Finger clip type oximeter dynamic adjustment light driving method and device and storage medium

Abstract

The invention discloses a finger clip type oximeter dynamic adjustment light driving method and device and a storage medium, when a finger clip type oximeter works, an AD value of red light is adjusted to be within a set ideal range, and red light driving current at the moment is set as initial driving current; whether the signal quality of the red light and the infrared light meets a set threshold condition or not is judged, and if yes, the driving current of the red light is adjusted; and when the driving current of the red light is not the minimum driving current, adjusting the driving current of the infrared light according to the AD value of the red light. By judging whether the red light signal quality, the infrared light signal quality and the blood oxygen difference meet the preset conditions or not, the driving current of the red light and the infrared light is adjusted in real time, and therefore the accurate blood oxygen value is measured with the lowest power consumption.

Description

Technical Field

[0001] This invention relates to the field of wearable device technology, and in particular to a method for dynamically adjusting the light drive of a finger clip pulse oximeter. Background Technology

[0002] The principle of a finger clip pulse oximeter is mainly based on the difference in absorption characteristics of oxyhemoglobin and deoxyhemoglobin to different wavelengths of red and infrared light. Signals are collected by a photoelectric sensor and calculated using an algorithm. The entire measurement process can be divided into the following steps: 1. The instrument is clipped onto the finger (usually the nail area), with the LED and photodetector located on either side of the finger; 2. The LED alternately emits red and infrared light through the finger tissue; 3. The photodetector receives the intensity of the transmitted light and converts it into an electrical signal; 4. The instrument extracts the AC (alternating current component, reflecting the pulsatile changes in arterial blood with the heartbeat) and DC (direct current component, reflecting the constant absorption of other tissues (venous blood, skin, etc.)) components from the total signal using an algorithm, and calculates the R value corresponding to different blood oxygen levels (the R value is a dimensionless value calculated by comparing the ratio of red and infrared light absorption changes; it directly corresponds to blood oxygen saturation). In the second step, the intensity of the red and infrared light needs to be adjusted according to different finger types to ensure that the collected effective signal characteristics are clear and free of excessive noise.

[0003] Currently, most finger-clip pulse oximeters adjust the red and infrared light by adjusting the current based on the AD data collected by the optical sensor after the user places their finger in the measurement position. This ensures that the AD values ​​of the two lights are within the ideal range set by the PPG baseline. Once the AD values ​​of the two lights reach the ideal range, the drive remains stable and no longer adjusted. This adjustment process typically determines the final drive current for the red and infrared lights before the device outputs the R value. This dimming method aims to ensure the ADC collects an ideal PPG signal. However, within the ideal drive range, appropriately lowering or raising the current has little impact on the calculated blood oxygen saturation results. Therefore, there is still significant room for improvement in the current technology regarding overall power consumption during measurement. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method, device and storage medium for dynamically adjusting the light drive of a finger clip pulse oximeter, which reduces the power consumption of the finger clip pulse oximeter and extends the battery life of the device while ensuring accurate measurement of blood oxygen value.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for dynamically adjusting the light drive of a finger clip pulse oximeter, comprising the following steps:

[0006] S1. When the finger clip pulse oximeter is working, adjust the AD value of the red light to the set ideal range, and set the red light driving current at this time as the initial driving current.

[0007] S2. Determine whether the signal quality of both red light and infrared light meets the set threshold conditions. If so, adjust the driving current of red light.

[0008] S3. When the driving current of the red light is at its minimum, determine whether the difference between two adjacent blood oxygen values ​​is not greater than a set threshold. If so, the dimming is considered successful. Otherwise, determine whether this is the first adjustment. If it is the first adjustment, restore the driving current of the red light to the initial driving current and return to step S2. If it is not the first adjustment, increase the driving current of the red light to the driving current of the previous adjustment, and adjust the driving current of the infrared light according to the AD value of the red light, then return to step S2. If the driving current of the red light does not reach the minimum driving current, decrease the driving current of the red light, adjust the driving current of the infrared light according to the AD value of the red light, and return to step S2.

[0009] This invention determines whether the quality of the red light signal, the quality of the infrared light signal, and the blood oxygen difference meet predetermined conditions, and adjusts the driving current of the red light and infrared light in real time, thereby measuring the accurate blood oxygen value with the lowest power consumption.

