A pulse oximetry detection method and detection system

Abstract

The application provides a pulse blood oxygen saturation detection method and system, which comprises the following steps: receiving the light signal emitted to the surface of the light receiving tube and converting it into a first received electric signal to form a red light sampling channel when the red light is generated; receiving the light signal emitted to the surface of the light receiving tube and converting it into a second received electric signal to form an infrared light sampling channel when the infrared light is generated; detecting the first received electric signal in real time, identifying the driving output change of the red light emitting tube, and outputting a first signal state bit; judging the change of the detection rate of the pulse wave based on the signal state bit, when the detection rate of the pulse wave rises, calculating the output blood oxygen saturation value according to the first received electric signal and the second received electric signal. According to the comprehensive analysis of the blood oxygen sampling signal and / or the state of the driving current adjustment state in time, whether there is a suspected non-physiological state marker is determined.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical monitoring, in particular to a pulse blood oxygen saturation detection method and a detection system. BACKGROUND

[0002] In clinical medical monitoring, pulse blood oxygen saturation (PPG) detection is widely used as an important method for non-invasive measurement of blood oxygen saturation. It detects blood oxygen information through infrared or fluorescent sensors to detect small changes in the skin, etc., and has the advantages of non-invasiveness and convenience, facilitating real-time monitoring of patient blood oxygen by medical staff.

[0003] However, there are many problems affecting the accuracy of detection in actual application. First, pulse wave signals are easily disturbed by environmental light. The environmental light is complex in different environments of a hospital, and changes in environmental light may be misjudged by the sensor and superimposed on the pulse wave signal, affecting the extraction of the true signal and blood oxygen detection. Second, electromyographic signals are also a source of interference. When a patient is still, the electromyographic signals produced by the slight contraction of the muscles overlap with the pulse wave signals in frequency, making it difficult for the sensor to distinguish between them, which reduces the signal quality and causes deviations in blood oxygen detection.

[0004] In addition, when a band-type blood oxygen probe is idle, it will be disturbed by environmental light and suddenly output incorrect blood oxygen and pulse rate values, misleading medical staff. At the same time, the probes of many blood oxygen detection devices cannot accurately identify non-physiological media, and non-physiological media such as a pen will also give incorrect measurement values, affecting the reliability of the data. The LED light of a repeatedly used probe will attenuate over time, losing the function of detecting physiological media in place, and no human physiological media will also output values. The device also has abnormal use conditions such as medical staff pinching the clamping part of the probe to the maximum angle, which will also cause incorrect values to be output, reflecting the imperfect response mechanism and the damage to the probe affecting measurement.

[0005] The deviations in blood oxygen detection caused by non-physiological factors such as light interference, incorrect operation, changes in environmental light, and other signal interference need to be addressed. SUMMARY

[0006] The purpose of the present application is to provide a pulse blood oxygen saturation detection method and a detection system to solve the problem of blood oxygen detection deviations caused by non-physiological factors in the prior art.

[0007] To solve the above technical problems, the present application provides a pulse blood oxygen saturation detection method, which comprises:

[0008] a red light emitting tube is used to generate red light of a first wavelength;

[0009] an infrared light emitting tube is used to generate infrared light of a second wavelength;

[0010] The light receiving tube receives the optical signal emitted to the surface of the light receiving tube and converts it into a first received electric signal when the red light is generated, forming a red light sampling channel;

[0011] The light receiving tube receives the optical signal emitted to the surface of the light receiving tube and converts it into a second received electric signal when the infrared light is generated, forming an infrared light sampling channel;

[0012] Real-time detection of the first received electric signal identifies changes in the driving output of the red light emitting tube, and outputs a first signal state bit;

[0013] Real-time detection of the second received electric signal identifies changes in the driving output of the infrared light emitting tube, and outputs a second signal state bit;

[0014] Based on the first received electric signal, the signal AC component and the signal DC component of the red light sampling channel are identified in real time;

[0015] Based on the second received electric signal, the signal AC component and the signal DC component of the infrared light sampling channel are identified in real time;

[0016] Real-time detection of at least one of the signal AC component of the red light sampling channel and the signal AC component of the infrared light sampling channel identifies changes in the signal AC component, and outputs a third signal state bit;

[0017] Real-time detection of at least one of the signal DC component of the red light sampling channel and the signal DC component of the infrared light sampling channel identifies changes in the signal DC component, and outputs a fourth signal state bit;

[0018] According to the first received electric signal and the second received electric signal, the pulse wave is detected in real time, and the detection rate of the pulse wave is identified; and,

[0019] Determine whether at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit changes, when at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit changes, determine the change of the detection rate of the pulse wave, when the detection rate of the pulse wave rises, calculate the output of the blood oxygen saturation value according to the first received electric signal and the second received electric signal.

[0020] In one of the embodiments, the method further comprises the steps of: outputting a confidence level of the pulse wave detection signal, determining a change in the detection rate of the pulse wave when at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit changes, outputting a first confidence level when the detection rate of the pulse wave increases, outputting a second confidence level and / or prohibiting the output of the blood oxygen saturation value when the detection rate of the pulse wave decreases, the first confidence level being greater than the second confidence level.

[0021] In one of the embodiments, the steps of real-time detecting the first received electrical signal, identifying a change in the driving output of the red light emitting tube, outputting a first signal state bit, and real-time detecting the second received electrical signal, identifying a change in the driving output of the infrared light emitting tube, outputting a second signal state bit, comprise:

[0022] real-time detecting the first received electrical signal, acquiring a first signal quality of the first received electrical signal, adjusting the driving output of the red light emitting tube according to the first signal quality, and outputting the first signal state bit when the driving output of the red light emitting tube changes; and,

[0023] real-time detecting the second received electrical signal, acquiring a second signal quality of the second received electrical signal, adjusting the driving output of the infrared light emitting tube according to the second signal quality, and outputting the second signal state bit when the driving output of the infrared light emitting tube changes.

[0024] In one of the embodiments, the steps of adjusting the driving output of the red light emitting tube according to the first signal quality and outputting the first signal state bit when the driving output of the red light emitting tube changes, and adjusting the driving output of the infrared light emitting tube according to the second signal quality and outputting the second signal state bit when the driving output of the infrared light emitting tube changes, comprise:

[0025] determining the signal quality of the first received electrical signal, and increasing the driving current or voltage of the red light emitting tube when the signal quality of the first received electrical signal is lower than a first preset range, and outputting the first signal state bit when the driving current or voltage of the red light emitting tube changes; and,

[0026] determining the signal quality of the second received electrical signal, and increasing the driving current or voltage of the infrared light emitting tube when the signal quality of the second received electrical signal is lower than a second preset range, and outputting the second signal state bit when the driving current or voltage of the infrared light emitting tube changes.

[0027] In one of the embodiments, the step of identifying, in real time, the signal AC component and the signal DC component of the red light sampling channel based on the first received electrical signal and identifying, in real time, the signal AC component and the signal DC component of the infrared light sampling channel based on the second received electrical signal comprises:

[0028] filtering and resolving the first received electrical signal to obtain the signal AC component and the signal DC component of the red light sampling channel,

[0029] filtering and resolving the second received electrical signal to obtain the signal AC component and the signal DC component of the infrared light sampling channel; and,

[0030] The step of detecting, in real time, the pulse wave based on the first received electrical signal and the second received electrical signal to identify the detection rate of the pulse wave comprises:

[0031] Compensating the signal AC component of the red light sampling channel and the signal AC component of the infrared light sampling channel based on the signal DC component of the red light sampling channel and the signal DC component of the infrared light sampling channel;

[0032] Obtaining waveform data based on the compensated signal AC component of the red light sampling channel and the compensated signal AC component of the infrared light sampling channel;

[0033] Searching for the pulse wave in the waveform data within a preset sliding time window;

[0034] Searching for the pulse wave satisfying the pulse wave waveform feature from the pulse wave; and,

[0035] Calculating the proportion of the pulse wave within the preset sliding time window to output the detection rate of the pulse wave.

[0036] In one of the embodiments, the step of detecting, in real time, at least one of the signal AC component of the red light sampling channel and the signal AC component of the infrared light sampling channel to identify the signal change of the signal AC component and output the third signal state bit comprises:

[0037] Detecting, in real time, the first signal AC component of the red light sampling channel to determine whether the feature of the first signal AC component has a mutation trend,

[0038] Detecting, in real time, the second signal AC component of the infrared light sampling channel to determine whether the feature of the second signal AC component has a mutation trend, and,

[0039] Outputting the third signal state bit when the feature of any one of the first signal AC component and the second signal AC component has a mutation trend; and,

[0040] The step of detecting at least one of the signal DC components of the red light sampling channel and the signal DC components of the infrared light sampling channel in real time, identifying the signal change of the signal DC component, and outputting the fourth signal state bit comprises:

[0041] The step of detecting the first signal DC component of the red light sampling channel in real time and determining whether the characteristic of the first signal DC component has a mutation trend,

[0042] The step of detecting the second signal DC component of the infrared light sampling channel in real time and determining whether the characteristic of the second signal DC component has a mutation trend, and

[0043] When the characteristic of any one of the first signal DC component and the second signal DC component has a mutation trend, output the fourth signal state bit.

[0044] In one embodiment, the method, the step of detecting the first received electrical signal in real time, identifying the driving output change of the red light emitting tube, and outputting the first signal state bit is repeated every preset sliding time window.

[0045] In one embodiment, the time range of the preset sliding time window is greater than 5 seconds and less than 10 seconds.

[0046] In one embodiment, the step of determining the change of the detection rate of the pulse wave further comprises at least one of the following steps:

[0047] According to the first received electrical signal and the second received electrical signal, time-frequency domain transformation is performed to obtain time domain signals and frequency domain signals, the characteristic change of the base frequency peak of the energy spectrum on the frequency spectrum of the frequency domain signals is identified, and when the characteristic change conforms to the physiological characteristic, the blood oxygen saturation value is output; and

[0048] According to the first received electrical signal and the second received electrical signal, time-frequency domain transformation is performed to obtain time domain signals and frequency domain signals, and a plurality of continuous pulse wave signals are searched from the time domain signals, and when at least one of the rhythm, amplitude and ejection time of the searched plurality of continuous pulse wave signals conforms to the physiological characteristic, the blood oxygen saturation value is output.

