Invasive blood pressure sensor and pressure correction and sensitivity calibration method

Abstract

The invention discloses an invasive blood pressure sensor and a pressure correction and sensitivity calibration method, and relates to the technical field of medical instruments.The invasive blood pressure sensor comprises a position correction unit, a pressure sensor, a substrate and two pre-charging structures, and the position correction unit and the pressure sensor are both electrically connected with an upper computer; the position correction unit, the pressure sensor and the two pre-charging structures are all arranged on a substrate, a pressure measuring through hole is formed in the substrate, the pressure sensor is arranged at the pressure measuring through hole, the two pre-charging structures are arranged on the two sides of the substrate respectively, and the pressure sensor is arranged in the pressure measuring through hole. And the positions of the two pre-charging structures correspond to the positions of the pressure sensors. According to the invasive blood pressure sensor and the pressure correction and sensitivity calibration method, the pressure value can be calibrated.

Description

Technical Field

[0001] The present invention relates to the technical field of medical instruments, and in particular to an invasive blood pressure sensor, a pressure correction method and a sensitivity calibration method. Background Art

[0002] Although the sensitivity of existing sensors has been calibrated, changes in position will still cause changes in sensor output readings when they are actually used. This disturbance is the main source of clinical invasive blood pressure measurement. Summary of the invention

[0003] The purpose of the present invention is to provide an invasive blood pressure sensor, a pressure correction and sensitivity calibration method, and to calibrate the pressure value.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides an invasive blood pressure sensor, comprising: a position correction unit, a pressure sensor, a substrate and two pre-filling structures, wherein the position correction unit and the pressure sensor are electrically connected to a host computer, the position correction unit, the pressure sensor and the two pre-filling structures are arranged on the substrate, a pressure measuring through hole is opened on the substrate, the pressure sensor is arranged at the pressure measuring through hole, the two pre-filling structures are respectively arranged on both sides of the substrate, and the positions of the two pre-filling structures correspond to the positions of the pressure sensors.

[0006] Preferably, the pre-filling structure includes a pre-filling body, a pressure measuring interface and a pre-filling interface, a pre-filling cavity is arranged in the pre-filling body, the pressure measuring interface and the pre-filling interface are both connected to the pre-filling cavity, and the pressure measuring interface and the pre-filling interface are arranged in a V shape.

[0007] Preferably, the position correction unit comprises an angle measurement unit and a first height measurement unit, the angle measurement unit is used to determine the angle of the substrate deviation, and the first height measurement unit is used to measure the vertical height change value of the substrate.

[0008] Preferably, it further comprises a floating position correction unit, which is located at the part to be measured and is electrically connected to a host computer.

[0009] Preferably, the floating position correction unit comprises a second height measurement unit, and the second height measurement unit is used to measure a vertical height change value of the part to be measured.

[0010] Preferably, the angle measurement unit is a gyroscope, the first height measurement unit is an accelerometer or an absolute pressure sensor, and the second height measurement unit is an accelerometer or an absolute pressure sensor.

[0011] Preferably, a calibration syringe is also included, which includes a syringe barrel and a piston push rod, the piston push rod is slidably connected to the syringe barrel, the side wall of the syringe barrel is provided with a temperature scale, the syringe barrel is used to connect with the prefilling interface, and the rear end of the syringe barrel and the rear end of the piston push rod can be connected by a snap-fit ​​structure.

[0012] The present invention also provides a method for pressure correction and sensitivity calibration using the invasive blood pressure sensor, comprising:

[0013] When the position of the pressure sensor and the position of the part to be measured are not fixed, the pressure correction process is as follows:

[0014] The pressure correction value ΔP1 obtained by offset angle correction is as follows:

[0015] ΔP1=(1-cosα)hρg

[0016] Wherein, h is the vertical height change value of the substrate measured by the first height measurement unit, α is the angle of deviation of the substrate from the vertical direction measured by the angle measurement unit, ρ is the density of the pre-filled medium, and g is the gravitational acceleration;

[0017] The pressure correction value ΔP2 obtained by altitude correction is as follows:

[0018] ΔP2=xρg

[0019] Wherein, x is the vertical height change value of the measured part measured by the second height measurement unit, ρ is the density of the pre-filled medium, and g is the gravitational acceleration;

[0020] The pressure value measured by the pressure sensor is ΔP3;

[0021] Furthermore, the pressure correction value P is as follows:

[0022] P = ΔP1 + ΔP2 + ΔP3;