[0010] In step S1, the specific implementation process of adjusting the AD values ​​of the red and infrared light samples to the set ideal range includes:

[0011] 1) Determine if the red light AD value is within the set ideal range;

[0012] 2) If the red light AD value is within the set ideal range, adjust the infrared light driving current according to the red light AD value. When the ratio of the red light AD value to the infrared light AD value approaches 1, set the red light driving current at this time as the initial driving current. If the red light AD value is greater than the upper limit of the set ideal range, reduce the red light driving current and return to step 1. If the red light AD value is less than the lower limit of the set ideal range, increase the red light driving current and return to step 1.

[0013] The above adjustment process is completed before the initial blood oxygenation result is calculated, which can further improve the accuracy of drive current adjustment and reduce power consumption.

[0014] The process of determining the set threshold conditions includes:

[0015] When step S2 is executed for the first time, the threshold condition is set as the initial threshold. When the signal quality of both red light and infrared light is lower than the initial threshold, it is determined that the set threshold condition is met.

[0016] When dimming is determined to be successful, if the previous dimming was to reduce the red light drive current, then if the signal quality of the red light or the infrared light is lower than the set threshold, the set threshold condition will be updated and adjusted to the updated threshold. For red light, the updated threshold is the current red light signal quality value. If the previous dimming was to increase the red light drive current, then the set threshold condition will be directly updated and adjusted to the updated threshold. For red light, the updated threshold is the current red light signal quality value, and for infrared light, the updated threshold is the current infrared light signal quality value.

[0017] When step S2 is executed again, the updated threshold is used as the set threshold condition, and so on.

[0018] The threshold of this invention can be dynamically adjusted according to different light intensities, and the light drive value can be adjusted in real time according to different human fingers, rather than being limited to a fixed empirical value. This further reduces the power consumption of the whole machine during measurement, thereby increasing the usage time.

[0019] In this invention, the initial threshold is 0.5.

[0020] In this invention, in step S3, the set threshold is 3%.

[0021] A dynamic adjustment light-driven device for a finger-clip pulse oximeter, characterized in that it comprises:

[0022] The initial drive module is used to adjust the AD values ​​of red light and infrared light sampling to the set ideal range when the finger clip pulse oximeter is working, and set the red light drive current at this time as the initial drive current.

[0023] The dynamic drive module is used to determine whether the signal quality of both red and infrared light meets the set threshold conditions. If so, it reduces the drive current of the red light. When the drive current of the red light is at its minimum, it adjusts the drive current of the infrared light according to the AD value of the red light. At the same time, it determines whether the difference between two adjacent blood oxygen saturation values ​​is not greater than the set threshold. If so, it repeats the operation of the dynamic drive module until the finger clip pulse oximeter stops working. Otherwise, it increases the drive current of the red light to the initial drive current and repeats the operation of the dynamic drive module until the finger clip pulse oximeter stops working.

[0024] As an inventive concept, the present invention also provides a wearable device, including a memory, a processor, and a computer program stored in the memory; the processor executes the computer program to implement the steps of the above method.

[0025] As an inventive concept, the present invention also provides a computer-readable storage medium having a computer program / instructions stored thereon; when the computer program / instructions are executed by a processor, they implement the steps of the above-described method.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention greatly reduces the power consumption of the whole machine by dynamically changing the driving current of red light and infrared light, and dynamically changing the judgment threshold K value of red light and infrared light signal quality, while ensuring the accuracy of blood oxygen value measurement. Attached Figure Description

[0027] Figure 1 This is a flowchart illustrating the initial driver module of an embodiment of the present invention.

[0028] Figure 2 This is a flowchart illustrating the workflow of the dynamic driving module in an embodiment of the present invention.

[0029] Figure 3 This is a flowchart illustrating the overall framework of blood oxygen calculation in an embodiment of the present invention.

[0030] Figure 4 This is a structural diagram of the ADC sampling module according to an embodiment of the present invention;

[0031] Figure 5 This is a structural diagram of the drive adjustment module according to an embodiment of the present invention;

[0032] Figure 6 This is a flowchart of the calculation module in an embodiment of the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] The dynamic adjustment light-driven method for the finger-clip pulse oximeter in this embodiment is as follows:

[0036] S1. Insert your finger into the device to enter the initial driver module. The flowchart of the initial driver module is as follows: Figure 1 Then proceed to the calculation module ( Figure 6 Start calculating red light SQI, infrared light SQI, and blood oxygen level.

