Ring type continuous blood pressure measurement and perfusion measurement system and equipment

Abstract

The invention provides a ring-type continuous blood pressure measurement and perfusion measurement system and equipment, and the system comprises a signal collection module which is used for collecting a photoelectric signal of a finger part of a user, a pressure signal of an air bag and a skin temperature signal; the signal processing module is used for calculating continuous blood pressure and perfusion values according to the collected photoelectric signals of the finger parts, the pressure signals of the air bags and the skin temperature signals, and measuring information of the user is obtained; and the data storage module is used for storing the measurement information of the user and realizing data extraction. According to the invention, continuous blood pressure measurement and perfusion measurement are combined with synchronous measurement, and the measurement precision of blood pressure measurement based on a volume compensation method in a low perfusion state is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of non-invasive continuous blood pressure monitoring, and in particular to a finger-ring type continuous blood pressure measurement and perfusion measurement system and equipment. Background Art

[0002] For decades, cardiovascular disease has been the leading cause of death worldwide. With its high incidence, high disability rate, high recurrence rate and high mortality rate, it poses a major threat to human health and has brought heavy social and economic burdens to all countries. Among them, hypertension has been identified as one of the main risk factors for cardiovascular and cerebrovascular diseases. Hypertension and its related complications are also the main types of cardiovascular and cerebrovascular diseases. Long-term hypertension can induce a variety of cardiovascular and cerebrovascular diseases, such as myocardial infarction, stroke, and damage to important organs. However, in my country, the control rate of hypertension is only about 12%. Therefore, research on hypertension diagnosis and treatment technology is particularly important.

[0003] Blood pressure is an important physiological monitoring indicator, which changes every moment within 24 hours. For patients at risk of cardiovascular and cerebrovascular diseases, such as patients with sleep apnea, hypertension and diabetes, continuous blood pressure monitoring results are closely related to medication effect evaluation, improvement of lifestyle habits and risk warning. However, among people with a high risk of cardiovascular and cerebrovascular diseases, the elderly account for the absolute majority, and the elderly are more likely to have peripheral blood circulation problems, resulting in insufficient finger perfusion and inaccurate continuous blood pressure monitoring results. Therefore, measuring the perfusion of the fingers, accurately and quickly obtaining the individual's blood circulation information, and timely intervening and treating the perfusion situation are of great significance for timely understanding of vascular health status and preventing cardiovascular diseases.

[0004] Existing blood pressure measurement equipment and methods mainly include single measurement, dynamic measurement and continuous measurement. Screening for hypertension usually uses a single sphygmomanometer, such as a traditional cuff sphygmomanometer, but this type of device has the so-called "white coat effect" and cannot measure blood pressure at night, and can only measure the average blood pressure over a period of time. Dynamic sphygmomanometers, such as portable cuff sphygmomanometers, are usually used to diagnose hypertension. Such devices usually start measurement at regular intervals, but frequent cuff expansion may cause discomfort and may affect sleep at night. Intensive care usually uses a continuous sphygmomanometer, that is, an invasive sphygmomanometer, to measure blood pressure. However, since this method is an invasive measurement, there is a risk of infection and it is not suitable for use outside the hospital.

[0005] In addition, most of the current mainstream wearable continuous blood pressure measurement devices based on pulse wave transit time method and volume compensation method cannot solve the traditional low perfusion problem and cannot accurately measure in real time.

[0006] In summary, the prior art has the following defects:

[0007] (1) Existing wearable continuous blood pressure measurement devices are mainly for wrists, but their accuracy is not as good as continuous blood pressure measurement at the fingers. Continuous blood pressure measurement devices based on fingers are relatively large and cannot be wearable.

[0008] (2) Existing instruments based on laser Doppler technology and orthogonal polarization spectroscopy are large in size and weight, and are very expensive. They are only suitable for use in hospital wards and cannot be integrated into wearable devices.

[0009] (3) Existing devices do not combine continuous blood pressure measurement and perfusion measurement for synchronous measurement.

[0010] (4) Existing devices do not have a module for restoring the finger perfusion function.

[0011] (5) The existing equipment has low measurement accuracy when measuring blood pressure based on the volume compensation method under low perfusion conditions. Summary of the invention

[0012] In view of this, the present invention provides a finger-ring type continuous blood pressure measurement and perfusion measurement system and device to at least solve the above problems.

[0013] The present invention provides a finger-ring type continuous blood pressure measurement and perfusion measurement system, comprising a signal acquisition module for collecting photoelectric signals from a user's finger, pressure signals from an air bag, and skin temperature signals; a signal processing module for calculating continuous blood pressure and perfusion values ​​based on the collected photoelectric signals from the finger, pressure signals from the air bag, and skin temperature signals to obtain measurement information of the user; and a data storage module for storing the user's measurement information and realizing data extraction.

