JPS61203942A - Input apparatus of electrocardiograph - 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] [Industrial Application Field] The present invention relates to a device for amplifying and detecting biological signals by attaching lead-out electrodes to the human body, and particularly relates to a device for amplifying and detecting biological signals derived from a total of 10 points in the limbs and the chest. The present invention relates to a standard 12-lead electrocardiogram input device obtained by combining signals.

[Conventional technology]

Conventionally, the amplifier of this type of electrocardiogram input device outputs a 12-lead waveform synthesized using a resistor network by switching the leads every 3 channels and dividing the waveform into several parts. It became necessary, and the signals were not at the same time.

Furthermore, at least three isolation sections were required.

[Problems to be solved]

The conventional electrocardiograph described above synthesizes the 12-lead electrocardiogram using a resistance network and outputs the electrocardiogram while switching 414 times. Therefore, the electrocardiogram cannot be obtained at the same time point, and the electrocardiogram cannot be output at the same point in time.

There were resistor network errors, which made the circuit complex and reduced reliability.

Furthermore, at least three isolation sections are required, which increases the cost due to the addition of two large-capacity parts of the isolation power supply, and increases the failure rate due to the complexity of the circuit.

R-wave detection involves simple addition of l-lead or 2-lead signals, and if the amplitude is small, it may become uncertain, or it may be detected at the falling point of the R wave, or it may be difficult to detect signals mixed with noise. There are problems such as false detection.

[Means for solving problems]

The present invention solves the above-mentioned problems, and has a main amplifier section that generates a signal for the target induction site from multiple signals including in-phase components, and a signal with a larger amplitude by combining signals from two or more arbitrary channels. It consists of an R-wave detection amplifier section that detects an R-wave signal and generates a detection pulse synchronized with the R-wave.

〔Example〕

Next, an example thereof will be explained with reference to FIG.

FIG. 1 is a block diagram of a circuit of an embodiment of an electrocardiogram input device according to the present invention.

In the figure, this circuit roughly consists of main amplifier section 1. R detection amplifier section 2. and an isolation power supply 8 that supplies power to the isolation section of the amplifier.

The main amplifier section 1 includes differential amplifiers 3. Multiplexer 4, isolation amplifier 5. Consisting of a sample hold 6 and an AD converter 7, the required signals are only 8 channels, and the required 12 visits are II = -R+F, n[= -L+F
, C'n = Cn-F (n = 1 to 6) at the same time, and is calculated by software when outputting later. Also multiplexer 4 and sample hold 6
Only one isolation amplifier 5 is added between the two and is insulated from the human body side.

Similarly, in the R detection amplifier section 2 which is insulated, two or more arbitrary signals are inputted to the maximum value selector 9, and a larger R
The wave signal is detected, and the next bandpass filter O1 and half-wave rectifier circuit 11 extract the second-order differentiated R wave and the rising portion. Next, the hysteresis comparator 12A of the hysteresis comparator generator 12 is triggered at a threshold sufficiently higher than the noise level, and the one-shot generator 12B generates a detection signal with a constant pulse width.

〔Effect of the invention〕

As explained above, the present invention inputs electrocardiographic signals using the isolated 8-channel differential amplifier 3,
(2) lead uses the directly input signal as II=F-R, and III lead uses the directly input signal (2)=F-L, and l lead is calculated from l=I [l-11, and the following KaVB=71+''.

aV:b=-111,+4, aVy,=T
(II 10 m) and the chest as Vn = C'
n+, (II+III) (where c'n= Cn-
By calculating K (F (n=1 to 6)) using software, waveforms at any given point in time can be output in any combination. In addition, the hardware is extremely simple as it can consist of exactly the same 8 channel amplifiers.

Further, the use of only one isolation amplifier 5 reduces the cost of the device and improves reliability at the same time. Furthermore, by creating the shield and N (right foot) drive signals from the reference signal F, the effect can be given to all channels by K. By increasing the maximum value selector 9 of the R wave detection signal input, signals of two or more arbitrary channels can be used for detection, and reliability can be increased. Also, the value of the bandpass filter 1o is set to a bandwidth B=6. By selecting i sharpness Q-2,1 and center frequency fo -14,3 and combining it with half-wave rectifier circuit 11, it is possible to trigger at the rising edge of the normal KR wave, making it clear that it is different from the Q, S, and 'r waves. Separation becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a circuit of an embodiment of an electrocardiogram input device according to the present invention. 1... Main amplifier section 2... R detection amplifier section 3
...Differential amplifier 4...Multiplexer 5...
...Isolation amplifier 6...Sample hold 7...AD conversion section 8.
...Isolation power supply 9...Maximum value selector

Claims (2)

[Claims] (1) A main amplifier section that generates a signal for the target induction region from multiple signals including in-phase components, and a combination of signals from two or more arbitrary channels to detect an R-wave signal with a larger amplitude. An electrocardiogram input device comprising: an R wave detection amplifier section that generates a detection pulse synchronized with the R wave. (2) The electrocardiogram input device according to claim 1, wherein the main amplifier section includes one isolation amplifier.