阅读说明：本技术 血氧测量装置和系统及其血氧信号检测方法 (Blood oxygen measuring device and system and blood oxygen signal detection method thereof ) 是由 叶继伦 刘春生 王凡 蒋芸 于 2019-09-24 设计创作，主要内容包括：血氧测量装置和系统及血氧信号检测方法中包括至少四个光电放大电路；主控制模块依次分别将四个光电放大电路接入获取四个测量信号,在其中选取测量信号最先在700至900毫伏之间的光电放大电路用作后续测量光电放大电路。当所述四个测量信号不在700至900毫伏之间,调节光源输出功率为之前输出功率的N倍或1/N倍,直至至少一个光电放大电路的测量信号在700至900毫伏之间。采用多路光电放大和光驱动联合调整的方法,并据此设置后级的放大电路的放大倍数和偏置,使电路快速适应外部测量条件,大大缩短了光信号和外部测量条件之间的适配过程,从而实现了快速的血氧测量,尤其是初始的血氧响应时间上远远优于现有技术。(the blood oxygen measuring device and system and the blood oxygen signal detection method comprise at least four photoelectric amplification circuits; the main control module sequentially and respectively accesses the four photoelectric amplification circuits to obtain four measurement signals, wherein the photoelectric amplification circuit with the measurement signal between 700 and 900 millivolts is selected to be used as a subsequent measurement photoelectric amplification circuit. When the four measuring signals are not between 700 and 900 millivolts, the output power of the light source is adjusted to be N times or 1/N times of the previous output power until the measuring signal of the at least one photoelectric amplifying circuit is between 700 and 900 millivolts. The method adopts the method of combining and adjusting the multi-path photoelectric amplification and the optical drive, and sets the amplification factor and the offset of the amplifying circuit at the back stage according to the method, so that the circuit can adapt to the external measuring condition quickly, the adaptation process between the optical signal and the external measuring condition is greatly shortened, the quick blood oxygen measurement is realized, and especially the initial blood oxygen response time is far superior to the prior art.)

1. An oximetry device comprising:

The first-order amplifying circuit comprises at least four photoelectric amplifying circuits with different amplifying times, and the four photoelectric amplifying circuits are respectively as follows: the photoelectric amplifier comprises a first photoelectric amplifying circuit, a second photoelectric amplifying circuit, a third photoelectric amplifying circuit and a fourth photoelectric amplifying circuit, wherein the amplification factors of the four photoelectric amplifying circuits are arranged in a step shape;

The bias setting module is used for setting the bias of the amplifier circuit; the input end of the secondary amplifying circuit is electrically connected with the output end of the primary amplifying circuit to obtain a primary amplified blood oxygen measuring signal; the output end of the secondary amplifying circuit is electrically connected with the main control module and outputs a secondary amplified blood oxygen measuring signal to the main control module; one end of the bias setting module is electrically connected with the bias input end of the secondary amplifying circuit, and the other end of the bias setting module is electrically connected with the main control module; when measurement is started, the main control module sequentially acquires blood oxygen measurement signals subjected to primary amplification by the four photoelectric amplification circuits;

The main control module acquires each path of blood oxygen measurement signals after primary amplification, performs signal quality evaluation respectively, and selects one photoelectric amplification circuit with the blood oxygen measurement signal amplitude in a set range firstly from the four photoelectric amplification circuits as a photoelectric amplification circuit for subsequent blood oxygen measurement;

the main control module outputs a bias setting value to the bias setting module according to the obtained magnitude of the first-stage amplified blood oxygen measurement signal output by the selected photoelectric amplification circuit, and the bias setting value is used as a bias value of the second-stage amplification circuit.

2. the oximetry device of claim 1, wherein:

In the signal quality evaluation, the set range of the oximetry signal amplitude is 700 to 900 mv.

3. the oximetry device of claim 1, wherein:

The main control module outputs the bias setting value to the bias setting module, wherein the bias setting value is 0.8 to 1.2 times of the blood oxygen measurement signal quantity after the first-stage amplification, and the bias setting value is used as the bias value of the second-stage amplification circuit.

