CN117918834A

CN117918834A - Blood gas monitoring method and blood gas monitoring device for extracorporeal circulation system

Info

Publication number: CN117918834A
Application number: CN202410129166.7A
Authority: CN
Inventors: 李苗苗; 张震
Original assignee: Suzhou Hengrui Hongyuan Medical Technology Co ltd
Current assignee: Suzhou Hengrui Hongyuan Medical Technology Co ltd
Priority date: 2024-01-30
Filing date: 2024-01-30
Publication date: 2024-04-26

Abstract

The application discloses a blood gas monitoring method and a blood gas monitoring device for an extracorporeal circulation system, wherein the blood gas monitoring method comprises the following steps: controlling the first light source to emit emergent light rays with a first wavelength, wherein the difference degree of the extinction coefficients of the oxygenated hemoglobin and the reduced hemoglobin on the light rays with the first wavelength is smaller than or equal to a first preset value; acquiring a first wavelength detection value reflected by blood received by a first detection module; controlling the second light source to emit emergent light rays with a third wavelength, wherein the extinction coefficient of the oxyhemoglobin and the reduced hemoglobin on the light rays with the third wavelength is smaller than or equal to a second preset value; acquiring a third wavelength detection value reflected by blood received by the second detection module; and calculating the blood gas parameter value by using the emergent light intensity value of the first wavelength, the emergent light intensity value of the third wavelength, the first wavelength detection value and the third wavelength detection value. Because only water absorbs the light intensity at the third wavelength, the oxygenated hemoglobin and the reduced hemoglobin do not absorb the light intensity, and the hematocrit monitoring precision can be improved.

Description

Blood gas monitoring method and blood gas monitoring device for extracorporeal circulation system

Technical Field

The application belongs to the technical field of medical equipment, and particularly relates to a blood gas monitoring method and a blood gas monitoring device for an extracorporeal circulation system.

Background

In extracorporeal circulation operation, in order to ensure the safety of the patient in extracorporeal circulation operation, maintain the stability of the respiratory function of the patient and provide sufficient oxygen supply to the patient, so as to ensure the safety of the patient during and after the operation, various physiological indexes of the patient need to be monitored, and therefore, blood gas monitoring for the extracorporeal circulation system becomes an indispensable monitoring item in extracorporeal circulation operation.

However, the current domestic and foreign monitoring instruments and equipment have lower monitoring accuracy on blood and gas parameter values, which is not beneficial to medical staff to accurately judge patients.

Disclosure of Invention

The application provides a blood gas monitoring method and a blood gas monitoring device for an extracorporeal circulation system, which are used for solving the technical problem of low monitoring accuracy of the current blood gas parameter value.

In order to solve the technical problems, the application adopts a technical scheme that: a blood gas monitoring method of a blood gas monitoring device, the blood gas monitoring device comprising a first light source assembly and a second light source assembly, the first light source assembly comprising a first light source and a first detection module, the second light source assembly comprising a second light source and a second detection module, the method comprising: controlling the first light source to emit emergent light rays with a first wavelength, wherein the difference degree of the extinction coefficients of the oxygenated hemoglobin and the reduced hemoglobin on the light rays with the first wavelength is smaller than or equal to a first preset value; acquiring a first wavelength detection value reflected by blood received by a first detection module; controlling the second light source to emit emergent light rays with a third wavelength, wherein the extinction coefficient of the oxyhemoglobin and the reduced hemoglobin on the light rays with the third wavelength is smaller than or equal to a second preset value; acquiring a third wavelength detection value reflected by blood received by the second detection module; and calculating a blood gas parameter value by using the emergent light intensity value of the first wavelength, the emergent light intensity value of the third wavelength, the first wavelength detection value and the third wavelength detection value.

According to an embodiment of the present application, the first detection module includes a first proximal detector and a first distal detector, the first proximal detector is closer to the first light source than the first distal detector, and the obtaining the first wavelength detection value reflected by the blood received by the first detection module includes: acquiring a first wavelength near-end detection value reflected by blood received by a first near-end detector and a first wavelength far-end detection value reflected by blood received by a first far-end detector; the second detection module includes a second near-end detector and a second far-end detector, the second near-end detector is closer to the second light source than the second far-end detector, and obtaining a third wavelength detection value reflected by blood received by the second detection module includes: and acquiring a third wavelength near-end detection value reflected by the blood received by the second near-end detector and a third wavelength far-end detection value reflected by the blood received by the second far-end detector.

According to an embodiment of the present application, the acquiring the blood gas parameter value using the first wavelength emission light intensity value, the third wavelength emission light intensity value, the first wavelength detection value, and the third wavelength detection value includes: the hematocrit HCT is calculated using a first formula, which is ：HCT＝a₁x₁ ²+a₂x₁+a₃x₂ ²+a₄x₂+a₅, as follows,I ₁₀ is the output light intensity value of the first wavelength, and I ₃₀ is the output light intensity value of the third wavelength; i _1j is the first wavelength near-end detection value, I _3J is the third wavelength near-end detection value, I _1y is the first wavelength far-end detection value, I _3y is the third wavelength far-end detection value, and a ₁ to a ₅ are preset fitting coefficients.

According to an embodiment of the application, the method further comprises: controlling the first light source to emit emergent light rays with a second wavelength, wherein the difference degree of the extinction coefficients of the oxygenated hemoglobin and the reduced hemoglobin on the light rays with the second wavelength is larger than or equal to a third preset value; acquiring a second wavelength near-end detection value reflected by blood received by a first near-end detector and a second wavelength far-end detection value reflected by blood received by a first far-end detector; and obtaining a blood gas parameter value by using the emergent light intensity value of the first wavelength, the emergent light intensity value of the second wavelength, the first wavelength near-end detection value, the first wavelength far-end detection value, the second wavelength near-end detection value, the second wavelength far-end detection value and the hematocrit value.

According to an embodiment of the present application, the acquiring the blood gas parameter value using the first wavelength emission light intensity value, the second wavelength emission light intensity value, the first wavelength near-end detection value, the first wavelength far-end detection value, the second wavelength near-end detection value, the second wavelength far-end detection value, and the hematocrit value includes: the blood oxygen saturation SvO ₂ is calculated using a second formula as follows: wherein, Y ₂ is the value of the hematocrit; i ₁₀ is the emergent light intensity value of the first wavelength, I ₂₀ is the emergent light intensity value of the second wavelength, I _1j is the near-end detection value of the first wavelength, I _1y is the far-end detection value of the first wavelength, I _2j is the near-end detection value of the second wavelength, I _2y is the far-end detection value of the second wavelength, and p ₁ to p ₈ are preset fitting coefficients.

According to an embodiment of the present application, each light source assembly further includes a calibration detector, a portion of outgoing light emitted by each light source is transmitted as detection light, and a portion of outgoing light is reflected as calibration light, the detection light is used for irradiating into blood, the calibration light is used for reflecting to the calibration detector, and each wavelength detection value is a signal of the detection light reflected back by the blood; before the calculating the blood gas parameter value, the method further comprises: acquiring calibration detection values corresponding to the calibration light received by each calibration detector; judging whether the difference value between the calibration detection value and the corresponding calibration preset value is smaller than the corresponding preset difference value or not; if yes, executing the step of calculating the blood gas parameter value; if not, calibrating the emergent ray intensity of the corresponding light source according to the calibrated detection value, and returning to the step of controlling the first light source to emit emergent rays with the first wavelength.

According to an embodiment of the present application, the calibrating the outgoing light intensity of the corresponding light source according to the calibration detection value includes: calibrating the emergent ray intensity of the corresponding light source by using a third formula, wherein the third formula is as follows: Wherein, I ₀₁ is a calibration preset value, I ₁ is a current calibration detection value, W ₁₀ is an initial set value of the intensity of the outgoing light of the light source, and W ₁ is the intensity of the outgoing light after the light source is calibrated.

