JPS5892340A - Zero compensating apparatus of hemomanometer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a zero correction device for automatically correcting the output value of a pressure sensor in a blood pressure monitor for accurate display.

In a pressure sensor such as a semiconductor used as a pressure sensor in a blood pressure monitor, the relationship between the sensor output and the pressure applied to the pressure sensor is an ideal one that passes through the origin as shown by the broken line, as shown in Figure 1. It does not form a straight line (A), but due to the unique properties of the sensor, a certain value, ie, the offset value Vow, is output even when the applied pressure is zero, and the offset value ■ is a straight line indicated by a solid line starting from 0 ( B), and the offset value vO fluctuates due to the influence of the atmosphere such as temperature.

When the pressure sensor described above is used in a blood pressure monitor, an air connector 1 is generally attached to the cuff (not shown) as shown in FIG.
A pressure sensor 2 connected to the cuff detects the pressure inside the cuff from the space communicated with the cuff, and an analog-to-digital converter 3 converts the output of the pressure sensor 2 into a digital signal.
An information processing device 4 into which the digital signal and a signal from a microphone (not shown) that detects Korotkoff sound are input.
The configuration is such that the blood pressure is appropriately processed and displayed on the display device 5.

By the way, conventionally, in the information processing device 4, the means for correcting the offset value Vo described above assumes that the pressure inside the cuff at that time is zero and determines the output of the pressure sensor 2 every time the power is turned on. The offset value vO is stored and used to indicate when the cuff is pressurized later.

However, with the correction means for the offset value Vo as described above, if the blood pressure monitor is turned on when pressure is applied inside the cuff or when the air inside the cuff is not sufficiently released, the current The output value of the pressure sensor in the pressurized state is stored in the information processing device 4 as an offset value Vo, and there are cases where a value completely different from the true cuff pressure is displayed when blood pressure is measured later. Blood pressure monitors, which are consumer devices used by the general public, are prone to erroneous measurements due to the above-mentioned operational errors, which is a serious drawback.

In view of the above-mentioned drawbacks, the present invention provides an information processing bag W that appropriately processes pressure values within the cuff and Korotkoff sound signals to determine blood pressure.
A storage means whose memory contents do not disappear is provided in the storage means, the offset value of the pressure sensor is stored in the storage means, and a switch is actuated to detect that the connection between the cuff and the pressure sensor through a rubber tube or the like is disconnected. It is an object of the present invention to provide a zero correction device for a sphygmomanometer, which updates its memory contents only when the blood pressure monitor is operated, and which can be operated easily, reliably, and accurately.

Hereinafter, one embodiment using the present invention will be described in detail with reference to FIGS. 3 and 4. FIG. 3 shows the basic configuration of the present invention, in which numeral 10 is an air connector for connecting a rubber tube led out from a cuff (not shown), and numeral 11 is an air connector for connecting a rubber tube, etc., to the cuff (not shown). 12 is an analog-to-digital converter that converts the analog signal output from the pressure sensor 11 into a digital signal; 13 is the analog-to-digital converter 12; and an output of a microphone (not shown) for detecting Korotkoff sounds are input, and 13a is an information processing device that determines blood pressure by processing each piece of information according to a predetermined program; A storage section provided inside the device 13, as shown in the figure, consists of a battery backup memory that is constantly connected to the backup power source 14, or a non-volatile memory (not shown). Reference numeral 15 denotes a switch that generates a signal for renewing the information processing device, which operates in conjunction with the insertion and removal of the air connector 10. When the air connector 10 is inserted, the switch 16 is activated as shown in the figure. When the switch 16 is opened and the air connector 10 is removed, the switch 16 is closed and grounded.

In the embodiment shown in the figure, when the power is turned on and the blood pressure is measured while the air connector 10 is connected to the cuff, the switch 16 is opened in conjunction with the air connector 10. Yes, the output from the pressure sensor 11 is converted into a digital signal by the analog-to-digital converter 12, and the information processing device 13 subtracts the value corresponding to the offset value 0 previously stored in the recording unit 13a, Based on this, the blood pressure is appropriately processed together with a Korotkoff sound signal (not shown) and displayed on the display device 15 as blood pressure.

If the power is turned on with the air connector 10 removed, or if the air connector 10 is removed while the power is turned on, the switch 16 is closed in conjunction with the air connector 10, and the corresponding The signal line connected to the switch 16 is grounded and has a low potential, and at the same time the pressure sensor 1
1 becomes zero, the pressure sensor 11 outputs the offset value Vo mentioned above, and the information processing device replaces the contents of the storage unit that have been stored up to now with the offset value vO, In subsequent blood pressure measurements, blood pressure measurements are performed based on the newly updated offset value VO.