[0014] In one implementation, the signal acquisition module includes a photoelectric acquisition module, a pressure acquisition module and a thermistor; the photoelectric acquisition module includes a light-emitting diode and a photodiode, the light-emitting diode alternately emits infrared light with wavelengths of 660nm and 880nm, and the photodiode is used to receive the light signal transmitted through the finger and transmit it to the subsequent signal processing circuit to realize the acquisition of the photoelectric signal; the pressure acquisition module includes a pressure sensor and peripheral circuits, which are used to collect the pressure changes in the airbag to perform numerical calculations of continuous blood pressure; the thermistor is used to measure the temperature of the skin near the light-emitting diode to dynamically control the heating time.

[0015] In another implementation, when the signal processing module calculates continuous blood pressure and perfusion values ​​through an algorithm, the calculation of the continuous blood pressure depends on the control of the air pump, the signal processing module accurately calculates the blood pressure through a volume compensation method, and the calculation of the perfusion value involves heating regulation by controlling infrared radiation when the perfusion is lower than a specific threshold.

[0016] In another implementation, the signal processing module calculates the perfusion value using near-infrared perfusion measurement technology, which establishes a relationship between a substance's ability to absorb light and its concentration and light path length based on a modified Beer-Lambert model:

[0017]

[0018] Among them, A λ is the light attenuation of wavelength λ, I O is the intensity of the emitted light, I is the intensity of the detected light, and ε λ is the molar absorption rate of C at wavelength λ, [C] is the concentration of the color base C, d is the distance between the emitter and the photodetector, DPF is the differential path length factor, and G is the scattering factor. Due to the different light absorption characteristics of oxygenated hemoglobin and deoxygenated hemoglobin, dual wavelengths are added to calculate the concentrations of the two, and G is eliminated by the difference method to obtain the formula:

[0019]

[0020] Δ[tHb]=Δ[HHb]+Δ[HbO2]

[0021] Where, Δ[HHb] is the concentration of deoxygenated hemoglobin, Δ[HbO2] is the concentration of oxyhemoglobin, Δ[tHb] is the total concentration of deoxyhemoglobin and oxyhemoglobin, and ΔA λ1 is the attenuation at wavelength λ1, ΔA λ2 is the attenuation at wavelength λ2, ε HHb is the molar absorptivity of HHb at wavelengths λ1 and λ2, ε HbO2 is the molar absorptivity of HbO2 at the two wavelengths λ1 and λ2.

[0022] In another implementation, the calculation of the perfusion value involves that when the perfusion is lower than a specific threshold, the signal processing module controls infrared radiation to perform heating regulation, which belongs to the perfusion recovery process. The perfusion recovery process is implemented by heating control and airbag control. The signal processing module regulates the heating process according to the calculation result of the perfusion value to improve the perfusion effect of the finger.

[0023] In another implementation, the light emitting diode is controlled to emit light in a time-division multiplexing manner, and the signal of the photodiode is selectively received at the same time.

[0024] The present invention also provides a finger-ring type continuous blood pressure measurement and perfusion measurement device, comprising a shell, an electronic screen, a button, a charging port, a circuit board and a finger-ring structure; wherein the charging port is used to realize charging and data transmission functions, the button comprises a start button and a setting button, the start button is used to control the start and stop of the finger-ring structure, and the setting button is used to complete basic use operations, the circuit board integrates a single-chip microcomputer and peripheral circuits, a micro air pump and a lithium battery, the finger-ring structure comprises an air bag, an air inlet, an exhaust port, a pressure sensor, a thermistor, a light-emitting diode and a photoelectric diode, the light-emitting diode and the photoelectric diode constitute a photoelectric acquisition module of a signal acquisition module, the pressure sensor and the peripheral circuit constitute a pressure acquisition module of the signal acquisition module, the photoelectric acquisition module, the pressure acquisition module and the thermistor constitute the signal acquisition module; the air bag is inflated and exhausted by the micro air pump, and the light-emitting diode and the photoelectric diode are combined to realize real-time measurement of continuous blood pressure based on a volume compensation method and measurement of perfusion at different time sequences.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The system and device of the present invention are more accurate and have higher measurement precision than existing devices based on the principle of photoplethysmography.

[0027] (2) The new flexible electronic technology perfusion measurement hardware circuit system architecture proposed in the present invention is more comfortable to use, does not cause pressure load on the fingers, and does not affect the continuous blood pressure measurement based on the volume compensation method.

[0028] (3) The time-division multiplexing near-infrared spectroscopy technology proposed in the present invention can realize the synchronous measurement of continuous blood pressure and perfusion of fingers.

[0029] (4) The finger perfusion recovery process through heating control and airbag control proposed in the present invention is helpful for finger perfusion recovery, which is not available in other wearable perfusion measurement devices.

