JPH0634780B2 - Blood pressure waveform correction device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a blood pressure waveform correction device used in an open blood pressure monitoring system for obtaining an accurate blood pressure waveform.

[Prior Art] In recent years, invasive blood pressure monitoring systems have been widely used in medical fields. However, in this system, a flexible blood pressure tube or the like filled with an infusion agent as a pressure transmitting medium is interposed in the blood pressure measuring line between the blood pressure measuring site of the patient and the pressure transducer. At this time, if the damping coefficient and resonance frequency, which are unique to the system and are determined by the physical characteristics of the blood pressure tube, are not appropriate values, the blood pressure waveform measured by the pressure transducer may be significantly distorted compared to the original waveform. May be. In the case of a normal system, the damping coefficient is 0.15 to 0.3, which is an underdamping state, and there is a problem in accurate measurement of the blood pressure waveform.

Therefore, in recent years, the following damping devices have been devised.

Insert a variable resistor in series in the blood pressure measurement line to prevent fluid movement due to resonance wave vibration (USP443100)
9).

The blood pressure measurement line incorporates a membrane with appropriate compliance, which prevents fluid movement due to resonant wave vibration (USP4779625).

A variable resistance and an air chamber are installed in the blood pressure measurement line, and fluid movement due to resonance wave vibration is blocked by using the compliance of the air in the air chamber (USP4335729).

Incorporating a fixed resistor and air chamber in the blood pressure measurement line,
By using the compliance of air in the air chamber, fluid movement due to resonance wave vibration is prevented (Japanese Patent Laid-Open No. 1-204646).

[Problems to be Solved by the Invention] However, the position where the variable resistance is incorporated in the blood pressure measurement line is limited, and if the position is incorrect, the flash cannot be performed because of the variable resistance. In addition, there is a problem that a fine adjustment of the degree of damping is required at the time of setup, and the device must be separated from the circuit when the device is not used during measurement.

In the same manner as above, there is a problem that the device must be separated from the circuit when the device is not used during measurement.

Requires a fine adjustment of the variable resistance that reaches the air chamber during setup, and if the device is not used during measurement, it can be disabled by closing the variable resistance. There is a problem that the variable resistance needs to be finely adjusted again when it is reused.

Can be used without adjusting the resistor, but there is a problem that the device must be separated from the circuit when the device is not used during measurement.

INDUSTRIAL APPLICABILITY The present invention does not limit the position to be incorporated in the blood measurement line, does not require fine adjustment during setup, and can be brought into an unused state without being separated from the circuit when not in use, and can be easily re-used. It is an object of the present invention to provide a blood pressure waveform correction device that can be put in use.

[Means for Solving the Problems] The present invention according to claim 1 is such that an air chamber having at least one opening communicates with one end of the air chamber through the opening and the other end of the air chamber communicates with the air chamber. A resistor which is connected to the blood pressure measurement line and has a passage whose cross-sectional area is sufficiently smaller than the cross-sectional area of the pressure transmission tube of the blood pressure measurement line, and the liquid in the blood pressure measurement line passes through the resistor. In the blood pressure waveform correction device configured to provide damping to an abnormal pressure wave transmitted through the blood pressure measurement line by flowing into the air chamber as described above, at least a part of the resistor is formed of an elastic body. The elastic body portion of the resistor is deformed to include a resistance adjusting portion capable of adjusting the passage area of the resistor.

According to a second aspect of the present invention, in addition to the first aspect of the present invention, the resistor has a passage area of 2 × 10 ^{−3 to} 160.
× 10 ⁻³ mm ² , and the passage length is 0.5 to 40 mm.

According to a third aspect of the present invention, in addition to the first or second aspect of the present invention, the volume of the air chamber is 1 to 150 μm.

The present invention according to claim 4 is the damping according to any one of claims 1 to 3, further including damping of a blood pressure measurement line, which is changed by adjusting the passage area of the resistor by the resistance adjusting portion. The range of the coefficient change is such that the blood pressure waveform is not corrected at all and the damping coefficient is changed to 1.0.