According to an embodiment of the present application, the method further includes calculating an output light intensity value for each wavelength, the calculating the output light intensity value for each wavelength including: taking the calibration detection value, of which the difference value with the calibration preset value is smaller than the corresponding preset difference value, as a calibration detection effective value; determining an outgoing light intensity value of outgoing light rays with corresponding wavelengths according to a fourth formula, wherein the fourth formula is as follows: i _n＝K_nI_{n School and school}+b_n, wherein I _n is an outgoing light intensity value of outgoing light rays with corresponding wavelengths, I _{n School and school} is a calibrated detection effective value of the outgoing light rays with corresponding wavelengths, and K _n and b _n are preset fitting coefficients.

According to an embodiment of the present application, the obtaining the first wavelength detection value reflected by the blood received by the first detection module includes: acquiring a first wavelength acquisition signal reflected by blood received by the first detection module; controlling the first light source and the second light source to be turned off; acquiring first wavelength acquisition dark noise reflected by blood received by a first detection module; and subtracting the first wavelength acquisition dark noise from the first wavelength acquisition signal to obtain a first wavelength detection value.

According to an embodiment of the present application, before the calculating of the blood gas parameter value, further includes: and performing constant false alarm rate filtering processing on each wavelength detection value.

According to an embodiment of the application, the method further comprises: and acquiring a current blood temperature and a current blood flow rate, and calibrating the blood gas parameter value by using the current blood temperature and the current blood flow rate.

According to an embodiment of the application, said calibrating said blood gas parameter value using said current blood temperature and said current blood flow rate comprises: and determining fitting coefficients of the first formula and the second formula under the current blood temperature and the current blood flow rate according to a pre-stored corresponding relation table of the blood temperature, the blood flow rate and the fitting coefficients.

According to an embodiment of the application, said calibrating said blood gas parameter value using said current blood temperature and said current blood flow rate comprises: the hematocrit HCT _{School and school} is calibrated using a fifth formula as follows: HCT _{School and school}＝HCT_{_0}(1+N₁(T-T₀)+N₂(V-V₀)), wherein T ₀ is a predetermined blood temperature, V ₀ is a predetermined blood flow rate, T is the current blood temperature, V is the current blood flow rate, HCT _{_0} is a hematocrit value calculated according to the first formula, and N ₁ and N ₂ are preset fitting coefficients; the blood oxygen saturation SvO _{2 School and school} is calibrated using a sixth formula, which is as follows: svO _{2 School and school}＝SvO_{2_0}(1+Q₁(T-T₀)+Q₂(V-V₀), wherein T ₀ is a predetermined blood temperature, V ₀ is a predetermined blood flow rate, T is the current blood temperature, V is the current blood flow rate, svO _{2_0} is a blood oxygen saturation value calculated according to the second formula, and Q ₁ and Q ₂ are preset fitting coefficients.

In order to solve the technical problems, the application adopts another technical scheme that: the blood gas monitoring device comprises a first light source assembly, a second light source assembly and a controller, wherein the first light source assembly comprises a first light source and a first detection module, the second light source assembly comprises a second light source and a second detection module, and the controller is coupled with the first light source assembly and the second light source assembly and used for controlling the first light source assembly and the second light source assembly to realize the blood gas monitoring method.

In order to solve the technical problems, the application adopts another technical scheme that: a computer readable storage medium storing program data executable to implement the blood gas monitoring method described above.

The beneficial effects of the application are as follows: because the extinction coefficients of oxyhemoglobin and reduced hemoglobin are highly similar or even identical at the first wavelength, and the extinction coefficients of oxyhemoglobin and reduced hemoglobin are low or even approximately zero at the third wavelength; and calculating and obtaining the ratio of the absorbance of blood at the first wavelength to the absorbance at the third wavelength by using the emergent light intensity value of the first wavelength, the emergent light intensity value of the third wavelength, the first wavelength detection value and the third wavelength detection value, so as to obtain the hematocrit value. In addition, as the third wavelength is selected, only water absorbs the light intensity in the wave band, and the oxygenated hemoglobin and the reduced hemoglobin do not absorb the light intensity, the hematocrit monitoring precision and the monitoring stability can be improved, and the hematocrit value also affects the calculation of other blood gas parameter values, so the scheme of the application can improve the blood gas parameter value monitoring accuracy.

Drawings

For a clearer description of the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, it being obvious that the drawings in the description below are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art, wherein:

FIG. 1 is a flow chart of a blood gas monitoring method according to an embodiment of the application;

FIG. 2 is a flow chart of a blood gas monitoring method according to another embodiment of the present application;

FIG. 3 is a schematic diagram of a frame structure of a blood gas monitoring device according to an embodiment of the present application;

Fig. 4 is a schematic overall structure of a blood gas monitoring device according to an embodiment of the present application.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. It is to be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present application are shown in the drawings. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

Referring to fig. 1, fig. 1 is a flow chart of a blood gas monitoring method according to an embodiment of the application.

An embodiment of the application provides a blood gas monitoring method of a blood gas monitoring device. The blood gas monitoring device comprises a first light source assembly and a second light source assembly. The first light source component comprises a first light source and a first detection module. The second light source assembly comprises a second light source and a second detection module. The blood gas monitoring method specifically comprises the following steps:

S11: the first light source is controlled to emit emergent light rays with a first wavelength.

The first light source is controlled to be turned on and emit emergent light rays with a first wavelength for irradiation into blood. At this time, the second light source is in an off state.

Wherein the difference between the extinction coefficients of the oxygenated hemoglobin and the reduced hemoglobin for the light of the first wavelength is less than or equal to a first preset value.

For subsequent calculation of the blood gas parameter values, the first wavelength selects a band of wavelengths in which the extinction coefficients of oxyhemoglobin and reduced hemoglobin are the same or nearly the same. The first preset value may be determined according to the actual monitoring accuracy requirement, and specifically, the first preset value may be 0.5L/(cm·mmol). The difference in extinction coefficient between oxyhemoglobin and reduced hemoglobin for light of the first wavelength may be specifically 0L/(cm. Mmol), 0.05L/(cm. Mmol), 0.13L/(cm. Mmol), 0.22L/(cm. Mmol), 0.37L/(cm. Mmol), 0.46L/(cm. Mmol), or 0.5L/(cm. Mmol).

The first wavelength may be determined by absorption tests of the oxygenated hemoglobin and the reduced hemoglobin for light of different wavelengths, preferably by choosing an extinction coefficient as close as possible. Specifically, the first wavelength may be 800nm, 803nm, 805nm, or 808nm; at this time, the extinction coefficients of the oxyhemoglobin and the reduced hemoglobin for the light of the first wavelength are the same or nearly the same.

S12: and acquiring a first wavelength detection value reflected by the blood received by the first detection module.

The first detection module is arranged at a position capable of receiving the light reflected by the blood. And acquiring a first wavelength detection value reflected by the blood received by the first detection module for calculating a subsequent blood gas parameter value.

In some embodiments, the first detection module includes a first proximal detector and a first distal detector, the first proximal detector being closer to the first light source than the first distal detector. The obtaining a first wavelength detection value reflected by blood received by the first detection module comprises the following steps:

the method comprises the steps of obtaining a first wavelength near-end detection value reflected by blood received by a first near-end detector and a first wavelength far-end detection value reflected by blood received by a first far-end detector. By arranging the near-end detector and the far-end detector, the acquisition accuracy and stability of the light reflected by blood can be improved.

Specifically, the distance from the first distal detector to the tissue position at which the outgoing light of the first light source is incident is greater than the distance from the first proximal detector to the tissue position at which the outgoing light of the first light source is incident. The difference in distance of the first distal detector and the first proximal detector from the tissue location at which the outgoing light is incident is 3mm-5mm, e.g. 3mm, 3.3mm, 4mm, 4.2mm, 5mm, etc.

Specifically, the first near-end detector and the first far-end detector are both silicon photodetectors, and the spectral response range is 400nm-1000nm.

S13: and controlling the second light source to emit emergent light with a third wavelength.

The second light source is controlled to be turned on and emit emergent light rays with a third wavelength for irradiating blood. At this time, the first light source is in an off state.

Wherein the extinction coefficient of the oxyhemoglobin and the reduced hemoglobin for the light of the third wavelength is less than or equal to a second preset value.

