JP2006288914A - Structure of cuff for tonometer utilizing shape memory alloy actuator generating heat and contracting action when electricity is turned on - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cuff for a tonometer which does not necessitate a device for expanding a fluid bag by using a method for pressing a measurement section without expanding the fluid bag disposed on the inner side of a non-stretchable belt although the cuff for pressing the measurement section is used when measuring a blood pressure. <P>SOLUTION: The belt into which a fiber-like shape memory alloy actuator which generates heat and contracts when the electricity is turned on is woven is wound around the section where the blood pressure is to be measured. The pressure necessary of measuring the blood pressure can be applied to the pressing section by contracting the belt. The fluid bag is sandwiched between the pressing section and the contracting belt, and the pressure applied to the section where the blood pressure is to be measured can be made uniform. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a compression method using a cuff for a blood pressure monitor, and relates to the structure of the cuff.

A conventional cuff for measuring blood pressure compresses a measurement site by inflating a fluid bag provided inside a non-contractible band wound around a measurement site of a living body and fixed in a cylindrical shape.

In order to inflate the fluid bag constituting the cuff, a device such as a pump or a cylinder or a compressor for sending fluid to the fluid bag and a tube for connecting the fluid bag to the device and feeding fluid are used.

The cuff component realized by the expansion of the fluid bag includes a device for feeding fluid and a tube.

An object of the present invention is to realize a sphygmomanometer cuff that does not require a device for feeding fluid and a tube by using a technique of compressing a measurement site using a contracting band without inflating an air bag.

Since the cuff for a sphygmomanometer according to the present invention does not inflate the fluid bag as a method of pressing the measurement site, a device such as a pump or a cylinder or a compressor necessary for inflating the fluid bag and a tube connecting the cuff and the device are not required. .

In order to achieve the object of the present invention, measurement is performed by wrapping a band woven with a fibrous shape memory alloy actuator that generates heat when energized and develops a contracting action at a constant temperature, and shrinks the shape memory alloy. This is a method of compressing the artery at the site.

FIG. 1 shows a normal state of the coil-shaped shape memory alloy actuator, and FIG. 2 shows a state in which force is applied to both ends of the coil-shaped shape memory alloy actuator. When the coiled shape memory alloy actuator is connected to both ends of the coiled shape and is energized, the shape memory alloy actuator generates heat due to Joule heat and exerts a force that deforms and contracts to the normal state of FIG.

FIG. 3 is a simplified diagram of a state in which the coil-shaped shape memory alloy actuator is woven into the cuff strip 31. FIG. The end of the shape memory alloy actuator is connected to a conducting wire connected to the electrode 32.

In the state of FIG. 3, when a current is passed through the electrode and a current is passed through the coil-shaped shape memory alloy actuator, Joule heat is generated in the shape memory alloy actuator, a shape restoring action is activated, and a force that contracts the entire band is activated. 4 is transformed into the state of FIG.

In the state shown in FIG. 4, by cutting off the current applied to the electrode 42, the shape memory alloy actuator 43 is not restored to the memorized state, the contracting force of the entire band 41 does not work, and the band is extended by applying external pressure. As a result, the state of FIG. 3 is restored.

FIG. 5 is a top view, a side view, and a bottom view of a cuff including a band 51, a fluid bag 52, and men fasteners 53a and 53b woven with a coiled shape memory alloy actuator.

FIG. 6 shows a cross-sectional view of the state where the cuff of FIG. 5 in a state where the coiled shape memory alloy actuator is extended is wound around the compression portion 64 of the upper arm and fixed using the hook-and-loop fasteners 53a and 53b.

The upper arm 64 is composed of the humerus 65, the upper arm bilateral muscle 67, the upper arm third muscle 68, the artery 66, and the like. The compression bag is covered with a fluid bag 62, and a coiled shrink memory alloy is woven from the outside. 61 is covered.

When the coil-shaped shape memory alloy actuator is energized, a contracting force is applied to the band 61, the fixed band is contracted, the compression site 64 is tightened through the fluid bag 62, and pressure is applied to the artery 66.

When energization is stopped, the contraction action disappears, the contracting cuff is stretched by the elasticity of the upper arm, and the pressure on the artery 66 decreases

The blood pressure can be measured by adjusting the pressure applied to the artery 66 by the contraction and extension and measuring the behavior of the artery.

By eliminating the device required for inflating the fluid bag, the parts constituting the sphygmomanometer can be reduced in size and weight.

In the conventional sphygmomanometer, the fluid bag is inflated by sending the fluid to the fluid bag with a pump, a cylinder, or a compressor, and thus sounds such as fluid sounds and motor sounds are generated during the operation of sending the fluid. In the case of a cylinder, the number of uses is limited, and it is necessary to refill the cylinder with a fluid or replace the cylinder. The present invention is characterized in that since the power required for the operation is only electric power, no extra device is required and no drive parts and air are sent out, so that no sound and vibration are generated during compression.

It is a figure of the state which the coil-shaped shape memory alloy actuator has contracted It is a figure of the state which has extended the coil-shaped shape memory alloy actuator. FIG. 4 is a top view and a side view of a contracted state of a strip-shaped cuff woven with a contracting coil-shaped shape memory alloy actuator. FIG. 6 is a top view and a side view of a state in which a strip-shaped cuff woven with a contracting coil-shaped shape memory alloy actuator is stretched. FIG. 6 is a top view, a side view, and a bottom view of a sphygmomanometer cuff integrated with a fluid bag and a hook-and-loop fastener. It is sectional drawing of the upper arm part equipped with the cuff for blood pressure monitors.

Explanation of symbols

31: belt
32: Conductor that sends electricity to shape memory alloy actuator
33: Expanded coiled shape memory alloy actuator

41: Belt
42: Conductor sending electricity to shape memory alloy actuator
43: coiled shape memory alloy actuator in contracted state

51: A strip woven with coiled shape memory alloy actuator
52: Fluid bag
53a, 53b: hook and loop fastener

61: A strip woven with a coiled shape memory alloy actuator
62: Fluid bag
64: upper arm
65: humerus
66: Arteries
67: Biceps
68: Tertiary muscle

Claims (1)

In a cuff for a sphygmomanometer that compresses the artery at the measurement site of the living body, a fluid bag that equalizes the pressure applied to the compression site wrapped around the measurement site of the living body is built in. When the conductor is energized, it generates heat and returns to the memorized state. It is a belt-like thing that can shrink in one direction with a built-in shape memory alloy actuator that expresses the restoring force to be restored as tension, and applies pressure to the measurement site by the action of the shrinking tension of the shape memory alloy actuator. A sphygmomanometer cuff that can measure blood pressure.

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