of the present application, when measuring human impedance and pulse wave, the user presses the pulp of the finger onto the pulse wave sensor, and the two sides of the pulp will correspondingly press onto the first metal electrode and the second metal electrode. The control module controls the pulse wave sensor and the impedance measurement module to start measuring. After the measurement is completed, the control module sends the electrical signals of the pulse wave sensor and the impedance measurement module to the display device. It can be seen that when using the fingertip biological signal acquisition device of the present application to collect human impedance and pulse wave, or to collect any one of the parameters, only one finger is needed to complete the collection, simplifying the process, saving time, and improving the collection efficiency.

[0020] 2. The present application highly integrates the pulse wave sensor and the impedance measurement module, and its size is slightly larger than that of an adult's finger. Compared with the measurement devices in the prior art, the volume of the device is greatly reduced, which is convenient for carrying and is also conducive to being integrated into other measurement devices. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 It is a structural schematic diagram of a fingertip biological signal acquisition device shown according to an embodiment of the present application;

[0023] Figure 2 It is Figure 1 The block diagram of the composition of the fingertip biological signal acquisition device in

[0024] Figure 3 It is Figure 1 An overall structural schematic diagram of the fingertip biological signal acquisition device of

[0025] Figure 4 It is Figure 3 The side view of the fingertip biological signal acquisition device in

[0026] Figure 5 It is Figure 3 The top view of the fingertip biological signal acquisition device in

[0027] Figure 6 as the root Figure 3 Schematic diagram of the support structure of the fingertip biological signal acquisition device;

[0028] Figure 7 for use Figure 1 Graph of the change in skin impedance value measured by the fingertip biological signal acquisition device;

[0029] Figure 8 for use Figure 1 Pulse curve graph measured by the fingertip biological signal acquisition device;

[0030] Figure 9 for use Figure 1 Frequency domain analysis graph of heart rate variability measured by the fingertip biological signal acquisition device;

[0031] Figure 10 for use Figure 1 Time domain analysis graph of heart rate variability measured by the fingertip biological signal acquisition device;

[0032] Figure 11 for use Figure 1 Block diagram of a biological signal acquisition system measured by the fingertip biological signal acquisition device.

[0033] In the figure: 10, pulse wave sensor; 20, impedance measurement module; 21, first metal electrode; 22, second metal electrode; 23, gap; 24, notch; 30, control module; 31, wireless communication module; 40, support structure; 41, base; 42, vertical plate; 43, spring; 100, host computer. Specific implementation manners

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and illustrated herein can be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application claimed, but merely represents the selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0036] According to the first aspect of the present application, first, a fingertip biological signal acquisition device is provided. Refer to Figure 1 and 2, the fingertip biological signal acquisition device includes a pulse wave sensor 10, an impedance measurement module 20, and a control module 30. The impedance measurement module 20 includes a first metal electrode 21 and a second metal electrode 22 that do not touch each other and are symmetric to each other. The pulse wave sensor 10 is installed between the first metal electrode 21 and the second metal electrode 22. The pulse wave sensor 10 constructs a pulse wave detection area attached to the fingertip pulp, and the first metal electrode 21 and the second metal electrode 22 construct an impedance detection area surrounding the periphery of the pulse wave detection area. The control module 30 is electrically connected to the pulse wave sensor 10 and the impedance measurement module 20, and is used to send the electrical signals of the pulse wave sensor 10 and / or the impedance measurement module 20 to the outside.

[0037] In the above embodiment, when measuring the human impedance and pulse wave, the user presses the pulp of the finger onto the pulse wave sensor 10, and the two sides of the pulp will correspondingly press onto the first metal electrode 21 and the second metal electrode 22. The control module 30 controls the pulse wave sensor 10 and the impedance measurement module 20 to start measuring. After the measurement is completed, the control module 30 sends the electrical signals of the pulse wave sensor 10 and the impedance measurement module 20 to the display device. It can be seen that when using the fingertip biological signal acquisition device of this embodiment to collect the human impedance and pulse wave, or collect any one of the parameters, only one finger is needed to complete the collection, which simplifies the process, saves time, and improves the collection efficiency.

[0038] In the above embodiment, the pulse wave sensor 10 and the impedance measurement module 20 are highly integrated, and its size is slightly larger than that of an adult's finger. Compared with the measurement devices in the prior art, the volume of the device is greatly reduced, which is convenient to carry and is also very conducive to being integrated into other measurement devices.