[0023] When the position of the pressure sensor is not fixed and the position of the part to be measured is fixed, the pressure correction process is as follows:

[0024] The pressure correction value ΔP1 obtained by offset angle correction is as follows:

[0025] ΔP1=(1-cosα)hρg

[0026] Wherein, h is the vertical height change value of the substrate measured by the first height measurement unit, α is the angle of substrate deviation measured by the angle measurement unit, ρ is the density of the pre-filled medium, and g is the gravitational acceleration;

[0027] The pressure correction value ΔP2 obtained by altitude correction is as follows:

[0028] ΔP2=xρg

[0029] Wherein, x is the vertical height change value of the measured part measured by the second height measurement unit, ρ is the density of the pre-filled medium, and g is the gravitational acceleration;

[0030] Furthermore, the pressure correction value P is as follows:

[0031] P = ΔP1 + ΔP2;

[0032] The sensitivity calibration process is as follows:

[0033] Pull the piston push rod of the calibration syringe to the scale value shown by the current room temperature, then connect the syringe barrel to the pre-filling interface, close the pressure measuring interface, push the piston push rod to the bottom of the syringe barrel, and connect the syringe barrel and the piston push rod through the snap structure. At this time, the pressure in the pre-filling structure is the set pressure value.

[0034] Compared with the prior art, the present invention has achieved the following technical effects:

[0035] The present invention provides a position correction unit, taking into account the influence of the sensor position on the pressure value measurement, and by providing the position correction unit, the pressure value can be corrected to ensure the accuracy of the pressure measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 It is a front view of the invasive blood pressure sensor of the present invention;

[0038] Figure 2 It is a top view of the invasive blood pressure sensor of the present invention (without the pre-filling structure);

[0039] Figure 3 It is a top view of the invasive blood pressure sensor of the present invention (excluding the pre-filling structure and the pressure sensor);

[0040] Figure 4 A schematic diagram of a calibration syringe of the present invention;

[0041] Figure 5 For practical use of cross-sections;

[0042] In the figure: 1-position correction unit, 2-pressure sensor, 3-substrate, 4-pressure measuring through hole, 5-pre-filling body, 6-pressure measuring interface, 7-pre-filling interface, 8-floating position correction unit, 9-syringe, 10-piston push rod, 11-clamp structure, 12-silk screen, 13-sensitivity correction circuit board. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] The purpose of the present invention is to provide an invasive blood pressure sensor, a pressure correction and sensitivity calibration method, and to calibrate the pressure value.

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] Embodiment 1

[0047] like Figures 1 to 5 As shown, this embodiment provides an invasive blood pressure sensor, including: a position correction unit 1, a pressure sensor 2, a substrate 3 and two pre-filling structures, the position correction unit 1 and the pressure sensor 2 are electrically connected to the upper computer, the position correction unit 1, the pressure sensor 2 and the two pre-filling structures are arranged on the substrate 3, the pressure sensor 2 is preferably a piezoresistive pressure sensor, a pressure measuring through hole 4 is opened on the substrate 3, the pressure sensor 2 is arranged at the pressure measuring through hole 4, the edge of the pressure sensor 2 is sealed and connected to the substrate 3, the two pre-filling structures are respectively arranged on both sides of the substrate 3 and are sealed and connected to the substrate 3, and the positions of the two pre-filling structures correspond to the positions of the pressure sensor 2, that is, they are installed on Figure 2 At the silk screen 12 in the figure, the pressure sensor 2 is located in a space formed by one of the pre-filled structures and the substrate 3.

[0048] Specifically, in this embodiment, the pre-filling structure includes a pre-filling body 5, a pressure measuring interface 6 and a pre-filling interface 7. The pressure measuring interface 6 is used to connect to the pressure measuring tube, and the pre-filling interface 7 is used to pre-fill physiological saline or calibrate the sensitivity. By pre-filling the pre-filling structure with physiological saline, it is possible to prevent bubbles from entering the body being tested during use. A pre-filling cavity is provided in the pre-filling body 5, and the pressure measuring interface 6 and the pre-filling interface 7 are both connected to the pre-filling cavity. The pressure measuring interface 6 and the pre-filling interface 7 are arranged in a V-shape, which can realize the measurement of differential pressure.

[0049] In this embodiment, the position correction unit 1 includes an angle measurement unit and a first height measurement unit. The angle measurement unit is used to measure the offset angle of the substrate 3 , and the first height measurement unit is used to measure the vertical height change value of the substrate 3 .

