CN111956234A

CN111956234A - Accurate blood oxygen saturation measuring method and device based on photoacoustic technology

Info

Publication number: CN111956234A
Application number: CN202010837730.2A
Authority: CN
Inventors: 赵晓杰; 欧志龙; 邹然
Original assignee: Advanced Optowave Corp
Current assignee: Advanced Optowave Corp
Priority date: 2020-08-19
Filing date: 2020-08-19
Publication date: 2020-11-20

Abstract

The invention discloses a method and device for accurate measurement of blood oxygen saturation based on photoacoustic technology. The method includes the following steps: an excitation light source emits two beams of different specific wavelengths, irradiates the surface of the tissue to be measured through an optical system, and penetrates into the Inside the tissue, the oxygenated hemoglobin and reduced hemoglobin in the tissue to be tested absorb the light beam to generate an ultrasonic signal, the ultrasonic signal is collected and measured by the ultrasonic signal acquisition module, the ultrasonic signal is processed by the ultrasonic signal processing module, and obtained through an image reconstruction algorithm Regarding the relative concentrations of oxyhemoglobin and reduced hemoglobin in blood, the absolute value of the blood oxygen saturation of the measured tissue blood is calculated according to the relative values of the relative concentrations. The measurement accuracy of the measurement method proposed in the embodiment of the present invention is greater than that of the existing blood oxygen saturation measuring instrument technology, and simultaneously solves the technical problem that the existing blood oxygen instrument cannot measure the blood oxygen saturation in the venous blood vessel.

Description

Accurate blood oxygen saturation measuring method and device based on photoacoustic technology

Technical Field

The invention relates to the technical field of medical measurement, in particular to a method and equipment for accurately measuring blood oxygen saturation based on a photoacoustic technology.

Background

Oxygen in the human body is mainly provided by the reversible combination of oxygenated hemoglobin and reduced hemoglobin in the blood with oxygen. The volume of hemoglobin in blood, which is oxygenated as a percentage of the total available oxygen and hemoglobin volume, i.e., the concentration of oxygen in blood, is usually expressed as the blood oxygen saturation, which is an important index reflecting the oxygen supply condition in the human body and is one of the basic monitoring parameters in clinical medicine. The higher the oxygen content in the blood, the better the human metabolism, and the too low will cause insufficient oxygen supply to the body. The normal human body has an arterial blood oxygen saturation of 98% and a venous blood saturation of 75%.

At present, the blood oxygen instruments for measuring the saturation concentration of blood oxygen on the market are mainly classified into monitoring, finger clipping and pulse type, and the main principle is to detect the change of the absorption amount of blood to different wavelengths of light and determine the percentage of the oxyhemoglobin in all hemoglobin, thereby directly obtaining the degree of oxyhemoglobin saturation. Such oximeters have two light emitting diodes facing the part of the patient to be measured, usually the finger tip or the earlobe. One diode emits a beam with a wavelength of 660 nm and the other emits a beam with a wavelength of 905, 910 or 940 nm, and the absorption coefficients of oxygen-containing hemoglobin in human tissue at the two wavelengths are greatly different from those of oxygen-free hemoglobin. By using the property, the proportion of two types of hemoglobin can be calculated, and the blood oxygen saturation concentration value can be calculated. Although these oximeters provide a convenient continuous non-invasive method of oximetry, there are many application limitations. Most of currently used oximeters are blood oxygen saturation calculation models derived based on the lambert-beer law, and the established premise is to ignore the scattering effect of human tissues and blood components on light, only consider the absorption effect, ignore the light absorption effect of water in tissue blood, and greatly influence the detection accuracy because the proportion of water in blood is more than 80%.

Although this method simplifies the measurement of the arterial blood oxygen saturation concentration, it introduces measurement error in principle, resulting in low measurement accuracy, and when the blood oxygen concentration is low, the measurement error is increased significantly.