[0039] In one implementation, the pulse wave sensor 10 can be piezoelectric, piezoresistive, optoelectronic, etc. In this embodiment, an optoelectronic volume pulse wave sensor is used to collect the pulse wave. Optoelectronic is a non-contact measurement. Therefore, after the finger contacts the first metal electrode 21 and the second metal electrode 22, there is a certain gap between the fingertip pulp and the optoelectronic pulse wave sensor, and the position of the fingertip pulp is exactly within the effective measurement distance of the optoelectronic pulse wave sensor. If a contact-type pulse wave sensor is used, the height of the pulse wave sensor 10 is adjusted accordingly so that when the finger contacts the first metal electrode 21 and the second metal electrode 22, the fingertip pulp contacts the contact-type pulse wave sensor at the same time. In addition, after the finger presses the metal electrode, the optoelectronic window (or sensing position) of the pulse wave sensor 10 is completely covered by the finger, excluding environmental and motion interference noises. In terms of algorithms, a band-pass digital filter can be used to obtain a large-amplitude, low-noise effective signal.

[0040] In one implementation, see Figure 1, a gap 23 is reserved between the first metal electrode 21 and the second metal electrode 22, and the gap 23 is greater than or equal to 1 mm. In actual measurement, if the distance between the first metal electrode 21 and the second metal electrode 22 is too close and there is too much sweat or body fluid on the skin surface, the first metal electrode 21 and the second metal electrode 22 may be short-circuited, resulting in inaccurate measurement. In this embodiment, the gap 23 is set to be greater than or equal to 1 mm, and measurement experiments are carried out on multiple values of 1 mm and greater than 1 mm (such as 1.5 mm, 1.8 mm, 2 mm, etc.), and no short-circuit situation occurs, and relatively accurate and stable test results can be obtained. Figure 7 It is the skin impedance measurement result when the gap 23 is 1 mm, and the abscissa represents the number of times. In one embodiment, the impedance acquisition frequency is set to 10 Hz, and the average value of the impedance values collected 10 times in 1 s is used as a measurement value for one time. Figure 7 It is the change diagram of multiple impedance measurement values, and the final value tends to be stable, for example Figure 7 The impedance value at the last time point in it is 24.76 kΩ. The measurement method of skin impedance is not limited here, and it can be collected according to time or the average value can be obtained by collecting a certain number of times.

[0041] In one implementation scheme, a gap 23 is reserved between the first metal electrode 21 and the second metal electrode 22. The gap 23 can be less than 1 mm, and a barrier layer or barrier strip can be installed in the gap 23 to prevent the short circuit of the first metal electrode 21 and the second metal electrode 22.

[0042] In one implementation scheme, see Figure 1 , notches 24 are provided on the sides of the first metal electrode 21 and the second metal electrode 22 close to each other, and the notches 24 on the first metal electrode 21 and the second metal electrode 22 form an opening larger than the outer shape of the pulse wave sensor 10. The above scheme effectively integrates the first metal electrode 21, the second metal electrode 22 and the pulse wave sensor 10 in a fingertip-sized area. In addition, the opening formed by the notch 24 can be circular, square, etc., and the shape of the notch 24 can be flexibly designed and adjusted according to the shape of the pulse wave sensor 10.

[0043] In one implementation scheme, see Figure 2 , the control module 30 includes a wireless communication module 31, and the wireless communication module 31 is used to send the electrical signals of the pulse wave sensor 10 and the impedance measurement module 20 to the outside.

[0044] In one implementation scheme, see Figure 2, the control module 30 further includes a power module, an amplification module, a filtering module, etc. In the impedance measurement module 20, in view of the low impedance value of the fingertip, a double-proportion amplification link is added to the circuit to improve the low-impedance measurement accuracy, and low-pass digital filtering and smoothing digital filtering are adopted to effectively improve the signal-to-noise ratio.

[0045] In one embodiment, referring to Figure 3 and 4 , both the first metal electrode 21 and the second metal electrode 22 are downwardly concave arc-shaped metal sheets, and the arc-shaped metal sheets are more conducive to fitting the skin of the fingertip, so that the circuit connection remains stable during measurement.

[0046] In one embodiment, referring to Figure 3 , it further includes a support structure 40, and the support structure 40 includes a base 41, a vertical plate 42 and a spring 43. Referring to Figure 6 , the vertical plate 42 and the base 41 enclose a first cavity, a second cavity and a central cavity. The central cavity is located in the middle of the base 41, and the first cavity and the second cavity are adjacent to the central cavity and are symmetrically distributed. Referring to Figure 1 , a plurality of springs 43 are respectively installed on the base 41 in the first cavity and the second cavity. The back side of the first metal electrode 21 is installed on the spring 43 in the first cavity, and the back side of the second metal electrode 22 is installed on the spring 43 in the second cavity. Referring to Figure 4 , the heights of the first metal electrode 21 and the second metal electrode 22 are greater than or equal to the height of the vertical plate 42. Referring to Figure 3 and Figure 5 , the pulse wave sensor 10 is installed in the central cavity.