4. The oximetry device of claim 1, wherein:

The device also comprises a light source driving circuit capable of adjusting the output power of the red light source or the infrared light source;

when the four paths of blood oxygen measurement signals output by the four photoelectric amplification circuits are all smaller than 700 millivolts, the light source driving circuit adjusts the output power of the light source to be N times of the previous output power, and the blood oxygen measurement signals output by the four photoelectric amplification circuits are detected again until the blood oxygen measurement signal of at least one photoelectric amplification circuit is larger than or equal to 700 millivolts;

when the blood oxygen measuring signals output by the four photoelectric amplifying circuits are all larger than 900 millivolts,

the light source driving circuit adjusts the output power of the light source to be 1/N times of the previous output power, and the blood oxygen measuring signals output by the four photoelectric amplifying circuits are detected again until the blood oxygen measuring signal of at least one photoelectric amplifying circuit is less than or equal to 900 millivolts;

Wherein N is a natural number greater than 1.

5. The oximetry device of claim 1, wherein:

The first selection control circuit of the photoelectric amplification channel is used for selecting the photoelectric amplification channel from four photoelectric amplification circuits of the primary amplification circuit;

One end of a first selection control circuit of the photoelectric amplification channel is connected with the sensor to obtain an original blood oxygen measurement signal;

The other end of the first selection control circuit of the photoelectric amplification channel is electrically connected with the input end of one of the four photoelectric amplification circuits;

The control end of the first selection control circuit of the photoelectric amplification channel is electrically connected with the main control module; the first selection control circuit of the photoelectric amplification channel is controlled by the main control module and selects the photoelectric amplification circuit which is electrically communicated with the first selection control circuit of the photoelectric amplification channel.

6. Blood oxygen measuring system based on the blood oxygen measuring device of any one of claims 1 to 5, characterized in that:

Comprises a second-stage amplification channel selection control circuit;

The second-stage amplification channel selection control circuit is used for controlling the connection of the second-stage amplification circuit and each photoelectric amplification circuit;

The input end of the second-stage amplification channel selection control circuit is selected and electrically connected with the output ends of the four photoelectric amplification circuits; the output end of the second-stage amplification channel selection control circuit is electrically connected with the input end of the second-stage amplification circuit;

the control end of the second-stage amplification channel selection control circuit is electrically connected with the main control module;

the second-stage amplification channel selection control circuit is controlled by the main control module, and selects one of the four photoelectric amplification circuits to be electrically communicated with the input end of the second-stage amplification circuit.

7. an oximetry signal detection method based on the oximetry device of any one of claims 1 to 5, comprising the following steps:

step A: sequentially connecting a first photoelectric amplification circuit, a second photoelectric amplification circuit, a third photoelectric amplification circuit and a fourth photoelectric amplification circuit to a main measurement circuit; acquiring a blood oxygen measurement signal after primary photoelectric amplification;

and B: acquiring various paths of blood oxygen measurement signals subjected to primary photoelectric amplification by a main control module, and respectively evaluating the quality of the blood oxygen measurement signals;

And C: the photoelectric amplifying circuit which is selected from the four photoelectric amplifying circuits and outputs the blood oxygen measuring signal in the set range firstly is used as the photoelectric amplifying circuit for subsequent measurement.

8. The blood oxygen signal detection method according to claim 7, wherein:

In step C, the set range for the oximetry signal quality assessment is 700 to 900 mv.

9. The blood oxygen signal detection method according to claim 7, further comprising,

Step D: the main control module outputs a bias setting value to the bias setting module according to the obtained magnitude of the first-stage amplified blood oxygen measurement signal output by the selected photoelectric amplification circuit, and the bias setting value is used as a bias value of the second-stage amplification circuit.

10. The blood oxygen signal detection method according to claim 7, wherein:

The blood oxygen measuring device also comprises a light source driving circuit which can adjust the output power of the light source;

In step C, when the measurement signals output by the four photoelectric amplification circuits are all less than 700 millivolts, the light source driving circuit adjusts the output power of the light source to be N times of the previous output power, and the blood oxygen measurement signals output by the four photoelectric amplification circuits are detected again until the blood oxygen measurement signal output by at least one photoelectric amplification circuit is more than or equal to 700 millivolts;

In the step C, when the measurement signals output by the four photoelectric amplification circuits are all larger than 900 millivolts, the light source driving circuit adjusts the output power of the light source to be 1/N times of the previous output power, and the blood oxygen measurement signals output by the four photoelectric amplification circuits are detected again until the blood oxygen measurement signal of at least one photoelectric amplification circuit is less than or equal to 900 millivolts; wherein N is a natural number greater than 1.