[0049] In one embodiment, the step of determining whether at least one of the first signal state bit, the second signal state bit, the third signal state bit, and the fourth signal state bit has changed, and determining the change in the detection rate of the pulse wave when at least one of the first signal state bit, the second signal state bit, the third signal state bit, and the fourth signal state bit has changed, includes:

[0050] Determine whether any one of the first signal status bits and the second signal status bits has changed; when any one of the first signal status bits and the second signal status bits has changed, determine whether any one of the third signal status bits and the fourth signal status bits has changed.

[0051] If any one of the third signal state bits and the fourth signal state bit changes, the step of judging the change in the detection rate of the pulse wave is executed.

[0052] The present invention also provides a pulse oximetry detection system, wherein the detection system comprises:

[0053] Red light-emitting diode, used to generate red light of the first wavelength;

[0054] Infrared LEDs are used to generate infrared light of a second wavelength.

[0055] The red light driving adjustment unit is used to output a driving signal to the red light-emitting tube and generate red light of the first wavelength using the red light-emitting tube;

[0056] An infrared light drive adjustment unit is used to output a drive signal to the infrared light-emitting tube and use the infrared light-emitting tube to generate infrared light of a second wavelength.

[0057] The signal receiving unit is used to receive the light signal emitted onto the surface of the light receiving tube when the red light is generated and convert it into a first received electrical signal to form a red light sampling channel; and to receive the light signal emitted onto the surface of the light receiving tube when the infrared light is generated and convert it into a second received electrical signal to form an infrared light sampling channel.

[0058] The red light drive change detection unit is used to detect the first received electrical signal in real time, identify the change in the drive output of the red light-emitting tube, and output the first signal status bit.

[0059] An infrared light drive change detection unit is used to detect the second received electrical signal in real time, identify the drive output change of the infrared light-emitting tube, and output a second signal status bit.

[0060] A direct current identification unit is configured to identify, in real time, a signal direct current component of the red light sampling channel and a signal direct current component of the infrared light sampling channel based on the first received electrical signal and the second received electrical signal.

[0061] An alternating current identification unit is configured to identify, in real time, a signal alternating current component of the red light sampling channel and a signal alternating current component of the infrared light sampling channel based on the first received electrical signal and the second received electrical signal.

[0062] A direct current variation detection unit is configured to detect, in real time, at least one of the signal direct current component of the red light sampling channel and the signal direct current component of the infrared light sampling channel, identify a signal variation of the signal direct current component, and output a fourth signal state bit.

[0063] An alternating current variation detection unit is configured to detect, in real time, at least one of the signal alternating current component of the red light sampling channel and the signal alternating current component of the infrared light sampling channel, identify a signal variation of the signal alternating current component, and output a third signal state bit.

[0064] A physiological pulse wave detection and analysis unit is configured to detect, in real time, a pulse wave based on the first received electrical signal and the second received electrical signal, and identify a detection rate of the pulse wave.

[0065] A physiological result output unit is configured to calculate and output a blood oxygen saturation value based on the first received electrical signal and the second received electrical signal.

[0066] A non-physiological waveform detection and analysis unit is configured to determine whether at least one of the first signal state bit, the second signal state bit, the third signal state bit, and the fourth signal state bit has changed, determine a change in the detection rate of the pulse wave when at least one of the first signal state bit, the second signal state bit, the third signal state bit, and the fourth signal state bit has changed, and cause the physiological result output unit to output the blood oxygen saturation value when the detection rate of the pulse wave increases.

[0067] In one embodiment, the non-physiological waveform detection and analysis unit further performs the following steps:

[0068] The non-physiological waveform detection and analysis unit further outputs a confidence level of the pulse wave detection signal, determines a change in the detection rate of the pulse wave when at least one of the first signal state bit, the second signal state bit, the third signal state bit, and the fourth signal state bit has changed, and outputs a first confidence level when the detection rate of the pulse wave increases, outputs a second confidence level and / or prohibits output of the blood oxygen saturation value when the detection rate of the pulse wave decreases, the first confidence level being greater than the second confidence level.

[0069] The physiological result output unit is configured to output the blood oxygen saturation value, the first confidence level and the second confidence level.

[0070] In one of the embodiments, the system, the red light driving change detection unit implements the steps of real-time detection of the first received electrical signal, identification of the driving output change of the red light emitting tube, and output of the first signal state bit, by the following steps: real-time detection of the first received electrical signal, acquisition of the first signal quality of the first received electrical signal, judgment of the signal quality of the first received electrical signal, if the signal quality of the first received electrical signal is lower than the first preset range, the driving current or voltage of the red light emitting tube is increased, and when the driving current or voltage of the red light emitting tube changes, the first signal state bit is outputted.

[0071] The infrared light driving change detection unit implements the steps of real-time detection of the second received electrical signal, identification of the driving output change of the infrared light emitting tube, and output of the second signal state bit, by the following steps: real-time detection of the second received electrical signal, acquisition of the second signal quality of the second received electrical signal, judgment of the signal quality of the second received electrical signal, if the signal quality of the second received electrical signal is lower than the second preset range, the driving current or voltage of the infrared light emitting tube is increased, and when the driving current or voltage of the infrared light emitting tube changes, the second signal state bit is outputted.

[0072] In one of the embodiments, the physiological pulse wave detection and analysis unit implements the steps of real-time detection of the pulse wave and identification of the detection rate of the pulse wave based on the first received electrical signal and the second received electrical signal, by the following steps:

[0073] Based on the signal DC component of the red light sampling channel and the signal DC component of the infrared light sampling channel, the signal AC component of the red light sampling channel and the signal AC component of the infrared light sampling channel are compensated.

[0074] Based on the compensated signal AC component of the red light sampling channel and the compensated signal AC component of the infrared light sampling channel, waveform data is obtained.

[0075] In a preset sliding time window, a pulse wave in the waveform data is searched.

[0076] From the pulse wave, a pulse wave satisfying the pulse wave waveform morphological feature is searched; and,

[0077] The proportion of the pulse wave in the preset sliding time window is calculated, and the detection rate of the pulse wave is outputted.

[0078] In one of the embodiments, the AC quantity variation detecting unit implements the real-time detection of at least one of the AC signal quantity of the red light sampling channel and the AC signal quantity of the infrared light sampling channel, the identification of the signal variation of the AC signal quantity, and the output of the third signal state bit by using the following steps:

[0079] real-time detection of the first AC signal quantity of the red light sampling channel, judgment of whether the first AC signal quantity has a mutation trend,

[0080] real-time detection of the second AC signal quantity of the infrared light sampling channel, judgment of whether the second AC signal quantity has a mutation trend, and

[0081] when the mutation trend of the AC signal quantity of any one of the first AC signal quantity and the second AC signal quantity occurs, output of the third signal state bit; and

[0082] The DC quantity variation detecting unit implements the real-time detection of at least one of the DC signal quantity of the red light sampling channel and the DC signal quantity of the infrared light sampling channel, the identification of the signal variation of the DC signal quantity, and the output of the fourth signal state bit by using the following steps:

[0083] real-time detection of the first DC signal quantity of the red light sampling channel, judgment of whether the first DC signal quantity has a mutation trend,

[0084] real-time detection of the second DC signal quantity of the infrared light sampling channel, judgment of whether the second DC signal quantity has a mutation trend, and

[0085] when the mutation trend of the DC signal quantity of any one of the first DC signal quantity and the second DC signal quantity occurs, output of the fourth signal state bit.

[0086] In one of the embodiments, the physiological result output unit further comprises at least one of the following steps for calculating and outputting a blood oxygen saturation value according to the first received electrical signal and the second received electrical signal:

[0087] performing time-frequency domain transformation according to the first received electrical signal and the second received electrical signal to obtain time domain signals and frequency domain signals, identifying the characteristic variation of the base frequency peak of the energy spectrum on the frequency spectrum of the frequency domain signals, and determining that the characteristic variation conforms to a physiological characteristic, and then outputting the blood oxygen saturation value; and

[0088] According to the first received electrical signal and the second received electrical signal, a time-frequency domain transformation is performed to obtain a time domain signal and a frequency domain signal, and a plurality of continuous pulse wave signals are retrieved from the time domain signal, and when at least one of the rhythm, amplitude and ejection time of the retrieved plurality of continuous pulse wave signals conforms to a physiological characteristic, the blood oxygen saturation value is output.

[0089] In one of the embodiments, the non-physiological waveform detection analysis unit adopts the following steps to realize the step of judging whether the change of the detection rate of the pulse wave occurs when at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit changes:

[0090] It is judged whether any one of the first signal state bit and the second signal state bit changes, and when any one of the first signal state bit and the second signal state bit changes, it is judged whether any one of the third signal state bit and the fourth signal state bit changes, and when any one of the third signal state bit and the fourth signal state bit changes, the step of judging the change of the detection rate of the pulse wave is executed.

[0091] The pulse blood oxygen saturation detection method and system provided by the present application can quickly and timely perform comprehensive analysis according to the blood oxygen sampling signal and / or the driving current adjustment state, so as to determine whether there is a suspected non-physiological state marker, and then determine whether to output the currently calculated physiological parameter signal (such as the blood oxygen saturation value) according to the change of the detection rate of the pulse wave. In addition, the detection method adopts a sliding time window mode, so that a more accurate blood oxygen saturation value can be obtained within a shorter time (such as 10 seconds). BRIEF DESCRIPTION OF DRAWINGS

[0092] Figure 1 is a non-physiological medium detection state diagram during pulse blood oxygen saturation detection;

[0093] Figure 2 is a structural schematic diagram of the pulse blood oxygen saturation detection system provided by the present application;

[0094] Figure 3 is a flowchart of the pulse blood oxygen saturation detection method provided by the present application. DETAILED DESCRIPTION

[0095] The typical embodiments embodying the features and advantages of the present application will be described in detail in the following description. It should be understood that the present application can be practiced with various modifications and alterations within the scope thereof and such claims are not to be construed as limited to the specific processes and conditions described in the following description and as such claims are intended to cover any and all adaptive forms which come within the scope of the present application and appropriate scope of equivalents thereof.

[0096] In order to further illustrate the principles and configurations of the present application, preferred embodiments of the present application will now be described in detail in connection with the accompanying drawings.

[0097] The present application is based on an improvement of a pulse blood oxygen saturation detection device, especially an improvement of a non-invasive pulse blood oxygen saturation detection method.