Therefore, most oximeters have a measurement uncertainty of 2% to 3% in the 75% to 100% blood oxygen saturation range; and at 50% blood oxygen saturation, the measurement uncertainty can reach 20%. Most instruments do not provide any provisions for measuring uncertainty under the condition that the blood oxygen saturation is lower than 70%, so that the venous blood oxygen saturation concentration cannot be measured by the conventional method, and the detection of the venous blood saturation concentration has important clinical value for detecting the cardiopulmonary diseases. Furthermore, a measurement error of 2% is not favorable for the index value for the patient to switch from mild disease to severe disease for the patient with the present stage of the novel coronavirus pneumonia.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

For the above reasons, the applicant proposes a method and an apparatus for accurately measuring blood oxygen saturation based on photoacoustic technology, aiming to solve the above problems.

Disclosure of Invention

In order to meet the above requirements, a first object of the present invention is to provide a method for accurately measuring blood oxygen saturation based on photoacoustic technology, and it should be noted that the method belongs to an ultrasonic medical imaging method, although the last imaged data can be used for detecting some diseases, the method does not use the last imaging to perform a disease diagnosis step, and the blood oxygen saturation obtained by the method can be applied to an application scene of electronic equipment and the like for easily obtaining the metabolism information of the current user.

A second object of the present invention is to provide an accurate blood oxygen saturation measuring apparatus based on photoacoustic technology.

On one hand, the invention discloses a method for accurately measuring the blood oxygen saturation based on a photoacoustic technology, which comprises the following steps:

the method comprises the steps that an excitation light source emits two beams of light beams with different specific wavelengths, the light beams are irradiated to the surface of a tissue through an optical system and penetrate into the tissue, so that oxyhemoglobin and reduced hemoglobin in the tissue to be detected absorb the light beams to generate ultrasonic signals, an ultrasonic signal acquisition module is used for acquiring and measuring the ultrasonic signals, an ultrasonic signal processing module is used for processing the ultrasonic signals, the relative concentrations of the oxyhemoglobin and the reduced hemoglobin in blood are acquired through an image reconstruction algorithm, and the absolute value of the blood oxygen saturation of the blood of the tissue to be detected is calculated according to the relative values of the relative concentrations;

preferably, the excitation light source is at least one of a laser light source and an LED light source.

In one possible embodiment, when the excitation light source is a laser, the pulse width of the laser pulse emitted by the excitation light source is less than 1 ms.

In one possible embodiment, the excitation light source emits two light beams of specific wavelengths, the two light beams of specific wavelengths being light beams having a wavelength difference of less than 300nm and different excitation coefficients for oxygenated hemoglobin and reduced hemoglobin.

Preferably, when the excitation light source is two laser light sources, the wavelengths of the two light beams with specific wavelengths are 532nm and 559nm respectively.

In another preferred embodiment, when the excitation light source is two laser light sources, the wavelengths of the two light beams of specific wavelengths are 584nm and 600nm, respectively.

In one possible embodiment, the optical system comprises one or more of a mirror, a coupling fiber, an objective lens, a prism assembly, and an opto-acoustic coupler.

In one possible embodiment, the ultrasound signal acquisition module comprises one or more of a single-probe ultrasound probe, a multi-probe array ultrasound probe, a piezoceramic, PVDF, a magnetostrictive ultrasound probe, and a capacitive micromachined ultrasound probe.

In another aspect, an embodiment of the present application further provides an apparatus for accurately measuring blood oxygen saturation based on photoacoustic technology, including the following modules:

the excitation light source generator module is used for emitting two beams of light beams with different specific wavelengths as an excitation light source, and the excitation light source comprises at least one of a laser light source and an LED light source;

the optical system is used for irradiating the excitation light source to the surface of the tissue to be detected and penetrating into the tissue, so that different ultrasonic signals are emitted in the tissue to be detected due to different absorption coefficients of substances/molecules contained in the tissue to be detected to different wavelengths;

the ultrasonic signal acquisition module is used for acquiring and measuring ultrasonic signals radiated outwards by oxygenated hemoglobin and reduced hemoglobin in the object to be measured;

and the ultrasonic signal processing module is used for detecting the collected ultrasonic signals, acquiring the relative concentration of the oxygenated hemoglobin and the reduced hemoglobin in the blood through an image reconstruction algorithm, and calculating the absolute value of the blood oxygen saturation concentration of the blood of the detected tissue according to the relative value of the relative concentration.