For the subsequent calculation of the blood gas parameter values, the third wavelength selects a wavelength band in which oxyhemoglobin and reduced hemoglobin hardly absorb, and only water is absorbed after the third wavelength is irradiated to the blood. The second preset value may be determined according to the actual monitoring accuracy requirement, and specifically, the second preset value may be 0.3L/(cm·mmol). The extinction coefficient of oxyhemoglobin and reduced hemoglobin for light of the third wavelength may be specifically 0L/(cm. Mmol), 0.06L/(cm. Mmol), 0.13L/(cm. Mmol), 0.26L/(cm. Mmol), or 0.3L/(cm. Mmol), etc.

The third wavelength can be determined according to the absorption test of the oxyhemoglobin and the reduced hemoglobin on light with different wavelengths, and the extinction coefficient is preferably selected to be closest to zero. Specifically, the third wavelength of the emitted light from the second light source may be near infrared light in a band of 1300nm to 1500nm, for example, 1300nm, 1400nm, or 1500nm; at this time, the extinction coefficient of oxyhemoglobin and reduced hemoglobin for light of the third wavelength is approximately 0.

S14: and obtaining a third wavelength detection value reflected by the blood received by the second detection module.

The second detection module is arranged at a position capable of receiving the light reflected by the blood. And acquiring a third wavelength detection value reflected by the blood received by the second detection module for calculating a subsequent blood gas parameter value.

In some embodiments, the second detection module includes a second proximal detector and a second distal detector, the second proximal detector being closer to the second light source than the second distal detector. The obtaining of the third wavelength detection value reflected by the blood received by the second detection module comprises the following steps:

And acquiring a third wavelength near-end detection value reflected by the blood received by the second near-end detector and a third wavelength far-end detection value reflected by the blood received by the second far-end detector. By arranging the near-end detector and the far-end detector, the acquisition accuracy and stability of the light reflected by blood can be improved.

Specifically, the distance from the second distal detector to the tissue position at which the outgoing light of the second light source enters is greater than the distance from the second proximal detector to the tissue position at which the outgoing light enters. The difference in distance of the second distal detector and the second proximal detector from the tissue location at which the outgoing light is incident is 3mm-5mm, e.g. 3mm, 3.3mm, 4mm, 4.2mm, 5mm, etc.

Specifically, the second proximal detector and the second distal detector are both InGaAs sensors.

S15: and calculating the blood gas parameter value by using the emergent light intensity value of the first wavelength, the emergent light intensity value of the third wavelength, the first wavelength detection value and the third wavelength detection value.

It should be noted that, in some embodiments, the emission intensity value of the first wavelength and the emission intensity value of the third wavelength may be default fixed values according to the light source characteristics. Of course, in other embodiments, the output intensity value of the first wavelength and the output intensity value of the third wavelength may also be detected in real time to improve accuracy.

Because the extinction coefficients of oxyhemoglobin and reduced hemoglobin are highly similar or even identical at the first wavelength, and the extinction coefficients of oxyhemoglobin and reduced hemoglobin are low or even approximately zero at the third wavelength; the ratio of the absorbance of blood at the first wavelength to the absorbance at the third wavelength can be calculated by using the emission light intensity value of the first wavelength, the emission light intensity value of the third wavelength, the first wavelength detection value and the third wavelength detection value, so as to obtain the Hematocrit (HCT) value. Because the third wavelength is particularly added in the scheme, only water absorbs the light intensity in the wave band, and the oxygenated hemoglobin and the reduced hemoglobin do not absorb the light intensity, the hematocrit monitoring precision and the monitoring stability can be improved, and the hematocrit value also affects the calculation of other blood gas parameter values, so the scheme of the application can improve the blood gas parameter value monitoring accuracy.

In some embodiments, when the first detection module includes a first proximal detector and a first distal detector, and the second detection module includes a second proximal detector and a second distal detector, obtaining the blood gas parameter value using the first wavelength of the outgoing light intensity value, the third wavelength of the outgoing light intensity value, the first wavelength detection value, and the third wavelength detection value includes:

The hematocrit HCT is calculated using a first formula as follows:

HCT＝a₁x₁ ²+a₂x₁+a₃x₂ ²+a₄x₂+a₅,

wherein, I ₁₀ is the output light intensity value of the first wavelength, and I ₃₀ is the output light intensity value of the third wavelength; i _1j is a first wavelength near-end detection value, I _3J is a third wavelength near-end detection value, I _1y is a first wavelength far-end detection value, I _3y is a third wavelength far-end detection value, and a ₁ to a ₅ are preset fitting coefficients.

Through setting up two detectors at first detection module to and set up two detectors at the second detection module, can synthesize near-end detector and far-end detector's detection value, and then obtain the hematocrit value after the comprehensive calculation, reduce single detector acquisition error, improved the monitoring accuracy and the stability of hematocrit value.

In some embodiments, the blood gas monitoring method further comprises:

S16: the first light source is controlled to emit emergent light rays with a second wavelength.

The first light source is controlled to be turned on and emit emergent light rays with a second wavelength for irradiating blood. At this time, the second light source is in an off state.

Wherein the difference between the extinction coefficients of the oxyhemoglobin and the reduced hemoglobin for the light of the second wavelength is greater than or equal to a third preset value.

For subsequent calculation of the blood gas parameter values, the second wavelength selects a wavelength band in which the extinction coefficients of oxyhemoglobin and reduced hemoglobin differ. The third preset value can be determined according to the actual monitoring accuracy requirement. Specifically, the third preset value may be 2L/(cm·mmol), and the degree of difference in extinction coefficient of oxyhemoglobin and reduced hemoglobin to light of the second wavelength may be 2L/(cm·mmol), 2.1L/(cm·mmol), 2.7L/(cm·mmol), 3L/(cm·mmol), or 5L/(cm·mmol), or the like.

The second wavelength can be determined according to the absorption test of the oxyhemoglobin and the reduced hemoglobin on light with different wavelengths, and the extinction coefficient is preferably selected to have larger difference. Specifically, the second wavelength selects a different wavelength band from the first wavelength between 650-1000nm, such as 650nm, 690nm, 700nm, 860nm, 940nm, 1000nm, etc. The second wavelength is different from the first wavelength in extinction coefficient.

S17: a second wavelength detection value is obtained from the first proximal detector that receives the blood reflection.

The first detection module is also used for receiving a second wavelength detection value reflected by blood, and comprises a first near-end detector for receiving the second wavelength near-end detection value reflected by blood and a first far-end detector for receiving the second wavelength far-end detection value reflected by blood.

S18: and obtaining a blood gas parameter value by using the emergent light intensity value of the first wavelength, the emergent light intensity value of the second wavelength, the first wavelength detection value, the second wavelength detection value and the value of the hematocrit.

In some embodiments, the blood oxygen saturation SvO ₂ may be calculated using a second formula, which is as follows:

wherein, Y ₂ is the value of hematocrit; i ₁₀ is an emergent light intensity value of a first wavelength, I ₂₀ is an emergent light intensity value of a second wavelength, I _1j is a near-end detection value of the first wavelength, I _1y is a far-end detection value of the first wavelength, I _2j is a near-end detection value of the second wavelength, I _2y is a far-end detection value of the second wavelength, and p ₁ to p ₈ are preset fitting coefficients.

According to the application, the blood oxygen saturation is calculated by adopting the combination of different wavelengths of light in the first light source caused by the blood oxygen saturation and different detection values caused by the optical path difference of the near-end detector and the far-end detector, and the hematocrit value with high accuracy is brought into calculation, so that the calculation accuracy and the calculation stability of the blood oxygen saturation can be fully improved.

It should be noted that, steps S16 to S17, steps S11 to S12, and steps S13 to S14 may be sequentially performed in any order, and after the first wavelength near-end detection value, the first wavelength far-end detection value, the second wavelength near-end detection value, the second wavelength far-end detection value, the third wavelength near-end detection value, and the third wavelength far-end detection value are obtained, step S15 and step S18 are performed. Therefore, the acquisition time of each detection value is close, and the blood gas parameter value is more accurate. Of course, in other embodiments, steps S16-S18 may be performed after steps S11-S15 are performed.