[0037] The three data points—S2, red SQI, infrared SQI, and blood oxygen saturation—are continuously updated until the red SQI and infrared SQI exceed a set threshold, at which point the dynamic drive module is activated. The flowchart for the dynamic drive module is as follows: Figure 2 .

[0038] S3, the dynamic drive module runs repeatedly until the finger is removed or the device is turned off.

[0039] In S1, the signal quality of red light under normal operating conditions is calculated. and infrared light signal quality The method is as follows:

[0040] During normal measurement, the number N of PPG waveforms that meet the blood oxygen calculation conditions within the recording time t (taking the traditional sampling frequency of 100Hz as an example, after downsampling to 50Hz, if the algorithm sets the calculation array size to 200, then it takes 4 seconds to fill the calculation array) (the recording condition for this waveform count is that both red light and infrared light PPG waveforms meet the blood oxygen calculation requirements. If either the red light or infrared light PPG waveform does not meet the calculation requirements at the same time point, it will not be counted) and the corresponding AC and DC components of red light and infrared light respectively.

[0041] The following are the formulas for calculating the SQI of red and infrared light:

[0042]

[0043] In the above formula, AC represents the alternating current component of red or infrared light; DC represents the direct current component of red or infrared light. When calculating the SQI of red light, the alternating current component of red light is used; when calculating the SQI of infrared light, the alternating current component of infrared light is used.

[0044] i=1: Summation lower limit, representing that the summation variable i starts from 1 and increments. In this embodiment, it represents the first PPG waveform that meets the calculation conditions found each time SQI is calculated.

[0045] i=N: Summation upper limit, representing the summation variable i increments to N and ends. In this embodiment, it represents the last PPG waveform that meets the calculation conditions found in each SQI calculation.

[0046] N: In this embodiment, N represents the total number of PPG waveforms that meet the calculation conditions each time SQI is calculated.

[0047] SQI is used to evaluate the signal quality of the PPG waveforms of red and infrared light under the current driving conditions.

[0048] Because the finger thickness varies among different groups of people, it affects the absorption rate of red and infrared light, leading to inaccurate and unstable blood oxygen saturation measurements. Therefore, after a finger is inserted, in S1, the first step is to determine whether the AD value of the red light is within the set ideal range (the set ideal range can be obtained according to different device parameters, which will not be elaborated here). Then, based on the determination result, the red light driving current is reduced or increased, and the infrared light driving current is adjusted. During this process, it is determined whether the ratio of the red light AD value to the infrared light AD value approaches 1. If so, the red light driving current and the infrared light driving current are maintained, and the initial drive is completed. The initial drive module adjusts the drive according to different finger types so that the AD values ​​of the red and infrared light samples reach the set ideal range (the set ideal data sampling frame). This adjustment process is completed before the first calculation of the blood oxygen saturation result. Figure 1 Schematic diagram of the initial driver module process.

[0049] In S2, the blood oxygen value under normal measurement conditions is calculated and recorded, and the dynamic adjustment light drive function is enabled.

[0050] like Figure 2 Flowchart of the secondary drive module. Start calculating and recording the current blood oxygen level. After a period of time, a new blood oxygen value is obtained. Calculate the difference in blood oxygen levels during this period. This yields the blood oxygen fluctuation value. The formula for calculating blood oxygen value is as follows:

[0051]

[0052] The R-value is the ratio of the absorption (or transmittance) of red light (typically around 660 nm) to that of infrared light (typically around 940 nm). The instrument converts the measured R-value into the percentage of blood oxygen saturation (SpO2) displayed on the screen, based on a pre-set calibration curve. The R-value is a dimensionless value calculated by comparing the ratio of changes in red and infrared light absorption; it directly corresponds to blood oxygen saturation.

[0053] In S2, during dynamic driving, the signal quality of the red light... and infrared light signal quality Blood oxygen levels are constantly updated until the signal quality of the red light is assessed. and infrared light signal quality Whether it exceeds the set threshold. When the SQI of red light and infrared light exceeds the initial set threshold at a certain moment, the dynamic adjustment light drive function is activated. When this function is activated, the blood oxygen difference will be monitored in real time. The SQI of red light and infrared light are used together to determine whether the conditions for decreasing / increasing the red light driving current are met.