[0047] In the above embodiment, the support structure 40 plays a role of bearing. When the finger presses on the metal electrode, the spring 43 gives the metal electrode a separating force from the base 41, so that the first metal electrode 21 and the second metal electrode 22 are closely attached to the side of the finger pulp. The vertical plate 42 can effectively separate the first metal electrode 21 and the second metal electrode 22, effectively reducing or even avoiding the occurrence of short circuits, thereby minimizing the gap 23 between the first metal electrode 21 and the second metal electrode 22 and further reducing the overall volume.

[0048] In one embodiment, referring to Figure 4 and 6 , the upper end of the vertical plate 42 is a downwardly concave arc-shaped structure, which is adapted to the outer shapes of the first metal electrode 21 and the second metal electrode 22, both of which are arc-shaped metal sheets, facilitating the formation of an arc-shaped support when the finger presses, and facilitating the formation of the metal electrode to fit the finger.

[0049] In one embodiment, referring to Figure 4, the wireless communication module 31 is provided with a pluggable electronic plug, and one side of the base 41 is provided with an electronic jack adapted to the electronic plug. The pluggable type of the wireless communication module 31 facilitates replacement. The wireless communication module 31 can be a Bluetooth module, a local area network wireless module, etc. After unplugging the wireless communication module 31, a data cable can be inserted into the electronic jack to make a wired connection with the display device, increasing the expandability of the device interface and enriching the applicable scenarios of the device.

[0050] For the technical solution of this embodiment, an example of using this device to collect skin impedance and pulse wave is shown. An optoelectronic volume pulse wave sensor is adopted. The gap between the first metal electrode 21 and the second metal electrode 22 is 1 mm (the actual error does not exceed ±0.5 mm). The collection site is selected as the pulp of the index finger. The pulse wave collection frequency can be 100 Hz, and the collection time can be from 1 s to 100 s (no special requirements for time setting). Try to keep the surface of the finger pulp dry during collection, keep the finger naturally relaxed, and place it on the pulse wave sensor 10 and the metal electrode. During the collection process, keep the mood calm and breathe evenly. The room temperature during collection is 23 - 26 °C, and there is no noise, strong light, or strong magnetic field interference in the room, and the air is circulating. After multiple measurements, the results do not differ much. It is relatively stable. One of the measurement results is selected for display. See Figures 7 - 10 . The pulse curve, blood oxygen saturation, and heart rate variability can all be calculated from the data collected by the pulse wave sensor 10 via the control module 30 or its computer device. Figure 7 is the resistance value of the skin impedance. Figure 8 is the pulse curve graph during the measurement process. Figure 9 is the frequency domain analysis graph of heart rate variability during the measurement time, and the ratio of high-frequency component to low-frequency component (LF / HF) is 0.51. Figure 10 is the time domain analysis graph of heart rate variability during the measurement time. Combining the pulse wave sensor and the obtained Figure 8 , 9 and 10, the average heart rate can also be obtained as 79, and the average blood oxygen saturation is 99.4%. In multiple measurements of the same finger of the same person, the measurement results differ little from the Figures 7 - 10 values, indicating that this device is relatively stable and the values are relatively accurate.

[0051] In one implementation, the pulse wave sensor can adopt MAX30102. MAX30102 has one red light and one infrared light. When calculating the blood oxygen saturation, for the red light and infrared light reflection intensity values collected, after filtering, the DC component and AC component are obtained, and the AC of the red light divided by the DC of the red light (i.e., ACred / DCred) and the AC of the infrared light divided by the DC of the infrared light component (i.e., ACired / DCired) are calculated respectively, and then the two are divided to obtain R. The formula is as follows:

[0052]

[0053] Get R and then look up the table to obtain the blood oxygen value. The blood oxygen saturation can also be calculated through the following blood oxygen calibration calculation formula:

[0054] SpO2 = -45.060 * R * R + 30.354 * R + 94.845

[0055] Indicators such as heart rate, blood oxygen saturation, and sweat secretion are closely related to the degree of human fatigue. The heart rate and blood oxygen saturation can both be obtained by collecting and converting through the pulse wave sensor 10. The skin sweat secretion can be evaluated by measuring the skin impedance under a specific frequency excitation. At the end of the human body, the fingertips and the palm are two parts where sweat secretion is relatively concentrated. Therefore, it is reasonable to select the fingertips to detect sweat secretion in this embodiment. Although the area is small and there is a large instability, the embodiments of the application can obtain stable fingertip skin impedance data. In addition, the technology of collecting pulse waves at the fingertips is relatively mature, and it is also reasonable to collect pulse wave signals at the fingertips. Indicators such as heart rate and blood oxygen saturation are calculated after obtaining the pulse wave. The skin impedance is measured by applying a specific frequency alternating current excitation signal through a contact metal electrode. Collecting two parameters at the same part simultaneously greatly improves the integrity and convenience of the instrument and is very convenient to be integrated into other devices.