[0098] As shown in the pulse blood oxygen saturation detection process, the introduction of non-physiological factors such as light interference, incorrect operation, environmental light changes, non-physiological media and other signal interference will reduce the detection accuracy of blood oxygen saturation and produce false values, thereby misleading the measured object, so it is necessary to distinguish and identify non-physiological signals and physiological signals. Figure 1 As shown in the pulse blood oxygen saturation detection process, the introduction of non-physiological factors such as light interference, incorrect operation, environmental light changes, non-physiological media and other signal interference will reduce the detection accuracy of blood oxygen saturation and produce false values, thereby misleading the measured object, so it is necessary to distinguish and identify non-physiological signals and physiological signals.

[0099] Figure 3 As shown in the pulse blood oxygen saturation detection process, the introduction of non-physiological factors such as light interference, incorrect operation, environmental light changes, non-physiological media and other signal interference will reduce the detection accuracy of blood oxygen saturation and produce false values, thereby misleading the measured object, so it is necessary to distinguish and identify non-physiological signals and physiological signals.

[0100] Step 110, using a red light emitting tube to generate red light of a first wavelength, and using an infrared light emitting tube to generate infrared light of a second wavelength.

[0101] Preferably, the first wavelength is about 660 nm and the second wavelength is about 940 nm or 905 nm.

[0102] Preferably, the red light emitting tube and the infrared light emitting tube can be two independent light source devices or can be the same integrated light source device.

[0103] Preferably, the two steps of using a red light emitting tube to generate red light of a first wavelength and using an infrared light emitting tube to generate infrared light of a second wavelength occur alternately. In order to stabilize and consistency of the light signal, the red light emitting tube and the infrared light emitting tube are usually packaged and integrated on the same plane as a light emitting assembly, and then the light emitting assembly is controlled by time-sharing to perform the two processes of using a red light emitting tube to generate red light of a first wavelength and using an infrared light emitting tube to generate infrared light of a second wavelength.

[0104] ​Step 120, using the light receiving tube to receive the light signal reflected to the surface of the light receiving tube and convert it into a first received electric signal when the red light is generated, forming a red light sampling channel; and to receive the light signal reflected to the surface of the light receiving tube and convert it into a second received electric signal when the infrared light is generated, forming an infrared light sampling channel.

[0105] Preferably, the red light receiving channel and the infrared light receiving channel are opened alternately in time. The light receiving tube here can be a light receiving tube assembly or two light receiving tubes packaged and integrated on the same plane as a same light receiving assembly. Preferably, in order to save costs, the light receiving tube here can use a same light receiving assembly to realize the reception of the red light reflection signal and the infrared light reflection signal through time division multiplexing, thereby forming the red light receiving channel and the infrared light receiving channel.

[0106] In one embodiment, step 120 can include using the light receiving tube to form a red light receiving channel and an infrared light receiving channel respectively, the red light receiving channel being used to convert the light signal reflected to the surface of the light receiving tube after the red light penetrates the medium into a first received electric signal, i.e., a red light sampling signal, and the infrared light receiving channel being used to convert the light signal reflected to the surface of the light receiving tube after the infrared light penetrates the medium into a second received electric signal, i.e., an infrared light sampling signal.

[0107] In one embodiment, the red light sampling signal and the infrared light sampling signal are obtained by alternating time division sampling, for example, at a first time, using the red light emitting tube to generate red light of a first wavelength, converting the light signal reflected to the surface of the light receiving tube after the red light penetrates the medium into a first received electric signal, thereby forming a red light receiving channel; and at a second time, using the infrared light emitting tube to generate infrared light of a second wavelength, converting the light signal reflected to the surface of the light receiving tube after the infrared light penetrates the medium into a second received electric signal, thereby forming an infrared light receiving channel.

[0108] The medium herein includes biological tissue containing hemoglobin, air, liquid, etc. If the medium is a physiological medium containing hemoglobin biological tissue, the first received electrical signal is a red light sampling channel signal (red light sampling signal) containing physiological information, and the second received electrical signal is an infrared light sampling channel signal (infrared light sampling signal) containing physiological information; if the medium is a non-physiological medium not containing hemoglobin biological tissue, the first received electrical signal is a red light sampling channel signal containing non-physiological information, and the second received electrical signal is an infrared light sampling channel signal containing non-physiological information. The non-physiological medium may be one of air, liquid, solid matter, etc. without containing flowing hemoglobin, and the non-physiological medium here is often accompanied by light interference such as sunlight, blue light, incandescent light, surgical light, etc., resulting in random white noise and disturbance signals of the sampling signal. Therefore, it can be seen that during the switching process of the non-physiological medium and the physiological medium, the first received signal of the red light sampling channel may include the red light sampling signal and the red light sampling channel signal; similarly, during the switching process of the non-physiological medium and the physiological medium, the second received signal of the infrared light sampling channel may include the infrared light sampling signal and the infrared light sampling channel signal; and the purpose of the present application is to distinguish the non-physiological detection signal and the physiological detection signal through the adaptive detection method.

[0109] Step 130, real-time detection of the first received electrical signal obtained in step 120, identification of the driving output change of the red light emitting tube, output of the first signal state bit.

[0110] Step 140, real-time detection of the second received electrical signal obtained in step 120, identification of the driving output change of the infrared light emitting tube, output of the second signal state bit.

[0111] The driving output change mentioned in steps 130 and 140 can be a change in the driving current of the red light emitting tube or a change in the driving voltage of the red light emitting tube, preferably a change in the driving current.

[0112] That is, in the preferred embodiment, in step 130, the first received electrical signal obtained in step 120 is detected in real time to identify the driving current change of the red light emitting tube, and the first signal state bit is output. In the preferred embodiment, in step 140, the second received electrical signal obtained in step 120 is detected in real time to identify the driving current change of the infrared light emitting tube, and the second signal state bit is output.

[0113] The first signal state bit and the second signal state bit can be at least one flag bit of the cache, which is used to record the state of the driving current or driving voltage of the red light emitting tube changing from the default value, and / or used to record the state of the driving current or driving voltage of the infrared light emitting tube changing from the default value. For example, the flag bit can be 0 when the driving current or driving voltage is at the default value, and the flag bit is changed to 1 when the driving current or driving voltage is changed and is no longer the default value. Of course, one flag bit can be used to achieve this, or two flag bits can be used to record the state of the driving current of the red light emitting tube or the infrared light emitting tube being at the default value respectively. In one of the embodiments, in step 130, the first received electrical signal obtained in step 120 is detected in real time, and when the driving current of the red light emitting tube changes from the default value, the first signal state bit is output to represent the change state of the driving current of the red light emitting tube between the default value and the non-default value. In step 140, the second received electrical signal obtained in step 120 is detected in real time, and when the driving current of the infrared light emitting tube changes from the default value, the second signal state bit is output to represent the change state of the driving current of the infrared light emitting tube between the default value and the non-default value.

[0114] In step 150, the signal alternating current component and the signal direct current component of the red light sampling channel are identified in real time based on the first received electrical signal, and the signal alternating current component and the signal direct current component of the infrared light sampling channel are identified in real time based on the second received electrical signal.

[0115] The signal alternating current component mentioned herein refers to the component of the change in light absorption, for example, the arterial pulsatile blood component (the change in blood flow at the moment, causing the corresponding change in absorption), and the signal alternating current component reflects the part of the photoelectric signal that changes periodically with the heartbeat and contains the key information required for blood oxygen saturation detection. The signal alternating current component can be extracted from the first received electrical signal by a traditional filtering method. The signal direct current component refers to the component of the constant light absorption, for example, the skin, bone, fat, and venous blood. The signal direct current component represents the average level of the photoelectric signal (the first received electrical signal and the second received electrical signal) and is an important reference for calculating the blood oxygen saturation. The signal direct current component specifically represents the stable part of the photoelectric signal that does not change with the heartbeat and reflects the average absorption of the tissue to light. The signal direct current component can be extracted by long-time averaging or low-pass filtering of the preprocessed photoelectric signal (the first received electrical signal and the second received electrical signal). From a physiological point of view, the order of magnitude of the direct current component is much larger than that of the alternating current component, and therefore, the direct current component can be used for calibration and compensation of the pulse wave detection signal, and the alternating current component can be used for pulse wave detection.

[0116] Preferably, in step 150, the first received electrical signal is filtered and decomposed to obtain the signal AC component and the signal DC component of the red light sampling channel, and the second received electrical signal is filtered and decomposed to obtain the signal AC component and the signal DC component of the infrared light sampling channel. The filtering and decomposing method here can be using filters with different center frequencies and bandpass ranges to distinguish the signal AC component and the signal DC component.

[0117] Step 160, real-time detection of at least one of the signal AC component of the red light sampling channel and the signal AC component of the infrared light sampling channel, identification of the signal change of the signal AC component, and output of a third signal state bit.

[0118] Step 170, real-time detection of at least one of the signal DC component of the red light sampling channel and the signal DC component of the infrared light sampling channel, identification of the signal change of the signal DC component, and output of a fourth signal state bit.

[0119] The third signal state bit and the fourth signal state bit can be at least one flag bit of the buffer, used to record the state of the signal AC component of the photoelectric signal (e.g., the first received electric signal and the second received electric signal) changing, and / or used to record the state of the signal DC component of the photoelectric signal (e.g., the first received electric signal and the second received electric signal) changing, such as the signal AC component greatly reducing, the third signal state bit being 0; the signal AC component greatly increasing, the third signal state bit being 1; the signal DC component greatly reducing, the fourth signal state bit being 0; the signal DC component greatly increasing, the fourth signal state bit being 1; the change from 0 to 1 can be used to determine that the signal state bit has changed. Secondly, the third signal state bit can be a state bit, when at least one of the signal AC component of the red light sampling channel and the signal AC component of the infrared light sampling channel changes, the third signal state bit is outputted and configured with a new value. The third signal state bit can also be two separate state bits, used to record the signal change of the signal AC component of the red light sampling channel and the signal AC component of the infrared light sampling channel, respectively. For example, the third signal state bit includes a red light third signal state bit and an infrared light third signal state bit, the red light third signal state bit is used to record the signal change of the signal AC component of the red light sampling channel, and the infrared light third signal state bit is used to record the signal change of the signal AC component of the infrared light sampling channel. Similarly, the fourth signal state bit can be a state bit, when at least one of the signal AC component of the red light sampling channel and the signal AC component of the infrared light sampling channel changes, the fourth signal state bit is outputted and configured with a new value. The fourth signal state bit can also be two separate state bits, used to record the signal change of the signal DC component of the red light sampling channel and the signal DC component of the infrared light sampling channel, respectively. For example, the fourth signal state bit includes a red light fourth signal state bit and an infrared light fourth signal state bit, the red light fourth signal state bit is used to record the signal change of the signal DC component of the red light sampling channel, and the infrared light fourth signal state bit is used to record the signal change of the signal DC component of the infrared light sampling channel.