In addition, the fitting coefficients in the first and second formulas may be determined by the following calibration method:

Under the condition that the blood temperature and the blood flow rate are set, the actual HCT and the SvO ₂ are indicated under the current condition by the calibrated blood gas monitoring equipment, meanwhile, the detection value of each detector is used for calculating the value x ₁,x₂,y₁,y₂ in the equation, the specific fitting coefficient values of a ₁ to a ₅ in the first equation and p ₁ to p ₈ in the second equation are calculated by convergence based on the quasi-Newton method.

Of course, in other embodiments, other methods may be employed to determine the fitting coefficient values of the first and second formulas.

In addition, the application also provides an embodiment to supplement the determination of the second formula:

If the blood line is illuminated with two different wavelengths of light lambda ₁,λ₂ while the reflected light passing through the blood is received by two detectors at a distance ρ ₁ρ₂ from the light source, respectively, and the distances ρ ₁ and ρ ₂ are closer, the optical path lengths received by the two detectors are approximately equal, so the following pre-correction formula is given:

Wherein I ₀ is the light intensity of the blood which does not pass through, I is the light intensity received by the detector after passing through the blood, The ratio of the initial intensity of light at a wavelength lambda ₁ received by the detector 2 and the intensity of light I after reflection from the blood.The extinction coefficients of the oxyhemoglobin and the oxyhemoglobin under different wavelengths lambda 1 and lambda 2 are constants; so SvO ₂ is/>Since SvO ₂ is affected by HCT, the HCT value y ₂ is added to the solution formula of SvO ₂ before correction to calculate the blood oxygen saturation SvO ₂, thereby obtaining the second formula (i.e. the corrected blood oxygen saturation calculation formula).

With continued reference to fig. 2, fig. 2 is a flow chart of a blood gas monitoring method according to another embodiment of the application.

Still another embodiment of the present application provides a blood gas monitoring method of a blood gas monitoring device. The blood gas monitoring device comprises a first light source assembly and a second light source assembly, wherein the first light source assembly comprises a first light source, a first detection module and a first calibration detector. The first detection module comprises a first proximal detector and a first distal detector. The emergent light rays with the first wavelength emitted by the first light source are partially transmitted to be first detection light, and partially reflected to be first calibration light, the first detection light is used for irradiating blood, the first calibration light is used for being reflected to the first calibration detector, and the first wavelength detection value is a signal of the first detection light reflected back by the blood.

Similarly, the outgoing light of the second wavelength emitted by the first light source is partially transmitted as second detection light, and partially reflected as second calibration light, the second detection light is used for being irradiated into blood, the second calibration light is used for being reflected to the first calibration detector, and the second wavelength detection value is a signal of the second detection light reflected back by the blood.

Likewise, the second light source assembly includes a second light source, a second detection module, and a second calibration detector. The second detection module comprises a second proximal detector and a second distal detector. The emergent light rays with the third wavelength emitted by the second light source are partially transmitted to form third detection light, and are partially reflected to form third calibration light, the third detection light is used for irradiating blood, the third calibration light is used for reflecting to the second calibration detector, and the third wavelength detection value is a signal of the third detection light reflected by the blood.

The blood gas monitoring method comprises the following steps:

S21: the first light source is controlled to emit emergent light rays with a first wavelength.

S22: and acquiring a first wavelength detection value reflected by the blood received by the first detection module.

The obtaining the first wavelength detection value reflected by the blood received by the first detection module includes:

S221: and acquiring a first wavelength acquisition signal reflected by blood received by the first detection module.

Specifically, a first wavelength proximal acquisition signal E ₁ of the first proximal probe that receives the first probe light reflected back from blood may be acquired, and a first wavelength distal acquisition signal E ₂ of the first distal probe that receives the first probe light reflected back from blood may be acquired.

At the same time, the first calibration acquisition signal E ₃ of the first calibration light received by the first calibration detector may also be synchronously acquired.

Specifically, the first near-end detector, the first far-end detector and the first calibration detector are all silicon photodetectors, and the spectral response range is 400nm-1000nm.

S222: the first light source and the second light source are controlled to be turned off.

S223: and acquiring first wavelength acquisition dark noise reflected by blood received by the first detection module.

Specifically, a first wavelength near-end collected dark noise F ₁ reflected back from the blood received by the first near-end detector and a first wavelength far-end collected dark noise F ₂ reflected back from the blood received by the first far-end detector may be acquired.

At the same time, the first calibration dark noise F ₃ received by the first calibration detector may also be synchronously acquired.

S224: and subtracting the first wavelength acquisition dark noise from the first wavelength acquisition signal to obtain a first wavelength detection value.

Specifically, the first wavelength near-end acquisition signal E ₁ may be used to subtract the first wavelength near-end acquisition dark noise F ₁ to obtain a first wavelength near-end detection value I _1j; the first wavelength far-end detection value I _1y can be obtained by subtracting the first wavelength far-end acquisition dark noise F ₂ from the first wavelength far-end acquisition signal E ₂.

Meanwhile, the first calibration acquisition signal E ₃ may be used to subtract the first calibration dark noise F ₃ to obtain the first calibration detection value a ₁.

S23: the first light source is controlled to emit emergent light rays with a second wavelength.

S24: and obtaining a second wavelength detection value reflected by the blood received by the first detection module.

The obtaining the second wavelength detection value reflected by the blood received by the first detection module includes:

s241: and acquiring a second wavelength acquisition signal reflected by the blood received by the first detection module.

Specifically, a second wavelength near-end acquisition signal G ₁ of the second probe light reflected back by the first near-end probe may be acquired, and a second wavelength far-end acquisition signal G ₂ of the second probe light reflected back by the first far-end probe may be acquired.

Meanwhile, the second calibration acquisition signal G ₃ of the second calibration light received by the first calibration detector can be acquired synchronously.

S242: the first light source and the second light source are controlled to be turned off.

S243: and acquiring dark noise collected by the second wavelength reflected by the blood received by the first detection module.

Specifically, the second wavelength near-end collected dark noise H ₁ reflected back by the first near-end detector and the second wavelength far-end collected dark noise H ₂ reflected back by the first far-end detector may be obtained.

At the same time, the second calibration dark noise H ₃ received by the first calibration detector may also be synchronously acquired.

S244: and subtracting the second wavelength acquisition dark noise from the second wavelength acquisition signal to obtain a second wavelength detection value.

Specifically, the second wavelength near-end acquisition signal G ₁ may be used to subtract the first wavelength near-end acquisition dark noise H ₁ to obtain a second wavelength near-end detection value I _2j; the second wavelength far-end acquisition signal G ₂ may be used to subtract the second wavelength far-end acquisition dark noise H ₂ to obtain a second wavelength far-end detection value I _2y.

Meanwhile, the second calibration dark noise H ₃ may be subtracted from the second calibration acquisition signal G ₃ to obtain the first calibration detection value a ₂.

S25: and controlling the second light source to emit emergent light with a third wavelength.

S26: and obtaining a third wavelength detection value reflected by the blood received by the second detection module.

Wherein, obtaining the third wavelength detection value reflected by the blood received by the second detection module includes:

S261: and acquiring a third wavelength acquisition signal reflected by the blood received by the second detection module.

Specifically, a third wavelength near-end acquisition signal M ₁ of the third probe light reflected back by the second near-end probe may be acquired, and a third wavelength far-end acquisition signal M ₂ of the third probe light reflected back by the second far-end probe may be acquired.

Meanwhile, a third calibration acquisition signal M ₃ of the third calibration light received by the second calibration detector may also be synchronously acquired.

Specifically, the second proximal detector, the second distal detector, and the second calibration detector are all InGaAs sensors.

S262: the first light source and the second light source are controlled to be turned off.

S263: and acquiring the third wavelength acquisition dark noise reflected by the blood received by the second detection module.

Specifically, a third wavelength near-end acquisition dark noise reflected back by the second near-end detector S ₁ and a third wavelength far-end acquisition dark noise reflected back by the second far-end detector S ₂ may be acquired.

At the same time, the third calibration dark noise S ₃ received by the second calibration detector may also be synchronously acquired.

S264: and subtracting the third wavelength acquisition dark noise from the third wavelength acquisition signal to obtain a third wavelength detection value.