[0050] In actual use, the position of the part to be measured may change. Therefore, the present embodiment further includes a floating position correction unit 8, which is located at the part to be measured and is electrically connected to the host computer. The floating position correction unit 8 includes a second height measurement unit, which is used to measure the vertical height change value of the part to be measured.

[0051] In this embodiment, the angle measurement unit is a gyroscope, the first height measurement unit is an accelerometer or an absolute pressure sensor, and the second height measurement unit is an accelerometer or an absolute pressure sensor.

[0052] When the sensor is in different temperature environments, its sensitivity will change with temperature. Therefore, the present embodiment also includes a calibration syringe, which includes a syringe barrel 9 and a piston push rod 10. The piston push rod 10 is slidably connected to the syringe barrel 9. The side wall of the syringe barrel 9 is provided with a temperature scale. The syringe barrel 9 is used to connect with the pre-filling interface 7. The rear end of the syringe barrel 9 and the rear end of the piston push rod 10 can be connected through a snap-fit ​​structure 11.

[0053] When in use, use physiological saline to pre-fill the pre-fill structure through the pre-fill interface 7, discharge the air in the pre-fill structure, and fill the entire pre-fill structure with physiological saline. After the pre-filling is completed, close the pressure measuring interface 6 and the pre-filling interface 7, set the pressure to zero, connect the pressure measuring interface 6 to the pressure measuring tube, and start pressure measurement.

[0054] The invasive blood pressure sensor of this embodiment can be calibrated for sensitivity during use, thereby improving the accuracy of the sensor; and the error caused by clinical disturbance can be corrected by the position correction unit 1 and the floating position correction unit 8.

[0055] Embodiment 2

[0056] The hydraulic pressure difference caused by the relative position change between the sensor and the blood vessel to be measured will affect the output of the sensor. Therefore, this embodiment also provides a pressure correction and sensitivity calibration method of the invasive blood pressure sensor using the first embodiment, which specifically includes:

[0057] When the position of the pressure sensor 2 and the position of the part to be measured are not fixed, the pressure correction process is as follows:

[0058] The pressure correction value ΔP1 obtained by offset angle correction is as follows:

[0059] ΔP1=h-(1-cosα)hρg

[0060] Wherein, h is the vertical height change value of the substrate 3 measured by the first height measurement unit, α is the angle of deviation of the substrate 3 from the vertical direction measured by the angle measurement unit, ρ is the density of the pre-filled medium, and g is the gravitational acceleration;

[0061] The pressure correction value ΔP2 obtained by altitude correction is as follows:

[0062] ΔP2=xρg

[0063] Wherein, x is the vertical height change value of the measured part measured by the second height measurement unit, ρ is the density of the pre-filled medium, and g is the gravitational acceleration;

[0064] The pressure value measured by pressure sensor 2 is ΔP3;

[0065] Furthermore, the pressure correction value P is as follows:

[0066] P = ΔP1 + ΔP2 + ΔP3;

[0067] When the position of the pressure sensor 2 is not fixed and the position of the part to be measured is fixed, the pressure correction process is as follows:

[0068] The pressure correction value ΔP2 obtained by altitude correction is as follows:

[0069] ΔP2=xρg

[0070] Wherein, x is the vertical height change value of the measured part measured by the second height measurement unit, ρ is the density of the pre-filled medium, and g is the gravitational acceleration;

[0071] The pressure value measured by pressure sensor 2 is ΔP3;

[0072] Furthermore, the pressure correction value P is as follows:

[0073] P = ΔP1 + ΔP2;

[0074] The sensitivity calibration process is as follows:

[0075] This embodiment calibrates the sensitivity based on the compressible properties of gas and the gas equation. When the number of gas molecules in the closed chamber is constant, its pressure can be determined by the chamber volume and the current temperature. This embodiment uses a calibration syringe with an invasive blood pressure sensor to pull the piston push rod 10 of the calibration syringe to the scale value shown at the current room temperature, and connects the syringe 9 to the pre-filling interface 7, closes the pressure measuring interface 6, pushes the piston push rod 10 to the bottom of the syringe 9, and connects the syringe 9 to the piston push rod 10 through the buckle structure 11. At this time, the pressure in the pre-filling structure is the set pressure value. The sensor sensitivity can be calibrated according to the set pressure value, and then the sensitivity correction is performed through the sensitivity correction circuit. The sensitivity correction circuit is a prior art, and the sensitivity correction circuit board 13 is arranged on the substrate 3.