Technical Field

The invention relates to the technical field of medical equipment, in particular to a blood oxygen measuring device and system for performing pulse blood oxygen measurement by using red light and infrared light and a blood oxygen signal detection method.

background

The oxygen saturation level (SpO2) is the percentage of the volume of oxygenated hemoglobin bound by oxygen (HbO2) in the blood to the total bindable hemoglobin (Hb) volume, i.e. the concentration of blood oxygen in the blood, which is an important physiological parameter of the respiratory cycle. Monitoring arterial oxygen saturation (SaO2) allows an estimate of the oxygenation of the lungs and the hemoglobin oxygen carrying capacity. The normal human arterial blood has a blood oxygen saturation of 98% and venous blood of 75%.

Pulse oximetry is a medical device that measures the oxygen content of a patient's arterial blood. Pulse oximeters provide a method of measuring blood oxygen saturation or arterial hemoglobin saturation in a non-invasive manner and measuring the heart rate of a patient. Pulse oxygen monitoring is one of the key parameters in modern clinical operation, intensive care, routine care and other applications, is widely applied, and can be applied to multi-parameter monitors, portable multi-parameter monitors and respiratory sleep monitors.

the pulse oxygen measurement technique currently applied in each of the above instruments is generally to alternately irradiate a tested area (generally, a circulation peripheral part such as a fingertip, an earlobe or a forehead) with two light sources of a visible red light spectrum (660 nm) and an infrared spectrum (940 nm), the amount of light absorbed by the two lights during blood pulsation is related to the oxygen content in blood, so that the change of the amount of light absorbed during pulsation of the artery is detected, the ratio of the energy of the two absorbed spectra is calculated, and the result is compared with a saturation value table in a memory, thereby obtaining the blood oxygen saturation. The photoelectric driving light source and the photoelectric conversion circuit amplify and digitize the electric signals and then carry out digital signal processing and calculation to obtain human body parameter indexes such as pulse oxygen saturation value, pulse rate, perfusion index and the like.

disclosure of Invention

In order to avoid the defects of the prior art, the invention provides a blood oxygen measuring device, a blood oxygen measuring system and a blood oxygen signal detecting method which can carry out blood oxygen measurement quickly, the invention adopts the matching of an amplifying circuit with parallel 4 circuit amplification performance step-shaped and a light source driving circuit, the times of the driving circuit and the amplifying circuit which are suitable for the current medium to be measured are found quickly by sequentially circulating each stage of amplifying circuit, and the offset setting adjustment of the secondary amplification is carried out by utilizing the signal output by the stage of amplifying circuit, and the two are cooperated, thereby greatly shortening the adaptation process of the system between the optical signal and the medium to be measured, realizing the quick blood oxygen measurement, and particularly the initial blood oxygen response time is far superior to the prior art.

The technical problem to be solved by the present invention is to avoid the deficiencies of the above technical solutions, and the proposed technical solution is a blood oxygen measuring device, comprising: the first-order amplifying circuit comprises at least four photoelectric amplifying circuits with different amplifying times, and the four photoelectric amplifying circuits are respectively as follows: the photoelectric amplifier comprises a first photoelectric amplifying circuit, a second photoelectric amplifying circuit, a third photoelectric amplifying circuit and a fourth photoelectric amplifying circuit, wherein the amplification factors of the four photoelectric amplifying circuits are arranged in a step shape; the bias setting module is used for setting the bias of the amplifier circuit; the input end of the secondary amplifying circuit is electrically connected with the output end of the primary amplifying circuit to obtain a primary amplified blood oxygen measuring signal; the output end of the secondary amplifying circuit is electrically connected with the main control module and outputs a secondary amplified blood oxygen measuring signal to the main control module; one end of the bias setting module is electrically connected with the bias input end of the secondary amplifying circuit, and the other end of the bias setting module is electrically connected with the main control module; when measurement is started, the main control module sequentially acquires blood oxygen measurement signals subjected to primary amplification by the four photoelectric amplification circuits; the main control module acquires each path of blood oxygen measurement signals after primary amplification, performs signal quality evaluation respectively, and selects one photoelectric amplification circuit with the blood oxygen measurement signal amplitude in a set range firstly from the four photoelectric amplification circuits as a photoelectric amplification circuit for subsequent blood oxygen measurement; the main control module outputs a bias setting value to the bias setting module according to the obtained magnitude of the first-stage amplified blood oxygen measurement signal output by the selected photoelectric amplification circuit, and the bias setting value is used as a bias value of the second-stage amplification circuit.

