JP2834836B2 - Automatic blood pressure monitor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an automatic sphygmomanometer that measures a blood pressure by automatically wrapping an arm band around an arm of a human body, for example.

(Prior art)

Conventionally, a cuff wound in a substantially cylindrical shape automatically wraps around a human arm inserted inside the substantially cylindrical shape of this cuff,
There are various types of devices for automatically measuring blood pressure while air is press-fitted into a rubber bag existing inside the arm band and then bleeding the air.

It is desirable that the size of the rubber bag be changed according to the size of the arm. Otherwise, the pressure on a small child's arm would be the same as that of an adult, causing pain and incorrect measurements.

Therefore, in recent years, a sphygmomanometer has been devised in which the same device can measure different thicknesses of the upper arm from a child to an adult. For example, an air bag corresponding to the rubber bag is disassembled into a plurality of sections, and the section to be used is determined by a human by checking the thickness of the upper arm (Japanese Patent Laid-Open No. 60-92737).
Alternatively, instead of the human being making the determination, air is supplied or discharged to the air bag, and the pressure change at that time is measured to automatically determine (Japanese Patent Application Laid-Open No. 62-11431). Have been.

[Problem to be solved by the invention]

However, according to the former technique of the prior art, the person using the sphygmomanometer has to determine the thickness of the upper arm, and in a situation where automation of the sphygmomanometer is desired, the operation of the device is troublesome and complicated. I had to say that it was. In particular, if the person using the sphygmomanometer is a child,
The troublesome operation was almost impossible. In the latter technique, it is difficult to always keep the pressure of the supplied or discharged air constant, and it is difficult to make a correct determination. In particular, the process of pressure change depends on the frequency of use of the air pump. Further, the secular change of the characteristics of the air pump used for each device also differs for each air pump, and it is difficult to predict in advance the secular change and the change accompanying the frequency of use. In addition, air must be supplied and discharged in order to make the determination, which takes too much time.

The present invention has been made to solve the above problems, and an automatic sphygmomanometer capable of automatically, accurately, and quickly determining the thickness of a part of a living body to be inserted into an arm band. The purpose is to provide.

[Means for solving the problem]

The present invention has been made to achieve the above object, and a cuff wound in a substantially cylindrical shape automatically wraps around a part of a living body inserted in the cylindrical shape to measure blood pressure. In the automatic sphygmomanometer, a plurality of air bags of different sizes provided in the arm band, pipes connected to each of the plurality of air bags, and switching for switching supply and discharge of gas to and from the plurality of pipes Means, automatic winding means for performing winding of the arm band by winding of a wire rope and automatically stopping, and determining means for determining the thickness of the body part by the winding amount of the wire rope. Switching operation commanding means for operating the switching means in response to this determination.

[Action]

According to the configuration of the present invention, the arm band is wound around the body part by winding the wire rope, and the size of the body part can be determined based on the winding amount of the wire rope. There is no need to make a determination based on the change in the pressure. Therefore, it is possible to prevent the determination from being likely to be inaccurate due to the frequency of use of the air pump or aging, and the determination does not take much time.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 2 is an overall view of the automatic sphygmomanometer of the present embodiment, and is a perspective view showing a state where the apparatus case 10 is removed. Equipment case
10 is provided with an opening for inserting an arm. The arm inserted through the opening 12 passes through an arm band 14 which is maintained in a substantially cylindrical shape, and penetrates through an opening 12 (not shown) on the opposite side. The arm band 14 has a floating base together with a motor and clutches for winding and rewinding the arm band 14.
Placed on 16 This floating base 16
It is provided swingably with respect to the apparatus main body chassis 18 via a leaf spring. The leaf spring is arranged between the floating base 16 and the apparatus main body chassis 18 in parallel with each other, and one end is provided on the apparatus main body chassis 18 and the other end is provided on the floating base 16.
Is fixed by screws. By the action of the leaf spring, the floating base 16 can swing with respect to the apparatus body chassis 18.