Specifically, the third wavelength near-end acquisition signal M ₁ may be used to subtract the third wavelength near-end acquisition dark noise S ₁ to obtain a third wavelength near-end detection value I _3j; the third wavelength far-end acquisition signal G ₂ may be used to subtract the third wavelength far-end acquisition dark noise H ₂ to obtain a third wavelength far-end detection value I _3y.

Meanwhile, the third calibration acquisition signal G ₃ may be used to subtract the third calibration dark noise S ₃ to obtain the third calibration detection value a ₃.

Through the steps S21-S26, nine groups of detection values after noise reduction may be obtained, which are a first wavelength near-end detection value, a first wavelength far-end detection value, a first calibration detection value, a second wavelength near-end detection value, a second wavelength far-end detection value, a second calibration detection value, a third wavelength near-end detection value, a third wavelength far-end detection value, and a third calibration detection value, respectively. The noise-reduced detection value can remove interference, improve the signal to noise ratio, and further improve the accuracy and stability of the final blood gas parameter value obtained after operation.

The inventor of the application researches for a long time to find that the light intensity of the light emitted by the light source changes along with the temperature change and the light intensity of the incident blood changes along with the aging of the light-emitting components, so that the light intensity obtained by the blood oxygen monitoring module after the diffuse reflection of the blood also fluctuates, and the accuracy of the final blood gas parameter value is directly affected. The current monitoring instrument can not calibrate the light intensity of the light source in real time in the use process, so that the blood gas parameter value has larger error due to the fluctuation of the light intensity of the detection light, and the accurate judgment of a patient by medical staff is not facilitated.

Therefore, the blood gas monitoring method of the present application further includes the step of calibrating the first light source and the second light source in real time, specifically as follows:

S27: and judging whether the difference value between the calibration detection value and the corresponding calibration preset value is smaller than the corresponding preset difference value.

Respectively judging whether the difference value between the first calibration detection value and the first calibration preset value is smaller than the first preset difference value; judging whether the difference value between the second calibration detection value and the second calibration preset value is smaller than the second preset difference value or not; and judging whether the difference value between the third calibration detection value and the third calibration preset value is smaller than the third preset difference value.

Specifically, the range of the first preset difference is-3% -3%, such as-3%, -1.6%, 0.5%, 1.6% or 3%, etc., and can be set according to the actual precision requirement.

S28: if not, calibrating the intensity of the emergent light of the corresponding light source according to the calibrated detection value, and returning to the step S21 of controlling the first light source to emit the emergent light of the first wavelength.

If the difference between the calibration detection value and the corresponding calibration preset value is greater than or equal to the corresponding preset difference, it can be considered that the light source intensity of at least one light source is changed beyond a reasonable range, and the light intensity needs to be adjusted. Therefore, the process returns to step S21 to re-enter the loop until the difference between each calibration detection value and the corresponding calibration preset value is smaller than the corresponding preset difference, and the subsequent calculation steps can be entered.

If yes, the subsequent step of calculating the blood-gas parameter value is continued. At this time, since the difference between each calibration detection value and the corresponding calibration preset value is smaller than the corresponding preset difference, the light source intensity is not changed, or the fluctuation of the light source intensity is within a reasonable range, and the calculation of the subsequent blood gas parameter value is not affected, so that the subsequent step of calculating the blood gas parameter value can be directly and continuously executed.

The change of emergent light rays with corresponding wavelengths of the light sources is perceived in real time according to the light intensity change of the calibration detection values, and feedback is formed for the device to calibrate automatically, so that the luminous intensity of the light sources in the detection process is always kept in a constant linear interval, and the influence on detection data caused by the light intensity change of the light sources is reduced. The emergent light intensity of the first light source and the emergent light intensity of the second light source are kept in a stable state and are not changed along with the change of time and temperature, the light intensity monitored by each detector is only related to blood data, the interference of the monitored light intensity after the diffuse reflection of blood caused by the change of the light intensity of the light source is reduced, and the accuracy of the blood gas parameter value obtained by final operation is improved.

It should be noted that, in some embodiments, for real-time performance of each detection value acquisition, step S21 may be directly returned to acquire all detection values again. In still other embodiments, when a significant change in the calibration detection value is detected, only the light source with the wavelength corresponding to the calibration detection value may be calibrated, and the detection value corresponding to the wavelength may be reacquired.

In some embodiments, calibrating the outgoing light intensity of the first light source according to the first calibration detection value comprises:

and calibrating the emergent ray intensities of the first light source and the second light source by using a third formula.

In some embodiments, the outgoing light intensities of the first light source and the second light source may be calibrated using a third formula, which is as follows:

When the intensity of the emergent light of the first wavelength of the first light source needs to be calibrated, I ₀₁ is a first calibration preset value, I ₁ is a current first calibration detection value, W ₁₀ is an initial set value of the intensity of the emergent light of the first wavelength, and W ₁ is the intensity of the emergent light of the first wavelength after calibration; when the intensity of the emergent light of the second wavelength of the first light source needs to be calibrated, I ₀₁ is a second calibration preset value, I ₁ is a current second calibration detection value, W ₁₀ is an initial set value of the intensity of the emergent light of the second wavelength, and W ₁ is the intensity of the emergent light of the second wavelength after calibration; when the intensity of the emergent light of the third wavelength of the second light source needs to be calibrated, I ₀₁ is a third calibration preset value, I ₁ is a current third calibration detection value, W ₁₀ is an initial set value of the emergent light intensity of the third wavelength, and W ₁ is the emergent light intensity of the third wavelength after calibration.

S29: and performing constant false alarm rate filtering processing on each wavelength detection value.

Specifically, constant false alarm rate filtering processing may be performed on the first wavelength near-end detection value, the first wavelength far-end detection value, the first calibration detection value, the second wavelength near-end detection value, the second wavelength far-end detection value, the second calibration detection value, the third wavelength near-end detection value, the third wavelength far-end detection value, and the third calibration detection value, respectively.

The constant false alarm rate filtering processing is carried out on each detection value, so that noise and power frequency interference can be effectively removed, meanwhile, details of signals are reserved, and meanwhile, the data calculation delay time is reduced. Meanwhile, the filtering efficiency and the filtering precision can be improved by adopting the constant false alarm rate filtering process, if the traditional FIR filtering is used, 75 sampling points are needed for removing the interference on the same signal when the sampling frequency is 25Hz, so that the delay time is 3s, the same signal is filtered by adopting the constant false alarm rate method, the delay time is only 10 points, the delay time is shortened to 0.4s, the integral calculation time of an algorithm is greatly shortened on the premise of keeping the details of the acquired signal, the instantaneity of acquiring the blood gas parameter value is improved, and the medical staff can judge the condition of the patient more timely according to the blood gas parameter value.

It should be noted that, in some embodiments, the filtered detection value may be used to enter the subsequent calculation, and of course, in other embodiments, the detection value before the filtering may be directly used to enter the subsequent calculation.

In addition, in some embodiments, the filtering process of step S30 may be performed after steps S27-S29 to calibrate the light source intensity before filtering, so as to avoid the waste of computing resources caused by repeated filtering; of course, in other embodiments, step S30 may be further disposed before steps S27-S29, so as to perform filtering processing on the detection values before calibration, so as to reduce error interference, and make the detection values used for calibration more accurate.

S30: the intensity value of the emitted light at each wavelength is calculated.

In some embodiments, calculating the output intensity value for each wavelength specifically includes:

S301: and taking the calibration detection value with the difference value smaller than the corresponding preset difference value as the calibration detection effective value.

S302: and determining the emergent light intensity value of emergent light rays with the corresponding wavelength according to a fourth formula.

In some embodiments, the fourth formula is as follows:

I_n＝K_nI_{n School and school}+b_n，

Wherein, I _n is the output light intensity value of the output light with the corresponding wavelength, I _{n School and school} is the effective value of the calibration detection of the output light with the corresponding wavelength, and K _n and b _n are preset fitting coefficients.

Specifically, the calculation formula of the outgoing light intensity value of the outgoing light ray of the first wavelength is as follows:

I₁₀＝K₁I_{1 School and school}+b₁，

Wherein, I ₁₀ is the output light intensity value of the output light of the first wavelength, I _{1 School and school} is the effective value of the calibration detection of the output light of the first wavelength, and K ₁ and b ₁ are preset fitting coefficients.