FIG. 4 shows a more specific example using the present invention.
, when an air connector for transmitting the cuff internal pressure and a signal line connector 1 for transmitting the Korotkoff sound signal are integrally formed, 17 is the air plug of the air connector, 18 is the socket of the air connector, and 19 is the treatment. The signal line plug of the signal line connector, 2° is the signal line jack of the signal line connector, the air plug 17 of the air connector, the signal line plug 19 of the signal line connector, and the air socket of the air connector are the port 18 and the signal line jack of the signal line connector. The signal line jacks 20 of the line connectors are each integrally formed, and the air connector and the signal line connector are inserted and removed at the same time. 21 is a microphone, 22 is a resistor, and 23 is a field effect transistor, which constitute a microphone circuit. The signal line jack 2o of the signal line connector has a first terminal 20a that contacts the base of the signal line plug 19 to ground it when the signal line plug 19 is inserted, and a first terminal 20a that connects the signal line plug 19 to the base of the signal line plug 19 to ground it.
a second terminal 20b that contacts the tip of the plug 19 to transmit the Korotkoff sound signal; and a second terminal 20b that contacts the second terminal 20b when the signal line plug 19 is not inserted;
When the signal line plug 19 is inserted, the second
A third terminal 20c is provided so as to be disconnected from the terminal 20b, the first terminal 20a and the third terminal 20c are grounded, and the second terminal 20b is connected to the The Korotkoff sound signal is transmitted to an information processing device.

When the connector is connected, the contact between the second terminal 20b and the third terminal 20c of the signal line shutter 20 is broken, and the second terminal 20b is connected to the field effect transistor 2.
3, and the potential increases by the bias voltage of the field effect transistor. When the connector is removed, the second terminal 20b and the third terminal 20c of the signal line jack 20 come into contact, and the second terminal 20b is grounded and drops to zero potential. That is, when the air connector is connected, the signal line connector is also connected and the potential of the second terminal 20b of the signal line jack 20 increases, and when the air connector is removed, the pressure applied to the pressure sensor becomes zero. When this happens, the signal line connector is also pulled out and the potential of the second terminal 20b of the signal line jack 20 becomes zero. Therefore, when a signal in which the potential of the second terminal 20b changes is input to the information processing device as shown in FIG. 3, and the signal becomes a low potential, the pressure applied to the pressure sensor at that time is Since is zero, the output of the pressure sensor is stored as the offset value VO, and thereafter blood pressure is measured based on this newly stored offset value Voi.

As described above, the present invention provides a switch that is linked to the insertion and removal of the air connector connecting the cuff and the pressure sensor, detects that the air connector is removed, and sets the output of the pressure sensor at that time to an offset value. The memory contents are stored in a storage means that does not disappear as vO, and subsequent blood pressure measurements are performed based on this memory contents, and when the air connector is removed, the pressure applied to the pressure sensor is always zero. Therefore, it is possible to set an accurate offset value Vo=i at that time, and the stored contents are updated every time the air connector is removed, so it is possible to correspond to fluctuations in the offset value. It has the advantage of being able to measure blood pressure accurately.

[Brief explanation of drawings]

Fig. 1 is a characteristic diagram of a pressure sensor used in a blood pressure monitor, and Fig. 2 is a block diagram showing the schematic configuration of a conventional blood pressure monitor.
FIG. 3 is a block diagram showing the basic configuration of a blood pressure monitor using the present invention, and FIG. 4 is a more specific configuration diagram of one embodiment using the present invention. 10・・Air connector, 11・Pressure sensor, 12
・Analog-digital converter, 13 ・Information processing device,
13a ・Storage unit, 14- Backup power supply, 15
・Display device, 16 ・Switch, 17-・Air plug, 18 Air receiver port, 19 ・Signal line plug, 20
・Shinkin wire jack 1.20a・ 1st terminal, 20b・
-Second terminal, 20c...Third terminal. Figure 3: Route 4

Claims (1)

[Claims] A sphygmomanometer that automatically displays blood pressure by processing with an electronic information processing device based on Korotkoff sounds detected by a microphone and pressure inside the cuff detected by a pressure sensor, the can and the pressure A quick disconnection means connected to the sensor so as to be disconnectable, a switch operated in conjunction with the disconnection of the connection means, and a storage means whose stored contents are not erased in the information processing device, The operation of the switch when the means is disconnected updates the memory contents of the memory means with the output value of the pressure sensor, and when measuring blood pressure, the output value of the pressure sensor and the value stored in the memory means are updated. A zero correction device for a blood pressure monitor, characterized in that the difference is displayed as a true value of the intracuff pressure.