The arm band 14 has a band shape as a whole, and its surface is covered with a cloth cover 26 as shown in FIGS.
Inside, a band-shaped core 28 of the arm band 14 is doubly arranged.
This band-shaped core is a flexible plate material made of polypropylene and has a lower rigidity than the conventional arm band 14, so that the entire arm band 14 can be wound in and out with a small force. ing. The elastic body 30 is inserted into the double-ended end 28A of the belt-shaped core 28 bent back. This elastic body 30 is a cylindrical rubber material,
Has the function of increasing the pressure and rounding the end portion 28A of the rim.

An air bag 32 is provided inside the cylindrical shape of the belt-shaped core 28.
As a rubber bag. This air bag 32 is
As shown in the figure, it is divided into two air bags 32A and 32B having different sizes. This division is performed in the axial direction of the substantially cylindrical shape of the arm band. The larger air bag 32A has an axial width LA of 90 mm and the smaller air bag has a width LB of 30 mm.
It is. And the circumference of the arm inserted into this cuff is 22 cm
In the case of the above (for adults), air is supplied to both air bags 32A and 32B. When the circumference of the arm is 22 cm or less (for children), air is supplied only to the large air bag 32A. These supplies are each connected to a bladder pipe
Performed by 33A and 33B. A switching valve 35 is provided on a pipe 33B connected to a small air bag, and after the two pipes merge, the two pipes branch into two, one being a supply pipe 37 connected to an air pump and the other being a supply pipe 37. Discharge pipe 39
Thus, an exhaust valve 41 is provided.

Near the inner tip of the arm band 14 (see FIG. 3),
Is fixed to the floating base 16. On the other hand, the outer end of the cuff 14 is stopped by a slider 36 that slides along the guide ring 24. A coil spring 37 is wound around the guide ring 24, and the end of the coil spring 37 presses the slider 36 in a state where the arm band 14 is wound. By this pressing,
At the time of rewinding after the arm band 14 has been wound, a trigger is provided for the slider 36 to move in the rewinding direction, so that smooth rewinding is performed.

The stopper 34 further includes a wire rope for winding.
38 tips are fixed. This winding wire rope
38 is arranged along the outer surface of the arm band 14 and is wound around the rope pulley 94. A rewind wire rope 42 is fixed to the slider 36, and is wound around the same rope pulley 94 along the guide ring 24 in a direction opposite to the rewind wire rope 38. The rewind wire rope 42 is adjusted by a rope tensioner 44 so as not to be loosened. As described later, the rope pulley 94 is driven by a motor via a clutch. The rope pulley, clutch, motor, etc.
Is placed on top.

Next, the mounting structure of the slider 36 will be described with reference to FIG. As described above, the slider 36 slides along the guide ring 24. At the same time, the end of the arm band 14 is stopped, and the rewind wire rope is fixed. That is, the slider body 45 is united with the slider mounting plate 46 by the screws 48. And the slider body 45
A notch 50 for sliding the guide ring 24 and a notch 52 into which the rewind wire rope 42 is fitted are formed on the combined surface side. A spherical stopper 54 is fixed to the end of the rewind wire rope 42, and the stopper 54 is fixed in a state where the rewind wire rope 42 is fitted in the notch.
Are engaged with the slider body 45. Further, the terminal end of the arm band 14 is sandwiched between the slider body 45 and the slider mounting plate 46, and the screw 48 is inserted into the screw holes 56 formed in the slider body 45, the terminal end of the arm band 14, and the slider mounting plate 46, respectively. Penetrates the arm band 14 and stops. Further, the slider mounting plate 46 is united with the slider main body 45 in a state where the slider mounting plate 46 passes through a protective member 58 made of a tubular elastic body. By the function of the protection member 58, the contact between the slider 36 and the arm band 14 can be made smooth, and the arm band 14 can be protected from the contact.

Next, the clutch will be described with reference to FIG. FIG. 1A is a longitudinal sectional view before assembling, and FIG. 1B is a side view before assembling. As described above, this clutch is disposed on the same axis as the rope pulley 94. That is, the winding clutch 60 that transmits the driving force of the motor to the rope pulley 94,
A rewind clutch 62 and a locking clutch 64 for stopping loosening during pressurization are arranged coaxially with the rope pulley 94, and the shaft 66 and the motor 68 are mounted on the floating base 16 (see FIG. 3). .