[0054]

[0055] In S2, during the initial dynamic adjustment of the light drive, it first checks whether the SQI of the red and infrared light meets the set threshold condition (described in the following paragraph). If it does, the drive current of the red light is reduced, causing a change in the AD sampling data of the red light. The drive current of the infrared light is then adjusted based on the AD value of the red light. The purpose of determining whether the red light has reached the minimum drive current is to limit the lower limit of the current. After the drive current of the infrared light is adjusted, it waits for the new blood oxygen calculation results. If the deviation exceeds the set threshold, the adjustment is considered a failure, and the two-light drive current is restored to its previous state. If the set threshold is not exceeded, the adjustment is considered successful. Then, a new SQI for both lights is recalculated, and the above steps are repeated until the finger is removed or the device is turned off. Adjusting the infrared light drive current based on the red light's AD value ensures that the PPG signal values ​​of the red and infrared lights are close, reducing DC component interference and improving the accuracy of blood oxygen saturation calculation.

[0056] Throughout the adjustment process The judgment is primary. The SQI judgment threshold K (hereinafter referred to as K value) is an empirical value used as an auxiliary judgment, initially usually around 0.5. When adjusting the drive of the two beams so that the SQI of both beams is lower than K value, if... If the value still meets the set threshold (this threshold is set at ±3%, and the national standard YY0784-2010 stipulates that when the pulse oxygen saturation is within the range of 70% to 100%, the accuracy should not exceed ±3%), it indicates that the driving current of the two lights may still have room to decrease. Therefore, the SQI values ​​of the two lights are updated to a new K value, and this K value is then used as the new judgment criterion. If the value exceeds the set threshold, it indicates that the driving current of the two lights is insufficient to support accurate measurement of blood oxygen saturation. Therefore, the intensity of the red light will be increased, thereby raising the SQI of the red light until... The value meets the set threshold, and the SQI of the two lights at this time is used as the new K value for judgment; this allows the judgment threshold of SQI to change dynamically according to different light intensities, rather than being limited to a fixed empirical value. It realizes the real-time adjustment of the light drive value according to different human fingers, reduces the power consumption of the whole machine during measurement, and thus increases the usage time.

[0057] This embodiment reduces the overall power consumption by dynamically changing the current driven by red and infrared light, as well as dynamically changing the judgment threshold K value of SQI.

[0058] Example 2

[0059] This embodiment provides a dynamic adjustment light drive device for a finger-clip pulse oximeter, comprising:

[0060] The initial drive module is used to adjust the AD values ​​of red light and infrared light sampling to the set ideal range when the finger clip pulse oximeter is working, and set the red light drive current at this time as the initial drive current.

[0061] The dynamic drive module is used to determine whether the signal quality of both red and infrared light meets the set threshold conditions. If so, it reduces the drive current of the red light. When the drive current of the red light is at its minimum, it adjusts the drive current of the infrared light according to the AD value of the red light. At the same time, it determines whether the difference between two adjacent blood oxygen saturation values ​​is not greater than the set threshold. If so, it repeats the operation of the dynamic drive module until the finger clip pulse oximeter stops working. Otherwise, it increases the drive current of the red light to the initial drive current and repeats the operation of the dynamic drive module until the finger clip pulse oximeter stops working.

[0062] The specific workflow of each module in this embodiment is the same as in Embodiment 1, and will not be repeated here.

[0063] Example 3

[0064] Embodiment 3 of the present invention provides an apparatus corresponding to Embodiment 1 above, including a memory, a processor, and a computer program stored in the memory; the processor executes the computer program in the memory to implement the steps of the method of Embodiment 1 above.

[0065] In some implementations, the memory may be high-speed random access memory (RAM), and may also include non-volatile memory, such as at least one disk storage device.

[0066] In other implementations, the processor can be any type of general-purpose processor, such as a central processing unit (CPU) or a digital signal processor (DSP), and there is no limitation here.

[0067] Example 3

[0068] Embodiment 3 of the present invention provides a computer-readable storage medium corresponding to Embodiment 1 above, on which a computer program / instructions are stored. When the computer program / instructions are executed by a processor, they implement the steps of the method of Embodiment 1 above.