in the blood oxygen measuring device, the setting range of the blood oxygen measuring signal amplitude is 700 to 900 millivolts in the signal quality evaluation.

the main control module outputs the bias setting value to the bias setting module, wherein the bias setting value is 0.8 to 1.2 times of the blood oxygen measurement signal quantity after the first-stage amplification, and the bias setting value is used as the bias value of the second-stage amplification circuit.

the blood oxygen measuring device also comprises a light source driving circuit which can adjust the output power of the red light source or the infrared light source; when the four paths of blood oxygen measurement signals output by the four photoelectric amplification circuits are all smaller than 700 millivolts, the light source driving circuit adjusts the output power of the light source to be N times of the previous output power, and the blood oxygen measurement signals output by the four photoelectric amplification circuits are detected again until the blood oxygen measurement signal of at least one photoelectric amplification circuit is larger than or equal to 700 millivolts; when the blood oxygen measuring signals output by the four photoelectric amplifying circuits are all larger than 900 millivolts, the light source driving circuit adjusts the output power of the light source to be 1/N times of the previous output power, and the blood oxygen measuring signals output by the four photoelectric amplifying circuits are detected again until the blood oxygen measuring signals of at least one photoelectric amplifying circuit are smaller than or equal to 900 millivolts; wherein N is a natural number greater than 1.

The blood oxygen measuring device also comprises a first selection control circuit of the photoelectric amplification channel, wherein the first selection control circuit of the photoelectric amplification channel is used for selecting the photoelectric amplification channel from four photoelectric amplification circuits of the primary amplification circuit; one end of a first selection control circuit of the photoelectric amplification channel is connected with the sensor to obtain an original blood oxygen measurement signal; the other end of the first selection control circuit of the photoelectric amplification channel is electrically connected with the input end of one of the four photoelectric amplification circuits; the control end of the first selection control circuit of the photoelectric amplification channel is electrically connected with the main control module; the first selection control circuit of the photoelectric amplification channel is controlled by the main control module and selects the photoelectric amplification circuit which is electrically communicated with the first selection control circuit of the photoelectric amplification channel.

The blood oxygen measuring device comprises a two-stage amplification channel selection control circuit, a first-stage amplification channel selection control circuit, a second-stage amplification channel selection control circuit and a first-stage amplification channel selection control circuit, wherein the first-stage amplification channel selection control circuit is connected with the first-stage amplification channel selection control circuit; the second-stage amplification channel selection control circuit is used for controlling the connection of the second-stage amplification circuit and each photoelectric amplification circuit; the input end of the second-stage amplification channel selection control circuit is selected and electrically connected with the output ends of the four photoelectric amplification circuits; the output end of the second-stage amplification channel selection control circuit is electrically connected with the input end of the second-stage amplification circuit; the control end of the second-stage amplification channel selection control circuit is electrically connected with the main control module; the second-stage amplification channel selection control circuit is controlled by the main control module, and selects one of the four photoelectric amplification circuits to be electrically communicated with the input end of the second-stage amplification circuit.

The technical solution for solving the above technical problem can also be a blood oxygen signal detection method, based on the above blood oxygen measurement device, comprising the following steps: step A: sequentially connecting a first photoelectric amplification circuit, a second photoelectric amplification circuit, a third photoelectric amplification circuit and a fourth photoelectric amplification circuit to a main measurement circuit; acquiring a blood oxygen measurement signal after primary photoelectric amplification; and B: acquiring various paths of blood oxygen measurement signals subjected to primary photoelectric amplification by a main control module, and respectively evaluating the quality of the blood oxygen measurement signals; and C: the photoelectric amplifying circuit which is selected from the four photoelectric amplifying circuits and outputs the blood oxygen measuring signal in the set range firstly is used as the photoelectric amplifying circuit for subsequent measurement.