First, the winding clutch 60 will be described. The driving force from the motor 68 is supplied to the belt pulley via the timing belt 70.
The belt pulley 40 is capable of idling with respect to the shaft 66. After the idle bushing 72 is fitted to the belt pulley 40, the pin 76 is inserted into the pin hole 74 of the shaft 66. Then, the clutch spring 78 is fitted on the outer periphery of the idle bushing 72, and one end of the clutch spring 78 is engaged. A rotary armature 80 is fitted to the other end of the spring 78. The rotary armature 80 has an idling portion 82 that engages with the other end of the clutch spring 78 and idles, an idling plate 84, and a fixing portion 86 that engages with both ends of the pin 76 and is fixed to the shaft 66. It consists of 88. A field 92 is arranged near the fixing plate 88 via a shim 90 for facilitating sliding. When the clutch 60 is engaged, the idling plate 84 is attracted to the fixing plate 88 and pressed.

Next, a rope pulley 94 integrated with the shaft 66 via a key 96 is provided on a side of the belt pulley 40 opposite to the side where the winding clutch 60 is provided. The rewind clutch 62 exists as a one-way clutch built in the belt pulley 40. A winding wire rope 38 and a rewinding wire rope 42 are wound around the rope pulley 94. This one-way clutch is free in the winding direction (disengaged),
It is in a locked state (engaged state) in the rewind direction. Accordingly, when the belt pulley 40 rotates in the rewinding direction, the rope pulley 94 is driven in the rewinding direction by the action of the rewinding clutch 62, but the rewinding clutch 62 operates even when the belt pulley 40 rotates in the rewinding direction. Without rope pulley 94
Are not driven in the winding direction.

Further, the lock clutch 64 will be described. The emergency stop clutch 64 has substantially the same structure as the winding clutch 60, and the same portions are denoted by the same reference numerals. The difference is that the electric winding clutch 60 transmits the rotational driving force of the belt pulley 40 to the shaft 66, but the emergency stop clutch 64 locks the rotational driving force of the rotating shaft.
The point is that the shaft 66 is transmitted to the stop plate 98 and the shaft 66 is suddenly braked.

In this manner, the rope pulley 94, the winding clutch 60, the rewinding clutch 62, and the locking clutch 64 of the present embodiment are arranged on the same shaft, are arranged on a plurality of shafts, and are used as gears which are interlocking mechanisms. Lighter than when connected by a belt. The shaft 66 is mounted directly below the arm band 14 and parallel to the axis of the arm band 14.

Next, the operation of the clutch 60 will be described. When the motor 68 is turned on, the driving force is transmitted to the belt pulley 40 via the timing belt 70, and the belt pulley 40 starts idling. With this idling, the clutch spring of the winding clutch 60, the idling portion 82 of the rotary armature, and the idling plate 84 idle. Here, when the winding clutch 60 is engaged, an electric current flows in the field, magnetic force is generated, and the idling plate 84 is attracted toward the fixed plate 88, and both plates start rotating integrally. The fixing plate 88 of the rotary armature is fixed to the shaft insertion 66 via a fixing portion 86, and the rotational driving force is transmitted to a rope pulley 94 fixed to the shaft 66 via a key 96. Thereby, the winding wire rope 38 is pulled, and the arm band 14 is wound. When the winding is sufficiently performed, the arm band 14 is wound around the arm to generate a large resistance, the current flowing through the motor 68 becomes a large value, and an increase in this current is detected, and the motor 68 stops. At the same time when the motor 68 stops, the locking clutch 64 functions as locking means. The blood pressure measurement operation is performed in this state.
When the blood pressure measurement is completed, the lock using the lock clutch 64 is released, and the motor 68 rotates in the reverse direction. At the same time, the rewind clutch 62 operates to expand the arm band 14 and return to the initial state. If it becomes necessary to stop the winding or rewinding suddenly while the winding or rewinding is being performed, a separately provided stop switch 100 (see FIG. 2) By pressing, the locking clutch 64 and the winding clutch 60 are turned off (disengaged state), the shaft 66 becomes free, and the arm band can be easily loosened.