According to the present invention described in claim 5, one end communicates with the air chamber having at least one opening, the other end communicates with the air chamber through the opening, and the other end communicates with the blood pressure measurement line. And a resistor having a passage whose cross-sectional area is sufficiently smaller than the cross-sectional area of the pressure transmission tube of the blood pressure measurement line, and the liquid in the blood pressure measurement line flows into the air chamber through the low antibody. Thus, in the blood pressure waveform correction device configured to give damping to the abnormal pressure wave transmitted through the blood pressure measurement line, the resistance opening / closing for controlling the conduction state of the resistor in two positions, either open or substantially closed. It is equipped with a child.

According to a sixth aspect of the present invention, in addition to the fifth aspect of the present invention, at least a part of the resistor is formed of an elastic body, and the elastic body portion of the resistor is deformed to form the resistor. Further, a resistance adjusting portion capable of adjusting the passage area of is provided.

The present invention according to claim 7 is the present invention according to claim 5 or 6, wherein the resistor has a passage area of 2 × 10 ^−3.
˜160 × 10 ⁻³ mm ² , and the passage length is 0.5 to 40 mm.

The present invention according to claim 8 is the same as in the present invention according to any one of claims 5 to 7, wherein the volume of the air chamber is 1 to 1.
It is set to be 50μ.

The present invention according to claim 9 is the damping according to the present invention according to any one of claims 6 to 8, in which the blood pressure measurement line is changed by adjusting the passage area of the resistor by the resistance adjusting section. The range of the coefficient change is such that the blood pressure waveform is not corrected at all and the damping coefficient is changed to 1.0.

In the present invention, the "passage area" means a cross-sectional area orthogonal to the passage communication direction.

[Operation] According to the present invention described in claims 1 to 9, since the air chamber communicates with the blood measurement line via the resistor, a part of the liquid in the blood pressure measurement line applied by the blood pressure is It flows into the air chamber through the resistor. At this time, the pressure wave traveling in the blood pressure measurement line using the fluid as a medium also reaches the air chamber through the resistor and is damped by the compliance of the air in the air chamber. Therefore, the damping coefficient of the entire blood pressure measurement line is appropriate. It should be

At this time, according to the present invention as set forth in claim 1, there is the following action.

The position to be incorporated in the blood pressure measurement line is not limited.

The resistance adjusting unit deforms the elastic body portion of the resistor to adjust the passage area of the resistor, whereby the damping coefficient can be set to an appropriate value quickly and easily, and no delicate adjustment is required during setup.

When it is desired not to apply damping, the resistance adjusting portion can make the passage area of the resistor sufficiently small to bring it into a non-operating state. Therefore, when not in use, the circuit can be easily put into a non-use state without being separated from the circuit.

According to the present invention described in claim 2, the following effects are obtained.

The cross-sectional area of the resistor, which is the passage, is 2 × 10 ^{-3 to} 160 × 10 ^-3 mm.
^It should be in the range of ² , preferably 5 × 10 ^{-3 to} 100 × 10
^-3 mm ² , more preferably 15 × 10 ^-3 to 70 × 10 ^-3 mm ² . If this cross-sectional area is smaller than 2 × 10 ^-3 mm ² or larger than 160 × 10 ^-3 mm ² , suitable damping coefficient D and resonance frequency f cannot be obtained, so that an accurate blood waveform cannot be obtained. .

The length of the resistor, which is this passage, may be in the range of 0.5 to 40 mm, preferably in the range of 1 to 30 mm, and more preferably in the range of 3 to 20 mm. If this length is shorter than 0.5 mm or longer than 40 mm, the damping coefficient D and the resonance frequency f are not suitable, so that accurate blood pressure measurement cannot be obtained. If the length is shorter than 0.5 mm, air may be mixed in the blood pressure measurement line.

According to the present invention described in claim 3, there is the following action.

The air chamber is formed to have a volume in the range of 1 to 150μ, preferably 5 to 80μ, and more preferably 10 to 60μ.
It is good to be in the range. If this capacitance is smaller than 1 μ or larger than 150 μ, the damping coefficient D and the resonance frequency f are not suitable, so that an accurate blood pressure waveform cannot be obtained.

According to the present invention described in claim 4, there is the following action.