[0069] A computer-readable storage medium can be a tangible device that holds and stores instructions for use by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any combination thereof.

[0070] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application can be implemented in various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0071] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0072] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0073] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0074] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for dynamically adjusting the light drive of a finger-clip pulse oximeter, characterized in that, Includes the following steps: S1. When the finger clip pulse oximeter is working, adjust the AD value of the red light sampling to the set ideal range, and set the red light driving current at this time as the initial driving current. S2. Determine whether the signal quality of both red light and infrared light meets the set threshold conditions. If so, adjust the driving current of red light. S3. When the driving current of the red light is the minimum driving current, determine whether the difference between two adjacent blood oxygen values ​​is not greater than the set threshold. If so, the dimming is determined to be successful. Otherwise, determine whether it is the first adjustment. If it is the first adjustment, restore the driving current of the red light to the initial driving current and return to step S2. If this is not the first adjustment, increase the driving current of the red light to the driving current of the previous adjustment, and adjust the driving current of the infrared light according to the AD value of the red light, then return to step S2; if the driving current of the red light does not reach the minimum driving current, decrease the driving current of the red light, adjust the driving current of the infrared light according to the AD value of the red light, then return to step S2.

2. The method for dynamically adjusting the light drive of a finger-clip pulse oximeter according to claim 1, characterized in that, In step S1, the specific implementation process of adjusting the AD value of the red light sampling to the set ideal range includes: 1) Determine if the red light AD value is within the set ideal range; 2) If the red light AD value is within the set ideal range, adjust the infrared light driving current according to the red light AD value. When the ratio of the red light AD value to the infrared light AD value approaches 1, set the red light driving current at this time as the initial driving current. If the red light AD value is greater than the upper limit of the set ideal range, reduce the red light driving current and return to step 1. If the red light AD value is less than the lower limit of the set ideal range, increase the red light driving current and return to step 1.

3. The method for dynamically adjusting the light drive of a finger-clip pulse oximeter according to claim 1, characterized in that, The process of determining the set threshold conditions includes: When step S2 is executed for the first time, the threshold condition is set as the initial threshold. When the signal quality of both red light and infrared light is lower than the initial threshold, it is determined that the set threshold condition is met. When dimming is determined to be successful, if the previous dimming was to reduce the red light drive current, then if the signal quality of the red light or the infrared light is lower than the set threshold, the set threshold condition will be updated and adjusted to the updated threshold; if the previous dimming was to increase the red light drive current, then the set threshold condition will be directly updated and adjusted to the updated threshold. For red light, the updated threshold is the current red light signal quality value, and for infrared light, the updated threshold is the current infrared light signal quality value. When step S2 is executed again, the updated threshold is used as the set threshold condition, and so on.

4. The method for dynamically adjusting the light drive of a finger-clip pulse oximeter according to claim 3, characterized in that, The initial threshold is 0.

5.

5. The method for dynamically adjusting the light drive of a finger-clip pulse oximeter according to claim 1, characterized in that, In step S3, the set threshold is 3%.

6. A dynamic adjustment optical drive device for a finger-clip pulse oximeter, characterized in that, include: The initial drive module is used to adjust the AD value of the red light to the set ideal range when the finger clip pulse oximeter is working, and set the red light drive current at this time as the initial drive current. The dynamic drive module is used to determine whether the signal quality of both red light and infrared light meets the set threshold conditions. If so, the drive current of the red light is adjusted. When the driving current of the red light is the minimum driving current, it is determined whether the difference between two adjacent blood oxygen values ​​is not greater than the set threshold. If so, the dimming is determined to be successful. Otherwise, determine whether it is the first adjustment. If it is the first adjustment, restore the driving current of the red light to the initial driving current and repeat the operation of the dynamic driving module. If this is not the first adjustment, increase the driving current of the red light to the driving current of the last adjustment, and adjust the driving current of the infrared light according to the AD value of the red light, repeating the operation of the dynamic driving module. If the driving current of the red light does not reach the minimum driving current, the driving current of the red light is reduced, and the driving current of the infrared light is adjusted according to the AD value of the red light, and the operation of the dynamic driving module is repeated.

7. A wearable device, comprising a memory, a processor, and a computer program stored in the memory; characterized in that, The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program / instructions stored thereon; characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method according to any one of claims 1 to 5.

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