[0056] Using the solution of the present application to obtain bioimpedance and heart rate, and combining the two to perform early detection and evaluation of mental fatigue status. The combination of the two can effectively reduce detection errors and improve the accuracy of fatigue judgment. And using the same finger can exclude certain irrelevant variables, and further analyze whether there is a correlation between the skin impedance and the pulse wave on the same finger in the future.

[0057] According to the second aspect of the present application, refer to Figure 11 , a bio-signal acquisition system is further provided, including a host computer 100 and the fingertip bio-signal acquisition device in the above solution. The control module 30 of the fingertip bio-signal acquisition device is communicatively connected to the host computer 100. The communication between the control module 30 and the host computer 100 can be wireless communication or wired connection. For different application scenarios, the control module 30 is equipped with a general-purpose interface.

[0058] According to the third aspect of the present application, a portable device is further provided, including the fingertip bio-signal acquisition device in the above solution. The fingertip bio-signal acquisition device with a high degree of integration is more easily integrated into the portable device. The portable device includes but is not limited to intelligent wearable devices, handheld devices, etc.

[0059] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A fingertip biological signal acquisition device, characterized in that It includes a pulse wave sensor (10), an impedance measurement module (20), and a control module (30): The impedance measurement module (20) includes a first metal electrode (21) and a second metal electrode (22) that do not touch each other and are symmetric to each other. The pulse wave sensor (10) is installed between the first metal electrode (21) and the second metal electrode (22); The pulse wave sensor (10) constructs a pulse wave detection area that adheres to the fingertip pulp. The first metal electrode (21) and the second metal electrode (22) construct an impedance detection area surrounding the periphery of the pulse wave detection area; The control module (30) is electrically connected to the pulse wave sensor (10) and the impedance measurement module (20), and is used to send the electrical signals of the pulse wave sensor (10) and / or the impedance measurement module (20) to the outside; Both the first metal electrode (21) and the second metal electrode (22) are downwardly concave arc-shaped metal sheets; The fingertip biological signal acquisition device further includes a support structure (40). The support structure includes a base (41), a vertical plate (42), and a spring (43). The vertical plate (42) and the base (41) enclose a first cavity, a second cavity, and a central cavity. The central cavity is located in the middle of the base (41). The first cavity and the second cavity are adjacent to the central cavity and are symmetrically distributed. A plurality of the springs (43) are respectively installed on the base (41) in the first cavity and the second cavity; The back side of the first metal electrode (21) is installed on the spring (43) in the first cavity. The back side of the second metal electrode (22) is installed on the spring (43) in the second cavity. The heights of the first metal electrode (21) and the second metal electrode (22) are greater than or equal to the height of the vertical plate (42). The pulse wave sensor (10) is installed in the central cavity; The upper end of the vertical plate (42) is a downwardly concave arc-shaped structure, which is adapted to the outer shapes of the first metal electrode (21) and the second metal electrode (22) that are both arc-shaped metal sheets.

2. The fingertip biological signal acquisition device according to claim 1, characterized in that A gap (23) is reserved between the first metal electrode (21) and the second metal electrode (22), and the gap (23) is greater than or equal to 1 mm.

3. The fingertip biological signal acquisition device according to claim 1, wherein On the side where the first metal electrode (21) and the second metal electrode (22) are close to each other, notches (24) are provided. The notches (24) on the first metal electrode (21) and the second metal electrode (22) form an opening larger than the outer shape of the pulse wave sensor (10).

4. The fingertip biological signal acquisition device according to any one of claims 1-3, characterized in that, The control module (30) includes a wireless communication module (31). The wireless communication module (31) is used to send the electrical signals of the pulse wave sensor (10) and the impedance measurement module (20) to the outside.

5. The fingertip biological signal acquisition device according to claim 4, characterized in that, The wireless communication module (31) is provided with a pluggable electronic plug. On one side of the base (41), an electronic socket adapted to the electronic plug is provided.

6. A biological signal acquisition system, characterized in that, It includes: A host computer (100); The fingertip biological signal acquisition device according to any one of claims 1-5, wherein a communication connection is established between the control module (30) of the fingertip biological signal acquisition device and the host computer (100).

7. A portable device, characterized in that, It includes the fingertip biological signal acquisition device according to any one of claims 1-5.

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