JPH0523393A - Blood pressure measuring device - Google Patents

Abstract

PURPOSE:To make good use of the title device for the sake of the prevention of trouble by relatively calculating that there is no abnormality in a blood pressure value at the time of extracorporeal circulation of blood to continuously measure and monitor blood pressure to respond to the abnormality of blood pressure at an early stage. CONSTITUTION:The blood stream flowing out of the body is supplied to a dialyser 16 through the elastically displaced tube 12 in the blood pressure measuring part 11 of a blood pressure measuring device 10. The space between the receiving body 13 of the blood pressure measuring part 11 and the tube 12 is filled with a pressure medium from the outside and the pressure transmitted through the tube 12 elastically displaced corresponding to the pulsation of the blood stream is converted to an electric signal by a converter 14 through a tube 15. A monitor 17 displays the supplied electric signal to emit an alarm at an abnormal time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood pressure measuring device used for circulating blood extracorporeally.

[0002]

2. Description of the Related Art Measurement of blood pressure is generally used as an index for knowing the physiological state of a living body, and is measured for the brachial artery. As a pre-stage of this measurement, the measurer supplies air into a so-called manchette consisting of a rubber bag wrapped around the upper arm to increase the pressure in the rubber. At the time of measurement, the blood pressure measurement value is defined as the systolic blood pressure when the pulse touches for the first time or the blood vessel sound is heard for the first time while gradually lowering the air pressure in the manchette. Also, the lowest blood pressure is
For example, it is measured as a place where the sound drops sharply.

[0003]

By the way, in a hospital or the like, a patient may temporarily circulate a large amount of blood, which is a body fluid, outside the body. The extracorporeal circulation of blood is performed by, for example, physiological treatment. Specific examples of the above include artificial dialysis and artificial heart-lung machine. When the above cardiopulmonary function is artificially performed, since it is an essential function for life support, it is constantly monitored automatically. Further, the life support device such as the artificial heart-lung machine is very expensive. In the case of performing artificial dialysis, the blood pressure is measured about every 15 minutes because the risk is lower than that in the case of operating the artificial heart-lung. Also in the case of this artificial dialysis, if an accident occurs due to the circulation of arterial blood outside the body, the blood pressure may drop sharply with a large amount of blood loss and fall into a shock state.

However, at present, in order to prevent the above-mentioned accidents, doctors and nurses cannot always accompany the patient during the dialysis period of about 3 to 4 hours. Further, the automatic monitoring monitor that constantly monitors is an expensive device, and a simple blood pressure measuring device may not be able to quickly detect a blood pressure drop due to an accident.

[0005] Therefore, an object of the present invention is to provide a blood pressure measuring device capable of continuously measuring and monitoring blood pressure by using blood taken out of the body during extracorporeal circulation.

[0006]

A blood pressure measuring device according to the present invention comprises an elastically displacing portion which is elastically displaced and which is formed in a part of a conduit through which blood circulates extracorporeally when it circulates outside the body. A pressure mediating substance filling part in which a container covering the outer peripheral part of the displacement part is arranged and a pressure mediating substance is filled in the container, and the pulsation of blood supplied to the elastic displacement part via the pressure mediating substance. A pressure detecting means for detecting a pressure that fluctuates in accordance with the above, and a conduit for connecting blood with at least the storage body, a conduit for supplying a pressure mediator and mediating pressure, By using a material that does not affect the pressure fluctuation of the pressure mediator,
The problems described above are solved.

[0007]

The blood pressure measuring device according to the present invention converts the blood flow rate of the blood to be extracorporeally circulated as a relative pressure value and continuously monitors it.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the blood pressure measuring device according to the present invention will be described with reference to the schematic block diagram shown in FIG. Extracorporeal circulation of blood is often carried out in order to remove waste products accumulated in various organs and adjust the physiological balance of the living body due to the condition of the living body through blood as a body fluid. In the present embodiment, a case of artificial dialysis in which the renal function is replaced will be described as an example.

When performing artificial dialysis, arterial blood is allowed to flow from the artery of the artificial dialyzer to the dialysis machine through the tube 15 for extracorporeal circulation. The arterial blood is sent via the blood pressure measuring device 10 to the dialysis device 16 which has the same physiological and chemical function as the renal function. Blood in the dialysis device 16 is
By dialysis, waste products and the like are removed. The blood is returned from the dialysis device 16 to the artificial dialyzate person at a blood pressure according to the pulsation via a pump 21 for returning the blood to the vein of the artificial dialyzate person.