[0030] (5) The present invention measures continuous blood pressure and perfusion measurement and recovery, the monitoring information is more comprehensive and the device is light and portable, which is conducive to being used as a monitoring device for a home medical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural block diagram of a finger-ring type continuous blood pressure measurement and perfusion measurement system according to an embodiment of the present invention;

[0032] Figure 2For Figure 1 Schematic diagram of the corresponding ring-type continuous blood pressure measurement and perfusion measurement system;

[0033] Figure 3 It is a schematic diagram of the structure of a finger ring type continuous blood pressure measurement and perfusion measurement device;

[0034] Figure 4 It is a schematic diagram of the data processing module;

[0035] Figure 5 Flow chart of low-latency and low-noise digital acquisition for VCM continuous blood pressure module;

[0036] Figure 6 It is a schematic diagram of the heating control process flow;

[0037] Figure 7 Timing diagram for the operation of light emitting diode and photodiode;

[0038] Figure 8 It is a schematic diagram of the data storage module;

[0039] Fig. 9 The front view and top view of the flexible sensor with integrated micro-LED and micro-photodiode. DETAILED DESCRIPTION

[0040] For ease of understanding, before describing the specific embodiments of the present invention in detail, the prior art of the method of the present invention is first exemplified. In the prior art, the current mainstream continuous peripheral blood pressure measurement method is mainly based on three theories: the vascular unloading theory based on volume compensation, the radial artery tension measurement theory, and the pulse wave conduction time and blood pressure correlation theory. The measurement methods corresponding to these theories are the volume compensation method, the tension method, and the pulse wave conduction time method. Among them, the volume compensation method is the most widely used non-invasive continuous blood pressure measurement method in clinical practice. It does not require calibration and has extremely high time resolution, and can calculate relevant hemodynamic parameters.

[0041] The volume compensation method (VCM) is a non-invasive continuous arterial blood pressure measurement method. This method allows the volume of the finger artery to be fixed at a preset value by a servo-controlled air bag bundle, so that the finger artery remains unloaded. At this time, the pressure in the air bag should be equal to the blood pressure, thereby measuring continuous blood pressure. The principle of continuous blood pressure measurement using the volume compensation method was first proposed by Czech physiologist Penaz in 1973. In the 1980s, the Dutch Wesseling team developed a non-invasive continuous blood pressure prototype based on this principle. Since then, the technology has gradually been industrialized and used in clinical practice, and has gradually become the most widely used non-invasive continuous blood pressure measurement method in clinical practice.

[0042] With the rise of wearable technology, flexible sensing systems have been more widely used. It can be integrated into various wearable devices such as clothing, watches, glasses, etc. It not only does not affect the appearance, but also can realize a variety of sensing functions, such as heart rate monitoring, posture detection, etc., to provide users with more comprehensive information feedback. The flexible sensing system is mainly based on electrohydrodynamic inkjet printing technology, which is an advanced printing technology that uses electric fields to act on liquid inkjet. The basic principle of this technology involves the migration of charges in an electric field and the deformation of liquids under electric field forces. This technology was proposed as early as the 1990s. At that time, it was limited by the backwardness of nanotechnology and material solubilization technology, and was mainly used in the field of simple microfluidic control synthesis. Subsequently, researchers have continuously improved and optimized the technologies of printing heads, droplet formation and control, which have significantly improved the printing accuracy, speed and stability. Nowadays, E-jet technology has demonstrated many unique advantages, such as high precision (resolution higher than 1μm), low cost, contactless, and easy compatibility with large-scale fine preparation. It has become an important micro-nano preparation technology and is widely used in the electronics industry, optics and biological fields, such as the processing and preparation of conductive electrodes, LEDs, PDs, transistors, lenses, displays, biosensors, etc.

[0043] Peripheral perfusion measurement is a technique used to assess blood flow in peripheral tissues, evaluate blood supply to peripheral tissues, and guide clinical interventions in various medical conditions. It plays an important role in early detection of impaired perfusion, assessment of circulatory status, predictive indicators, and monitoring of therapeutic interventions. Early methods for assessing peripheral tissue perfusion are mainly based on clinical observation and examination. However, with the advancement of medical technology and a deeper understanding of circulatory physiology, peripheral perfusion measurement techniques and indicators have continued to evolve. These developments have provided medical staff with valuable tools to objectively and quantitatively assess peripheral tissue perfusion. The application of these technologies has been significantly promoted by improving diagnostic accuracy, guiding therapeutic interventions, and strengthening monitoring of affected tissue perfusion. Until now, some commonly used methods for measuring peripheral perfusion include: temperature gradient, optical monitoring, percutaneous measurement, and sublingual capillary measurement. When choosing a suitable method, we mainly consider factors such as non-invasiveness, accuracy, multi-parameter evaluation, and interference with blood flow. Among them, optical monitoring methods have received widespread attention in perfusion measurement and indicator model construction due to their unique characteristics.