[0120] Preferably, the signal change in the signal change of the identification signal alternating current component or the signal change of the identification signal direct current component refers to at least one characteristic of the identification signal alternating current component and the identification signal direct current component, such as amplitude, frequency, width, etc., changing, in particular, the relevant characteristic changing substantially. Substantial change includes at least one characteristic of the signal alternating current component or the signal direct current component obtained at two consecutive time points changing by more than 50%; or at least one characteristic of the signal alternating current component or the signal direct current component detected within a preset sliding time window continuously changing in the same trend. The same trend change here refers to the same characteristic continuously changing in a downward trend or the same characteristic continuously changing in an upward trend.

[0121] Step 180, detecting the pulse wave in real time according to the first received electrical signal and the second received electrical signal, and identifying the detection rate of the pulse wave.

[0122] In step 180, the detection rate of the pulse wave is based on the preset sliding time window, and the detection rate of the pulse wave is detected in real time according to the first received electrical signal and the second received electrical signal. The pulse wave detection rate mentioned in this step refers to the proportion of the pulse wave in the preset sliding time window. Here, the pulse wave refers to the successfully detected pulse wave, that is, the pulse wave form conforms to the physiological characteristics, and the standard pulse wave form template is usually used to obtain the corresponding physiological characteristics. When the physiological characteristics of the two are the same or similar, it means that the pulse wave is successfully detected. The proportion of the pulse wave is the proportion of the successfully detected pulse wave to all detected pulse wave forms.

[0123] Step 190, judging whether at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit changes.

[0124] Step 191, when at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit changes, judging the change of the detection rate of the pulse wave. When the detection rate of the pulse wave rises, it means that it is in the physiological medium detection state, and step 192 is executed: calculating the output blood oxygen saturation value according to the first received electrical signal and the second received electrical signal. When the detection rate of the pulse wave decreases, it means that it is in the non-physiological medium detection state, and the calculated blood oxygen saturation value is prohibited to be output.

[0125] The rising of the detection rate of the pulse wave and the falling of the detection rate of the pulse wave refer to that the detection rate of the pulse wave starts to show a rising trend or a falling trend. For example, if the detection rate of the pulse wave corresponding to two adjacent sampling moments increases by more than 10%, it is considered to have a rising trend; if the detection rate of the pulse wave corresponding to two adjacent sampling moments decreases by more than 10%, it is considered to have a falling trend; or if the detection rate of the pulse wave continuously rises for a period of time, it is considered to have a rising trend; or if the detection rate of the pulse wave continuously falls for a period of time, it is considered to have a falling trend.

[0126] The method of the present application mainly captures the mutation of the signal in the process of switching between physiological medium and non-physiological medium, so that the blood oxygen saturation detection system can quickly respond to the medium change, thereby giving the correct blood oxygen saturation value. Moreover, based on the judgment of multiple signal state bits, the accuracy of judgment relying only on the detection rate of the pulse wave can be improved.

[0127] In the steps 190 and 191, the preset sliding time window is used to cyclically execute the process of judging whether at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit changes, and judging the change of the detection rate of the pulse wave when at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit changes. That is, based on the first received electrical signal and the second received electrical signal, the step 130 of real-time detecting the first received electrical signal, identifying the change of the driving output of the red light emitting tube and outputting the first signal state bit is cyclically executed in the preset sliding time window; the step 140 of real-time detecting the second received electrical signal, identifying the change of the driving output of the infrared light emitting tube and outputting the second signal state bit; the step 150 of real-time detecting at least one of the signal alternating component of the red light sampling channel and the signal alternating component of the infrared light sampling channel, identifying the signal change of the signal alternating component and outputting the third signal state bit; and the step 180 of real-time detecting at least one of the signal direct current component of the red light sampling channel and the signal direct current component of the infrared light sampling channel, identifying the signal change of the signal direct current component and outputting the fourth signal state bit.

[0128] The time range of the preset sliding time window mentioned herein is greater than 5 seconds and less than 30 seconds. Preferably, the time range of the preset sliding time window is greater than 5 seconds and less than 10 seconds. Preferably, the time range of the preset sliding time window is greater than 5 seconds and less than 8 seconds. If the time range of the preset sliding time window is too short, there will be insufficient effective information to cause misjudgment; if the time range of the preset sliding time window is too long, the phenomenon of a pseudo value lasting for a long time will occur.

[0129] Of course, the aforementioned steps 130, 140, 160, 170, 180 can also be performed once within a preset sliding time window to determine whether to output the currently calculated blood oxygen saturation value once. That is, the aforementioned steps 130, 140, 160, 170, 180, 190, 191 are repeated once every preset sliding time window to perform the process from steps 130, 140, 160, 170, 180, 190 to 191.

[0130] In the manner of a sliding time window, the identification and determination of each signal state bit and the pulse wave detection rate are performed within a preset sliding time window to quickly determine whether to output the currently calculated physiological parameter signal (e.g., blood oxygen saturation value) to ensure the accuracy of the currently measured blood oxygen value.

[0131] Further, in one embodiment, when the aforementioned step 190 is performed and none of the first, second, third, and fourth signal state bits changes, the output of the blood oxygen saturation value can be determined according to the change in the pulse wave detection rate. When the pulse wave detection rate rises, step 192 is performed to calculate and output the blood oxygen saturation value based on the first and second received electrical signals. When the pulse wave detection rate falls, the calculated blood oxygen saturation value is not output. Alternatively, when the aforementioned first, second, third, and fourth signal state bits do not change beyond the preset sliding time window, it can be determined that the process of switching from a physiological medium to a non-physiological medium or vice versa has reached a stable state of the physiological medium or non-physiological medium, and thus the output of the blood oxygen saturation value can be determined according to the change in the pulse wave detection rate. When the pulse wave detection rate rises, step 192 is performed to calculate and output the blood oxygen saturation value based on the first and second received electrical signals. When the pulse wave detection rate falls, the calculated blood oxygen saturation value is not output.

[0132] In the process of pulse blood oxygen saturation detection, the introduction of non-physiological factors leads to the decrease of blood oxygen saturation detection accuracy, the appearance of error value, and the misleading of the measured object. Therefore, it is necessary to distinguish and identify non-physiological signals and physiological signals, so as to prohibit the calculation and output of blood oxygen saturation when the non-physiological signal detection state is identified. In the method of the present application, the switching change of physiological medium and non-physiological medium can be quickly analyzed based on the blood oxygen sampling signal and / or the driving current adjustment state, so as to determine whether there is a suspected non-physiological state mark, and then determine whether to output the current calculated physiological parameter signal (such as blood oxygen saturation value) according to the change of pulse wave detection rate. Secondly, the detection method adopts a sliding time window mode to obtain relatively accurate blood oxygen saturation value within a short time (such as 10 seconds).

[0133] In one embodiment, the pulse blood oxygen saturation detection method further comprises the following steps:

[0134] The confidence level of the output pulse wave detection signal is output when at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit changes. When the detection rate of the pulse wave rises, the first confidence level is output; when the detection rate of the pulse wave decreases, the second confidence level and / or the output of the blood oxygen saturation value is prohibited. The first confidence level and the second confidence level are used to output and display in the form of a bar chart or a percentage on the interface of the pulse blood oxygen saturation detection system, so as to prompt the user to judge whether the output blood oxygen saturation value is accurate and reliable in combination with the confidence level. The greater the confidence value is, the more accurate the output is, and the more display levels of the confidence bar chart, the more accurate the output is.

[0135] In one embodiment, in the pulse blood oxygen saturation detection method, the real-time detection of the pulse wave in step 180 according to the first received electrical signal and the second received electrical signal includes the following steps:

[0136] Based on the signal DC component of the red light sampling channel and the signal DC component of the infrared light sampling channel, the signal AC component of the red light sampling channel and the signal AC component of the infrared light sampling channel are compensated.

[0137] Based on the compensated signal AC component of the red light sampling channel and the signal AC component of the infrared light sampling channel, waveform data is obtained,

[0138] Searching for the pulse wave in the waveform data within a preset sliding time window,

[0139] Searching for the pulse wave satisfying the pulse wave waveform feature from the pulse wave, and

[0140] The proportion of the pulse wave in the preset sliding time window is calculated, and the detection rate of the pulse wave is output.

[0141] In this embodiment, the step of compensating the signal AC component of the red light sampling channel and the signal AC component of the infrared light sampling channel based on the signal DC component of the red light sampling channel and the signal DC component of the infrared light sampling channel is compensated in the following manner:

[0142] The ratio of the signal DC component of the infrared light sampling channel to the signal DC component of the red light sampling channel is calculated, and the signal AC component of the red light sampling channel is replaced by the ratio multiplied by the signal AC component of the red light sampling channel obtained by real-time identification.

[0143] The first received electrical signal and the second received electrical signal are sampled and analyzed in a sliding time window, so that the success rate of pulse wave detection in the current sampling signal can be fed back in real time, and the accuracy of data measurement under non-physiological medium detection can be better reflected.

[0144] In this embodiment, the pulse wave in the waveform data in the preset sliding time window is searched, and the pulse wave satisfying the pulse wave waveform feature is searched from the pulse wave in the following steps:

[0145] The waveform data is calculated in a combination of time domain algorithm and frequency domain algorithm to obtain time domain signals and frequency domain signals;

[0146] The feature of the base frequency peak of the energy spectrum on the frequency spectrum is identified from the frequency domain signals, and the feature is within the physiological feature range; and

[0147] Based on the waveform range, a plurality of continuous pulse wave signals are retrieved from the corresponding time domain signals, and the rhythm, amplitude and ejection time of the plurality of continuous pulse wave signals retrieved conform to the physiological feature, so that the searched pulse wave is obtained.