Next, a determination means for determining the thickness of the upper arm inserted into the arm band will be described with reference to FIG. FIG. 1A is a perspective view, and FIG. 1B is a view seen from the axial direction in FIG. 1A. This determination means is an apparatus using a cam and a limit switch.

That is, the two cams 104 and 106 provided coaxially with the cam base 102 are coaxially connected to the shaft 66 in FIG. 7 via a connection shaft (not shown). Thus, when the shaft 66 rotates, the two cams also rotate. One notch 108 is formed in one cam 104 and the other cam 10
6 has two notches 110 and 112 formed therein. Notches 108,11
0,112 are staggered between the two cams. The two cams 104, 106 are provided with limit switches 114, 116, respectively, and the notches 108, 110, 112 allow the limit switches 114, 116 to react. The cam 104 having one notch 108 is called an initial cam and indicates a winding start position. The cam 106 in which the other two notches 110 and 112 are formed is called a determination cam. One notch 110 corresponds to a position where the circumference of the arm is 22 cm, and the other notch 112 is a position where the circumference of the arm is the minimum. Corresponding to

The operation of this determination means will be described with reference to FIG. In the figure, the positions of the notches 108, 110, 112 of the cams 104, 106 are
If the rotation of 68 is constant, it will be proportional to the time required for winding the winding wire rope 38. As described above, when the winding wire rope 38 is wound and the winding of the arm band 14 around the arm is completed, a large load is applied to the motor 68, and the load current becomes a large value. Then, the increase in the load current is detected, and the motor 68 stops. When this stop is performed before the limit switch 116 of the determination cam 106 first reacts, that is, the time t from when the limit switch 114 of the initial cam 104 reacts to when the stop is performed is 0 <t <t. If it is ₁ , the area around the inserted arm
It is determined that it is 22 cm or more. When the stop is performed before the limit switch 116 of the determination cam 106 reacts for the second time after the first reaction, that is, when t ₁ ≦ t <t ₂ , the circumference of the arm is 22 cm. Is determined to be less than. Further, if the stop is not performed by the second reaction of the limit switch 116 of the determination cam 106, that is, if t ₂ ≦ t, it is determined that the arm is not inserted into the arm band. .

Although the determination means measures the winding amount of the wire rope with a cam and a limit switch, the determination means in another embodiment directly determines the rotation speed of the motor 68 for winding the wire rope. Alternatively, the measurement may be performed by a rotary encoder or the like. A rotary encoder is provided with a rotating plate on the rotating shaft side of a motor, and receives and counts light passing through a slit formed in the rotating plate by a light receiving element, or receives and counts an approach of a magnet provided on the rotating plate by a Hall element. Etc. Since the counted number is digitized and processed, the processing device is simplified.

Next, FIG. 10 shows a control block diagram for controlling the automatic sphygmomanometer of the present embodiment. The control in the figure is mainly
The determination of the thickness of the inserted arm and the control of the original blood pressure measurement are shown.

First, since the measurement of blood pressure in the present embodiment is called an oscillometric method, this method will be described. In this method, the pressure of the arm band 14, that is, the pressure of the air sent to the air bladder 32 provided in the arm band 14, is raised above the systolic blood pressure, and then reduced. If the pressure of the arm band 14 is detected during the decompression, a small signal waveform appears in synchronization with the heart pulsation. This vibration waveform rapidly increases from around the systolic blood pressure, further increases with decompression, shows a maximum amplitude, and gradually decreases. Then, the pressure of the arm band at the point where the amplitude of the vibration waveform sharply increases is measured as the systolic blood pressure, and the pressure of the arm band at the point where the amplitude of the vibration waveform is maximum is measured as the average blood pressure. By measuring the pressure of the arm band at the point where the temperature suddenly decreases as the diastolic blood pressure, it is possible to measure those corresponding to the correct systolic blood pressure, average blood pressure, and diastolic blood pressure, respectively. Then, minute minute changes in the pressure of the arm band indicating the vibration are caused by the arm band 14.
Is captured by a pressure sensor C (see FIG. 10) set therein. The pressure sensor C is provided at a location that communicates with a pump P (see FIG. 10) that supplies air to the air bag 32 of the arm band 14.