Further, the blood pressure measuring device of the present invention is shown in FIG.
1 is a schematic diagram of the operation principle shown in FIG.
It will be specifically described with reference to. The blood pressure measurement device 1
Reference numeral 0 indicates a tube 12 which is an elastically displacing portion which is elastically displaced and which is formed in a part of a conduit through which the blood circulates extracorporeally when it circulates outside the body. Supply to 16. The tube 12 is made of an elastic material configured to be capable of pulsatingly repeating expansion and contraction in response to changes in blood pressure. Therefore, the tube 12 is repeatedly pulsatingly displaced according to the change in blood pressure.

The tube 12 of the blood pressure measuring unit 11
The tube, which is a conduit connected to the housing 13 that covers the outer periphery of the tube, is made of a material that does not affect the pressure fluctuation of the pressure mediator, and at least the tube 15 that allows blood flow through,
Tubes 22 and 23 are provided for supplying the pressure mediator and supplying the pressure mediator to the converter 14 which will be described later. The conduit made of a material that does not affect the pressure fluctuation of the pressure mediator is made of, for example, a Teflon resin material that does not expand or contract due to the fluctuation of blood pressure. The storage body 13
And a pressure mediating substance filling section 18 in which the pressure mediating substance is filled in the housing 13.
The housing 13 is made of a material having no elasticity, such as transparent acrylic resin or glass.

As described above, between the housing 13 and the tube 12 of the elastic displacement portion, a pressure mediator, for example, a liquid which is highly safe for the living body such as physiological saline, or a gas which is safe for the living body is provided. It is filled. In addition to the tube 15 for supplying blood, the tubes 22, 23 for filling the pressure mediator and for mediating the pressure
Are provided respectively. The two tubes 22 and 23 other than the tube 15 for supplying blood are for supplying the pressure mediator and mediating the pressure to the converter 14 described later, respectively, as described above. It does not matter which tube is the tube on the supply side of the pressure mediator or the tube which propagates the pressure to the converter 14 described later. For example, FIG. 1 and FIG.
A hole 20 is formed in the side portion 19 of the container 13 shown in FIG.

The physiological saline, which is the pressure mediator, is filled in the hole 20 through the tube 23 with the pressure mediator using, for example, a disposable syringe. After this filling, the tube 23 is connected to the converter 14. In addition, when the pressure mediator is a liquid or the like, the blood pressure measuring device uses the tube 22 disposed on the side portion 19 of the housing body 13 to discharge the air that has entered the housing body 13 or the converter 14. It is convenient for zeroing the pressure displayed on the (transducer) by supplementing or removing the pressure mediator. The tip 24 side of the tube 22 is
The cap 25 or the like prevents leakage or the like from the tube 22. Moreover, since the tube 22 is made of an elastic material that does not affect the pressure fluctuation of the pressure mediator, a method of easily preventing leakage from the tube 22 with a forceps, a clip or the like and securely plugging is also adopted. be able to.

The pressure mediator thus supplied from the container 13 is supplied to the transducer (transducer) 14 so that the pressure does not change along the way. The converter 14 is a pressure detection unit that detects a pressure that fluctuates according to the pulsation of blood supplied to the elastic displacement portion via a pressure mediator. Receiving this supply, converter 1
Reference numeral 4 zero-adjusts the level output from a sensor made of, for example, a piezoelectric element built in the converter 14 in a normal state by adjusting the filling amount of the pressure mediator according to the individual patient. The transducer 14 thus adjusted detects the deviation of the blood pressure relative to the normal blood pressure that pulsates within the blood pressure range via the pressure sensor during artificial dialysis. The deviation of the detected blood pressure is converted into an electric signal and supplied to the monitor 17 as the relative blood pressure displacement and displayed.

Since it is very difficult to directly convert the blood pressure displacement detected by the converter 14 into a blood pressure value, the blood pressure value, which is an index for knowing the physiological state of the living body, is displayed as a relative value. Are monitoring.

Next, the measurement principle of the blood pressure measuring device will be described with reference to the schematic diagram shown in FIG. 2 and, if necessary, FIG. Blood pressure is generally the lateral pressure that blood exerts on the vessel wall. The tube 12 that is elastically displaced inside the blood pressure measurement unit 11 shown in FIG. 1 corresponds to a blood vessel wall. The tube 12 is pulsatingly expanded, for example, from an average diameter 12a of the tube 12 in a normal state in the radial direction of the tube 12 by a side pressure exerted by the flow of blood flow, or a tube 12b or a tube having a reduced diameter. It is displaced to 12c. In accordance with the change in blood pressure in the tube 12, the pressure is transmitted to the pressure mediator 18 filled between the housing 12 and the tube 12, which is a rigid body. The pressure mediator 18 is connected to the transducer 14 by a tube 15 that does not change with pressure as shown in FIG.

The relative value indirectly obtained in this way is compared and detected by the converted electric signal in the monitoring monitor 17 to determine whether or not the blood pressure rise and blood pressure drop occur beyond the value of the ratio within the safe range. By doing so, it is possible to monitor as a relative value. Further, the present invention is not limited to the above-described case where the blood pressure is abnormally lowered, and can be used when detecting an abnormal increase in blood pressure during extracorporeal blood circulation. When this monitoring is performed, the abnormality can be detected early by setting the blood pressure allowable range narrow. Further, if an alarm or the like is installed on the monitoring monitor 17, a doctor or a nurse can use the alarm for swift treatment for a symptom such as a shock condition requiring urgency.

The blood pressure measuring unit of the blood pressure measuring device according to the present invention will be described with reference to a more specific example shown in FIG.
Here, common parts are denoted by the same reference numerals as those in FIG. 1, and description thereof is omitted. Arterial blood for extracorporeal circulation flows into the blood measurement unit 11 via the tube 15. The arterial blood that has flowed into the blood measurement unit 11 flows through the tube 12 that expands and contracts in diameter in the housing 13 of the blood measurement unit 11, flows out of the blood flow measurement unit 11, and is connected to, for example, a dialysis machine.

The tube 12 expands and contracts in diameter according to the pulsation of arterial blood. At this time, the pressure generated by the pulsation of the arterial blood is transmitted via the tube 12 to the pressure medium substance that does not harm the living body and is enclosed in the housing 13 through the tube 12. The tube 22 adhered to the hole 20 formed in the side portion 19 of the housing 13 in FIGS. 1 and 2 described above is used to supply a pressure mediator and to adjust the blood pressure to zero at normal times. As described above, the converter 1 for detecting the pressure of the tube 22 and converting it into an electric signal.
4 and conversely, the tube 23 may be used as a pressure mediator supply tube. Further, the converter 14 may be directly arranged so as to cover the hole 20 formed in the side portion 19 of the storage body 13. With this arrangement, the pressure can be converted into the converter 1.
No need for tubes to propagate up to 4. This converter 1
Based on the electric signal converted in 4, whether or not the blood pressure of the living body is normal is constantly checked and displayed on the monitor 17.
The monitor 17 can also give an alarm or the like when an abnormality in blood pressure is detected, for example.

Although this example shows artificial dialysis in which the function of the kidney is taken over, the present invention is not limited to this example, and ammonia or phosphorus accumulated in the liver may be removed or, for example, alkaline This blood pressure measuring device is effective for ensuring the safety of the living body even when the biochemically abnormal blood components such as acidemia and the like are adjusted by extracorporeal circulation.

With such a structure, the blood pressure abnormality can be continuously monitored at all times with a simple structure, and the blood pressure abnormality can be promptly dealt with. In addition, it is not necessary to press the vicinity of the blood pressure measurement site of the human body with a conventional manchette or the like, and the measurement can be performed without causing discomfort to the measurement subject.

[0022]

As is apparent from the above description, according to the blood pressure measuring device of the present invention, when blood is circulated extracorporeally, fluctuations in blood pressure depending on the pulsating state of the blood flow at normal times are pressure mediators. It is possible to continuously measure whether or not the blood pressure value of the measurement subject is within the relative blood pressure allowable range without any abnormality by continuously detecting the blood pressure value with the converter via. By performing this continuous measurement, the blood pressure abnormality can be monitored, and when the blood pressure abnormality is detected, the treatment can be promptly dealt with, which is also useful in preventing an accident.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing an embodiment of a blood pressure measurement device according to the present invention.

FIG. 2 is a schematic diagram showing the operating principle of a blood pressure measurement device when measuring blood pressure.

FIG. 3 is an external view showing a more specific blood pressure measurement unit in the blood pressure measurement device.

[Explanation of symbols]

10 ... Blood pressure measuring device 11 ... Blood pressure measuring unit 12 ... ..... Tubes that are elastically displaced 13. , 22, 23 ... Tube 17 ... Monitoring monitor

Claims (1)

Claim: What is claimed is: 1. An elastically displacing portion, which is elastically displaced, formed in a part of a conduit through which the extracorporeally circulating blood flows when the blood circulates outside the body, and an outer peripheral portion of the elastic displacing portion. A pressure mediator filling section in which a container is arranged and a pressure mediator is filled in the container, and a pressure that fluctuates according to the pulsation of blood supplied to the elastic displacement section via the pressure mediator is applied. A pressure detecting means for detecting the pressure fluctuation of the pressure mediator, and at least a conduit for connecting blood to the blood flow through the container and a conduit for supplying the pressure mediator and mediating pressure. Blood pressure measurement device made of non-affected material.