[0148] The real-time pulse detection rate depends on the design of the blood oxygen algorithm. Generally, it is roughly divided into time domain algorithm, frequency domain algorithm, etc. The present application selects a system combining time domain algorithm and frequency domain algorithm as the basis for identifying the pulse detection rate. Among them, the time domain signal is used for real-time detection of rhythmic pulse wave signals, and the rhythm matching, amplitude matching, ejection time matching, etc. of the plurality of continuous pulse wave signals retrieved are used to judge whether it is a physiological signal; the frequency domain algorithm identifies the number and amplitude change of the base frequency peak of the energy spectrum on the frequency spectrum to judge whether it is a physiological signal. Within the locked physiological signal range, the pulse wave conforming to the physiological feature (matching the physiological feature) is searched. The rhythm, amplitude and ejection time parameters conforming to the physiological feature can be obtained from the standard pulse waveform template.

[0149] In one embodiment, the steps of detecting the first received electrical signal in real time, identifying the change of the driving output of the red light emitting tube, obtaining the first signal state bit in step 130, and detecting the second received electrical signal in real time, identifying the change of the driving output of the infrared light emitting tube, obtaining the second signal state bit in step 140 include:

[0150] detecting the first received electrical signal in real time, obtaining the first signal quality of the first received electrical signal, adjusting the driving output of the red light emitting tube according to the first signal quality, and outputting the first signal state bit when the driving output of the red light emitting tube changes; and

[0151] detecting the second received electrical signal in real time, obtaining the second signal quality of the second received electrical signal, adjusting the driving output of the infrared light emitting tube according to the second signal quality, and outputting the second signal state bit when the driving output of the infrared light emitting tube changes.

[0152] When the signal quality changes from good to bad, it indicates that the suspected state is switched from the physiological medium detection state to the non-physiological medium detection state, and vice versa, when the signal quality changes from bad to good, it indicates that the suspected state is switched from the non-physiological medium detection state to the physiological medium detection state. The change of the signal quality will induce the detection method of the present application to adjust the driving output (such as the driving current or the driving voltage) of the red light emitting tube or the infrared light emitting tube, therefore, based on the output change of the driving output of the red light emitting tube or the infrared light emitting tube to mark the first signal state bit and the second signal state bit, the switching process of the non-physiological medium detection state and the physiological medium detection state can be identified, so as to accurately optimize the output of the blood oxygen saturation value of the detection method.

[0153] In one embodiment, the aforementioned steps of adjusting the driving output of the red light emitting tube according to the first signal quality, outputting the first signal state bit when the driving output of the red light emitting tube changes, and adjusting the driving output of the infrared light emitting tube according to the second signal quality, outputting the second signal state bit when the driving output of the infrared light emitting tube changes include:

[0154] judging the signal quality of the first received electrical signal, if the signal quality of the first received electrical signal is lower than the first preset range, increasing the driving current or voltage of the red light emitting tube, and outputting the first signal state bit when the driving current or voltage of the red light emitting tube changes; and

[0155] judging the signal quality of the second received electrical signal, if the signal quality of the second received electrical signal is lower than the second preset range, increasing the driving current or voltage of the infrared light emitting tube, and outputting the second signal state bit when the driving current or voltage of the infrared light emitting tube changes.

[0156] At this time, the first signal state bit and the second signal state bit are assigned to represent the change state of the driving current or voltage of the red light emitting tube and the change state of the driving current or voltage of the infrared light emitting tube in the embodiment, and the detection method can preliminarily determine that the suspected state is in the non-physiological medium detection state.

[0157] In one embodiment, the step of identifying the signal AC component and the signal DC component of the red light sampling channel in real time based on the first received electrical signal and identifying the signal AC component and the signal DC component of the infrared light sampling channel in real time based on the second received electrical signal in step 150 includes:

[0158] The first received electrical signal is filtered and decomposed to obtain the signal AC component and the signal DC component of the red light sampling channel, and

[0159] The second received electrical signal is filtered and decomposed to obtain the signal AC component and the signal DC component of the infrared light sampling channel.

[0160] For example, the signal DC components of the first received electrical signal and the second received electrical signal are obtained by low-pass filtering, and the signal AC components of the first received electrical signal and the second received electrical signal are obtained by high-pass filtering.

[0161] Preferably, the first received electrical signal and the second received electrical signal are high-pass filtered to obtain the first signal AC component of the red light sampling channel and the second signal AC component of the infrared light sampling channel; and the first received electrical signal and the second received electrical signal are low-pass filtered to obtain the first signal DC component of the red light sampling channel and the second signal DC component of the infrared light sampling channel.

[0162] In one embodiment, in step 160, the step of detecting at least one of the signal AC components of the red light sampling channel and the signal AC components of the infrared light sampling channel in real time, identifying the signal change of the signal AC component, and outputting the third signal state bit includes:

[0163] The first signal AC component of the red light sampling channel is detected in real time, and it is determined whether the characteristic of the first signal AC component has a jump trend;

[0164] The second signal AC component of the infrared light sampling channel is detected in real time, and it is determined whether the characteristic of the second signal AC component has a jump trend; and

[0165] When the characteristic of any one of the first signal AC component and the second signal AC component has a jump trend, the third signal state bit is outputted.

[0166] In one of the embodiments, in step 170, the step of detecting at least one of the signal direct current component of the red light sampling channel and the signal direct current component of the infrared light sampling channel in real time, identifying the signal change of the signal direct current component, and outputting the fourth signal state bit includes:

[0167] detecting the first signal direct current component of the red light sampling channel in real time, and judging whether the characteristic of the first signal direct current component has a jump trend;

[0168] detecting the second signal direct current component of the infrared light sampling channel in real time, and judging whether the characteristic of the second signal direct current component has a jump trend; and,

[0169] outputting the fourth signal state bit when the characteristic of any one of the first signal direct current component and the second signal direct current component has a jump trend.

[0170] The jump trend of the signal characteristic mentioned in the present text means that the signal characteristic obtained by the adjacent two times of sampling has a change of more than 30%. The signal characteristic obtained by the sampling can be at least one of the amplitude, frequency, and rhythm. For example, when the characteristic of any one of the first signal alternating current component and the second signal alternating current component has a jump trend, it means that at least one of the following situations exists: the signal characteristic of the first signal alternating current component obtained by the continuous sampling has a change of more than 30%; and the signal characteristic of the second signal alternating current component obtained by the continuous sampling has a change of more than 30%. When the characteristic of any one of the first signal direct current component and the second signal direct current component has a jump trend, it means that at least one of the following situations exists: the signal characteristic of the first signal direct current component obtained by the continuous sampling has a change of more than 30%; and the signal characteristic of the second signal direct current component obtained by the continuous sampling has a change of more than 30%. The jump trend can also be the sudden data inversion (such as data from yes to no, or from no to yes), or the sudden data doubling decrease or increase, etc. in addition to the judgment of the change of more than 30%. Here, 30% is only an example, and can also be a preset threshold value defined by any one of 20% to 100%. Therefore, the jump trend of the signal characteristic mentioned in the present text means that the signal characteristic obtained by the adjacent two times of sampling has a change of more than the preset threshold value.

[0171] In the present application, the third signal state bit and the fourth signal state bit are endowed with the jump state representing the signal AC component and the jump state of the signal DC component. The detection method can preliminarily determine the switching of the suspected non-physiological medium detection state and the physiological state. If at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit changes in the process of continuously collecting and outputting the successful pulse wave, it can be determined that the suspected non-physiological detection state is in the non-physiological detection state, and then combined with the change of the detection rate of the pulse wave to comprehensively determine whether it is in the non-physiological detection state. If at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit changes in the process of searching for the pulse wave and not successfully collecting and outputting the pulse wave, it can be determined that the suspected physiological detection state is in the physiological detection state, and then combined with the change of the detection rate of the pulse wave to comprehensively determine whether it is in the physiological detection state.

[0172] In one embodiment of the foregoing pulse blood oxygen saturation detection method, the step of determining the change of the detection rate of the pulse wave further comprises at least one of the following steps:

[0173] According to the first received electrical signal and the second received electrical signal, time-frequency domain transformation is performed to obtain time domain signals and frequency domain signals, and the characteristic change of the base frequency peak of the energy spectrum on the frequency spectrum of the frequency domain signals is identified. When the characteristic change is consistent with the physiological characteristics, the blood oxygen saturation value calculated according to the first received electrical signal and the second received electrical signal is output. And according to the first received electrical signal and the second received electrical signal, time-frequency domain transformation is performed to obtain time domain signals and frequency domain signals, and continuous multiple pulse wave signals are searched from the time domain signals. When at least one of the rhythm, amplitude and ejection time of the searched continuous multiple pulse wave signals is consistent with the physiological characteristics, the blood oxygen saturation value calculated according to the first received electrical signal and the second received electrical signal is output.

[0174] In the embodiment, the waveform features conforming to the physiological features include: the fundamental frequency peak corresponds to the heart rate (HR), usually located at 0.8-3.0 Hz (corresponding to 48-180 bpm). The multiple frequency peaks correspond to the harmonics of the heart rate, usually the integer multiples (2x, 3x, 4x) of the fundamental frequency, and the energy intensity gradually decreases. Therefore, after time-frequency domain transformation, the base multiple frequency peaks of the energy spectrum based on the red light sampling signal and the infrared light sampling signal are matched with the waveform features conforming to the physiological features, so as to confirm again whether the current is in the physiological medium detection state, and if it matches the waveform features conforming to the physiological features, it means that the current is in the physiological medium detection state, and the calculated blood oxygen saturation value can be output. The physiological features conforming to the physiological features means that at least one of the rhythm, amplitude and ejection time of the retrieved continuous multiple pulse wave signals matches the standard pulse waveform template. Therefore, at least one of the rhythm, amplitude and ejection time of the retrieved continuous multiple pulse wave signals conforms to the physiological features, which means that at least one of the waveform features of the rhythm, amplitude and ejection time of the retrieved continuous multiple pulse wave signals matches the corresponding features of the standard pulse waveform template.

[0175] In step 192 of the embodiment, the method for calculating the output blood oxygen saturation value according to the first received electrical signal and the second received electrical signal can be obtained by sampling the empirical equation. The core of the calculation of the blood oxygen saturation (SpO2) is the ratio of ratios. It calculates the proportion of oxygenated hemoglobin in the blood by comparing the difference in absorption of red light and infrared light by the blood. When calculating the blood oxygen saturation value, first calculate the blood oxygen saturation coefficient according to the following formula:

[0176]

[0177] Wherein, is the blood oxygen saturation coefficient; is the infrared light adaptive filtered alternating current component, that is, the signal alternating current component of the infrared light sampling channel;

[0178] is the red light adaptive filtered alternating current component with a simplified coefficient, that is, the red light sampling channel signal alternating current component compensated based on the signal direct current component of the red light sampling channel and the signal direct current component of the infrared light sampling channel according to the foregoing method.