The exhaust valve 41 for exhaust (see FIG. 1) has a structure in which two types of a constant speed exhaust valve 41B and a rapid exhaust valve 41A are provided in parallel as shown in FIG. The constant-speed exhaust valve 41B according to the present embodiment is
The constant-speed exhaust valve can switch the exhaust speed to three stages in accordance with the proper use or in order to perform accurate measurement. That is, as compared with the case where air is supplied and discharged to both air bags 32A and 32B as shown in FIG. 4 (AB in the figure), the air supply is performed when only one air bag 32A is supplied (A in the figure). Is relatively faster,
A drop (D in the figure) may occur at the transition from air supply to exhaust, and accurate blood pressure measurement may not be possible. Therefore, by reducing the air supply speed, the drop is eliminated and accurate measurement is performed. Further, the quick exhaust valve exhausts rapidly after measuring the systolic blood pressure until the diastolic blood pressure is measured, thereby shortening the entire time required for the measurement. Further, the determination result from the determining means (see FIG. 8) for determining the thickness of the arm provided in the automatic cuff winding device (see FIG. 7) is based on the measurement result of the pressure from the pressure sensor C. Along with the count value of the counter CT (see FIG. 10) for counting, it is input to a control circuit (CPU) to control the pump P, the exhaust valve 41 and the like. The display displays the highest blood pressure, the lowest blood pressure, the average blood pressure, etc. among the pressures of the arm band. The control circuit also controls the switching valve 35 based on the determination result of the determination means.
And the switching command of 41 is issued to select the pressure width of the cuff corresponding to the thickness of the arm, and keep the exhaust speed of the arm band constant regardless of the thickness of the arm.

Next, the operation of the entire embodiment will be described. First, as shown in FIG. 3, a state in which the arm band 14 is spread to fill the guide ring 24 is an initial state. In this state, the arm is inserted into the arm band 14 and the switch is turned on. Then, the winding wire rope starts winding, and at the same time, the rewinding wire rope 42 is sent out. The arm band 14 is pressed to the center by the winding wire rope to reduce the substantially cylindrical radius and perform winding. At this time, the slider 36 rises above the guide ring 24 in FIG. 3, and the terminal end 14E of the arm band 14 is smoothly fed in the winding direction. When the winding is completed, the motor 68 is stopped, and the shaft 66 is locked by the coupling of the locking clutch 64 so as not to move, so that the winding wire rope is locked. motor
The amount of time required for the 68 to stop (FIG. 9), that is, the rotation amount of the cam (FIG. 8) is used to accurately measure the amount of winding of the winding wire rope 38, and the thickness of the arm is proportional to the amount of winding. Is determined. Then, if the circumference of the arm is 22 cm or more, the switching valve 35 (FIG. 1) is opened to release air from the two air bladders 32.
Supply to A and 32B. As a result, pressure can be applied to the thick arm with an appropriate width, and accurate blood pressure measurement can be performed. When it is determined that the circumference of the arm is less than 22 cm, the switching valve 35 is closed and air is supplied only to the larger air bag 32A. As a result, pressure is applied to the thin arm with an appropriate width, and accurate blood pressure measurement can be performed without causing any pain. When this measurement is completed, the measured value is
It is displayed on the display unit in Figure 10. Then, the rewind wire rope 42 starts winding. At this time, at the end of the tightly wound arm band 14, the slider 36 is flipped by the coil spring wound around the guide ring 24, so that a rewind is smoothly performed. At the same time, the winding wire rope 38 is sent out, and the force of the winding wire rope 38 pressing the outer surface of the arm band 14 toward the center is relaxed. The slider 36 is pulled by the rewinding rope 42 and the guide ring 24
The upper part descends downward in FIG. As a result, the cuff 14 returns to the initial state in which the cuff 14 has spread to fill the guide ring 24.