In a possible embodiment, when the excitation light source generator module is a laser, the pulse width of the laser pulse emitted by the excitation light source generator module is less than 1 ms.

In one possible embodiment, the excitation light source emits two light beams of specific wavelengths, the two light beams of specific wavelengths being light beams having a difference in wavelength of less than 300nm and different excitation coefficients for oxygenated hemoglobin and reduced hemoglobin.

Compared with the prior art, the invention has the beneficial effects that: by adopting the measuring method and the measuring equipment of the scheme, the variation value of the oxyhemoglobin saturation can be accurately detected, the precision is higher than that of the existing oxyhemoglobin saturation measuring instrument technology, and the oxyhemoglobin information can be accurately and effectively acquired, for example: for outdoor/mountain climbers, when the heart rate does not exceed 100 at an altitude above 3000 m: the oxygen saturation degree is more than 90% and is normal, the oxygen saturation degree is between 80% and 90% and is mild hypoxia, the oxygen saturation degree is between 70% and 80% and is moderate hypoxia, and after an athlete violently moves in climbing a mountain, the athlete often cannot sense the self body state, the situation that the mountain hypoxia causes loss of life happens occasionally, if the oxygen saturation concentration can be detected, the athlete can be helped to judge whether the athlete is hypoxic, and the athlete can timely judge whether the athlete needs to rest or return to a camp site, so that the life danger of the athlete is prevented.

The invention is further described below with reference to the accompanying drawings and specific embodiments.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic flow chart of an embodiment of a method for accurately measuring blood oxygen saturation based on photoacoustic technology according to the present invention;

FIG. 2 is a schematic diagram of an application scenario of the embodiment of FIG. 1;

fig. 3 is a schematic diagram of a frame of an embodiment of an accurate blood oxygen saturation measuring device based on photoacoustic technology.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

The method flow shown in fig. 1 is a schematic diagram of a specific embodiment of the method for accurately measuring blood oxygen saturation based on photoacoustic technology disclosed by the present invention, and includes the following steps:

step S1, the excitation light source generator module emits two beams of light with different specific wavelengths as excitation light sources;

the two beams of light with different specific wavelengths are periodic light beams, and the excitation light source comprises at least one of a laser light source and an LED light source.

In some embodiments, when the excitation light source generator module is a laser, the pulse width of the emitted laser pulse is less than 1 ms.

In an embodiment, the excitation light source comprises two specific wavelengths, the difference of the two specific wavelengths being less than 300nm, and the oxygenated hemoglobin and the reduced hemoglobin present different absorption coefficients for the light beams of the two specific wavelengths.

The two light beams with specific wavelengths emitted by the excitation light source generator module respectively have strong absorption to oxyhemoglobin and reduced hemoglobin in blood, and the absorption coefficients of the two molecules for a certain wavelength are approximate, while the difference of the absorption coefficients for the other wavelength is larger. By using these two wavelengths as the excitation light source, the saturation concentrations of oxyhemoglobin and reduced hemoglobin in blood oxygen can be separated. In order to neglect the effect of the measured tissue on the scattering of the laser light, the two wavelengths are also very close.

In a preferred embodiment, when the excitation light source is two laser light sources, the wavelengths of the two light beams with specific wavelengths are 532nm and 559nm, respectively.

In another preferred embodiment, when the excitation light source is two laser light sources, the wavelengths of the two light beams with specific wavelengths are 584nm and 600nm, respectively.

Step S2, irradiating the excitation light source to the surface of the tissue to be detected through an optical system and penetrating into the tissue, so that different ultrasonic signals are emitted in the tissue to be detected due to different absorption coefficients of substances/molecules contained in the tissue to be detected to different wavelengths;

specifically, the optical system irradiates two laser pulses with different wavelengths to a substance to be measured (the substance to be measured may include human epidermal tissues such as fingertips or ears to be measured) through an optical element, blood in the epidermal tissues absorbs optical energy of the laser, energy of the excitation light source is deposited inside the tissues by taking tissue optical parameters as a distribution basis, so that temperature of the tissues is instantly and continuously increased, and the blood radiates an ultrasonic signal outwards due to expansion and contraction of volume caused by temperature change. Due to the different absorption coefficients of the oxygenated hemoglobin and the reduced hemoglobin in the blood to the laser light with different wavelengths, the deposited energy causes different temperature changes, thereby causing different intensities of the ultrasonic signals radiated outwards. The amplitude intensity of the ultrasonic signals generated by the oxyhemoglobin and the reduced hemoglobin is in direct proportion to the absorption coefficients of the ultrasonic signals to different wavelengths.