[0179] Then, according to the empirical formula, the blood oxygen saturation value expressed in percentage form is converted according to the obtained blood oxygen saturation coefficient.

[0180] In one of the embodiments, in the step 190, when the change of the at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit is determined, the step of determining the change of the detection rate of the pulse wave comprises:

[0181] When the change of the at least one of the first signal state bit and the second signal state bit is determined, the change of the at least one of the third signal state bit and the fourth signal state bit is determined.

[0182] When the change of the at least one of the third signal state bit and the fourth signal state bit is determined, the step of determining the change of the detection rate of the pulse wave is executed.

[0183] In the embodiment, the signal state detection of the driving output of the red light emitting tube and the infrared light emitting tube is performed first, and then the determination of the signal AC component and the signal DC component is performed, so as to accelerate the processing speed of the blood oxygen saturation detection method. Since the hardware adaptive recognition detection is adopted for the driving output of the light emitting tube, the blood oxygen saturation detection method can be more rapid and convenient.

[0184] The blood oxygen saturation detection method provides a dynamic capture technology of complex blood oxygen signals. The dynamic multi-dimensional signal screening capture technology is used to analyze and process the light absorption change signal of the physiological medium collected by the photoelectric sensor (light emitting tube and light receiving tube), so as to realize the high-precision measurement of the blood oxygen saturation under complex application environments (such as environments in which various non-physiological media and physiological media are switched and affected) and different physiological conditions.

[0185] Based on the blood oxygen saturation detection method, as shown in Figure 2 The application further provides a blood oxygen saturation detection system 200. The system 200 is used to realize the blood oxygen saturation detection method. Therefore, the system comprises the following components.

[0186] The red light emitting tube 211 is used to generate red light of a first wavelength.

[0187] The infrared light emitting tube 212 is used to generate infrared light of a second wavelength.

[0188] The red light driving adjustment unit 231 is used to output a driving signal to the red light emitting tube, and execute the step 110 of generating red light of the first wavelength by using the red light emitting tube.

[0189] The infrared light driving adjustment unit 232 is configured to output a driving signal to the aforementioned infrared light emitting tube, and to generate the aforementioned infrared light of the second wavelength by using the aforementioned infrared light emitting tube in the aforementioned step 110.

[0190] The signal receiving unit 220 is configured to receive the optical signal emitted to the surface of the aforementioned light receiving tube and convert it into a first received electrical signal to form a red light sampling channel when the aforementioned red light is generated, and to receive the optical signal emitted to the surface of the aforementioned light receiving tube and convert it into a second received electrical signal to form an infrared light sampling channel when the aforementioned infrared light is generated, i.e., to perform the aforementioned step 120.

[0191] The red light driving change detection unit 310 is configured to detect the aforementioned first received electrical signal in real time, identify the driving output change of the aforementioned red light emitting tube, and output a first signal state bit, i.e., to perform the aforementioned step 130.

[0192] The infrared light driving change detection unit 311 is configured to detect the aforementioned second received electrical signal in real time, identify the driving output change of the aforementioned infrared light emitting tube, and output a second signal state bit, i.e., to perform the aforementioned step 140.

[0193] The direct current component identification unit 241 is configured to identify the signal direct current component of the red light sampling channel and the signal direct current component of the infrared light sampling channel in real time based on the aforementioned first received electrical signal and the aforementioned second received electrical signal, i.e., to perform the signal direct current component identification part of the aforementioned step 150.

[0194] The alternating current component identification unit 242 is configured to identify the signal alternating current component of the red light sampling channel and the signal alternating current component of the infrared light sampling channel in real time based on the aforementioned first received electrical signal and the aforementioned second received electrical signal, i.e., to perform the signal alternating current component identification part of the aforementioned step 150.

[0195] The direct current component change detection unit 320 is configured to detect at least one of the signal direct current component of the aforementioned red light sampling channel and the signal direct current component of the aforementioned infrared light sampling channel in real time, identify the signal change of the aforementioned signal direct current component, and output a fourth signal state bit, i.e., to perform the aforementioned step 170.

[0196] The alternating current component change detection unit 330 is configured to detect at least one of the signal alternating current component of the aforementioned red light sampling channel and the signal alternating current component of the aforementioned infrared light sampling channel in real time, identify the signal change of the aforementioned signal alternating current component, and output a third signal state bit, i.e., to perform the aforementioned step 160.

[0197] The physiological pulse wave detection and analysis unit 250 is configured to detect the pulse wave in real time based on the aforementioned first received electrical signal and the aforementioned second received electrical signal, and identify the detection rate of the aforementioned pulse wave, i.e., to perform the aforementioned step 180.

[0198] a physiological result output unit 270 configured to calculate the blood oxygen saturation value according to the first received electrical signal and the second received electrical signal, i.e., to perform the step 192; and

[0199] a non-physiological waveform detection analysis unit 260 configured to determine whether at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit changes, and when at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit changes, to determine the change of the detection rate of the pulse wave, and when the detection rate of the pulse wave increases, to cause the physiological result output unit to output the blood oxygen saturation value, i.e., to perform the steps 190 and 191.

[0200] The various units in the blood oxygen saturation detection system of the present application are configured to complete the various steps of the blood oxygen saturation detection method, and the related concepts and specific steps are explained above, which will not be repeated here.

[0201] In one of the embodiments of the blood oxygen saturation detection system, the non-physiological waveform detection analysis unit further comprises the following steps:

[0202] outputting the confidence level of the pulse wave detection signal, when at least one of the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit changes, determining the change of the detection rate of the pulse wave, and when the detection rate of the pulse wave increases, outputting a first confidence level; and when the detection rate of the pulse wave decreases, outputting a second confidence level and / or prohibiting the output of the blood oxygen saturation value, the first confidence level being greater than the second confidence level; and

[0203] the physiological result output unit is configured to output the blood oxygen saturation value, the first confidence level and the second confidence level.

[0204] In one of the embodiments of the blood oxygen saturation detection system, the red light driving change detection unit realizes the step of real-time detecting the first received electrical signal, identifying the driving output change of the red light emitting tube, and outputting the first signal state bit by using the following steps:

[0205] real-time detecting the first received electrical signal, obtaining the first signal quality of the first received electrical signal, adjusting the driving output of the red light emitting tube according to the first signal quality, and when the driving output of the red light emitting tube changes, outputting the first signal state bit; and

[0206] The infrared light driving change detection unit realizes the steps of detecting the second received electrical signal in real time, identifying the driving output change of the infrared light emitting tube, and outputting the second signal state bit by the following steps: detecting the second received electrical signal in real time, obtaining the second signal quality of the second received electrical signal, adjusting the driving output of the infrared light emitting tube according to the second signal quality, and outputting the second signal state bit when the driving output of the infrared light emitting tube changes.

[0207] In one of the embodiments of the blood oxygen saturation detection system, the red light driving change detection unit realizes the steps of adjusting the driving output of the red light emitting tube according to the first signal quality and outputting the first signal state bit when the driving output of the red light emitting tube changes by the following steps: judging the signal quality of the first received electrical signal, increasing the driving current or voltage of the red light emitting tube if the signal quality of the first received electrical signal is lower than a first preset range, and outputting the first signal state bit when the driving current or voltage of the red light emitting tube changes.

[0208] The infrared light driving change detection unit realizes the steps of adjusting the driving output of the infrared light emitting tube according to the second signal quality and outputting the second signal state bit when the driving output of the infrared light emitting tube changes by the following steps: judging the signal quality of the second received electrical signal, increasing the driving current or voltage of the infrared light emitting tube if the signal quality of the second received electrical signal is lower than a second preset range, and outputting the second signal state bit when the driving current or voltage of the infrared light emitting tube changes.

[0209] In one of the embodiments of the blood oxygen saturation detection system, the direct current component identification unit realizes the identification process of the signal direct current component in the steps of identifying the signal alternating current component and the signal direct current component of the red light sampling channel based on the first received electrical signal and identifying the signal alternating current component and the signal direct current component of the infrared light sampling channel based on the second received electrical signal by the following steps:

[0210] Based on the first received electrical signal and the second received electrical signal, the signal direct current component of the red light sampling channel and the signal direct current component of the infrared light sampling channel are obtained by filter decomposition processing.

[0211] Preferably, the direct current component identification unit is a low-pass filter.

[0212] In one of the embodiments of the blood oxygen saturation detection system, the AC component identification unit implements the identification of the AC component of the red light sampling channel based on the first received electrical signal and the identification of the AC component of the infrared light sampling channel based on the second received electrical signal by the following steps:

[0213] The AC components of the red light sampling channel and the infrared light sampling channel are obtained by filtering and decomposing the first received electrical signal and the second received electrical signal.

[0214] Preferably, the AC component identification unit is a high-pass filter.

[0215] In one of the embodiments of the blood oxygen saturation detection system, the physiological pulse wave detection and analysis unit implements the real-time detection of the pulse wave and the identification of the detection rate of the pulse wave based on the first received electrical signal and the second received electrical signal by the following steps:

[0216] The AC components of the red light sampling channel and the infrared light sampling channel are obtained by filtering and decomposing the first received electrical signal and the second received electrical signal.

[0217] The waveform data is obtained based on the compensated AC components of the red light sampling channel and the infrared light sampling channel.

[0218] The pulse wave is searched in the waveform data within a preset sliding time window.

[0219] The pulse wave satisfying the pulse wave waveform feature is searched from the pulse wave.

[0220] The proportion of the pulse wave within the preset sliding time window is calculated, and the detection rate of the pulse wave is output.

[0221] In one of the embodiments of the blood oxygen saturation detection system, the AC component variation detection unit implements the real-time detection of at least one of the AC components of the red light sampling channel and the infrared light sampling channel, the identification of the signal variation of the AC component, and the output of the third signal state bit by the following steps:

[0222] The first AC component of the red light sampling channel is detected in real time, and it is determined whether the feature of the first AC component has a mutation trend.

[0223] The second AC component of the infrared light sampling channel is detected in real time, and it is determined whether the feature of the second AC component has a mutation trend.

[0224] When a mutation trend occurs in the characteristic of any one of the first signal AC component and the second signal AC component, the third signal state bit is outputted.