Specifically, the calculation formula of the outgoing light intensity value of the outgoing light ray of the second wavelength is as follows:

I₂₀＝K₂I_{2 School and school}+b₂，

Wherein, I ₂₀ is the output light intensity value of the output light of the second wavelength, I _{2 School and school} is the effective value of the calibration detection of the output light of the second wavelength, and K ₂ and b ₂ are preset fitting coefficients.

Specifically, the calculation formula of the outgoing light intensity value of the outgoing light ray of the third wavelength is as follows:

I₃₀＝K₃I_{3 School and school}+b₃，

Wherein, I ₃₀ is the output light intensity value of the third wavelength output light, I _{3 School and school} is the effective calibration detection value of the third wavelength output light, and K ₃ and b ₃ are preset fitting coefficients.

It should be noted that, the light intensity of each light source is gradually adjusted from low to high, meanwhile, the detector is used to record the actual light intensity of the light source with different wavelengths, and record the detection value of each calibration detector, and the specific fitting coefficient value of K ₁、K₂、K₃、b₁、b₂、b₃ can be calculated through first-order fitting.

S31: and calculating the hematocrit HCT by using the emergent light intensity value of the first wavelength, the emergent light intensity value of the third wavelength, the first wavelength detection value and the third wavelength detection value.

The content of step S31 is substantially the same as that of the corresponding step S15 in the above embodiment, and will not be described here again.

S32: and obtaining the blood oxygen saturation SVO ₂ by using the emergent light intensity value of the first wavelength, the emergent light intensity value of the second wavelength, the first wavelength detection value, the second wavelength detection value and the value of the hematocrit.

The content of step S32 is substantially the same as that of the corresponding step S18 in the above embodiment, and will not be described here again.

S33: the current blood temperature and the current blood flow rate are obtained, and the blood gas parameter value is calibrated by using the current blood temperature and the current blood flow rate.

In some embodiments, calibrating the blood gas parameter value with the current blood temperature and the current blood flow rate comprises:

S331: the hematocrit is calibrated using a fifth formula, which is as follows:

HCT_{School and school}＝HCT_{_0}(1+N₁(T-T₀)+N₂(V-V₀))，

Wherein, T ₀ is the predetermined blood temperature, V ₀ is the predetermined blood flow rate, T is the current blood temperature, V is the current blood flow rate, HCT _{_0} is the hematocrit value obtained by calculation according to the first formula in step S32, and N ₁ and N ₂ are preset fitting coefficients.

S332: the blood oxygen saturation is calibrated using a sixth formula, which is as follows:

SvO_{2 School and school}＝SvO_{2_0}(1+Q₁(T-T₀)+Q₂(V-V₀))，

Wherein, T ₀ is a predetermined blood temperature, V ₀ is a predetermined blood flow rate, T is a current blood temperature, V is a current blood flow rate, svO _{2_0} is a blood oxygen saturation value obtained by calculation according to a second formula in step S33, and Q ₁ and Q ₂ are preset fitting coefficients.

Wherein, T ₀ and V ₀ are the blood temperature and the blood flow rate set in the process of determining the fitting coefficients of the first formula and the second formula.

The calibration method of N ₁ and Q ₁ comprises the following steps: the blood temperature was fixed at T ₀ and the blood flow rate was V ₀ prior to the HCT and SvO ₂ coefficient fitting. The HCT and SvO ₂ values calculated in the current state are HCT _{_0}、SvO_{2_0} respectively, the blood flow rate is set unchanged, the temperature is adjusted once every other temperature gradient from 30 ℃ to 40 ℃, the HCT _{_0} and SvO _{2_0} calculated by the device each time are recorded, and the fitting coefficient N ₁、Q₁ in the fifth formula and the sixth formula is obtained by applying a least square method.

Similarly, the calibration method of N ₂ and Q ₂ comprises the following steps: the blood temperature was fixed at T ₀ and the blood flow rate was V ₀ prior to the HCT and SvO ₂ coefficient fitting. The HCT and SvO ₂ values calculated in the current state are HCT _{_0}、SvO_{2_0} respectively, the blood temperature is set unchanged, the flow rate is increased to 9L/min every 1 flow rate gradient from 1L/min, the HCT _{_0} and SvO _{2_0} calculated by the device each time are recorded, and the fitting coefficient K ₂、Q₂ in the fifth formula and the sixth formula is obtained by applying a least square method.

Generally, the coefficient fitting of the fifth formula and the sixth formula can be completed through a preset number of experiments. The preset number may be 15, 20 or 25. The experimental workload of the mode is lower, and the method is more convenient and simple.

In still other embodiments, calibrating the blood gas parameter value with the current blood temperature and the current blood flow rate includes:

And determining the fitting coefficients of the first formula and the second formula under the current blood temperature and the current blood flow rate according to a pre-stored corresponding relation table of the blood temperature, the blood flow rate and the fitting coefficients.

When it is necessary to calibrate the blood gas parameter values with the current blood temperature and the current blood flow rate in the manner in the present embodiment, it is necessary to perform step S33 before step S31 and apply the fitting coefficient matrix obtained after the review to the first and second formulas of step S31 and step S32.

Specifically, the pre-stored correspondence table of the blood temperature, the blood flow rate and the fitting coefficient is prepared as follows:

the adjustable range of the blood temperature T in the extracorporeal blood gas circulation can be set to 30-40 ℃ and the adjustable range of the blood flow velocity vL/min is 1-10L/min. Thus, the following look-up table 1 is prepared:

look-up table 1:

A ₁₁ to a _9B represent corresponding different matrices for each temperature and flow rate,

Aij＝[a1_ij,a2_ij,a3_ij,a4_ij,a5_ij,p1_ij,p2_ij,p3_ij,p4_ij,p5_ij,p6_ij,p7_ij,p8_ij].

It is therefore necessary to calibrate the fitting coefficients of HCT and SvO ₂ and store them in the lookup table 1, not at the same blood temperature and flow rate. Judging the current blood temperature T and the current blood flow velocity v, substituting the fitting coefficients corresponding to the closest blood temperature T and the blood flow velocity v recorded in the lookup table 1 into a first formula and a second formula, and calculating the readings of HCT and SvO ₂. If the two gradients in the table are intermediate, the calculation is performed according to a corresponding matrix for a larger blood temperature T and blood flow velocity v. The calculation method of the lookup table 1 is suitable for more accurate HCT and SvO ₂ registration calculation, and the lookup table is needed to be determined in advance through a certain number of calibration experiments and calibration workload, but in the monitoring process of the blood gas monitoring method, the fitting coefficient is determined by automatically consulting the lookup table 1 only when the blood gas parameter value is calculated.

With continued reference to fig. 3 and 4, fig. 3 is a schematic frame structure of a blood gas monitoring device according to an embodiment of the application; fig. 4 is a schematic overall structure of a blood gas monitoring device according to an embodiment of the present application.

Yet another embodiment of the present application provides a blood gas monitoring device 100. The blood gas monitoring device 100 includes a first light source assembly 110, a second light source assembly 120, and a controller 140. The first light source assembly 110 includes a first light source 111 and a first detection module 117. The second light source assembly 120 includes a second light source 121 and a second detection module 127, and the controller 140 is coupled to the first light source assembly 110 and the second light source assembly 120, for controlling the first light source assembly 110 and the second light source assembly 120 to implement the blood gas monitoring method of any of the above embodiments.

The controller 140 in the blood gas monitoring device 100 can control the first light source 111 and the second light source 121 to emit light signals according to a certain time sequence, and the first detection module 117 and the second detection module 127 receive the signals according to a certain time sequence, and after the controller 140 obtains the data of the first detection module 117 and the second detection module 127, the controller can directly calculate to obtain the blood gas parameter value; or the controller 140 may also transmit data to the mobile terminal 200 for algorithmic calculation and obtain blood gas parameter values.