In one embodiment, the optical system comprises one or more of a mirror, a coupling fiber, an objective lens, a prism assembly, and an opto-acoustic coupler.

S3, collecting ultrasonic signals radiated outwards by oxygenated hemoglobin and reduced hemoglobin in the object to be detected by an ultrasonic signal collection module;

the ultrasonic signal refers to a sound wave with a vibration frequency greater than 20000Hz, the vibration frequency (frequency) per second of the sound wave is very high and exceeds the general upper limit of human ear hearing (20000Hz), and people call the sound wave which is not heard as ultrasonic wave. Because of its high frequency, short wavelength, not serious diffraction, good directionality, the ultrasonic detection is commonly carried out by ultrasonic wave in industry and medicine.

Specifically, the ultrasonic signal acquisition module respectively collects ultrasonic signals generated by the action of two beams of laser with different wavelengths on oxygenated hemoglobin and reduced hemoglobin in epidermal tissue blood. On the premise of ensuring the uniformity of incident light, the collected ultrasonic signals contain abundant tissue characteristic information, especially the absorption distribution of pulse energy with different wavelengths.

In an embodiment, the ultrasonic signal acquisition module comprises one or more of a single-probe ultrasonic detector, a multi-probe array ultrasonic detector, piezoelectric ceramics, PVDF, a magnetostrictive ultrasonic detector, and a capacitive micromachined ultrasonic detector, wherein the devices are used for respectively collecting ultrasonic signals with different amplitudes generated by two beams of laser with different wavelengths, which are applied to oxygenated hemoglobin and reduced hemoglobin in blood of a substance to be detected.

Step S4, the ultrasound signal processing module detects the collected ultrasound signals, obtains the relative concentration of the oxygenated hemoglobin and the reduced hemoglobin in the blood by the image reconstruction algorithm, and calculates the absolute value of the blood oxygen saturation of the measured tissue blood according to the relative value of the relative concentration.

Wherein the relative concentration is hemoglobin concentration.

Specifically, the ultrasonic signal data processing module processes the collected ultrasonic signals, and an image model is established through an image reconstruction algorithm, at the moment, the concentrations of the oxygenated hemoglobin and the reduced hemoglobin can be represented by relative values of ultrasonic signal intensities generated by absorption of energy with different wavelengths, and the blood oxygen saturation of the blood of the tested tissue can be calculated through the relative values of the ultrasonic signal intensities of the oxygenated hemoglobin and the reduced hemoglobin and is an absolute value.

Fig. 2 is a schematic diagram of a specific application scenario of the method for accurately measuring blood oxygen saturation based on photoacoustic technology of the present invention, which can be used for detecting blood oxygen saturation of blood in epidermal tissue, wherein the laser emitter module 1, the optical system 2, the ultrasonic signal acquisition module 3, and the ultrasonic signal data processing module 4 can operate according to the flow shown in fig. 1.

The connection between the laser emitter module 1 and the optical system 2 represents the logical relationship between the starting point and the reaching point of the light beam irradiation, the processing method between the optical system 2 and the ultrasonic signal acquisition module 3 includes, but is not limited to, modulating laser pulses so that the periodic light beam emitted by the laser emitter module 1 is absorbed by blood of epidermal tissue and the like to generate an ultrasonic signal, the ultrasonic signal acquisition module 3 aims at absorbing the ultrasonic signal generated by the blood of the epidermal tissue, three circular arcs are shown to represent the ultrasonic signal, and the ultrasonic signal data processing module 4 aims at processing the ultrasonic signal received by the ultrasonic signal acquisition module 3, so that computer equipment and the like can calculate and obtain an accurate measurement result of blood oxygen saturation by using an image algorithm.