[0225] In one of the embodiments of the blood oxygen saturation detection system, the direct current variation detection unit implements the step of detecting at least one of the signal DC component of the red light sampling channel and the signal DC component of the infrared light sampling channel in real time, identifying the signal variation of the signal DC component, and outputting the fourth signal state bit by the following steps:

[0226] detecting the first signal DC component of the red light sampling channel in real time, judging whether a mutation trend exists in the characteristic of the first signal DC component,

[0227] detecting the second signal DC component of the infrared light sampling channel in real time, judging whether a mutation trend exists in the characteristic of the second signal DC component, and

[0228] When a mutation trend occurs in the characteristic of any one of the first signal DC component and the second signal DC component, the fourth signal state bit is outputted.

[0229] In one of the embodiments of the blood oxygen saturation detection system, the red light drive variation detection unit, the infrared light drive variation detection unit, the AC variation detection unit, and the direct current variation detection unit are cyclically executed in a preset sliding time window, and the steps include: detecting the first received electric signal in real time, identifying the drive output variation of the red light emitting tube, and outputting the first signal state bit; detecting the second received electric signal in real time, identifying the drive output variation of the infrared light emitting tube, and outputting the second signal state bit; detecting at least one of the signal AC component of the red light sampling channel and the signal AC component of the infrared light sampling channel in real time, identifying the signal variation of the signal AC component, and outputting the third signal state bit; and detecting at least one of the signal DC component of the red light sampling channel and the signal DC component of the infrared light sampling channel in real time, identifying the signal variation of the signal DC component, and outputting the fourth signal state bit.

[0230] In one of the embodiments of the blood oxygen saturation detection system, the time range of the preset sliding time window is greater than 5 seconds and less than 10 seconds.

[0231] In one of the embodiments of the blood oxygen saturation detection system, the physiological result output unit further includes at least one of the following steps:

[0232] According to the first received electrical signal and the second received electrical signal, time-frequency domain transformation is performed to obtain a time domain signal and a frequency domain signal, a characteristic change of a fundamental frequency peak of an energy spectrum on a frequency spectrum of the frequency domain signal is identified, and when the characteristic change is consistent with a physiological characteristic, the blood oxygen saturation value is outputted; and

[0233] According to the first received electrical signal and the second received electrical signal, time-frequency domain transformation is performed to obtain a time domain signal and a frequency domain signal, a characteristic change of a fundamental frequency peak of an energy spectrum on a frequency spectrum of the frequency domain signal is identified, and when the characteristic change is consistent with a physiological characteristic, the blood oxygen saturation value is outputted; and

[0234] In one of the embodiments of the blood oxygen saturation detection system, when the first signal state bit, the second signal state bit, the third signal state bit and the fourth signal state bit are changed, the step of judging the change of the detection rate of the pulse wave is executed according to the following process:

[0235] When the first signal state bit and the second signal state bit are changed, it is judged whether the third signal state bit and the fourth signal state bit are changed;

[0236] When one of the third signal state bit and the fourth signal state bit is changed, the step of judging the change of the detection rate of the pulse wave is executed.

[0237] The above-mentioned various embodiments of the blood oxygen saturation detection system are used to execute the specific steps of the above-mentioned various embodiments of the blood oxygen saturation detection method, and thus the specific steps executed by the units of the system will be explained in detail according to the explanation of the steps of the blood oxygen saturation detection method, which will not be repeated here.

[0238] In the process of pulse blood oxygen saturation detection, the introduction of non-physiological factors leads to the decrease of blood oxygen saturation detection accuracy, the appearance of error value, and the problem of misleading the measured object. Therefore, it is necessary to distinguish and identify non-physiological signals and physiological signals, so that when the non-physiological signal detection state is identified, the calculation and output of blood oxygen saturation should be prohibited. The blood oxygen saturation detection method and system of the present application adopts a dynamic capture technology of complex blood oxygen signals, which analyzes and processes the light absorption change signal of physiological medium collected by the photoelectric sensor (light emitting tube and light receiving tube) through dynamic multi-dimensional signal screening capture technology, and realizes high-precision measurement of blood oxygen saturation under complex application environment (such as environment affected by mutual switching of various non-physiological medium and physiological medium) and different physiological conditions. The present application can quickly analyze the state of blood oxygen sampling signal and / or driving current adjustment state in time according to the switching change of physiological medium and non-physiological medium, so as to determine whether there is a suspected non-physiological state marker, and then determine whether to output the current calculated physiological parameter signal (such as blood oxygen saturation value) according to the change of pulse wave detection rate. Secondly, the detection method and system of the present application can obtain more accurate blood oxygen saturation value in a relatively short time (such as 10 seconds) by using sliding time window.

[0239] Although the present application has been described with reference to several exemplary embodiments, it is understood that the terms used are illustrative and not restrictive, and that the use of such terms is not intended to limit the scope of the present application. Since the present application can be embodied in many different forms without departing from the spirit or essential characteristics thereof, it should be understood that the above-described embodiments are not limited to any of the foregoing details, but are to be broadly interpreted within the spirit and scope of the appended claims, and all changes and modifications that fall within the bounds of the claims or their equivalents should be covered by the claims.

Claims

1. A method for detecting pulse oxygen saturation, characterized in that, The method includes: The first wavelength of red light is generated using a red light-emitting diode; Infrared light of a second wavelength is generated using an infrared LED. When the red light is generated, the light receiving tube receives the light signal emitted to the surface of the light receiving tube and converts it into a first received electrical signal to form a red light sampling channel. When the infrared light is generated, the light receiving tube receives the light signal emitted to the surface of the light receiving tube and converts it into a second received electrical signal to form an infrared light sampling channel. The first received electrical signal is detected in real time, the change in the drive output of the red light-emitting tube is identified, and the first signal status bit is output. The second received electrical signal is detected in real time, the change in the drive output of the infrared light-emitting tube is identified, and the second signal status bit is output. Based on the first received electrical signal, the AC component and DC component of the red light sampling channel are identified in real time. Based on the second received electrical signal, the AC component and DC component of the infrared light sampling channel are identified in real time. Real-time detection of at least one of the signal AC components of the red light sampling channel and the infrared light sampling channel, identification of the signal changes of the signal AC component, and output of a third signal status bit; Real-time detection of at least one of the DC components of the signal from the red light sampling channel and the infrared light sampling channel; identification of signal changes in the DC component; and output of a fourth signal status bit. Based on the first received electrical signal and the second received electrical signal, the pulse wave is detected in real time, and the detection rate of the pulse wave is identified; and, Determine whether at least one of the first signal status bit, the second signal status bit, the third signal status bit, and the fourth signal status bit has changed. When at least one of the first signal status bit, the second signal status bit, the third signal status bit, and the fourth signal status bit has changed, determine the change in the detection rate of the pulse wave. When the detection rate of the pulse wave increases, calculate and output the blood oxygen saturation value based on the first received electrical signal and the second received electrical signal. The step of detecting the pulse wave in real time based on the first received electrical signal and the second received electrical signal, and identifying the detection rate of the pulse wave, includes the following steps: Based on the DC component of the signal from the red light sampling channel and the DC component of the signal from the infrared light sampling channel, compensation is made for the AC component of the signal from the red light sampling channel and the AC component of the signal from the infrared light sampling channel. Based on the compensated signal AC components of the red light sampling channel and the infrared light sampling channel, waveform data is obtained; Search for pulse waves in the waveform data within a preset sliding time window; Search for pulse waves that satisfy the waveform morphology characteristics from the pulse waves; and, Calculate the proportion of the pulse wave within the preset sliding time window and output the detection rate of the pulse wave.

2. The method for detecting pulse oxygen saturation according to claim 1, characterized in that, The method further includes the following steps: The confidence level of the output pulse wave detection signal is determined by the following: when at least one of the first, second, third, and fourth signal state bits changes, the change in the detection rate of the pulse wave is judged. When the detection rate of the pulse wave increases, a first confidence level is output; when the detection rate of the pulse wave decreases, a second confidence level is output and / or the output of the blood oxygen saturation value is prohibited. The first confidence level is greater than the second confidence level.

3. The method for detecting pulse oxygen saturation according to claim 1, characterized in that, The steps of real-time detection of the first received electrical signal, identification of changes in the drive output of the red light-emitting diode, and output of a first signal status bit, and real-time detection of the second received electrical signal, identification of changes in the drive output of the infrared light-emitting diode, and output of a second signal status bit include: The system continuously detects the first received electrical signal, obtains the first signal quality of the first received electrical signal, adjusts the drive output of the red light-emitting diode according to the first signal quality, and outputs the first signal status bit when the drive output of the red light-emitting diode changes; and, The second received electrical signal is detected in real time, the second signal quality of the second received electrical signal is obtained, the driving output of the infrared light-emitting diode is adjusted according to the second signal quality, and the second signal status bit is output when the driving output of the infrared light-emitting diode changes.

4. The pulse oxygen saturation detection method according to claim 3, characterized in that, The steps of adjusting the drive output of the red light-emitting diode according to the first signal quality, and outputting the first signal status bit when the drive output of the red light-emitting diode changes, and adjusting the drive output of the infrared light-emitting diode according to the second signal quality, and outputting the second signal status bit when the drive output of the infrared light-emitting diode changes, include: The signal quality of the first received electrical signal is determined. If the signal quality of the first received electrical signal is lower than a first preset range, the driving current or voltage of the red light-emitting diode is increased. When the driving current or voltage of the red light-emitting diode changes, the first signal status bit is output. The signal quality of the second received electrical signal is determined. If the signal quality of the second received electrical signal is lower than the second preset range, the driving current or voltage of the infrared light-emitting diode is increased. When the driving current or voltage of the infrared light-emitting diode changes, the second signal status bit is output.

5. The method for detecting pulse oxygen saturation according to claim 1, characterized in that, The steps of identifying the AC and DC components of the red light sampling channel in real time based on the first received electrical signal, and identifying the AC and DC components of the infrared light sampling channel in real time based on the second received electrical signal, include: The first received electrical signal is filtered and decomposed to obtain the AC component and DC component of the red light sampling channel, and... The second received electrical signal is filtered and decomposed to obtain the AC component and DC component of the infrared light sampling channel.