In some embodiments, the controller 140 controls the first light source 111 to emit the outgoing light with the first wavelength, and the difference between the extinction coefficients of the oxygenated hemoglobin and the reduced hemoglobin for the light with the first wavelength is less than or equal to the first preset value. The controller 140 obtains a first wavelength detection value reflected back from the blood received by the first detection module 117. The controller 140 controls the first light source 111 to emit the outgoing light with the second wavelength, and the difference degree of the extinction coefficient of the oxygenated hemoglobin and the reduced hemoglobin on the light with the second wavelength is greater than or equal to a third preset value. The controller 140 obtains a second wavelength detection value reflected back from the blood received by the first detection module 117. The controller 140 controls the second light source 121 to emit the outgoing light of the third wavelength, and the extinction coefficient of the oxygenated hemoglobin and the reduced hemoglobin for the light of the third wavelength is less than or equal to a second preset value. The controller 140 obtains a third wavelength detection value reflected back from the blood received by the second detection module 127. The controller 140 may calculate the blood gas parameter value using the output light intensity value of the first wavelength, the output light intensity value of the second wavelength, the output light intensity value of the third wavelength, the first wavelength detection value, the second wavelength detection value, and the third wavelength detection value.

The blood gas monitoring device 100 further includes a housing 150, a blood gas detection module 101, and a blood gas pipeline 102, wherein the blood gas detection module 101 is disposed in the housing 150, and the blood gas pipeline 102 is disposed outside the housing 150. The first light source assembly 110 and the second light source assembly 120 form a blood gas detection module 101. Before monitoring starts, blood can be led out to be communicated with the blood gas pipeline 102, and the shell 150 is fixed on the blood gas pipeline 102, so that the blood gas detection module 101 and the blood gas pipeline 102 are relatively fixed. The blood gas detection module 101 may initiate blood gas monitoring.

Further, the first light source assembly 110 further comprises a first calibration detector 113, the second light source assembly 120 further comprises a second calibration detector 123, and the controller 140 is coupled to the first calibration detector 113 and the second calibration detector 123, respectively. The outgoing light rays emitted by the light sources are partially transmitted as detection light and partially reflected as calibration light, the detection light is used for irradiating blood, and the calibration light is used for reflecting to the calibration detectors.

The controller 140 can sense the change of the emergent light of the corresponding wavelength of each light source in real time according to the change of the light intensity detected by each calibration detector, and form feedback for the device to calibrate automatically, so that the luminous intensity of each light source is always kept in a constant linear interval in the detection process, and the influence on detection data caused by the change of the light intensity of the light source is reduced. The light intensity emitted by the first light source 111 and the second light source 121 is kept in a stable state and does not change along with the change of time and temperature, the light intensity monitored by each detector is only related to blood data, the interference of the light intensity after the diffuse reflection of the monitored blood caused by the change of the light intensity of the light sources is reduced, and the accuracy of the blood gas parameter value obtained by final operation is improved.

Specifically, the beam splitter can be used for dividing the emergent light rays emitted by each light source into two paths. The first light source assembly 110 further includes a first beam splitter 112 and a second beam splitter 122, where the first beam splitter 112 is disposed on a propagation path of the outgoing light of the first light source 111, that is, on a propagation path of the outgoing light of the first light source 111. The second beam splitter 122 is disposed on a propagation path of the outgoing light of the second light source 121, that is, on a propagation path of the outgoing light of the second light source 121.

The first beam splitter 112 is configured to partially transmit the outgoing light of the first wavelength of the first light source 111 into first detection light, which is used to irradiate into blood. The first beam splitter 112 is further configured to partially reflect outgoing light rays of the first wavelength of the first light source 111 as first collimated light. The first calibration detector 113 is disposed on a propagation path of the first calibration light, and is used for detecting the light intensity of the first calibration light.

The first beam splitter 112 is also configured to partially transmit the outgoing light of the second wavelength of the first light source 111 into second probe light for irradiation into blood. The first beam splitter 112 is also used to reflect the outgoing light ray portion of the second wavelength of the first light source 111 as second calibration light. The first calibration detector 113 is disposed on a propagation path of the second calibration light, and is configured to detect a light intensity of the second calibration light.

The second beam splitter 122 is configured to partially transmit the outgoing light of the third wavelength of the second light source 121 into third detection light, which is used to irradiate the blood. The second beam splitter 122 is further configured to partially reflect outgoing light rays of the third wavelength of the second light source 121 into third collimated light. The second calibration detector 123 is disposed on the propagation path of the third calibration light, and is used for detecting the light intensity of the third calibration light.

In some embodiments, blood gas monitoring device 100 further includes a temperature sensor (not shown) and a blood flow rate detector (not shown). The temperature sensor is disposed inside the housing 150 and is located at a side of the housing 150 for detection. The temperature sensor is used for detecting the body temperature of the user. The blood flow rate detector is used for detecting the blood flow rate. The controller 140 is coupled to the temperature sensor and the blood flow rate detector.

Because the Hct and SvO2 readings solved are changed due to the difference of the blood temperature and the blood flow rate in the blood gas parameter value, the temperature sensor is adopted to monitor the blood temperature in real time, the blood flow rate detector is adopted to detect the blood flow rate, the blood temperature calibration and the blood flow rate calibration can be carried out on the blood gas parameter value, and the monitoring accuracy of the blood gas parameter value is higher.

The blood gas monitoring device 100 is a noninvasive extracorporeal circulation blood gas monitoring system capable of self-calibrating in real time, and can realize convenient, real-time and continuous blood gas parameter monitoring in clinic. The blood gas monitoring device 100 can be placed on an extracorporeal circulation intravenous line, and is at least used for monitoring blood gas parameters such as mixed venous blood oxygen saturation (SvO 2) and hematocrit (Hct) in venous blood; the blood gas monitoring device 100 may also be placed on an extracorporeal circulation arterial circuit for at least monitoring arterial blood oxygen saturation (SaO 2) and hematocrit (Hct) blood gas parameters in arterial blood.

Still another embodiment of the present application provides a computer-readable storage medium having stored thereon program data which, when executed by a processor, implements the blood gas monitoring method of any of the above embodiments.

In the several embodiments provided in the present application, it should be understood that the disclosed method and apparatus may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of modules or units is merely a logical functional division, and there may be additional divisions of actual implementation, e.g., units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical, or other forms.

The elements illustrated as separate elements may or may not be physically separate, and elements shown as elements may or may not be physical elements, may be located in one place, or may be distributed over network elements. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied in essence or a part contributing to the prior art or all or part of the technical solution in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor (processor) to execute all or part of the steps of the methods of the embodiments of the present application. And the aforementioned storage medium includes: a usb disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

The terms "first", "second", "third" in the present application are used for descriptive purposes only and are not to be construed as indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", and "a third" may explicitly or implicitly include at least one such feature. All directional indications (such as up, down, left, right, front, back … …) in the embodiments of the present application are merely used to explain the relative positional relationship, movement, etc. between the components in a particular gesture (as shown in the drawings), and if the particular gesture changes, the directional indication changes accordingly. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion. A process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed but may alternatively include other steps or elements not listed or inherent to such process, method, article, or apparatus.

It should be noted that the terms "horizontal", "vertical" and the like do not denote that the component is required to be absolutely horizontal or vertical, but may be slightly inclined; the terms "parallel", "perpendicular" and the like do not denote absolute parallelism or perpendicularity between the fittings, but may be offset by an angle. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined. Furthermore, references to orientations or positional relationships of the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., are based on the orientation or positional relationships shown in the drawings, or are orientation or positional relationships conventionally placed when the product of the present application is used, are merely for convenience in describing embodiments of the present application and to simplify description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

The foregoing description is only of embodiments of the present application, and is not intended to limit the scope of the application, and all equivalent structures or equivalent processes using the descriptions and the drawings of the present application or directly or indirectly applied to other related technical fields are included in the scope of the present application.