In the blood oxygen signal detecting method, in the step C, the setting range of the quality evaluation of the blood oxygen measuring signal is 700 to 900 mv.

The blood oxygen signal detection method further comprises the following steps: the main control module outputs a bias setting value to the bias setting module according to the obtained magnitude of the first-stage amplified blood oxygen measurement signal output by the selected photoelectric amplification circuit, and the bias setting value is used as a bias value of the second-stage amplification circuit.

in the blood oxygen signal detection method, the blood oxygen measuring device also comprises a light source driving circuit capable of adjusting the output power of the light source; in step C, when the measurement signals output by the four photoelectric amplification circuits are all less than 700 millivolts, the light source driving circuit adjusts the output power of the light source to be N times of the previous output power, and the blood oxygen measurement signals output by the four photoelectric amplification circuits are detected again until the blood oxygen measurement signal output by at least one photoelectric amplification circuit is more than or equal to 700 millivolts; in the step C, when the measurement signals output by the four photoelectric amplification circuits are all larger than 900 millivolts, the light source driving circuit adjusts the output power of the light source to be 1/N times of the previous output power, and the blood oxygen measurement signals output by the four photoelectric amplification circuits are detected again until the blood oxygen measurement signal of at least one photoelectric amplification circuit is less than or equal to 900 millivolts; wherein N is a natural number greater than 1.

Compared with the prior art, the invention has the beneficial effects that: 1. the four photoelectric amplifying circuits are adopted for primary screening of the measurement signals, and the bias setting of the secondary amplifying circuit is carried out according to the primary amplified blood oxygen measurement signals, so that the time for adapting to the measurement conditions is greatly accelerated; 2. the two-stage amplifying circuit with adjustable bias utilizes controllable bias on the amplifying circuit, so that the time for adjusting the reference voltage and the amplification factor of the amplifying circuit is further shortened, the adaptation process between the blood oxygen measuring system and the medium to be measured is further shortened, and the blood oxygen measuring conditions which are difficult to detect by conventional technical means such as thin measuring media and the like can be rapidly matched; 3, N times of light source driving combined adjustment mode enables primary light source adjustment to be sequentially applied to four photoelectric amplification circuits, and system adjustment time is further shortened; therefore, the rapid blood oxygen measurement can be carried out on different types of blood oxygen measurement, and particularly the initial blood oxygen response time is far superior to that of the prior art.

Drawings

FIG. 1 is a schematic block diagram of one embodiment of an oximetry device of the present invention;

FIG. 2 is a second schematic block diagram of an embodiment of an oximetry device of the present invention;

FIG. 3 is a schematic block diagram of a prior art blood oximetry device;

FIG. 4 is a schematic flow chart of a blood oxygen measurement method;

FIG. 5 is a second schematic flow chart of the blood oxygen measurement method.

Detailed Description

the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In one embodiment of the blood oxygen measuring device and system shown in fig. 1, the main control module is a microprocessor, and the main control module controls the optical driving circuit, the bias setting circuit, the first selection control circuit of the photoelectric amplification channel and the second selection control circuit of the second amplification channel respectively.

as shown in fig. 1, the photoelectric amplification channel first selection control circuit is arranged between the sensor and the four photoelectric amplification circuits, and is used for selecting the photoelectric amplification channel among the four photoelectric amplification circuits; one end of a first selection control circuit of the photoelectric amplification channel is connected with the sensor to obtain an original blood oxygen measurement signal; the other end of the first selection control circuit of the photoelectric amplification channel is electrically connected with the input end of one of the four photoelectric amplification circuits; the control end of the first selection control circuit of the photoelectric amplification channel is electrically connected with the main control module; the first selection control circuit of the photoelectric amplification channel is controlled by the main control module and selects the photoelectric amplification circuit which is electrically communicated with the first selection control circuit of the photoelectric amplification channel.

In one embodiment of the oximetry device and system shown in fig. 1, a two-stage amplification circuit and a two-stage amplification channel selection control circuit are included; the second-stage amplifying circuit is an amplifying circuit capable of adjusting bias; the device also comprises a bias setting module; one end of the bias setting module is electrically connected with the secondary amplifying circuit, and the other end of the bias setting module is electrically connected with the main control module; the main control module outputs a bias setting value to the bias setting module to be used as the bias of the secondary amplifying circuit.