[0044] The principles of the current mainstream wearable continuous blood pressure measurement equipment are mainly based on the pulse wave transmission time method and the volume compensation method. The pulse wave transmission time method mainly calculates the continuous blood pressure value by calculating the pulse wave transmission time and the pulse wave transmission velocity, such as the blood pressure watch for continuous blood pressure measurement of Shenzhen Jinyidi Technology Co., Ltd. (CN218552323U), Tsinghua University Shenzhen Graduate School (CN107854123B), and the United States (EP15833349). Typical products based on the volume compensation method are Nova from Finpares in the Netherlands, ClearSight from Edwards Lifesciences in the United States, and CNAP from CNSystems in Austria. In 2022, the Fortin team from Austria combined the VCM and PPG methods to design a theoretical model of a finger-type continuous non-invasive blood pressure measurement system based on a slow volume compensation method using a hydraulic brake constant volume device and a photoelectric sensor. Because it uses liquid drive, there are complex control and leakage risks, and it cannot solve the traditional low-injection problem, and it cannot accurately measure in real time. In 2023, the Panula team from Finland designed a continuous non-invasive blood pressure measurement model based on the low-frequency volume compensation method built at the fingertips using this method combined with a mechanical gear device and a dual-wavelength photoelectric sensor. It requires post-processing to correct errors caused by changes in the state of finger blood vessels and cannot achieve real-time measurement. In addition, there is Shenzhen Delikai Medical Electronics Co., Ltd. (CN108478204A).

[0045] The principle of the current mainstream wearable perfusion measurement equipment is mainly based on photoplethysmography, which calculates the ratio between the pulsating component and the non-pulsating component of the light reaching the detector in the arterial area. It is usually used in pulse oximeters, such as China Kangtai Medical Systems Co., Ltd. (CN201310223507.9), Qualcomm (EP15747302), Guangdong Jiankangshu Medical Technology Co., Ltd. (CN202010677359.8), Jiangsu Gairui Health Technology Co., Ltd. (CN201911253041.0), and Begmei Technology Co., Ltd. (CN202010832570.2). Others include perfusion measurement equipment based on laser Doppler technology, such as the patent for quantitative laser Doppler blood flow signal detection of arrhythmias and disease monitoring (US13193059), which is a medical device system for monitoring tissue perfusion in the patient's heart.

[0046] In terms of system design, in addition to basic perfusion measurement, some extended functions have been added, such as the automatic assessment of peripheral vascular conditions (US13791806) patent, which adds systolic blood pressure measurement, and the multi-parameter simultaneous physiological monitoring device with local and remote analysis capabilities (US16036551) patent, which can simultaneously monitor cuff blood pressure signals, blood oxygen saturation levels, electrocardiogram signals and temperature.

[0047] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] See also Figure 1 The embodiment of the present invention provides a finger-ring type continuous blood pressure measurement and perfusion measurement system, comprising:

[0049] A signal acquisition module is used to collect photoelectric signals from the user's fingers, pressure signals from the airbag, and skin temperature signals;

[0050] A signal processing module is used to calculate continuous blood pressure and perfusion values ​​based on the collected photoelectric signals of the finger, the pressure signals of the airbag, and the skin temperature signals to obtain the user's measurement information;

[0051] The data storage module is used to store the user's measurement information and realize data extraction.

[0052] It should be understood that the signal acquisition module, the signal processing module and the data storage module are communicatively connected.

[0053] Preferably, the signal acquisition module includes a photoelectric acquisition module, a pressure acquisition module and a thermistor; the photoelectric acquisition module includes a light-emitting diode and a photodiode, the light-emitting diode alternately emits infrared light with wavelengths of 660nm and 880nm, and the photodiode is used to receive light signals transmitted through the finger and transmit them to a subsequent signal processing circuit to realize the acquisition of the photoelectric signal; the pressure acquisition module includes a pressure sensor and peripheral circuits, which are used to collect pressure changes in the airbag to perform numerical calculations of continuous blood pressure; the thermistor is used to measure the temperature of the skin near the light-emitting diode to dynamically control the heating time.

[0054] Preferably, when the signal processing module calculates continuous blood pressure and perfusion values ​​through an algorithm, the calculation of the continuous blood pressure depends on the control of the air pump, the signal processing module accurately calculates the blood pressure through a volume compensation method, and the calculation of the perfusion value involves heating regulation by controlling infrared radiation when the perfusion is lower than a specific threshold.

[0055] Preferably, the signal processing module calculates the perfusion value using near-infrared perfusion measurement technology, which establishes the relationship between the ability of a substance to absorb light and its concentration and light path length based on the improved Beer-Lambert model:

[0056]

[0057] Among them, A λ is the light attenuation of wavelength λ, I O is the intensity of the emitted light, I is the intensity of the detected light, and ε λ is the molar absorption rate of C at wavelength λ, [C] is the concentration of the color base C, d is the distance between the emitter and the photodetector, DPF is the differential path length factor, and G is the scattering factor. Due to the different light absorption characteristics of oxygenated hemoglobin and deoxygenated hemoglobin, dual wavelengths are added to calculate the concentrations of the two, and G is eliminated by the difference method to obtain the formula:

[0058]

[0059] Δ[tHb]=Δ[HHb]+Δ[HbO2]

[0060] Where, Δ[HHb] is the concentration of deoxygenated hemoglobin, Δ[HbO2] is the concentration of oxyhemoglobin, Δ[tHb] is the total concentration of deoxyhemoglobin and oxyhemoglobin, and ΔA λ1 is the attenuation at wavelength λ1, ΔA λ2 is the attenuation at wavelength λ2, ε HHb is the molar absorptivity of HHb at wavelengths λ1 and λ2, ε HbO2 is the molar absorptivity of HbO2 at the two wavelengths λ1 and λ2.

[0061] Preferably, the calculation of the perfusion value involves that when the perfusion is lower than a specific threshold, the signal processing module controls infrared radiation to perform heating regulation, which belongs to the perfusion recovery process. The perfusion recovery process is achieved by heating control and airbag control. The signal processing module regulates the heating process according to the calculation result of the perfusion value to improve the perfusion effect of the finger.

[0062] Preferably, the light emitting diode is controlled to emit light in a time-division multiplexing manner, and the signal of the photodiode is selectively received at the same time.

[0063] Specifically, the scheme of the present invention is further described according to the following examples:

[0064] The present invention provides a ring-type continuous blood pressure measurement and perfusion measurement system composed of the following three core modules: a signal acquisition module, a signal processing module and a data storage module, wherein the signal processing module is further divided into two parts: continuous blood pressure measurement and perfusion measurement, which are respectively related to the two processes of airbag control and heating control. The specific system structure is as follows: Figure 2 shown.

[0065] The functions of each module are described in detail as follows:

[0066] 1. Signal acquisition module

[0067] The signal acquisition module consists of a photoelectric acquisition module, a pressure acquisition module and a thermistor. Its main function is to collect the photoelectric signal of the finger, the pressure signal of the airbag and the skin temperature signal. The photoelectric acquisition module consists of a light-emitting diode and a photodiode. The light-emitting diode alternately emits infrared light of 660nm and 880nm wavelengths. The photodiode is responsible for receiving the light signal passing through the finger and transmitting it to the subsequent signal processing circuit to realize the acquisition of the photoelectric signal. The pressure acquisition module consists of a pressure sensor and its peripheral circuits. It is mainly used to collect the pressure changes in the airbag for subsequent numerical calculation of continuous blood pressure. The function of the thermistor is to measure the temperature of the skin near the light-emitting diode to dynamically control the heating time.

[0068] 2. Signal processing module

[0069] The main function of the signal processing module is to calculate continuous blood pressure and perfusion values ​​through algorithms. The calculation of continuous blood pressure depends on the control of the air pump, and the accurate calculation of blood pressure is achieved through the volume compensation method. The calculation of perfusion values ​​involves controlling infrared radiation for heating regulation when the perfusion is below a specific threshold. The main working process is as follows: the corresponding photoelectric signals and pressure signals are collected by controlling the working mode of the photoelectric acquisition module, and these signals are processed by the amplification circuit and the analog / digital conversion circuit, and then input into the single-chip microcomputer for further continuous blood pressure and perfusion value calculation. In the process of continuous blood pressure measurement, the inflation and deflation process of the airbag is dynamically controlled; in the perfusion measurement process, the heating module is controlled according to the perfusion results, and the heating process is also regulated by the thermistor signal. Finally, all calculation results will be transmitted to the data storage module. The specific process is as follows. Figure 4 shown.

[0070] 2.1 Perfusion measurement

[0071] The main principle of vascular perfusion calculation is near infrared technology (NIRS). Near infrared perfusion measurement technology is a method of measuring tissue oxygen content and blood flow by analyzing the absorption characteristics of oxygenated hemoglobin and deoxygenated hemoglobin to near infrared light. It is mainly based on the improved Beer-Lambert model, which establishes the relationship between the ability of a substance to absorb light and its concentration and light path length:

[0072]

[0073] Among them, A λ is the light attenuation of wavelength λ, I O is the intensity of the emitted light, I is the intensity of the detected light, and ε λ is the molar absorption rate of C at wavelength λ, [C] is the concentration of the color base C, d is the distance between the emitter and the photodetector, DPF is the differential path length factor, and G is the scattering factor. Due to the different light absorption characteristics of oxygenated hemoglobin and deoxygenated hemoglobin, dual wavelengths are added to calculate the concentrations of the two, and G is eliminated by the difference method to obtain the formula:

[0074]

[0075]

[0076] Δ[tHb]=Δ[HHb]+Δ[HbO2]

[0077] Where, Δ[HHb] is the concentration of deoxygenated hemoglobin, Δ[HbO2] is the concentration of oxyhemoglobin, Δ[tHb] is the total concentration of deoxyhemoglobin and oxyhemoglobin, and ΔA λ1 is the attenuation at wavelength λ1, ΔA λ2 is the attenuation at wavelength λ2, ε HHb is the molar absorptivity of HHb at wavelengths λ1 and λ2, ε HbO2 is the molar absorptivity of HbO2 at two wavelengths of λ1 and λ2. The infrared light of wavelengths of 660nm and 880nm used in the present invention.

[0078] 2.2 Continuous blood pressure measurement

[0079] The volume compensation method (VCM) used for continuous blood pressure, the overall control system is as follows Figure 5As shown. Because the human pulse wave signal is weak, the ambient light has a great influence on the collection of the optical signal. In order to eliminate the influence of ambient light on blood pressure measurement, the light-emitting diode on the finger cuff emits infrared light according to the ambient light control timing. After passing through the finger blood vessels, it is received by the digital photoelectric detector (light-frequency conversion), and the optical signal is directly converted into a periodic square wave signal, which is then identified and converted into a digital signal by the counter according to the control timing. The volume tracing signal containing the pulse wave information is thus generated and transmitted to the digital control loop system for processing. The set value of the current no-load state is calculated by the control algorithm, and then compared with the signal collected by the pressure sensor through the comparator, and the signal generated is used to control the pressure in the airbag, so as to keep the finger blood vessels in a no-load state at all times, thereby non-invasively and continuously measuring blood pressure.

[0080] 2.3 Perfusion recovery

[0081] The perfusion recovery process is mainly achieved through heating control and airbag control. Its core function is to control the heating process according to the calculation results of the perfusion value, thereby improving the perfusion effect of the finger. The heating control mainly relies on infrared light with a power of 1mW to 500mW. The specific heating control process is as follows: Figure 6 As shown. The experiment shows that the accuracy of continuous finger blood pressure measurement based on the volume compensation method decreases significantly when the finger is cold. Therefore, the system first determines whether heating operation is needed based on the perfusion measurement results and determines the heating time. The heating time is divided into three gears: 1 minute, 3 minutes and 5 minutes. The system automatically selects the appropriate gear according to the difference between the perfusion measurement results and the normal perfusion value. During the heating process, the microcontroller monitors the temperature information transmitted by the thermistor in real time to avoid skin burns. When the heating timing ends, the system will send a command to stop heating and store the relevant data in the data module. If the perfusion value is still lower than the threshold after the heating ends, the system will issue a status abnormality warning and start the next heating operation.

[0082] In addition, the system of the present invention is also designed to achieve finger massage by controlling the airbag to expand and contract in a triangular wave manner, thereby further improving finger perfusion. This method cannot be performed synchronously when measuring blood pressure and perfusion.

[0083] 2.4 LED Timing Control

[0084] In the present invention, continuous blood pressure measurement, perfusion measurement and perfusion recovery all require the use of light-emitting diodes and photodiodes. To prevent ambient light interference and ensure the accuracy of the measurement signal, the system uses time-division multiplexing to control the light emission of the light-emitting diodes and selectively receives signals from the photodiodes.

[0085] Specifically, the light-emitting diodes emit light signals alternately according to a predetermined time sequence, and the photodiodes receive light signals transmitted through the finger within the corresponding time window. This timing control method effectively suppresses the interference of ambient light and improves the signal-to-noise ratio of the measurement signal. Figure 7 As shown. The high-power 880mm infrared light is mainly used in this time-division multiplexing strategy, which not only optimizes the utilization efficiency of the light source, but also ensures the independence and accuracy of the signal in different measurement modes. Through precise timing control, the system can switch measurement tasks in different time periods, avoiding signal confusion and interference, thereby achieving high-precision continuous blood pressure and perfusion data acquisition.

[0086] 3. Data storage module

[0087] The main function of the data storage module is to store the user's measurement information and realize data extraction using the type-C interface. The user's measurement information storage is as follows Figure 8 As shown, the type-C interface mainly provides USB flash drive data backup function.

[0088] 4. Flexible materials

[0089] Its main function is to perform infrared heating intervention on the fingertips according to the calculation results of the perfusion value to improve the finger perfusion, which is achieved through light-emitting diodes. Based on the theory of ultra-thin conformal bio-integrated electronics, this module directly integrates micro-LEDs and micro-photodiode devices on a flexible substrate as a flexible detection patch for the VCM optoelectronic system, forming a transmitter and a receiver. The heating belt is composed of a carbon-based film and a built-in infrared radiation lamp bead. The flexible substrate is placed on the airbag and adheres to the finger skin as the airbag expands. Then the airbag deflates, allowing the elastic flexible substrate to adhere to the skin. This structure helps prevent finger perfusion detection from causing errors in the monitoring of continuous blood pressure at the end of the finger. The airbag has a built-in pressure sensor, and the trachea provides an inflation and deflation pipeline for the airbag. The signal line is responsible for transmitting the collected photoelectric signals, pressure signals, and temperature signals to the microcontroller, and responds to the heating start and end signals of the microcontroller.

[0090] The flexible detection patch mainly uses electrohydrodynamic jet printing technology to programmatically integrate the flexible sensor composed of micro-light-emitting diodes and micro-photodiodes required for the near-infrared perfusion measurement system on a single flexible substrate. The electrohydrodynamic jet printing technology is divided into two key steps: the preparation of the ink required for printing and the design of the printing process.

[0091] The ink required for printing includes organic conductive electrode ink, near-infrared luminescent or photoelectric detection material ink, buffer layer ink and inorganic conductive electrode ink.

[0092] First, an organic conductive electrode ink is prepared, such as poly(p-styrene sulfonic acid) (PEDOT:PSS) / polyethylene oxide (PEO) ink. The PEDOT:PSS multi-solvent precursor solution and the PEO dimethylformamide (DMF) solution are stirred and mixed in a certain proportion to obtain a PEDOT:PSS / PEO composite ink. Secondly, a near-infrared luminescent or photoelectric detection material ink is prepared. To this end, the luminescent or photoelectric multi-solvent solution and the PEO solution are mixed and stirred in proportion to prepare the corresponding ink. Next, a buffer layer ink is prepared, and an organic polymer (such as polyetherimide PEI) is directly dissolved in a specific solvent as a buffer layer ink. Finally, an inorganic conductive electrode ink is prepared, such as silver nanowires or liquid metals. The purchased dispersion is mixed with other viscous solvents as needed to prepare the corresponding ink. In the process of preparing the ink, the luminescent or luminescent detection material is not set. In the experiment, the luminescent or luminescent detection material will be screened and controlled according to the system requirements.

[0093] In order to print micro-LED and micro-photodiode devices on a single flexible substrate, PEN is selected as the flexible substrate, and the corresponding ink is deposited layer by layer according to the design drawing. First, the organic conductive electrode is deposited on the flexible substrate, and after drying, the light-emitting layer is deposited and dried. The buffer layer and the inorganic electrode layer are deposited layer by layer in sequence to complete the preparation of the light-emitting diode. For a single PD device, the separated electrode materials are directly deposited according to the drawing. After drying, the selected photoelectric detection material is printed and deposited in the tiny separation area of ​​the electrode. Finally, the flexible substrate is bonded to complete the overall device packaging, such as Fig. 9 shown.

[0094] The present invention also provides a finger ring type continuous blood pressure measurement and perfusion measurement device, such as Figure 3 As shown, the left side is the outer structure, and the right side is the cross-sectional structure, including a shell 1, an electronic screen 2, a button 3, a charging port 4, a circuit board 5 and a finger ring structure 6; the shell 1 and the finger ring structure 6 are connected, the circuit board 5 is located inside the shell 1, and is respectively connected to the electronic screen 2, the button 3, and the charging port 4.

[0095] Among them, the charging port 4 is used to realize the charging and data transmission functions, the button 3 includes a start button and a setting button, the start button is used to control the start and stop of the ring structure, and the setting button is used to complete basic usage operations. The circuit board 5 integrates a single-chip microcomputer and peripheral circuits, a micro air pump 51 and a lithium battery 52.

[0096] The finger ring structure 6 includes an airbag 61, an air inlet 62, an air outlet 63, a pressure sensor 64, a thermistor 65, a light emitting diode 66 and a photodiode 67. The air inlet 62 and the air outlet 63 are closed to connect the micro air pump 51 and the airbag 61. The thermistor 65, the light emitting diode 66 and the photodiode 67 are located on the film of the airbag 61. The pressure sensor 64 is located in the airbag 61. The light emitting diode and the photodiode constitute a photoelectric acquisition module of a signal acquisition module. The pressure sensor and the peripheral circuit constitute a pressure acquisition module of the signal acquisition module. The photoelectric acquisition module, the pressure acquisition module and the thermistor constitute the signal acquisition module.

[0097] The finger ring structure 6 is the main part for realizing continuous blood pressure and perfusion measurement. The airbag 61 is inflated and exhausted by the micro air pump 51, and the light-emitting diode and the photodiode are combined to realize continuous real-time blood pressure measurement based on the volume compensation method. The structure is also used to synchronously realize perfusion measurement at different time sequences.

[0098] In addition, in order to improve perfusion and improve the accuracy of blood pressure measurement under low perfusion conditions, two methods are designed to improve the perfusion value. One is to achieve infrared heating by increasing the power of the light-emitting diode, increase the temperature of the finger to promote vasodilation, increase blood supply and thus improve the perfusion of the finger. This method can be performed simultaneously when measuring blood pressure and perfusion; the other is to control the micro air pump to achieve the expansion and contraction of the air bag to achieve the function of massaging the finger, thereby improving the perfusion of the finger. This method cannot be performed simultaneously when measuring blood pressure and perfusion.

[0099] The present invention makes full use of the miniaturization and skin-friendly advantages of flexible optoelectronic devices to achieve the design of a miniaturized and intelligent continuous blood pressure measurement, finger perfusion measurement, and perfusion recovery system. The introduction of perfusion recovery can effectively solve the problem of inaccurate fingertip blood pressure measurement due to insufficient perfusion in some people.

[0100] Compared with the prior art, the present invention has the following beneficial effects:

[0101] (1) The system and device of the present invention are more accurate and have higher measurement precision than existing devices based on the principle of photoplethysmography.

[0102] (2) The new flexible electronic technology perfusion measurement hardware circuit system architecture proposed in the present invention is more comfortable to use, does not cause pressure load on the fingers, and does not affect the continuous blood pressure measurement based on the volume compensation method.

[0103] (3) The time-division multiplexing near-infrared spectroscopy technology proposed in the present invention can realize the synchronous measurement of continuous blood pressure and perfusion of fingers.

[0104] (4) The finger perfusion recovery process through heating control and airbag control proposed in the present invention is helpful for finger perfusion recovery, which is not available in other wearable perfusion measurement devices.

[0105] (5) The present invention measures continuous blood pressure and perfusion measurement and recovery, the monitoring information is more comprehensive and the device is light and portable, which is conducive to being used as a monitoring device for a home medical system.

[0106] The flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems and devices according to multiple embodiments of the present invention. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of an instruction, and the module, a program segment or a part of an instruction contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or the flowchart, and the combination of the boxes in the block diagram and / or the flowchart can be implemented by a dedicated hardware-based system that performs the specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions. It is well known to those skilled in the art that it is equivalent to implement it by hardware, implement it by software, and implement it by combining software and hardware.

[0107] Embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the marketplace, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein. The scope of the present invention is defined by the appended claims.

Claims

1. A ring-type continuous blood pressure measurement and perfusion measurement system, characterized in that: include: A signal acquisition module is used to collect photoelectric signals from the user's fingers, pressure signals from the airbag, and skin temperature signals; A signal processing module is used to calculate continuous blood pressure and perfusion values ​​based on the collected photoelectric signals of the finger, the pressure signals of the airbag, and the skin temperature signals to obtain the user's measurement information; The data storage module is used to store the user's measurement information and realize data extraction.

2. The system according to claim 1, characterized in that The signal acquisition module includes a photoelectric acquisition module, a pressure acquisition module and a thermistor; The photoelectric collection module includes a light emitting diode and a photodiode. The light emitting diode emits infrared light with wavelengths of 660nm and 880nm alternately. The photodiode is used to receive the light signal transmitted through the finger and transmit it to the subsequent signal processing circuit to realize the collection of the photoelectric signal. The pressure acquisition module includes a pressure sensor and a peripheral circuit, which is used to collect the pressure changes in the airbag to perform continuous blood pressure numerical calculation; The thermistor is used to measure the temperature of the skin near the light emitting diode to dynamically adjust the heating time.

3. The system according to claim 2, characterized in that When the signal processing module calculates continuous blood pressure and perfusion values ​​through an algorithm, the calculation of the continuous blood pressure depends on the control of the air pump, the signal processing module accurately calculates the blood pressure through a volume compensation method, and the calculation of the perfusion value involves heating regulation by controlling infrared radiation when the perfusion is lower than a specific threshold.

4. The system according to claim 3, characterized in that The signal processing module calculates the perfusion value using near-infrared perfusion measurement technology, which establishes the relationship between the ability of a substance to absorb light and its concentration and light path length based on the improved Beer-Lambert model: Among them, A λ is the light attenuation of wavelength λ, I O is the intensity of the emitted light, I is the intensity of the detected light, and ε λ is the molar absorption rate of C at wavelength λ, [C] is the concentration of the color base C, d is the distance between the emitter and the photodetector, DPF is the differential path length factor, and G is the scattering factor. Due to the different light absorption characteristics of oxygenated hemoglobin and deoxygenated hemoglobin, dual wavelengths are added to calculate the concentrations of the two, and G is eliminated by the difference method to obtain the formula: Δ[tHb]=Δ[HHb]+Δ[HbO2] Where, Δ[HHb] is the concentration of deoxygenated hemoglobin, Δ[HbO2] is the concentration of oxyhemoglobin, Δ[tHb] is the total concentration of deoxyhemoglobin and oxyhemoglobin, and ΔA λ1 is the attenuation at wavelength λ1, ΔA λ2 is the attenuation at wavelength λ2, ε HHb is the molar absorptivity of HHb at wavelengths λ1 and λ2, ε HbO2 is the molar absorptivity of HbO2 at the two wavelengths λ1 and λ2.

5. The system according to claim 4, characterized in that The calculation of the perfusion value involves the perfusion recovery process in which the signal processing module controls infrared radiation to perform heating adjustment when the perfusion is lower than a specific threshold. The perfusion recovery process is achieved through heating control and airbag control. The signal processing module regulates the heating process according to the calculation result of the perfusion value to improve the perfusion effect of the finger.

6. The system according to claim 5, characterized in that The method also includes controlling the light emission of the light emitting diode in a time-division multiplexing manner and selectively receiving the signal of the photodiode.

7. A finger-ring type continuous blood pressure measurement and perfusion measurement device, characterized in that: Including a housing, an electronic screen, buttons, a charging port, a circuit board and a finger ring structure; Wherein, the charging port is used to realize charging and data transmission functions, the buttons include a start button and a setting button, the start button is used to control the start and stop of the finger ring structure, the setting button is used to complete basic use operations, the circuit board integrates a single-chip microcomputer and peripheral circuits, a micro air pump and a lithium battery, the finger ring structure includes an air bag, an air inlet, an exhaust port, a pressure sensor, a thermistor, a light-emitting diode and a photoelectric diode, the light-emitting diode and the photoelectric diode constitute a photoelectric acquisition module of a signal acquisition module, the pressure sensor and the peripheral circuit constitute a pressure acquisition module of the signal acquisition module, the photoelectric acquisition module, the pressure acquisition module and the thermistor constitute the signal acquisition module; The airbag is inflated and exhausted by the micro air pump, and the light emitting diode and the photodiode are combined to realize the continuous real-time measurement of blood pressure based on the volume compensation method and the measurement of perfusion at different time sequences.

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