[0076] Figure 5 It is the user interface during actual use, and the user section displays the correction parameters, the corrected pressure value (standard pressure) and the pressure waveform.

[0077] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An invasive blood pressure sensor, characterized in that: include: A position correction unit, a pressure sensor, a substrate and two pre-filling structures, wherein the position correction unit and the pressure sensor are electrically connected to a host computer, the position correction unit, the pressure sensor and the two pre-filling structures are arranged on a substrate, a pressure measuring through hole is opened on the substrate, the pressure sensor is arranged at the pressure measuring through hole, the two pre-filling structures are respectively arranged on both sides of the substrate, and the positions of the two pre-filling structures correspond to the positions of the pressure sensors.

2. The invasive blood pressure sensor according to claim 1, characterized in that: The pre-filling structure includes a pre-filling body, a pressure measuring interface and a pre-filling interface. A pre-filling cavity is arranged in the pre-filling body. The pressure measuring interface and the pre-filling interface are both connected to the pre-filling cavity. The pressure measuring interface and the pre-filling interface are arranged in a V shape.

3. The invasive blood pressure sensor according to claim 1, characterized in that: The position correction unit includes an angle measurement unit and a first height measurement unit. The angle measurement unit is used to determine the angle of the substrate deviation, and the first height measurement unit is used to measure the vertical height change value of the substrate.

4. The invasive blood pressure sensor according to claim 1, characterized in that: It also includes a floating position correction unit, which is located at the to-be-tested position and is electrically connected to a host computer.

5. The invasive blood pressure sensor according to claim 4, characterized in that: The floating position correction unit includes a second height measurement unit, and the second height measurement unit is used to measure the vertical height change value of the part to be measured.

6. The invasive blood pressure sensor according to claim 5, characterized in that: The angle measurement unit is a gyroscope, the first height measurement unit is an accelerometer or an absolute pressure sensor, and the second height measurement unit is an accelerometer or an absolute pressure sensor.

7. The invasive blood pressure sensor according to claim 2, characterized in that: It also includes a calibration syringe, which includes a syringe barrel and a piston push rod, the piston push rod is slidably connected to the syringe barrel, the side wall of the syringe barrel is provided with a temperature scale, the syringe barrel is used to connect to the pre-filling interface, and the rear end of the syringe barrel and the rear end of the piston push rod can be connected by a snap-fit ​​structure.

8. A method for pressure correction and sensitivity calibration of an invasive blood pressure sensor according to any one of claims 1 to 7, characterized in that: When the position of the pressure sensor and the position of the part to be measured are not fixed, the pressure correction process is as follows: The pressure correction value ΔP1 obtained by offset angle correction is as follows: ΔP1=(1-cosα)hρg Wherein, h is the vertical height change value of the substrate measured by the first height measurement unit, α is the angle of deviation of the substrate from the vertical direction measured by the angle measurement unit, ρ is the density of the pre-filled medium, and g is the gravitational acceleration; The pressure correction value ΔP2 obtained by altitude correction is as follows: ΔP2=xρg Wherein, x is the vertical height change value of the measured part measured by the second height measurement unit, ρ is the density of the pre-filled medium, and g is the gravitational acceleration; The pressure value measured by the pressure sensor is ΔP3; Furthermore, the pressure correction value P is as follows: P = ΔP1 + ΔP2 + ΔP3; When the position of the pressure sensor is not fixed and the position of the part to be measured is fixed, the pressure correction process is as follows: The pressure correction value ΔP1 obtained by offset angle correction is as follows: ΔP1=(1-cosα)hρg Wherein, h is the vertical height change value of the substrate measured by the first height measurement unit, α is the angle of substrate deviation measured by the angle measurement unit, ρ is the density of the pre-filled medium, and g is the gravitational acceleration; The pressure correction value ΔP2 obtained by altitude correction is as follows: ΔP2=xρg Wherein, x is the vertical height change value of the measured part measured by the second height measurement unit, ρ is the density of the pre-filled medium, and g is the gravitational acceleration; Furthermore, the pressure correction value P is as follows: P = ΔP1 + ΔP2; The sensitivity calibration process is as follows: Pull the piston push rod of the calibration syringe to the scale value shown by the current room temperature, then connect the syringe barrel to the pre-filling interface, close the pressure measuring interface, push the piston push rod to the bottom of the syringe barrel, and connect the syringe barrel and the piston push rod through the snap structure. At this time, the pressure in the pre-filling structure is the set pressure value.

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