JPS6034380B2 - Battery powered blood pressure monitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a battery-powered blood pressure monitor that measures blood pressure using Korotkoff sounds, in which the life of the battery 1 is detected and the sounding body 8 for displaying the Korotkoff sounds is activated to detect the Korotkoff sounds. This battery powered blood pressure monitor is equipped with a dead battery detecting device 9 that makes a sound at a frequency different from the sound, and its purpose is to detect when the battery for power supply has reached the end of its life on the meter, etc. An object of the present invention is to provide a battery-powered blood pressure monitor that can be configured in a simple manner without adding a display device.

In general, the standard clinical method for intercalary blood pressure measurement is based on Korotkoff's auscultation method. In other words, since the human upper arm has an artery near the epidermis, a cuff band is wrapped around this upper arm for 20 to 3 hours.
When air pressure is applied to the cuff band at a rate of mHg/sec and the pressurization value is set 10 to 2 skin mHg higher than the expected systolic blood pressure value, the arteries are compressed and blood flow ceases. Next, when the air pressure inside this cuff band, that is, the cuff pressure, is gradually exhausted at a rate of 2 to 3 mmHg/sec, the artery opens slightly, and the arterial blood flow, which is the same as that during cardiac systole, passes through at a high speed. Then, a damped vibration in the lateral direction of the blood vessel wall with a frequency higher than that of the arterial wave was discovered as the so-called Korotkoff sound.The cuff pressure at this time was taken as the systolic blood pressure value, and when the air was gradually continued to be evacuated from the cuff band, Korotkoff sounds also appear in synchronization with the arterial waves, and when the location of the Korotkoff sounds occurs during cardiac diastole, the arteries have already opened and the constriction of blood flow disappears, so the Korotkoff sounds disappear. The systolic/diastolic blood pressure values are indirectly determined by using the pressure as the diastolic blood pressure value. Conventionally, in order to improve usability, there are battery-powered blood pressure monitors for blood pressure measurement, and the meter is used to warn of battery life, or to use the battery life when it becomes impossible to measure naturally. I was trying to warn people.

In such conventional examples, the internal mechanism is complicated,
There was a drawback that the battery life could not be clearly recognized by the user. The present invention was provided to solve the above-mentioned drawbacks, and will be described in detail below based on one embodiment.

FIG. 1 is a block diagram showing the schematic configuration of one embodiment.
The figure is a time chart showing the operating state of the same as above. In the figure, 2 is a comparator that generates an output by comparing the input voltage with a reference voltage.The voltage obtained by dividing the power supply voltage of battery 1 by resistor R3 and resistor R4 is applied to the negative terminal of the comparator, which changes the power supply voltage. The potential at point B changes approximately in proportion to . ZD is a Zener diode as a constant voltage element, and the voltage divided by the resistors R and R2 is input to the positive terminal of the comparator 2. 3 is an oscillator with an oscillation period of 3 Hz, and 4 is an oscillator with an oscillation period of 3 Hz, and the outputs of both oscillators 3 and 4 are input to one input terminal of an OR gate 6 via an AND gate 5. There is.

Reference numeral 7 designates a Korotkoff sound detection circuit built into a battery-powered blood pressure monitor that measures blood pressure using Korotkoff sounds. A sounding body 8 for sound display is made to sound at a predetermined period.

The comparator 2, oscillators 3, 4, AND gate 5, OR gate 6, etc. constitute a dead battery detection device 9. Next, the operation will be explained. In Figure 2, A shows the voltage of battery 1, the voltage at point B, C shows the voltage at point A, and 2 shows point C. Now, if the voltage of battery 1 is high enough to drive the meter, The voltage at point B becomes higher than the reference voltage (comparison reference voltage corresponding to the lowest voltage that can drive the instrument), the output of comparator 2 is at low level, and therefore the output of AND gate 5 is at low level. The sounding body 8 is now driven only by the tokoff sound detection circuit 7.
The generation period of this Korotkoff sound is normally 64 times/minute.
Then, when the voltage of battery 1 gradually decreases and the voltage at point B becomes lower than that at point A, the output of comparator 2 is reversed and /
・The oscillator 3 is driven, and in combination with the oscillation output of the oscillator 4, which is constantly oscillating, the output of the AND gate 5 becomes as shown in FIG. Therefore, from the sounding body 8,
A sound with a period different from the Korotkoff sound detection sound will be generated as a low battery warning sound. This warning sound makes the user aware that the battery is dead. As described above, the present invention provides a battery-powered blood pressure monitor that measures blood pressure using Korotkoff sounds, in which the life of the battery is detected and the sounding body for displaying the Korotkoff sounds is different from the detection sound of the Korotkoff sounds. Since it is equipped with a dead battery detection device that makes a sound at a certain frequency, it is possible to use the sounding body for the Korotkoff sound display to indicate when the battery has reached the end of its life without adding an indicator such as a meter. It is possible to warn the user by using a functional element on the blood pressure monitor itself, and to indicate when the battery is low, eliminating the need to add new display parts and reducing the number of parts. , simple structure,
This has the effect of reducing costs and the like.

[Brief explanation of the drawing]

Fig. 1 is a schematic block diagram of an embodiment of the present invention;
The figure is a time chart for explaining the operation of the same as above, and FIG. 3 shows the output waveform of the AND gate same as above. 1 is a battery, 8 is a sounding body, and 9 is a dead battery detection device. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. Blood pressure is graduated using the Korotkoff sound, and in a battery-powered blood pressure monitor, the life of the battery is detected and the sounding body for displaying the Korotkoff sound is made to sound at a frequency different from that of the Korotkoff sound detection sound. A battery powered blood pressure monitor equipped with a battery exhaustion detection device.