On the other hand, as shown in fig. 3, a specific embodiment of the device for accurately measuring blood oxygen saturation based on photoacoustic technology provided by the present invention is schematically represented, and comprises the following modules:

an excitation light source generator module 201, configured to emit two different light beams with specific wavelengths as an excitation light source, where the excitation light source includes at least one of a laser light source and an LED light source;

the optical system 202 is used for irradiating the excitation light source to the surface of the tissue to be detected through the optical system and penetrating into the tissue, so that different ultrasonic signals are emitted in the tissue to be detected due to different absorption coefficients of substances/molecules contained in the tissue to be detected to different wavelengths;

an ultrasonic signal acquisition module 203, configured to acquire and measure ultrasonic signals of the object to be measured, where the ultrasonic signals are emitted from oxygenated hemoglobin and reduced hemoglobin;

and the ultrasonic signal processing module 204 is used for detecting the collected ultrasonic signals, acquiring the relative concentration of the oxygenated hemoglobin and the reduced hemoglobin in the blood through an image reconstruction algorithm, and calculating the absolute value of the blood oxygen saturation of the blood of the detected tissue according to the relative value of the relative concentration. Specifically, the ultrasound signal processing module 204 processes the collected ultrasound signals, and establishes an image model through an image reconstruction algorithm, at this time, the concentrations of oxyhemoglobin and reduced hemoglobin can be represented by the relative values of the ultrasound signal intensities generated by the absorption of different wavelength energies, and the blood oxygen saturation concentration of the tissue blood to be measured can be calculated as an absolute value by the relative values of the ultrasound signal intensities of oxyhemoglobin and reduced hemoglobin.

The two beams of specific laser wavelength have strong absorption to oxyhemoglobin and reduced hemoglobin in blood, and the absorption coefficients of the two molecules are similar to those of a certain wavelength, and the difference of the absorption coefficients of the two molecules is larger for the other wavelength. By using the light beams with the two wavelengths as the excitation light source, the saturation concentrations of the oxygenated hemoglobin and the reduced hemoglobin in the blood oxygen can be separated. In order to neglect the effect of the measured tissue on the scattering of the laser light, the two wavelengths are also very close. Such as 532nm and 559nm, and 584nm and 600 nm.

In one embodiment, when the excitation light source generator module 201 is a laser, the pulse width of the emitted laser pulse is less than 1 ms.

In one embodiment, the optical system 202 includes one or more of a mirror, a coupling fiber, an objective lens, a prism assembly, and an opto-acoustic coupler.

In one embodiment, the ultrasound signal acquisition module 203 comprises one or more of a single probe ultrasound probe, a multi-probe array ultrasound probe, a piezoceramic, PVDF, a magnetostrictive ultrasound probe, and a capacitive micromachined ultrasound probe. The device is used for respectively collecting ultrasonic signals with different amplitudes generated by the action of two beams of laser with different wavelengths on oxygenated hemoglobin and reduced hemoglobin in blood of a substance to be detected.

It should be noted that, as can be clearly understood by those skilled in the art, the specific implementation process of the electronic module may refer to the corresponding description in the foregoing method embodiment, and for convenience and brevity of description, no further description is provided herein.

Those of ordinary skill in the art will appreciate that the various illustrative modules and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention. It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described apparatuses and modules may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the embodiments provided in the present invention, it should be understood that the disclosed modules may be implemented in other manners. For example, the above-described module embodiments are merely illustrative. For example, the division of each module is only one logic function division, and there may be another division manner in actual implementation. For example, more than one module or component may be combined or may be integrated into another system, or some features may be omitted, or not implemented.

The steps in the method of the embodiment of the invention can be sequentially adjusted, combined and deleted according to actual needs.

Various other modifications and changes may be made by those skilled in the art based on the above-described technical solutions and concepts, and all such modifications and changes should fall within the scope of the claims of the present invention.

Claims

1. an accurate measurement method for blood oxygen saturation based on photoacoustic technology, is characterized in that, comprises the following steps:

The excitation light source emits two beams of different specific wavelengths, which are irradiated to the surface of the tissue to be tested through the optical system, and penetrate into the tissue, so that the oxygenated hemoglobin and reduced hemoglobin in the tissue to be tested absorb the beams to generate ultrasonic signals. The acquisition module collects and measures the ultrasonic signal, uses the ultrasonic signal processing module to process the ultrasonic signal, obtains the relative concentration of oxyhemoglobin and reduced hemoglobin in the blood through an image reconstruction algorithm, and calculates the relative value of the relative concentration according to the The absolute value of the blood oxygen saturation of the measured tissue blood;

The excitation light source is at least one of a laser light source and an LED light source.

2 . The method for accurately measuring blood oxygen saturation based on photoacoustic technology according to claim 1 , wherein when the excitation light source is a laser, the pulse width of the laser pulse emitted by the excitation light source is less than 1 ms. 3 .

3. The blood oxygen saturation accurate measurement method based on photoacoustic technology according to claim 1, is characterized in that, described excitation light source emits the light beam of two kinds of specific wavelengths, and the wavelength difference of the light beams of described two kinds of specific wavelengths is less than 300nm.

4. The method for accurately measuring blood oxygen saturation based on photoacoustic technology according to claim 1, characterized in that, when the excitation light source is two laser light sources, the wavelengths of the light beams of the two specific wavelengths can be respectively 532nm and 559nm, 584nm and 600nm.

5. The method for accurately measuring blood oxygen saturation based on photoacoustic technology according to claim 1, wherein the optical system comprises a mirror, a coupling fiber, an objective lens, a lens, a prism group, and a photoacoustic coupler. one or more;

The ultrasonic signal acquisition module includes one or more of a single-probe ultrasonic detector or a multi-probe array ultrasonic detector, piezoelectric ceramics, PVDF, magnetostrictive ultrasonic detectors, and capacitive micromachined ultrasonic detectors.

6. An accurate measuring device for blood oxygen saturation based on photoacoustic technology, characterized in that, comprising the following modules:

an excitation light source generator module for emitting two different beams of specific wavelengths as excitation light sources, the excitation light sources including at least one of a laser light source and an LED light source;

The optical system is used to irradiate the excitation light source to the surface of the tissue to be tested and penetrate into the tissue through the optical system, so that the tissue to be tested emits different ultrasonic waves due to the different absorption coefficients of substances/molecules contained in the tissue for different wavelengths Signal;

an ultrasonic signal acquisition module, used for acquiring and measuring the ultrasonic signals radiated from the oxyhemoglobin and reduced hemoglobin in the test substance;

The ultrasonic signal processing module is used to detect the collected ultrasonic signals, obtain the relative concentrations of oxyhemoglobin and reduced hemoglobin in blood through an image reconstruction algorithm, and calculate the relative concentration of the measured tissue blood according to the relative value of the relative concentration. The absolute value of blood oxygen saturation.

7. The blood oxygen saturation accurate measurement device based on photoacoustic technology according to claim 6, is characterized in that, when the excitation light source generator module is a laser, the pulse width of the laser pulse sent by the excitation light source generator module less than 1ms.

8. The blood oxygen saturation accurate measuring device based on photoacoustic technology according to claim 6, is characterized in that, described excitation light source emits the light beam of two kinds of specific wavelengths, and the light beam of described two kinds of specific wavelengths is the difference of wavelength less than 300nm.

9 . The device for accurately measuring blood oxygen saturation based on photoacoustic technology according to claim 6 , wherein when the excitation light sources are two laser light sources, the wavelengths of the light beams of the two specific wavelengths are respectively 9 . 532nm and 559nm, 584nm and 600nm.

10. The device for accurate measurement of blood oxygen saturation based on photoacoustic technology according to claim 6, wherein the optical system comprises a mirror, a coupling fiber, an objective lens, a lens, a prism group, and a photoacoustic coupler. one or more;

The ultrasonic signal acquisition module includes one or more of single-probe ultrasonic probes or multi-probe array ultrasonic probes, piezoelectric ceramics, PVDF, magnetostrictive ultrasonic probes, and capacitive micromachined ultrasonic probes.