Device and method for detecting tissue blood supply disorder

Abstract

The invention discloses a tissue blood supply obstacle detection device and a blood supply obstacle detection method.The tissue blood supply obstacle detection device comprises a signal collection front end and a main control rear end, and the signal collection front end comprises a temperature sensor, a light source emitter and a photoelectric detector; the master control rear end is connected with the temperature sensor, the light source emitter and the photoelectric detector; the temperature sensor is used for collecting the epidermal temperature of the biological tissue, the photoelectric detector is used for detecting a reflective photoelectric signal after light emitted by the light source emitter passes through the biological tissue, and the main control rear end is used for analyzing according to the dynamic change of the epidermal temperature of the tissue and the reflective photoelectric signal to realize tissue blood supply obstacle detection.

Description

Technical Field

[0001] The present invention specifically relates to a device and method for detecting tissue blood flow obstruction. Background Art

[0002] After tissue transplantation, the graft relies on a new blood circulation system to obtain oxygen and nutrients and remove metabolic waste. Once vascular obstruction occurs, such as vasospasm, thrombosis, or vascular compression, the graft can become ischemic and hypoxic. Monitoring vascular obstruction can promptly detect these problems and enable appropriate measures, such as adjusting vascular anastomosis techniques, administering anticoagulants, or relieving compression, to ensure adequate blood supply to the graft and improve graft survival. However, the most widely used method for monitoring vascular obstruction remains clinical assessment by physicians. This method relies heavily on clinical experience, is highly subjective, and has a significant lag in detecting vascular obstruction. Furthermore, existing vascular obstruction monitoring technologies, such as handheld portable ultrasound Doppler (ADS), color Doppler ultrasound (CDU), laser Doppler (LDF), and near-infrared spectroscopy (NIRS), have significant drawbacks, including rigid probes that can easily damage the graft, difficulty distinguishing the type of vascular obstruction, poor data interpretability, and high equipment usage and maintenance costs. Summary of the Invention

[0003] The purpose of the present invention is to provide a device and method for detecting tissue blood circulation disorders, which can realize tissue blood circulation disorder detection.

[0004] The technical solution adopted in the present invention is: A device for detecting tissue blood circulation disorders includes a signal acquisition front end and a main control back end. The signal acquisition front end includes a temperature sensor, a light source emitter and a photoelectric detector. The main control back end is connected to the temperature sensor, the light source emitter and the photoelectric detector. The temperature sensor is used to collect the epidermal temperature of biological tissue. The photoelectric detector is used to detect the reflected photoelectric signal of the light emitted by the light source emitter after passing through the biological tissue. The main control back end is used to realize tissue blood circulation disorder detection based on the dynamic change analysis of the tissue epidermal temperature and the reflected photoelectric signal.

[0005] Preferably, the signal acquisition front end further comprises a flexible base layer, a component layer, and a flexible packaging layer, wherein the component layer is arranged on the flexible base layer, and the flexible packaging layer encapsulates the component layer on the flexible base layer; The temperature sensor, light source emitter and photodetector are arranged on the component layer. The temperature sensor, light source emitter and photodetector are connected by flexible interconnection wires, and are connected to the main control back end through flexible interconnection wires and flexible conductive connecting lines.

[0006] Preferably, a flexible isolation layer is provided between the component layer and the flexible packaging layer.

[0007] Preferably, the main control backend includes a main control unit, a signal sending unit, and a current control unit. The main control unit is connected to the signal sending unit and the current control unit respectively. The main control unit is connected to the light source emitter through the current control unit. The main control unit is connected to the temperature sensor and the photodetector.

[0008] Preferably, the light source emitter, the temperature sensor, and the photodetector are arranged on the same plane and are distributed in sequence and at intervals along the same straight line.

[0009] Preferably, the central wavelength of the light emitted by the light source emitter is between 796-810 nm, and the wavelength corresponding to the maximum spectral sensitivity of the photodetector is between 750-850 nm.

[0010] Preferably, the light source emitter is a light emitting diode.