In one embodiment of the oximetry device and system shown in fig. 1, the secondary amplification channel selection control circuit is disposed between the four photo-electric amplification circuits and the adjustable bias secondary amplification circuit; the second-stage amplification channel selection control circuit is used for controlling the connection of the second-stage amplification circuit and each photoelectric amplification circuit; the input end of the second-stage amplification channel selection control circuit is selected and electrically connected with the output ends of the four photoelectric amplification circuits; the output end of the second-stage amplification channel selection control circuit is electrically connected with the input end of the second-stage amplification circuit; the control end of the second-stage amplification channel selection control circuit is electrically connected with the main control module; the second-stage amplification channel selection control circuit is controlled by the main control module, and selects one of the four photoelectric amplification circuits to be electrically communicated with the input end of the second-stage amplification circuit. In a specific embodiment of the blood oxygen measuring device and system shown in fig. 2, only one analog amplifier circuit is designed, a sensor is omitted in the figure, the main control module, i.e. the microprocessor, respectively controls the light output control circuit to perform light source adjustment and gain adjustment of the first-stage analog amplifier circuit, and a single channel performs dynamic range adjustment, so that a very high requirement is put on the dynamic range of a single amplifier circuit, and meanwhile, the circuit adjustment time is increased, rapid measurement cannot be realized, measurement requirements of different media to be measured cannot be rapidly adapted, and especially in blood oxygen measurement applications of newborns or poor peripheral circulation, a situation exceeding the dynamic range of the amplifier may occur, resulting in measurement failure.

As shown in fig. 4, a blood oxygen signal detecting method based on the blood oxygen measuring device includes the following steps:

Step A: sequentially connecting a first photoelectric amplification circuit, a second photoelectric amplification circuit, a third photoelectric amplification circuit and a fourth photoelectric amplification circuit to a main measurement loop; acquiring a blood oxygen measurement signal after photoelectric amplification, namely acquiring four paths of analog signals and preprocessing the signals;

and B: acquiring various paths of blood oxygen measurement signals subjected to photoelectric amplification by the main control module, and respectively evaluating the quality of the blood oxygen measurement signals, namely judging whether the acquired blood oxygen measurement signals are in a set threshold range by adopting signal window threshold judgment;

And C: selecting the photoelectric amplifying circuit of which the blood oxygen measuring signal is firstly in a set range from the four photoelectric amplifying circuits as the photoelectric amplifying circuit for subsequent measurement; the set range for the quality assessment of the blood oxygen measurement signal is 700 to 900 millivolts;

In step C, when the measurement signals output by the four photoelectric amplification circuits are all less than or equal to 700 millivolts, the light source driving circuit adjusts the output power of the light source to be N times of the previous output power, and the blood oxygen measurement signals output by the four photoelectric amplification circuits are detected again until the blood oxygen measurement signal output by at least one photoelectric amplification circuit is more than 700 millivolts; wherein N is a natural number greater than 1; n can be adjusted and set according to actual needs, if the obtained blood oxygen measurement signal is far less than 700 millivolts, the numerical value of N can be large, and the output power of the light source can be rapidly adjusted, for example, N is 8, 6 or 4, and the like, and is adjusted by a higher multiple; if the obtained blood oxygen measurement signal is close to 700 millivolts, the value of N can be small, and the micro-adjustment of the light source output power is carried out, for example, the fine adjustment of the light source output power is carried out when N is 3 or 2;

in the step C, when the measurement signals output by the four photoelectric amplification circuits are all larger than 900 millivolts, the light source driving circuit adjusts the output power of the light source to be 1/N times of the previous output power, and the blood oxygen measurement signals output by the four photoelectric amplification circuits are detected again until the blood oxygen measurement signal of at least one photoelectric amplification circuit is less than or equal to 900 millivolts; wherein N is a natural number greater than 1; if the obtained blood oxygen measurement signal is far greater than 900 millivolts, the value of N can be large, and the output power of the light source is rapidly adjusted, for example, N is 8, 6 or 4, and is adjusted by a higher multiple; if the obtained blood oxygen measurement signal is already close to 900 mv, the value of N may be small, and the micro-adjustment of the light source output power is performed, for example, the fine adjustment of the light source output power is performed by taking N to 3 or 2.