6. The method for detecting pulse oxygen saturation according to claim 1, characterized in that, The step of real-time detection of at least one of the signal AC components of the red light sampling channel and the infrared light sampling channel, identifying the signal changes of the signal AC component, and outputting a third signal status bit includes: The first signal AC component of the red light sampling channel is detected in real time to determine whether there is a sudden change trend in the characteristics of the first signal AC component. Real-time detection of the second signal AC component of the infrared light sampling channel, determining whether the characteristics of the second signal AC component exhibit a sudden change trend, and, When the characteristics of either the first signal AC component or the second signal AC component exhibit a sudden change trend, the third signal status bit is output; and... The step of real-time detection of at least one of the DC components of the signal from the red light sampling channel and the infrared light sampling channel, identifying the signal change of the DC component, and outputting a fourth signal status bit includes: The DC component of the first signal in the red light sampling channel is detected in real time to determine whether there is a sudden change trend in the characteristics of the DC component of the first signal. Real-time detection of the DC component of the second signal in the infrared light sampling channel, determining whether there is a sudden change trend in the characteristics of the DC component of the second signal, and, When the characteristics of either the DC component of the first signal or the DC component of the second signal exhibit a sudden change trend, the fourth signal status bit is output.

7. The method for detecting pulse oxygen saturation according to claim 1, characterized in that, The process of detecting the first received electrical signal in real time, identifying the change in the driving output of the red light-emitting diode, and outputting the first signal status bit is repeated once every preset sliding time window until the step of judging the change in the detection rate of the pulse wave is completed.

8. The pulse oximetry detection method according to claim 5 or 7, characterized in that, The preset sliding time window has a time range of more than 5 seconds and less than 10 seconds.

9. The method for detecting pulse oxygen saturation according to claim 1 or 2, characterized in that, The step of determining the change in the detection rate of the pulse wave is followed by at least one of the following steps: Based on the first received electrical signal and the second received electrical signal, a time-frequency domain transformation is performed to obtain a time-domain signal and a frequency-domain signal. The characteristic changes of the fundamental octave peak of the energy spectrum in the frequency-domain signal are identified. When it is determined that the characteristic changes conform to physiological characteristics, the blood oxygen saturation value is output; and... Based on the first received electrical signal and the second received electrical signal, a time-frequency domain transformation is performed to obtain a time-domain signal and a frequency-domain signal. Multiple consecutive pulse wave signals are retrieved from the time-domain signal. If at least one of the rhythm, amplitude, and ejection time of the retrieved multiple consecutive pulse wave signals conforms to physiological characteristics, the blood oxygen saturation value is output.

10. The method for detecting pulse oxygen saturation according to claim 1, characterized in that, The step of determining whether at least one of the first, second, third, and fourth signal status bits has changed, and determining the change in the detection rate of the pulse wave when at least one of the first, second, third, and fourth signal status bits has changed, includes: Determine whether any one of the first signal status bits and the second signal status bits has changed; when any one of the first signal status bits and the second signal status bits has changed, determine whether any one of the third signal status bits and the fourth signal status bits has changed. If any one of the third signal state bits and the fourth signal state bit changes, the step of judging the change in the detection rate of the pulse wave is executed.

11. A pulse oximetry detection system, characterized in that, The detection system includes: Red light-emitting diode, used to generate red light of the first wavelength; Infrared LEDs are used to generate infrared light of a second wavelength. The red light driving adjustment unit is used to output a driving signal to the red light-emitting tube and generate red light of the first wavelength using the red light-emitting tube; An infrared light drive adjustment unit is used to output a drive signal to the infrared light-emitting tube and use the infrared light-emitting tube to generate infrared light of a second wavelength. The signal receiving unit is used to receive the light signal emitted onto the surface of the light receiving tube when the red light is generated and convert it into a first received electrical signal to form a red light sampling channel; and to receive the light signal emitted onto the surface of the light receiving tube when the infrared light is generated and convert it into a second received electrical signal to form an infrared light sampling channel. The red light drive change detection unit is used to detect the first received electrical signal in real time, identify the change in the drive output of the red light-emitting tube, and output the first signal status bit. An infrared light drive change detection unit is used to detect the second received electrical signal in real time, identify the drive output change of the infrared light-emitting tube, and output a second signal status bit. A DC component identification unit is used to identify the DC component of the signal from the red light sampling channel and the DC component of the signal from the infrared light sampling channel in real time based on the first received electrical signal and the second received electrical signal. An AC signal identification unit is used to identify, in real time, the AC signal component of the red light sampling channel and the AC signal component of the infrared light sampling channel based on the first received electrical signal and the second received electrical signal. A DC change detection unit is used to detect at least one of the DC components of the signal from the red light sampling channel and the infrared light sampling channel in real time, identify the signal change of the DC component, and output a fourth signal status bit. An AC quantity change detection unit is used to detect at least one of the signal AC components of the red light sampling channel and the infrared light sampling channel in real time, identify the signal change of the signal AC component, and output a third signal status bit. The physiological pulse wave detection and analysis unit is used to detect the pulse wave in real time based on the first received electrical signal and the second received electrical signal, and to identify the detection rate of the pulse wave. The physiological result output unit is used to calculate and output a blood oxygen saturation value based on the first received electrical signal and the second received electrical signal; and, The non-physiological waveform detection and analysis unit is used to determine whether at least one of the first signal state position, the second signal state position, the third signal state position, and the fourth signal state position has changed. When at least one of the first signal state position, the second signal state position, the third signal state position, and the fourth signal state position changes, the unit determines the change in the detection rate of the pulse wave. When the detection rate of the pulse wave increases, the unit instructs the physiological result output unit to output the blood oxygen saturation value. The physiological pulse wave detection and analysis unit employs the following steps to implement the step of detecting the pulse wave in real time based on the first received electrical signal and the second received electrical signal, and identifying the detection rate of the pulse wave: Based on the DC component of the signal from the red light sampling channel and the DC component of the signal from the infrared light sampling channel, compensation is made for the AC component of the signal from the red light sampling channel and the AC component of the signal from the infrared light sampling channel. Waveform data is obtained based on the compensated AC signal components of the red light sampling channel and the infrared light sampling channel. Search for pulse waves in the waveform data within a preset sliding time window; Search for pulse waves that satisfy the waveform morphology characteristics from the pulse waves; and, Calculate the proportion of the pulse wave within the preset sliding time window and output the detection rate of the pulse wave.

12. The pulse oximetry detection system according to claim 11, characterized in that, The non-physiological waveform detection and analysis unit also performs the following steps: The confidence level of the output pulse wave detection signal is determined by the following: when at least one of the first, second, third, and fourth signal state positions changes, the change in the detection rate of the pulse wave is judged. When the detection rate of the pulse wave increases, a first confidence level is output; when the detection rate of the pulse wave decreases, a second confidence level is output and / or the output of the blood oxygen saturation value is prohibited. The first confidence level is greater than the second confidence level. and, The physiological result output unit is used to output the blood oxygen saturation value, the first confidence level, and the second confidence level.

13. The pulse oximetry detection system according to claim 11, characterized in that, The red light drive change detection unit adopts the following steps to realize the real-time detection of the first received electrical signal, identify the change in the drive output of the red light emitting tube, and output the first signal status bit: real-time detection of the first received electrical signal, acquisition of the first signal quality of the first received electrical signal, judgment of the signal quality of the first received electrical signal, if the signal quality of the first received electrical signal is lower than a first preset range, then increase the drive current or voltage of the red light emitting tube, and output the first signal status bit when the drive current or voltage of the red light emitting tube changes; and, The infrared light drive change detection unit adopts the following steps to realize the real-time detection of the second received electrical signal, identify the drive output change of the infrared light emitting tube, and output the second signal status bit: real-time detection of the second received electrical signal, acquisition of the second signal quality of the second received electrical signal, judgment of the signal quality of the second received electrical signal, if the signal quality of the second received electrical signal is lower than the second preset range, then increase the drive current or voltage of the infrared light emitting tube, and output the second signal status bit when the drive current or voltage of the infrared light emitting tube changes.

14. The pulse oximetry detection system according to claim 11, characterized in that, The AC quantity change detection unit employs the following steps to achieve real-time detection of at least one of the AC signal components from the red light sampling channel and the infrared light sampling channel, identify the signal changes of the AC signal component, and output a third signal status bit: The first signal AC component of the red light sampling channel is detected in real time to determine whether there is a sudden change trend in the characteristics of the first signal AC component. Real-time detection of the second signal AC component of the infrared light sampling channel, determining whether the characteristics of the second signal AC component exhibit a sudden change trend, and, When the characteristics of either the first signal AC component or the second signal AC component exhibit a sudden change trend, the third signal status bit is output; and... The DC change detection unit employs the following steps to achieve real-time detection of at least one of the DC components of the signal from the red light sampling channel and the infrared light sampling channel, identify the signal change of the DC component, and output a fourth signal status bit: The DC component of the first signal in the red light sampling channel is detected in real time to determine whether there is a sudden change trend in the characteristics of the DC component of the first signal. Real-time detection of the DC component of the second signal in the infrared light sampling channel, determining whether there is a sudden change trend in the characteristics of the DC component of the second signal, and, When the characteristics of either the DC component of the first signal or the DC component of the second signal change abruptly, the fourth signal status bit is output.

15. The pulse oximetry detection system according to claim 11, characterized in that, The physiological result output unit further includes at least one of the following steps to calculate and output a blood oxygen saturation value based on the first received electrical signal and the second received electrical signal: Based on the first received electrical signal and the second received electrical signal, a time-frequency domain transformation is performed to obtain a time-domain signal and a frequency-domain signal. The characteristic changes of the fundamental octave peak of the energy spectrum in the frequency-domain signal are identified. When it is determined that the characteristic changes conform to physiological characteristics, the blood oxygen saturation value is output; and... Based on the first received electrical signal and the second received electrical signal, a time-frequency domain transformation is performed to obtain a time-domain signal and a frequency-domain signal. Multiple consecutive pulse wave signals are retrieved from the time-domain signal. If at least one of the rhythm, amplitude, and ejection time of the retrieved multiple consecutive pulse wave signals conforms to physiological characteristics, the blood oxygen saturation value is output.

16. The pulse oximetry detection system according to claim 11, characterized in that, The non-physiological waveform detection and analysis unit employs the following steps to determine whether at least one of the first, second, third, and fourth signal state positions has changed, and when at least one of the first, second, third, and fourth signal state positions changes, to determine the change in the detection rate of the pulse wave: Determine whether any one of the first signal state bits and the second signal state bits has changed. If any one of the first signal state bits and the second signal state bits has changed, determine whether any one of the third signal state bits and the fourth signal state bits has changed. If any one of the third signal state bits and the fourth signal state bits has changed, then execute the step of determining the change in the detection rate of the pulse wave.

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