A damping coefficient of 0.5 to 0.7 is generally said to be in a preferable range, and if it exceeds 1.0, an overdamping state occurs and an accurate blood pressure waveform cannot be obtained.

According to the present invention described in claim 5, there is the following action.

The position to be incorporated in the blood pressure measurement line is not limited.

The resistance switch controls the conduction of the resistor in two positions, either open or closed. Therefore, the damping coefficient, which is determined according to the passage area of the resistor in the open state, can be quickly and easily set to an appropriate value, and no delicate adjustment is required during setup.

When it is not desired to apply damping, the resistance switch can be put into a non-operating state by closing the conducting state of the resistor. Therefore, when not in use, it can be easily put into a non-use state without being separated from the circuit.

According to the present invention described in claim 6, there is the following action.

By adjusting the passage area of the low antibody by deforming the elastic body part of the resistor using the resistance adjusting unit, the passage area of the resistor set to the open state by the resistance switch can be easily set to an appropriate value in advance. Can be set.

The present invention according to claim 7 has the following effects.

Same as above.

According to the present invention described in claim 8, there is the following action.

Same as above.

According to the present invention described in claim 9, there is the following action.

Same as above.

[Embodiment] FIG. 1 is a sectional view showing the first embodiment, FIG. 2 is an external perspective view of FIG. 1, and FIG. 3 is a perspective view showing a damping body.
FIGS. 5A and 5B are sectional views showing the usage state of the first embodiment, FIG. 5 is a sectional view showing the second embodiment, and FIG. 6A.
(B) is a sectional view showing the third embodiment, FIG. 7 is a sectional view showing the fourth embodiment, FIG. 8 is a schematic view showing an open blood pressure monitoring system, and FIG. 9 is an explanatory view of a damping coefficient. Is.

(First Example) As shown in FIG. 8, the open blood pressure monitoring system A includes a catheter 1 placed in a blood vessel of a patient M, at the other end thereof,
A flexible pressure transmission tube 2, a blood pressure waveform correction device with a three-way stopcock of the present invention (hereinafter simply referred to as a correction device) 3 and a pressure dome 4 are sequentially connected to form a blood pressure measurement line B. B is a pressure transducer 5
And a CRT display device 6 and a recording device. The blood pressure measurement line B contains, for example, physiological saline C as a pressure transmission medium,
The physiological saline (liquid) C transmits the blood pressure of the patient M to the diaphragm in the pressure dome 4, and the pressure received by the diaphragm is transmitted to the pressure transducer 5 and converted into an electric signal, and the CRT display device 6 and The blood pressure of the patient M is always directly monitored by a storage device or the like and further recorded.

The correction device 3 incorporated in the blood pressure measurement line B of the system A is composed of a correction section 3A and a three-way stopcock section 3B, as shown in FIGS. The correction unit 3A includes a housing 7, a damping body 8 that is liquid-tightly housed in the housing 7, and includes an air chamber 9 and a resistor 10.
And a plunger 11 incorporated in the housing 7. The three-way stopcock part 3B includes a valve body 12 formed integrally with the housing 7, and a valve member 1 housed in the valve body 12.
3 and 3.

The housing 7 is made of polycarbonate and has a box-shaped member 7.
A and a lid member 7B. The box-shaped member 7 </ b> A has a communication channel 14 that connects the valve body 12 and the resistor 10.

As shown in FIG. 3, the air chamber 9 of the damping body 8 has at least one opening 9A communicating with one end of the resistor 10 and has a substantially L shape. The volume of this air chamber 9 is
As described above, it is set to 1 to 150 μm, and in this embodiment, it is set to 58 μm.
is μ.

The resistor 10 of the damping body 8 is, as shown in FIG.
A groove-like passage formed by a straight line, a curved line, or a combination of straight lines and curved lines, one end of which is connected to the opening 9A of the air chamber 9 and the other end of which is connected to the blood pressure measurement line B through the communication flow passage 14 of the housing 7. ing. As described above, the resistor 10 has a passage cross-sectional area of 2 × 10 ₋₃ to 160 × 10 ⁻³ mm ² and a passage length of 0.
It is set to 5-40 mm. In this embodiment, the passage width is 0.2 to
0.3mm, passage depth 0.38mm, passage length about 17mm.

That is, in the correction device 3, the infusion agent in the blood pressure measurement line B is connected to the valve body 12 of the three-way stopcock part 3B, the communication channel 14,
It passes through the resistor 10 and flows into the air chamber 9. The pressure wave traveling with the infusate as a medium also reaches the air chamber 9,
It will be dumped.

At this time, the damping body 8 is made of an elastic material. In this embodiment, it is made of silicone rubber.

Then, the plunger 11 includes the left and right operation parts 15A and 15A.
B, a pressing portion 16 that presses the damping body 8, and a ratchet 18 that engages with a plurality of stages (three stages of left, middle, and right in this embodiment) engaging recesses 17 provided in the housing 7.

Accordingly, in the correction device 3, the blood pressure measurement line B
The damping coefficient of is controlled in the following three stages.

The ratchet 18 of the plunger 11 is engaged with the left engaging recess 17
, The pressing portion 16 does not compress and deform the damping main body 8 at all, or keeps the original state of only slightly pre-compressing the damping main body 8 so that the damping coefficient of the blood pressure measurement line B is relatively large. A state is formed (see FIG. 4 (A)).

In the drawing of the plunger 11, when the left operating portion 15A is pushed in and the ratchet 18 thereof is engaged with the intermediate engaging concave portion 17 and is retained, the pressing portion 16 compressively deforms in the vicinity of the resistor 10 of the damping main body 8 and the resistor 10 The flow passage resistance of the resistor 10 is increased by narrowing the passage area of, and as a result, the damping coefficient of the blood pressure measurement line B is reduced (see FIG. 4 (B)).

Replace the ratchet 18 of the plunger 11 with the right engaging recess 17
It is also possible to stop the damping function by making the passage area of the resistor 10 sufficiently small or closed by the pressing portion 16 when engaging with and stopping.

In order to recover the damping coefficient reduced state or the damping function stopped state to the damping coefficient original state, the correction device 3 pushes the right operation portion 15B in the drawing of the plunger 11 and pushes the ratchet 18 of the ratchet 18 into the left engagement recess. By returning to the engagement position with 17 and elastically recovering the deformation of the damping body 8, the passage area of the resistor 10 is restored to the original state, and as a result, the original state of the damping coefficient can be restored.

The correction device 3 is assembled as described in (1) and (2) below.

(1) The box-shaped member 7A of the housing 7 is inserted into the bottom surface of the housing 7 having the communication channel 14 so that the surfaces of the damping body 8 on which the air chamber 9 and the resistor 10 are formed are in close contact with each other.

(2) After the plunger 11 is mounted at a predetermined position, the lid member 7B is fitted and adhered to the box-shaped member 7A while the damping body 8 is pressed by the lid member B.

As a modified example of the correction device 3, a three-stage engagement recess 17 with which the ratchet 18 engages was incorporated into the blood pressure measurement line B, and as a result of an experiment, Table 1 was obtained. At this time, the blood pressure measuring line B was composed of a 20 G indwelling needle, a 30 cm tube and a 120 cm tube.

According to Table 1, by using the correction device 3, the damping coefficient can be changed by a simple operation,
Also, the damping function can be stopped. Is recognized.

The damping coefficient D is And x ₁ and x ₂ are the amplitudes shown in FIG. or,
The resonance frequency f is represented by f = 1 / t, and t is the time (sec) of one cycle shown in FIG. And this damping coefficient D is the pressure on the blood pressure measurement line, for example, 300 m.
mHg is applied, the three-way stopcock provided in this blood pressure measurement line is suddenly opened, and the amplitudes x ₁ and x ₂ of the waveform appearing on the CRT display device are measured, and these x ₁ and x ₂ are measured as described above.
It is obtained by introducing it into equation (1).

The correction device 3 has the following actions.

The position where the correction device 3 is incorporated in the blood pressure measurement line B is not limited.

The plunger 11 that constitutes the resistance adjusting unit deforms the resistor 10 made of an elastic body to adjust the passage area of the resistor 10, and thereby the damping coefficient can be set to an appropriate value quickly and easily. No adjustment required.

When it is desired not to apply damping, the plunger 11 can be made inactive by sufficiently reducing the passage area of the resistor 10. Therefore, when not in use, the circuit can be easily put into a non-use state without being separated from the circuit.

The three-way stopcock portion 3B is constructed by having the valve member 13 made of high density polyethylene rotatable in the valve body 12 made of polycarbonate as described above. Valve body 12
Is a first communication port 100A connected to the pressure dome 4,
A second communication port 100B connected to the pressure transmission tube 2 is provided in a straight line, and both the first and second communication ports 100 are provided.
A third communication port 100C is provided in a direction orthogonal to a straight line connecting A and 100B, and the communication flow path 14 as a fourth communication port facing the third communication port 100C. The valve member 13 includes three conduction paths that conduct in a T shape, and the four communication ports 100A to 100C and the communication flow path 14 described above.
At least three of them can communicate with each other.

However, the correction device 3 has the correction part 3A capable of turning on / off the damping function by the plunger 11, so that the damping function stop state is realized without operating the valve member 13 of the three-way stopcock part 3B. be able to.

That is, if the correction unit 3A does not have a function capable of turning on / off the damping function, and if the damping function is stopped while maintaining the state of being communicated with the blood pressure measurement line B, one of the T-shaped communication paths of the valve member 13 Must be directed to the third communication port 110C used as a blood sampling port. When the blood collection port is not used, the cap is covered, but since the port is frequently used, the cap is often attached and detached, and the pressure transducer 5
In some cases, the cap may be removed by opening to the atmosphere for adjustment (0 point adjustment). Therefore, it is difficult to maintain sterility by communicating with the blood sampling port, and it is difficult to ensure sterility of the entire circuit by communicating with blood sampling measurement line B.

Therefore, it is possible to eliminate the above-mentioned inconvenience by providing the correction unit 3A with means for stopping the damping function.

(Second Embodiment) The difference between the correction device 20 of FIG. 5 and the correction device 3 is that
This is because the ratchet 18 of the plunger 11 can be engaged with the adjusting screw 21 and the engaging recess 22 of the housing 7 in two steps.

As a result, the correction device 2 can adjust the adjustment screw 2 in the damping function state in which the ratchet 18 engages the adjustment screw 21.
The amount of pre-compression applied to the damping body 8 can be adjusted by adjusting the closing amount of 1, so that a desired damping coefficient can be imparted to the blood pressure measurement line B, and the resistance can be increased while the ratchet 18 is engaged with the engagement recess 22. The body 10 can make the passage area sufficiently small or closed to stop the damping function.

That is, the correction device 20 can control the conductive state of the resistor 10 by the plunger 11 in two positions, either the open state or the substantially closed state.

Then, the correction device 20 includes the plunger 11 and the adjusting screw 2
By 1, the damping body 8 can be elastically deformed and the passage area of the resistor 10 when opened can be adjusted in advance.

The correction device 20 has the following effects.

The position where the correction device 20 is incorporated in the blood pressure measurement line B is not limited.

The plunger 11 forming the resistance switch controls the conductive state of the resistor 10 in two positions, either open or closed. Therefore, the damping coefficient determined according to the passage area of the resistor 10 in the open state can be obtained quickly and easily,
Does not require subtle adjustments during setup.

When it is desired not to apply damping, the conductive state of the resistor 10 can be closed by the plunger 11 to bring it into a non-operating state. Therefore, when not in use, it can be easily put into a non-use state without being separated from the circuit.

The plunger 11 constituting the resistance adjusting portion and the adjusting screw 21 cooperate with each other to elastically deform the resistor 10 and adjust the passage area of the resistor 10 to adjust the plunger 11.
The passage area of the resistor 10 set to the open state by the above can be easily set to an appropriate value in advance.

(Third Embodiment) The difference between the correction device 30 of FIG. 6 and the correction device 3 is that
Gate valve 3 that allows the plunger 11 to open and close the communication channel 14
1, the ratchet 18 of the plunger 11 can be engaged with the left and right two-stage engaging recesses 32 of the housing 7 in two steps.

As a result, in the correction device 30, when the ratchet 18 is engaged with the left side engagement recess 32, the gate valve 31 causes the communication passage 1 to move.
4 is brought into a damping function operating state in which it is not closed (see FIG. 6 (A)), and when the ratchet 18 is engaged with the right engagement recess 32, the gate valve 31 is in a damping function stopped state in which the communication passage 14 is closed (see FIG. 6A). See FIG. 6 (B).

That is, the correction device 30 can control the conductive state of the resistor 10 by the plunger 11 in two positions, either open or closed.

The correction device 30 has the following effects.

The position where the correction device 30 is incorporated in the blood pressure measurement line B is not limited.

The gate valve 31 of the plunger 11 as a resistance switch controls the conductive state of the resistor 10 in two positions, either open or closed. Therefore, the damping coefficient determined according to the passage area of the resistor 10 in the open state can be obtained quickly and easily, and no delicate adjustment is required during setup.

When it is not desired to apply damping, the conductive state of the resistor 10 is closed by the gate valve 31 so that the resistor 10 can be deactivated. Therefore, when not in use, the circuit can be easily put into a non-use state without being separated from the circuit.

Fourth Embodiment The correction device 40 of FIG. 7 differs from the correction device 30 in that the adjusting screw 41 elastically deforms the damping body 8 to adjust the passage area of the resistor 10 when opened.

According to the correction device 40, the resistor 10 is elastically deformed by using the adjusting screw 41 as the resistance adjusting unit to adjust the passage area of the resistor, and thus the resistor which is set to the open state by the gate valve 31. The passage areas of 10 can be easily set to appropriate values in advance.

[Effects of the Invention] As described above, according to the present invention, the position to be incorporated in the blood measurement line is not limited, delicate adjustment is not required at the time of setup, and when it is not used, it is not used and separated from the circuit. It is possible to provide a blood pressure waveform correction device that can be used and that can be easily reused.

[Brief description of drawings]

1 is a sectional view showing the first embodiment, FIG. 2 is an external perspective view of FIG. 1, FIG. 3 is a perspective view showing a damping body, and FIG.
FIGS. 5A and 5B are sectional views showing the usage state of the first embodiment, FIG. 5 is a sectional view showing the second embodiment, and FIG. 6A.
(B) is a sectional view showing the third embodiment, FIG. 7 is a sectional view showing the fourth embodiment, FIG. 8 is a schematic diagram showing an open blood pressure monitoring system, and FIG. 9 is an explanatory diagram of a damping coefficient. is there. 3 ... Compensation device, 9 ... Air chamber, 10 ... Resistor, 11 ... Plunger, 20 ... Compensation device, 21 ... Adjusting screw, 30 ... Compensation device, 31 ... Gate valve, 40 ... Correction device, 41 ... Adjusting screw.

Claims (2)

[Claims] 1. An air chamber having at least one opening,
One end communicates with the air chamber through the opening, the other end communicates with the blood pressure measurement line, and has a cross-sectional area that is sufficiently smaller than the cross-sectional area of the pressure transmission tube of the blood pressure measurement line. A blood pressure measuring device which is composed of a resistor and is configured to provide damping to an abnormal pressure wave transmitted through the blood pressure measuring line when the liquid in the blood pressure measuring line flows into the air chamber through the resistor. In the waveform correction device, at least a part of the resistor is formed of an elastic body, and a resistance adjusting unit is provided that is capable of adjusting the passage area of the resistor by deforming the elastic body portion of the resistor. Blood pressure waveform correction device. 2. An air chamber having at least one opening,
One end communicates with the air chamber through the opening, the other end communicates with the blood pressure measurement line, and has a cross-sectional area that is sufficiently smaller than the cross-sectional area of the pressure transmission tube of the blood pressure measurement line. A blood pressure measuring device which is composed of a resistor and is configured to provide damping to an abnormal pressure wave transmitted through the blood pressure measuring line when the liquid in the blood pressure measuring line flows into the air chamber through the resistor. A blood pressure waveform correction device, comprising: a resistance opening / closing device for controlling the conductive state of the resistor in two positions, either open or substantially closed.