in some embodiments, not shown in the drawings, step D is also included: the main control module outputs a bias setting value to the bias setting module according to the obtained magnitude of the first-stage amplified blood oxygen measurement signal output by the selected photoelectric amplification circuit, and the bias setting value is used as a bias value of the second-stage amplification circuit.

in addition to the steps shown in fig. 4, the blood oxygen signal detecting method shown in fig. 5 further includes a step of selecting one of four analog signals, i.e. obtaining the blood oxygen measuring signal after the first-stage amplification in one of the four photoelectric amplifying circuits, and performing the second-stage signal amplification after the signal amplification again.

when the secondary signal is amplified, the blood oxygen measurement signal quantity output by the primary amplifying circuit can be utilized to carry out bias setting on the secondary signal amplifying circuit; the bias setting of the secondary signal amplifying circuit is based on the bias amplitude and the amplification factor of the signal after the signal acquisition and the signal preprocessing are carried out to obtain the target value of the bias setting and the adjustment; and after signal preprocessing, signal feature identification and calculation are carried out, and a waveform and calculation parameters are output. Usually, the main control module outputs the bias setting value to the bias setting module, which is 0.8 to 1.2 times of the amount of the blood oxygen measurement signal after the first-stage amplification, and the bias setting value is used as the bias value of the second-stage amplification circuit. In one embodiment, the bias value of the secondary signal amplification circuit can be set to be the oximetry signal amount; of course, a value of 0.8 to 1.2 times the magnitude of the oximetry signal may be selected for use as the offset value. The bias can be a voltage type bias or a current type bias, and can be converted into a corresponding voltage bias during the current type bias. The bias arrangement mode greatly improves the working efficiency and the adjusting time of the secondary amplifying circuit, and applies the amplifying capacity of the secondary amplifying circuit to the amplification of differential signals at the fastest speed.

The multiple first-stage photoelectric amplification circuits are additionally used for acquiring real-time signals output by the first-stage photoelectric amplification circuits, and the acquired first-stage amplified blood oxygen measurement signals are used for multiple first-stage photoelectric amplification selections and second-stage amplified gain-adjustable bias setting. A large circulation for adjusting the adaptation of the system and the external measurement condition is formed between the light source driving circuit and the primary amplifying circuit, and the primary amplifying circuit is adjusted to the state most suitable for the external measurement condition through the cooperative adjustment between the primary circuit and the light source driving circuit; on the basis, the small-cycle cooperative adjustment of the first-stage amplification circuit and the second-stage amplification circuit is performed, so that the locking of the measurement target condition is quickly realized, the quick acquisition of the pulse signal and the quick calculation of the blood oxygen are realized, the joint adjustment process of the two-stage amplification circuits belongs to the prior art, and the details are not repeated herein.

Compared with other technologies, the blood oxygen measuring device, the blood oxygen measuring system and the blood oxygen signal detection method adopt four photoelectric amplification circuits to carry out primary screening of measuring signals, and greatly accelerate the time for adapting to measuring conditions; the N times of light source driving combined adjustment mode enables primary light source adjustment to be sequentially applied to four photoelectric amplification circuits, and system adjustment time is further shortened; the two-stage amplifying circuit with adjustable bias utilizes controllable bias on the amplifying circuit, so that the time for adjusting the reference voltage and the amplification factor of the amplifying circuit is further shortened, the adaptation process between the blood oxygen measuring system and the medium to be measured is further shortened, and the blood oxygen measuring conditions which are difficult to detect by conventional technical means such as thin measuring media and the like can be rapidly matched; therefore, the rapid blood oxygen measurement can be carried out on different types of blood oxygen measurement, and particularly the initial blood oxygen response time is far superior to that of the prior art.

the blood oxygen signal detection method based on the combined adjustment mechanism of the multi-channel analog signal acquisition and the bidirectional light source drive can be quickly matched with different media to be measured for adjustment.

The method has excellent clinical application value, is one of the essential blood oxygen monitoring technologies for operation, intensive care and emergency rescue, can completely replace the imported similar measurement technology from the measurement function and key indexes, particularly the response capability of quickly responding and outputting the blood oxygen value, and can generate obvious economic benefit.

the above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the contents of the specification and the drawings, or applied directly or indirectly to other related technical fields, are included in the scope of the present invention.