Claims

1. The blood gas monitoring method of a blood gas monitoring device is characterized in that the blood gas monitoring device comprises a first light source assembly and a second light source assembly, the first light source assembly comprises a first light source and a first detection module, the second light source assembly comprises a second light source and a second detection module, and the method comprises the following steps:

controlling the first light source to emit emergent light rays with a first wavelength, wherein the difference degree of the extinction coefficients of the oxygenated hemoglobin and the reduced hemoglobin on the light rays with the first wavelength is smaller than or equal to a first preset value;

acquiring a first wavelength detection value reflected by blood received by a first detection module;

Controlling the second light source to emit emergent light rays with a third wavelength, wherein the extinction coefficient of the oxyhemoglobin and the reduced hemoglobin on the light rays with the third wavelength is smaller than or equal to a second preset value;

acquiring a third wavelength detection value reflected by blood received by the second detection module;

And calculating a blood gas parameter value by using the emergent light intensity value of the first wavelength, the emergent light intensity value of the third wavelength, the first wavelength detection value and the third wavelength detection value.

2. The blood gas monitoring method of claim 1, wherein the first detection module includes a first proximal detector and a first distal detector, the first proximal detector being closer to the first light source than the first distal detector, the obtaining a first wavelength detection value reflected back by the first detection module receiving blood includes:

acquiring a first wavelength near-end detection value reflected by blood received by a first near-end detector and a first wavelength far-end detection value reflected by blood received by a first far-end detector;

The second detection module includes a second near-end detector and a second far-end detector, the second near-end detector is closer to the second light source than the second far-end detector, and obtaining a third wavelength detection value reflected by blood received by the second detection module includes:

And acquiring a third wavelength near-end detection value reflected by the blood received by the second near-end detector and a third wavelength far-end detection value reflected by the blood received by the second far-end detector.

3. The blood gas monitoring method of claim 2, wherein the obtaining the blood gas parameter value using the first wavelength of the emitted light intensity value, the third wavelength of the emitted light intensity value, the first wavelength detection value, and the third wavelength detection value comprises:

The hematocrit HCT is calculated using a first formula as follows:

HCT＝a₁x₁ ²+a₂x₁+a₃x₂ ²+a₄x₂+a₅,

wherein, I ₁₀ is the output light intensity value of the first wavelength, and I ₃₀ is the output light intensity value of the third wavelength; i _1j is the first wavelength near-end detection value, I _3J is the third wavelength near-end detection value, I _1y is the first wavelength far-end detection value, I _3y is the third wavelength far-end detection value, and a ₁ to a ₅ are preset fitting coefficients.

4. The blood gas monitoring method of claim 3, further comprising:

controlling the first light source to emit emergent light rays with a second wavelength, wherein the difference degree of the extinction coefficients of the oxygenated hemoglobin and the reduced hemoglobin on the light rays with the second wavelength is larger than or equal to a third preset value;

Acquiring a second wavelength near-end detection value reflected by blood received by a first near-end detector and a second wavelength far-end detection value reflected by blood received by a first far-end detector;

And obtaining a blood gas parameter value by using the emergent light intensity value of the first wavelength, the emergent light intensity value of the second wavelength, the first wavelength near-end detection value, the first wavelength far-end detection value, the second wavelength near-end detection value, the second wavelength far-end detection value and the hematocrit value.

5. The method of claim 4, wherein said obtaining a blood gas parameter value using said first wavelength exit light intensity value, said second wavelength exit light intensity value, a first wavelength near-end detection value, a first wavelength far-end detection value, a second wavelength near-end detection value, a second wavelength far-end detection value, and said hematocrit value comprises:

The blood oxygen saturation SvO ₂ is calculated using a second formula as follows:

wherein, Y ₂ is the value of the hematocrit; i ₁₀ is the emergent light intensity value of the first wavelength, I ₂₀ is the emergent light intensity value of the second wavelength, I _1j is the near-end detection value of the first wavelength, I _1y is the far-end detection value of the first wavelength, I _2j is the near-end detection value of the second wavelength, I _2y is the far-end detection value of the second wavelength, and p ₁ to p ₈ are preset fitting coefficients.

6. The blood gas monitoring method of any one of claims 1-5, wherein each light source module further comprises a calibration detector, each light source emitting outgoing light that is partially transmitted as probe light for irradiation into blood and partially reflected as calibration light for reflection into the corresponding calibration detector, each wavelength probe value being a signal of the probe light reflected back by blood; before the calculating the blood gas parameter value, the method further comprises:

Acquiring calibration detection values corresponding to the calibration light received by each calibration detector;

Judging whether the difference value between the calibration detection value and the corresponding calibration preset value is smaller than the corresponding preset difference value or not;

If yes, executing the step of calculating the blood gas parameter value;

If not, calibrating the emergent ray intensity of the corresponding light source according to the calibrated detection value, and returning to the step of controlling the first light source to emit emergent rays with the first wavelength.

7. The blood gas monitoring method of claim 6, wherein calibrating the intensity of the outgoing light of the corresponding light source according to the calibrated detection value comprises:

calibrating the emergent ray intensity of the corresponding light source by using a third formula, wherein the third formula is as follows:

Wherein, I ₀₁ is a calibration preset value, I ₁ is a current calibration detection value, W ₁₀ is an initial set value of the intensity of the outgoing light of the light source, and W ₁ is the intensity of the outgoing light after the light source is calibrated.

8. The blood gas monitoring method of claim 6, further comprising calculating an exit light intensity value for each wavelength, the calculating an exit light intensity value for each wavelength comprising:

Taking the calibration detection value, of which the difference value with the calibration preset value is smaller than the corresponding preset difference value, as a calibration detection effective value;

determining an outgoing light intensity value of outgoing light rays with corresponding wavelengths according to a fourth formula, wherein the fourth formula is as follows:

I_n＝K_nI_{n School and school}+b_n，

9. The method of any one of claims 1-5, wherein the acquiring the first wavelength detection value reflected back from the blood by the first detection module comprises:

acquiring a first wavelength acquisition signal reflected by blood received by the first detection module;

Controlling the first light source and the second light source to be turned off;

acquiring first wavelength acquisition dark noise reflected by blood received by a first detection module;

And subtracting the first wavelength acquisition dark noise from the first wavelength acquisition signal to obtain a first wavelength detection value.

10. The blood gas monitoring method of any one of claims 1-5, further comprising, prior to the calculating the blood gas parameter value:

And performing constant false alarm rate filtering processing on each wavelength detection value.

11. The blood gas monitoring method of claim 5, further comprising:

and acquiring a current blood temperature and a current blood flow rate, and calibrating the blood gas parameter value by using the current blood temperature and the current blood flow rate.

12. The blood gas monitoring method of claim 11, wherein said calibrating the blood gas parameter value with the current blood temperature and the current blood flow rate comprises:

and determining fitting coefficients of the first formula and the second formula under the current blood temperature and the current blood flow rate according to a pre-stored corresponding relation table of the blood temperature, the blood flow rate and the fitting coefficients.

13. The blood gas monitoring method of claim 11, wherein said calibrating the blood gas parameter value with the current blood temperature and the current blood flow rate comprises:

The hematocrit HCT _{School and school} is calibrated using a fifth formula as follows:

HCT_{School and school}＝HCT_{_0}(1+N₁(T-T₀)+N₂(V-V₀))，

Wherein T ₀ is a predetermined blood temperature, V ₀ is a predetermined blood flow rate, T is the current blood temperature, V is the current blood flow rate, HCT _{_0} is a hematocrit value calculated according to the first formula, and N ₁ and N ₂ are preset fitting coefficients;

The blood oxygen saturation SvO _{2 School and school} is calibrated using a sixth formula, which is as follows:

SvO_{2 School and school}＝SvO_{2_0}(1+Q₁(T-T₀)+Q₂(V-V₀))，

Wherein T ₀ is a predetermined blood temperature, V ₀ is a predetermined blood flow rate, T is the current blood temperature, V is the current blood flow rate, svO _{2_0} is a blood oxygen saturation value calculated according to the second formula, and Q ₁ and Q ₂ are preset fitting coefficients.

14. A blood gas monitoring device, characterized in that the blood gas monitoring device comprises a first light source assembly, a second light source assembly and a controller, wherein the first light source assembly comprises a first light source and a first detection module, the second light source assembly comprises a second light source and a second detection module, and the controller is coupled with the first light source assembly and the second light source assembly and is used for controlling the first light source assembly and the second light source assembly to realize the blood gas monitoring method of any one of claims 1-13.

15. A computer readable storage medium, characterized in that the storage medium stores program data executable to implement the blood gas monitoring method according to any one of claims 1-13.