As described above, according to the automatic sphygmomanometer of the present embodiment, the winding amount of the winding wire rope 38 (see FIG. 3) for winding the arm band around the arm is determined by the winding wire rope 38. Is measured by the cams 104 and 106 and the limit switches 114 and 116 (see FIG. 8) connected to the shaft 66 (see FIG. 7) for winding the arm, and thereby the thickness of the arm can be determined. Does not need to be determined by a change in air pressure, and can be accurately performed. In other words, the air pump that supplies air is difficult to make the air discharge condition constant due to changes due to the frequency of use or aging, and it is difficult to make an accurate determination. Is directly reflected on the amount of winding of the winding wire rope 38, and the amount of winding is accurately represented in the rotation angles of the cams 104 and 106 because there is almost no need to consider the elongation of the wire rope. This rotation angle is limited by the limit switch 114,
With 116, the error is detected in an extremely small state. The winding of the winding wire rope 38 by the motor
It is performed more quickly than the supply and discharge of air by the air pump as in the prior art. Therefore, in the present embodiment, the thickness of the arm can be determined more accurately and quickly than in the conventional example.

Although the blood pressure measurement method of the above embodiment is based on the oscillometric method using a pressure sensor, in other embodiments, the blood pressure measurement method may be based on a Kortkov sound method using a microphone sensor instead of the pressure sensor. Good.

〔The invention's effect〕

As described above, according to the automatic sphygmomanometer of the present invention,
Since the thickness of the living body part is determined based on the amount of wire rope used to wind the arm band around the living body part, it is not necessary to determine the change based on the pressure change of the air as in the conventional case. It is possible to prevent the determination from becoming inaccurate due to the frequency of use or aging. In addition, the winding of the wire rope is performed more quickly than the supply and exhaust of air, and thus the determination is performed more quickly. For this reason, it is possible to contribute to shortening of the entire time required for the automatic blood pressure measurement.

[Brief description of the drawings]

FIG. 1 is a plan view of an air bag provided inside an arm band of an automatic sphygmomanometer according to one embodiment of the present invention, FIG. 2 is an overall perspective view of the automatic sphygmomanometer of the present embodiment with a device cover removed, FIG. 3 is a longitudinal sectional view showing the arm band portion of FIG. 2, FIG. 4 is a diagram showing a process of exhausting air from the air bag of FIG. 1 and depressurizing, and FIG. 5 is a V direction of FIG. FIG. 6 is an exploded view of FIG.
FIG. 7 shows the clutch mechanism shown in FIG. 2 when viewed from the direction of arrow VI. FIG. 7 (A) is a longitudinal sectional view, and FIG.
8A is a side view, FIG. 8A is a perspective view of a determination device provided to be connected to the shaft in FIG. 7, FIG. 8B is a front view seen from the axial direction in FIG. 9 is a diagram showing the timing chart of FIG. 8, and FIG. 10 is a schematic block diagram showing main control of the automatic sphygmomanometer of FIG. 14 ... arm band, 32A, 32B ... air bag, 33A, 33B ... pipe, 35 ... switching valve (switching means), 38 ... winding wire rope, 104, 106 ... cam, 114, 116 ... limit switch.

Continuation of the front page (56) References JP-A-60-92737 (JP, A) JP-A-62-11431 (JP, A) JP-A-59-181128 (JP, A) JP-A-1-256929 (JP) JP-A-57-180940 (JP, A) JP-A-61-179132 (JP, A) JP-A-57-200202 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB Name) A61B 5/022

Claims (1)

(57) [Claims] 1. An automatic sphygmomanometer for measuring blood pressure by automatically wrapping a cuff wound in a substantially cylindrical shape around one part of a living body inserted into the cylindrical shape, provided in the cuff. A plurality of air bags of different sizes, pipes connected to each of the plurality of air bags, switching means for switching the supply and discharge of gas to and from the plurality of pipes, and winding the arm band around a wire An automatic wrapping means for performing the wrapping of the rope and stopping automatically, a deciding means for judging the thickness of the part of the living body by the wrapping amount of the wire rope, and activating the switching means in accordance with the judgment An automatic blood pressure monitor, comprising: