JPH0451771Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a pulse wave detection device for detecting pulse waves generated from an artery.

PRIOR TECHNOLOGY The pressure sensor includes a housing having a cylindrical shape with a bottom as a whole, and a pressure sensor having a pressing surface in which a plurality of pressure detection elements are arranged and provided so as to be able to protrude from the open end of the housing. As a type of pulse wave detection device that detects pulse waves generated from an artery based on a plurality of pulse wave signals output from the plurality of pressure detection elements while being pressed onto an artery on the surface of a living body, a pressure sensor is installed in a housing. 2. Description of the Related Art Pulse wave detection devices are known that are movable in a direction that intersects arteries. For example, this is described in Japanese Utility Model Application Publication No. 1-82002, which was previously filed and published by the present applicant.

By the way, in the above type of pulse wave detection device, when the housing is attached, it is necessary to set the attachment position of the housing to the living body so that the artery is located in the center of the detection range of the pressure sensor. However, since the position of the artery can only be confirmed by touch, the mounting position of the housing must be determined by intuition, which means that the housing mounting position must be changed many times, making it relatively time-consuming to install the housing. There were cases where this was necessary.

On the other hand, in the above-mentioned pulse wave detection device,
As described in Publication No. 27284, when a pressure equal to or higher than a predetermined pressure is detected by any of the plurality of pressure detection elements, a technology is adopted that causes the display to display the position corresponding to that pressure detection element. If you get
It becomes possible to grasp the relative position of the pressure detection element above the predetermined pressure in the pressure detection range from the display.

However, in the pulse wave detection device as described above, the display is not attached to the housing so that the arrangement direction of the pressure detection elements matches the arrangement direction indicated by the display. The position of the artery relative to the housing cannot be easily determined from the device, and it has been difficult to accurately and quickly determine the mounting position of the housing.

In addition, in the above-mentioned conventional pulse wave detection device, the position of the pressure detection element that has detected a pressure equal to or higher than a predetermined pressure is displayed, so the pressing force of the pressure sensor on the body surface and the pulse wave detection device are displayed. If the size of the wave itself is too small for the predetermined pressure, nothing will be displayed on the display, and if the overall pressing force is too large, the positions corresponding to most or all of the pressure sensing elements will be It will be displayed. In such a case, the position of the artery relative to the pressure detection range is not appropriately reflected on the display, so the position of the artery relative to the housing cannot be easily grasped, and the housing installation work cannot be performed accurately and quickly.

The present invention was developed against the background of the above circumstances, and its purpose is to accurately and quickly attach the housing to the biological surface, regardless of the pressing force of the pressure sensor or the size of the pulse wave. An object of the present invention is to provide a pulse wave detection device that can reliably perform the following steps.

Means for Solving the Problems In order to achieve the above object, the gist of the present invention is to provide a housing having a cylindrical shape with a bottom as a whole, and a plurality of pressure detection elements arranged in the housing from the open end of the housing. and a pressure sensor having a pressing surface that is provided so as to be able to protrude, and detecting the plurality of pressures when the pressure sensor is mounted so that the arrangement direction of the pressure detection elements on the pressing surface of the pressure sensor intersects with an artery on the surface of the living body. A pulse wave detection device that detects a pulse wave generated from an artery based on a pulse wave signal obtained from an element, (a) having a display range corresponding to a pressure detection range in the arrangement direction of the pressure detection elements of the pressure sensor. and (b) a display provided on the outer surface of the housing so that the direction indicating the arrangement direction in the display range is the same as the actual arrangement direction; (c) maximum pulse wave signal determining means for determining the maximum pulse wave signal;
The present invention further includes a display control circuit that causes the display to display a position corresponding to the pressure detection point that outputs the maximum pulse wave signal determined by the maximum pulse wave signal determining means.

By doing this, a display device having a display range corresponding to the pressure detection range in the arrangement direction of the pressure detection elements of the pressure sensor can be configured such that the direction indicating the arrangement direction in the display range is the same as the actual arrangement direction. The display control circuit displays the maximum pulse wave signal having the maximum amplitude among the plurality of pulse wave signals determined by the maximum pulse wave signal determination means. The position corresponding to the pressure sensing element that outputs is displayed.

Effects of the invention Therefore, in the pulse wave detection device of the present invention, the arrangement direction of the pressure detection elements shown in the display range in the display mounted on the outer surface of the housing is made to match the actual arrangement direction, so that they are Compared to devices in which the arrangement directions of the arteries do not match, the position of the artery relative to the housing can be easily grasped, and the attachment position of the housing to the living body can be accurately and quickly determined while looking at the display.

Moreover, since the display displays the position corresponding to the pressure detection element that outputs the pulse wave signal with the maximum amplitude, the above-mentioned arterial The position can be reliably grasped, and the mounting position of the housing can be determined accurately and quickly.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

2 and 3, reference numeral 10 denotes a housing having a cylindrical shape with a bottom, which is detachably attached to the wrist 16 with a band 14 with its open end facing the body surface 12 of the human body. There is. A pressure sensor 20 is provided inside the housing 10 through a diaphragm 18 so as to be relatively movable and protrude from the open end of the housing 10, and a pressure chamber 22 is defined by the housing 10 and the diaphragm 18. It is formed. Pressure fluid such as pressurized air is supplied into this pressure chamber 22 from a fluid supply source 24 via a pressure regulating valve 26, so that the pressure sensor 20 is pushed according to the pressure of the pressure fluid. Pressure is applied to the body surface 12.

A pair of arc-shaped rubber bags 28 and 30 are sandwiched between the pressure sensor 20 and the inner wall of the housing 10 near the open end and at positions corresponding to both attachment parts of the band 14, respectively. Pressure fluid is selectively supplied into the rubber bags 28 and 30 from a fluid supply source 32 via a switching valve device 34. As a result, this pressure fluid causes the rubber bag 2 to
8 and 30 are selectively inflated and the pressure sensor 2
0 is moved in a direction substantially perpendicular to the artery 36. This switching valve device 34
The rubber bags 28 and 3 are closed until the mounting position of the housing 10 is determined and pulse wave detection is started.
However, as soon as the mounting position of the housing 10 is determined and pulse wave detection is started, the maintenance of the neutral position is canceled and the housing 10 enters the rubber bag 28. It can be switched to a position for supplying pressure fluid or a position for supplying pressure fluid into the rubber bag 30 as necessary.

The pressure sensor 20 is made of monocrystalline silicon or the like and has a pressing surface 38 that is pressed against the body surface 12.
The semiconductor chip 40 has a semiconductor chip 40 having
The pressure vibration of the pulse wave transmitted to 2 is detected. These pressure-sensitive diodes 42 correspond to the pressure detection elements of this embodiment, and are arranged in two rows alternately in the arrangement direction indicated by the arrow D _p in FIG. The size and spacing of the pressure-sensitive diodes 42 are set so that a plurality of pressure-sensitive diodes 42 can be located directly above the artery 36, and both pressure-sensitive diodes 42 in a direction substantially orthogonal to the artery 36 are arranged. The distance between the pressure-sensitive diodes 42 located on the outside, that is, the pressure detection range R _p of the pressure sensor 20 (see FIG. 3), is usually set to be larger than the maximum outer diameter of the artery 36 when pressed. The electrical signal output from each pressure-sensitive diode 42, that is, the pulse wave signal SM corresponding to the pressure vibration of the pulse wave, is supplied to the control device 44. The control device 44 is configured with a microcomputer, and outputs a drive signal SD1 to the pressure regulating valve 26 to adjust the pressure in the pressure chamber 22 according to a predetermined program, and outputs a display signal SI1. to display the position of the artery 36 on a display 50 (to be described later), while outputting a drive signal SD2 to the switching valve device 34 to switch the state of supply of pressure fluid to the rubber bags 28, 30, and at the same time displaying the input pulse wave. A pulse wave is detected based on the signal SM, and a display recording signal SI2 is outputted to cause the display/recording device 46 to display and record the detected pulse wave.

In this embodiment, as shown in FIG. 1, a display 50 made of, for example, a liquid crystal display is further integrally attached to the outer surface 48 of the bottom of the housing 10.
Three indicator lights 52, 54, and 56 made of LEDs are provided. The display range R _i of the display device 50 in a direction substantially perpendicular to the artery 36 corresponds to the pressure detection range R _p of the pressure sensor 20 in the arrangement direction D _p , and the pressure sensitive diode 42 in the display range R _i The outer surface 48 is arranged so that the direction D _i indicating the arrangement direction D _p of the outer surface 48 is the same as the actual arrangement direction D _p .
is attached to. And the control device 4
The display signal SI1 output from the display unit 5
The position of the artery 36 is displayed at 0. Furthermore, one of the indicator lights 52, 54, and 56 is turned on or blinks depending on the display position of the artery 36 on the display 50.

When detecting a pulse wave using the pulse wave detection device configured as described above, first, the housing 1
0 to the wrist 16 by the band 14,
The mounting position of the housing 10 is adjusted so as to be at a position suitable for detecting pulse waves. That is, when a start switch (not shown) is operated, step S1 is executed in the flowchart shown in FIG. 6, whereby pressure fluid is supplied into the pressure chamber 22 and the pressure is increased to a predetermined constant pressure. As a result, the pressure sensor 20 is pressed against the body surface 12 and a pulse wave signal is output from each pressure-sensitive diode 42.
SM will be supplied. The predetermined constant pressure may be close to a pressure at which a pulse wave can be suitably detected, or may be lower than that.
Next, by executing step S2, the amplitudes A of the pulse wave signals SM supplied from each pressure-sensitive diode 42 in step S1 are calculated, and the maximum amplitude of these amplitudes A is determined. The reference value A _s is calculated by multiplying the maximum amplitude by, for example, 0.8. FIG. 7 shows an example. In the following step S3, the pulse wave signal SMa that is equal to or higher than the reference value A _s is selected, and in step S4, the selected pulse wave signal SMa in the display range R _i of the display 50 is selected.
By filling out the portion corresponding to the pressure-sensitive diode 42 that outputs , the position of the artery 36 is displayed, as shown in FIG. 1, for example. Therefore, this step S4 corresponds to the display control circuit of this embodiment. In FIG. 1, the artery 36 is within the display range R _i , that is, the pressure detection range of the pressure sensor 20.
It is displayed at approximately the center position of R _p , and the indicator light 54
is lit (blinking) to indicate that the mounting position of the housing 10 is appropriate. 4 and 5 are diagrams showing other display examples, and in FIG. 4, the position of the artery 36 is displayed at a position shifted by a predetermined amount to the left in the display range R _i , The indicator light 52 is turned on (flashing) and the housing 10
On the other hand, in FIG. 5, the position of the artery 36 is displayed at a position that is greatly shifted to the right in the display range R _i , and the indicator light 56 lights up (flashing)
This indicates that it is necessary to move the housing 10 to the right in the figure. In addition,
In the display state shown in FIG.
6 is actually the pressure detection range R _p of the pressure sensor 20
Although there may be cases where the position of the artery 36 with respect to the pressure detection range R _p is not accurately indicated, the term "position of the artery" in the claims is used to include such cases. In this way, the indicator light 52 or 56 lights up (blinks)
In this case, by moving the housing 10 in the direction indicated by the indicator light to the state shown in _FIG. It will be located approximately in the center of the This means that the housing 10 is attached to a position suitable for detecting pulse waves. Note that during adjustment of the mounting position of the housing 10, as described above, the switching valve device 34 is maintained at the neutral position, and the pressure sensor 20 is moved relative to the housing 10 in the direction substantially perpendicular to the artery 36. Relative movement is prevented.

By executing step S5 following step S4, it is determined whether a switch (not shown) for starting pulse wave detection has been operated. If this determination is negative, step S5 is repeatedly executed, but if the determination is affirmative, a pulse wave detection routine (not shown) is executed. In this pulse wave detection routine, for example, the pressure in the pressure chamber 22 is adjusted such that a predetermined number or more of pulse wave signals SMa shown in FIG. 7 are obtained and the amplitudes of these pulse wave signals SMa are approximately equal. Pressure sensitive diode 4 whose value was adjusted and which outputted the pulse wave signal SMa
2, the pulse wave signal SM output from the central pressure-sensitive diode 42 is selected as the pulse wave signal SMp,
Thereafter, the pulse wave represented by the pulse wave signal SMp is displayed and recorded on the display/recording device 46. This pulse wave signal
SMp is normally output from a pressure-sensitive diode 42 that is directly above the artery 36 and pressed near the center thereof, and is less affected by the tension of the arterial wall, and the pulse wave signal SMp represents. The pressure value of the wave is very close to the actual pressure value of the pulse wave within the artery 42 in terms of absolute value.

In addition, during the pulse wave detection as described above, the pulse wave signal SMp is monitored to see if there is any fluctuation every time a certain period of time or every time a certain number of pulse waves are detected.
When there is a fluctuation, the pulse wave signal SMp for detecting the pulse wave is changed, while the pulse wave signal SMa is changed to the predetermined constant number every time a certain period of time or every time a certain number of pulse waves are detected. It is determined whether a predetermined number or more can be obtained, and if a predetermined number or more cannot be obtained, the position of the pressure sensor 20 with respect to the artery 36 is automatically adjusted by the rubber bags 28 and 30. Thereby, even if the pressure sensor 20 deviates from the artery 36 due to body movement of the subject during pulse wave detection, accurate pulse waves can be detected.

As described above, according to the pulse wave detection device of this embodiment,
In the display 50 attached to the outer surface 48 of the housing 10, the arrangement direction D _i of the pressure-sensitive diodes 42 shown in the display range R _i is the actual arrangement direction D _p
, so their alignment direction is
Compared to a device in which D _i and D _p do not match, the position of the artery 36 relative to the housing 10 can be easily grasped, and the attachment position of the housing 10 to the living body can be determined accurately and quickly while looking at the display 50. can do.

Moreover, the display 50 displays the information determined in step S2 corresponding to the maximum pulse wave signal determining means.
Since the position corresponding to the pressure sensitive diode 42 that outputs the pulse wave signal SM having the maximum amplitude is displayed,
The position of the artery 36 can be reliably grasped regardless of the pressing force of the pressure sensor 20 against the body surface or the magnitude of the pulse wave, and the mounting position of the housing 10 can be determined accurately and quickly.

Further, according to this embodiment, when adjusting the displacement of the mounting position of the housing 10, the housing 10
There is an advantage that the direction in which to move can be easily determined by the indicator lights 52 and 56.

In addition, in the above-mentioned embodiment, the indicator lights 52, 5
4, 56 and rubber bags 28, 30 are not necessarily necessary, and the effects of the present invention can be obtained even when no deflection is provided.

Further, in the above embodiment, the pressure sensor 2
0 is located directly above the artery 36 and within the pressure detection range
Although it is explained that the housing 10 is attached so that the artery 36 is located approximately in the center of R _p ,
In cases where the pressure detection range R _p is relatively wide, the artery 36 does not necessarily need to be located at the center of the pressure detection range R _p .

Further, in the above embodiment, the display width of the position of the artery 36 may be manually adjusted as appropriate by changing the reference value A _s or changing the pressure value of the pressure chamber 22. .

Further, in the above-described embodiment, the housing 10
It is also possible to display the position of the artery 36 not only when determining the attachment position of the artery but also after pulse wave detection is started.

In addition, various changes may be made to the present invention without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a view of the housing in FIG. 2, seen from the side opposite to the wrist, showing one example of display of the display. FIG. 2 is a view showing a circuit diagram of a pulse wave detection device to which the present invention is applied, with a part shown in cross section. FIG. 3 is a view of the housing in FIG. 2, seen from the wrist. FIG. 4 and FIG. 5 are views showing other examples of display of the display, and correspond to FIG. 1, respectively. FIG. 6 is a flow chart for explaining the operation of the pulse wave detection device in FIG. 2, from attaching the housing to the wrist until detection of the pulse wave is started. FIG. 7 is a view for explaining the tendency of change in the amplitude of the pulse wave signal in a direction approximately perpendicular to the artery when the display position of the artery is determined. 10...Housing, 12...Body surface, 36...
...artery, 38...pressure surface, 20...pressure sensor,
42: Pressure-sensitive diode (pressure detection element), 48
……Outer surface, 50……Indicator, Step S2……
Means for determining maximum pulse wave signal.

Claims (1)

[Claims for Utility Model Registration] A housing having a cylindrical shape with a bottom as a whole, and a pressure sensor having a pressing surface on which a plurality of pressure detection elements are arranged and protruding from the open end of the housing, Pulse generated from the artery based on pulse wave signals obtained from the plurality of pressure detection elements when the pressure sensor is attached such that the arrangement direction of the pressure detection elements on the pressing surface intersects with the artery on the surface of the living body. A pulse wave detection device that detects waves has a display range corresponding to a pressure detection range in the arrangement direction of the pressure detection elements of the pressure sensor, and a direction indicating the arrangement direction in the display range is the actual arrangement direction. an indicator provided on the outer surface of the housing so that the pulse wave signals are the same; maximum pulse wave signal determining means for determining the maximum pulse wave signal having the maximum amplitude among the plurality of pulse wave signals; A pulse wave detecting device comprising: a display control circuit that causes the display to display a position corresponding to the pressure detecting element that outputs the maximum pulse wave signal determined by the means.