[0011] A method for detecting blood circulation disorder using the above-described device for detecting tissue blood circulation disorder comprises the following steps: when detecting blood circulation disorder in tissue, the main control back end monitors the tissue epidermal temperature through a temperature sensor and monitors the reflected photoelectric signal through a photoelectric detector; The reflected photoelectric signal includes a photoplethysmography (PPG) signal and a noise signal. If the reflected photoelectric signal exhibits periodic pulse wave characteristics in the time domain, the signal is determined to be a PPG signal; otherwise, it is a noise signal. The tissue perfusion coefficient and tissue balance coefficient are obtained based on the PPG signal; If the reflected photoelectric signal is always a noise signal and the tissue surface temperature continues to drop, it means that the tissue has arterial blockage; If the reflected photoelectric signal is always a PPG signal, and the tissue epidermal temperature and tissue perfusion coefficient continue to decrease, it means that arterial spasm has occurred in the tissue; If the reflected photoelectric signal is always a PPG signal, the tissue epidermal temperature continues to drop, and the tissue balance coefficient is always less than 1, it means that venous congestion has occurred in the tissue.

[0012] Preferably, when detecting blood flow obstruction in tissue, multiple sets of temperature signals and reflective photoelectric signals are continuously collected. The tissue epidermal temperature is the average value of the tissue epidermal temperature signal continuously collected by the temperature sensor, the tissue perfusion coefficient is the average value of the perfusion index of the PPG signal, and the tissue balance coefficient is the average value of the balance index of the PPG signal.

[0013] Preferably, the specific steps of obtaining the tissue perfusion coefficient and the tissue balance coefficient according to a set of PPG signals include: The collected raw PPG signal is low-pass filtered, upper enveloped, and lower enveloped in sequence. According to the perfusion index calculation method of the PPG signal, the perfusion index of the PPG signal per second is calculated, and the average perfusion index of the group of PPG signals is calculated, that is, the tissue perfusion coefficient; The collected raw PPG signals were subjected to high-pass filtering, trough peak searching, and upper envelope in sequence. According to the balance index calculation method of the PPG signal, the balance index of the PPG signal in each cycle was calculated according to the amplitude of the corresponding trough and the amplitude of the next adjacent trough. The balance index of the PPG signal in each cycle was calculated, and the average balance index of the group of PPG signals, that is, the tissue balance coefficient, was calculated. The beneficial effects of the present invention are: The present invention collects tissue temperature and reflected photoelectric signals through temperature sensors, light source emitters and photoelectric detectors, calculates and monitors tissue epidermal temperature, tissue perfusion coefficient and tissue balance coefficient through the above signals, and realizes tissue blood circulation disorder detection based on the dynamic changes of reflected photoelectric signals and tissue epidermal temperature, tissue perfusion coefficient and tissue balance coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the structure of a device for detecting tissue blood flow disorders in an embodiment of the present invention.

[0015] Figure 2 Schematic diagram of an explosion of a device for detecting tissue blood flow disorders in an embodiment of the present invention.

[0016] Figure 3 2 is a schematic structural diagram of a signal sending unit in an embodiment of the present invention.

[0017] Figure 4 2 is a schematic diagram illustrating the calculation of the perfusion index in the blood flow disorder detection method according to an embodiment of the present invention.

[0018] Figure 5 2 is a schematic diagram illustrating the calculation of the balance index of the blood circulation disorder detection method in an embodiment of the present invention.

[0019] In the figure: 1- signal acquisition front end, 2- flexible conductive connection line, 3- main control back end, 4- flexible substrate layer, 5- flexible interconnect wire, 6- component layer, 7- flexible isolation layer, 8- flexible packaging layer, 9- PPG signal, 10- upper envelope, 11- lower envelope; 3-1- Main control unit, 3-2- Signal sending unit, 3-3- Current control unit, 3-4- Analog switch, 3-5- Resistors, 6-1- Light emitting diodes, 6-2- Photodetectors, 6-3- Temperature sensors, 6-4- Peripheral electronic components. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be 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.

[0021] In the description of the present invention, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like are used to indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0022] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, removable connections, or integral connections. They may refer to mechanical connections or electrical connections. They may refer to direct connections or indirect connections through an intermediary, and they may refer to internal communication between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0023] A device for detecting tissue blood flow disorders, such as Figures 1-3 As shown, it includes a signal acquisition front end 1 and a main control back end 3. The signal acquisition front end 1 includes a temperature sensor, a light source emitter and a photoelectric detector. The main control back end 3 is connected to the temperature sensor, the light source emitter and the photoelectric detector. The temperature sensor is used to collect the epidermal temperature of biological tissue, and the photoelectric detector is used to detect the reflected photoelectric signal of the light emitted by the light source emitter after passing through the biological tissue. The main control back end is used to realize tissue blood circulation disorder detection based on the dynamic change analysis of the tissue epidermal temperature and the reflected photoelectric signal.

[0024] Furthermore, the signal acquisition front end 1 is electrically connected to the main control back end 3 via the flexible interconnecting wires 5 and the flexible conductive connecting wires 2 .

[0025] Furthermore, the signal acquisition front end 1 further includes a flexible base layer 4, a component layer 6, and a flexible packaging layer 8. The component layer 6 is provided on the flexible base layer 4, and the flexible packaging layer 8 encapsulates the component layer 6 on the flexible base layer 4. The temperature sensor, light source emitter and photodetector are arranged in the component layer 6. The temperature sensor 6-3, light source emitter and photodetector 6-2 are connected through flexible interconnection wires 5, and are connected to the main control back end 3 through the flexible interconnection wires 5 via flexible conductive connecting wires 2.

[0026] Furthermore, the component layer 6 also includes four peripheral electronic components 6 - 4 , which are connected to other devices in the component layer through flexible interconnecting wires 5 and connected to the main control back end 3 through flexible conductive connecting wires 2 .

[0027] Furthermore, a flexible isolation layer 7 is provided between the component layer 6 and the flexible packaging layer 8. The flexible isolation layer 7 is used to isolate the flexible interconnection wires 5. The temperature sensor, light source emitter and photodetector can detect the tissue through the flexible isolation layer 7 and the flexible packaging layer 8.

[0028] Furthermore, the light source emitter is a light emitting diode 6 - 1 .

[0029] Furthermore, the signal acquisition front end 1 includes a flexible base layer 4, a flexible interconnection wire 5, a component layer 6, a flexible isolation layer 7, and a flexible packaging layer 8; the component layer 6 includes a light-emitting diode 6-1, a photodetector 6-2, a temperature sensor, and four peripheral electronic components 6-4; the light-emitting diode 6-1, the photodetector 6-2, the temperature sensor 6-3, and the peripheral electronic components 6-4 are electrically connected through the flexible interconnection wire 5, and the peripheral electronic components 6-4 include several capacitors and resistors.

[0030] Example 2 Based on Example 1, the main control backend is further limited, and the performance of Example 2 after the limitation is even better.

[0031] Furthermore, the main control back end 3 includes a main control unit 3-1, a signal sending unit 3-2, and a current control unit 3-3. The main control unit 3-1 is connected to the signal sending unit 3-2 and the current control unit 3-3 respectively. The main control unit 3-1 is connected to the light source emitter through the current control unit 3-3, and the main control unit 3-1 is connected to the temperature sensor and the photodetector; the main control back end 3 can control the signal acquisition front end 1 to synchronously acquire the temperature signal and the reflected photoelectric signal of the test tissue, the main control unit 3-1 adjusts the forward current of the light-emitting diode 6-1 serving as the light source emitter through the current control unit 3-3, and the main control back end 3 can send the signal collected by the signal acquisition front end 1 to the terminal through the signal sending unit 3-2.

[0032] Furthermore, the current control unit 3-3 includes a 4-to-1 analog switch 3-4 and four resistors 3-5 with different resistance values. The main control unit 3-1 can adjust the forward current of the light-emitting diode 6-1 by controlling the 4-to-1 analog switch 3-4.

[0033] Furthermore, the light source emitter, the temperature sensor, and the photodetector are arranged on the same plane and are distributed in sequence and at intervals along the same straight line.

[0034] Furthermore, the light-emitting diode 6-1, the photodetector 6-2 and the temperature sensor 6-3 are distributed in a straight line on a plane, the light-emitting diode 6-1 and the temperature sensor 6-3 are distributed on both sides of the photodetector 6-2, the center straight line distance between the light-emitting diode 6-1 and the photodetector 6-2 is 2-3 mm, and the center straight line distance between the temperature sensor 6-3 and the photodetector 6-2 is 5-6 mm.

[0035] Furthermore, the central wavelength of the light emitted by the light source emitter is between 796-810 nm, and the wavelength corresponding to the maximum spectral sensitivity of the photodetector 6-2 is between 750-850 nm.

[0036] Example 3 Based on Example 1 or Example 2, a blood circulation disorder detection method is implemented.

[0037] A blood circulation disorder detection method using the above-described device for detecting tissue blood circulation disorder comprises the following steps: when detecting blood circulation disorder in tissue, the main control back end 3 monitors the tissue epidermal temperature through the temperature sensor and monitors the reflected photoelectric signal through the photoelectric detector; The reflected photoelectric signal includes a photoplethysmography (PPG) signal and a noise signal. If the reflected photoelectric signal exhibits periodic pulse wave characteristics in the time domain, the signal is determined to be a PPG signal; otherwise, it is a noise signal. The tissue perfusion coefficient and tissue balance coefficient are obtained based on the PPG signal; Analyze multiple sets of temperature signals and reflective photoelectric signals. If the reflective photoelectric signal is always a noise signal and the tissue epidermal temperature continues to drop, it means that the tissue has arterial obstruction; If the reflected photoelectric signal is always a PPG signal, and the tissue epidermal temperature and tissue perfusion coefficient continue to decrease, it means that arterial spasm has occurred in the tissue; If the reflected photoelectric signal is always a PPG signal, the tissue epidermal temperature continues to drop, and the tissue balance coefficient is always less than 1, it means that venous congestion has occurred in the tissue.

[0038] Furthermore, when detecting blood flow obstruction of tissue, at least three sets of temperature signals and reflective photoelectric signals are continuously collected, wherein the collection time of each set of signals is t1 seconds, and the time interval between the collection of different sets of signals is t2; t1 is 20 to 40 seconds, in the best embodiment t1 is 30 seconds, and t2 is 1 to 2 hours.

[0039] The tissue epidermal temperature is the average value of the tissue epidermal temperature signal continuously collected by the temperature sensor, the tissue perfusion coefficient is the average value of the perfusion index of the PPG signal, and the tissue balance coefficient is the average value of the balance index of the PPG signal.

[0040] The monitoring indicators include tissue epidermal temperature, tissue perfusion coefficient, and tissue balance coefficient, among which the tissue epidermal temperature is the average value of the temperature signal, the tissue perfusion coefficient is the average value of the perfusion index of the PPG signal, and the tissue balance coefficient is the average value of the balance index of the PPG.

[0041] The balance index of the PPG signal is defined as the ratio of the amplitude of the first trough to the amplitude of the second trough in the PPG signal; The steps of calculating the tissue perfusion coefficient and the tissue balance coefficient based on a set of PPG signals include: like Figure 4 As shown, the collected raw PPG signals are subjected to low-pass filtering, upper envelope filtering, and lower envelope filtering in sequence. According to the perfusion index calculation method of the PPG signal, the perfusion index of the PPG signal is calculated per second. The perfusion index is the difference between the corresponding upper envelope value and the lower envelope value divided by the upper envelope value. The average perfusion index of the group of PPG signals is calculated, that is, the tissue perfusion coefficient; like Figure 5 As shown in the figure, the collected raw PPG signals are sequentially subjected to high-pass filtering, trough peak finding, and upper envelope. According to the balance index calculation method of the PPG signal, the balance index of the PPG signal in each cycle is calculated. The balance index is the amplitude of a corresponding trough divided by the amplitude of the next adjacent trough. The average balance index of the group of PPG signals is calculated, that is, the tissue balance coefficient.

[0042] Working principle of the present invention: (1) The tissue blood flow disorder detection device prepared by the present invention has a signal acquisition front end with obvious flexibility and will not cause tissue damage to the transplanted tissue.

[0043] (2) The tissue blood flow disorder detection device prepared by the present invention uses an LED light source with a wavelength between 796 and 810 nm. This wavelength is considered to be the isosbestic wavelength of oxyhemoglobin and deoxyhemoglobin. The use of this wavelength can effectively avoid tissue perfusion coefficient measurement artifacts caused by fluctuations in the human body's oxygenation level.

[0044] (3) Venous congestion can cause the tissue balance coefficient to change from a value greater than 1 to a value less than 1. Arterial spasm can cause the tissue perfusion coefficient to continue to decrease. Complete arterial blockage can cause the reflected photoelectric signal to be all noise signals. In addition, all types of blood circulation disorders will cause the tissue epidermal temperature to decrease. Therefore, the tissue blood circulation disorder detection method proposed in the present invention, that is, combining the tissue balance coefficient, tissue perfusion coefficient and tissue epidermal temperature to monitor the tissue blood circulation status, can effectively realize the detection of blood circulation disorders and distinguish specific situations; it can simultaneously collect tissue temperature and reflected photoelectric signals, and calculate and monitor tissue epidermal temperature, tissue perfusion coefficient and tissue balance coefficient through the above signals, and realize tissue blood circulation disorder detection based on the dynamic changes of the reflected photoelectric signal and the above three coefficients.

[0045] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0046] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A device for detecting tissue blood flow disorders, characterized in that: The invention comprises a signal acquisition front end (1) and a main control back end (3), wherein the signal acquisition front end (1) comprises a temperature sensor, a light source emitter and a photoelectric detector, and the main control back end (3) is connected to the temperature sensor, the light source emitter and the photoelectric detector; the temperature sensor is used to acquire the epidermal temperature of biological tissue, the photoelectric detector is used to detect the reflected photoelectric signal of the light emitted by the light source emitter after passing through the biological tissue, and the main control back end (3) is used to realize tissue blood flow disorder detection based on the dynamic change analysis of the tissue epidermal temperature and the reflected photoelectric signal.

2. The device for detecting tissue blood flow disorders according to claim 1, wherein: The signal acquisition front end (1) further comprises a flexible base layer (4), a component layer (6), and a flexible packaging layer (8), wherein the component layer (6) is arranged on the flexible base layer (4), and the flexible packaging layer (8) packages the component layer (6) on the flexible base layer (4); The temperature sensor, the light source emitter and the photodetector are arranged on the component layer (6); the temperature sensor (6-3), the light source emitter and the photodetector (6-2) are connected via a flexible interconnection wire (5), and are connected to the main control back end (3) via a flexible conductive connection line (2) via the flexible interconnection wire (5).

3. The device for detecting tissue blood flow disorders according to claim 2, wherein: A flexible isolation layer (7) is provided between the component layer (6) and the flexible packaging layer (8).

4. The device for detecting tissue blood flow disorders according to claim 1, wherein: The main control backend (3) includes a main control unit (3-1), a signal sending unit (3-2), and a current control unit (3-3). The main control unit (3-1) is connected to the signal sending unit (3-2) and the current control unit (3-3) respectively. The main control unit (3-1) is connected to the light source transmitter through the current control unit (3-3). The main control unit (3-1) is connected to the temperature sensor and the photodetector.

5. The device for detecting tissue blood flow disorders according to claim 1, wherein: The light source emitter, the temperature sensor and the photoelectric detector are arranged on the same plane and are distributed in sequence along the same straight line.

6. The device for detecting tissue blood flow disorders according to claim 1, wherein: The central wavelength of the light emitted by the light source emitter is between 796-810 nm, and the wavelength corresponding to the maximum spectral sensitivity of the photodetector (6-2) is between 750-850 nm.

7. The device for detecting tissue blood flow disorders according to claim 1, wherein: The light source emitter is a light emitting diode (6-1).

8. A method for detecting blood circulation disorders using the device for detecting tissue blood circulation disorders according to claim 1, characterized in that: The following steps are involved: When detecting blood flow obstruction of tissue, the main control back-end (3) monitors the temperature of the tissue epidermis through the temperature sensor and monitors the reflected photoelectric signal through the photoelectric detector; The reflected photoelectric signal includes a photoplethysmography (PPG) signal and a noise signal. If the reflected photoelectric signal exhibits periodic pulse wave characteristics in the time domain, the signal is determined to be a PPG signal; otherwise, it is a noise signal. The tissue perfusion coefficient and tissue balance coefficient are obtained based on the PPG signal; If the reflected photoelectric signal is always a noise signal and the tissue surface temperature continues to drop, it means that the tissue has arterial blockage; If the reflected photoelectric signal is always a PPG signal, and the tissue epidermal temperature and tissue perfusion coefficient continue to decrease, it means that arterial spasm has occurred in the tissue; If the reflected photoelectric signal is always a PPG signal, the tissue epidermal temperature continues to drop, and the tissue balance coefficient is always less than 1, it means that venous congestion has occurred in the tissue.

9. The blood circulation disorder detection method according to claim 8, wherein: When detecting blood flow disorders in tissues, multiple sets of temperature signals and reflective photoelectric signals are continuously collected; The tissue epidermal temperature is the average value of the tissue epidermal temperature signal continuously collected by the temperature sensor, the tissue perfusion coefficient is the average value of the perfusion index of the PPG signal, and the tissue balance coefficient is the average value of the balance index of the PPG signal.

10. The blood circulation disorder detection method according to claim 9, wherein: The specific steps for calculating the tissue perfusion coefficient and tissue balance coefficient based on a set of PPG signals include: The collected raw PPG signal is subjected to low-pass filtering, upper envelope filtering, and lower envelope filtering in sequence. According to the perfusion index calculation method of the PPG signal: the perfusion index of the PPG signal per second is calculated based on the corresponding upper envelope value and lower envelope value, and the average perfusion index of the group of PPG signals is calculated, that is, the tissue perfusion coefficient; The collected raw PPG signals were subjected to high-pass filtering, trough peak searching, and upper envelope in sequence. According to the balance index calculation method of the PPG signal, the balance index of the PPG signal in each cycle was calculated based on the amplitude of the corresponding trough and the amplitude of the next adjacent trough, and the average balance index of the group of PPG signals was calculated, that is, the tissue balance coefficient.

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