AD Precision Instrumentation Amplifier FEATURES Low Noise: V p-p 10 Hz Low Gain TC: 5 ppm max = 1) Low Nonlinearity: % max to ) High. a Precision. Instrumentation Amplifier AD FEATURES FUNCTIONAL BLOCK DIAGRAM Low Noise: V p-p Hz to 10 Hz Low Gain TC: 5 ppm max (G. AD datasheet, AD circuit, AD data sheet: AD – Precision Instrumentation Amplifier,alldatasheet, datasheet, Datasheet search site for Electronic.
|Published (Last):||3 February 2013|
|PDF File Size:||7.91 Mb|
|ePub File Size:||11.87 Mb|
|Price:||Free* [*Free Regsitration Required]|
Introduction to ECG measurement system. The ECG system is shown on Figure 1.
ECG Measurement System
The ECG system comprises four stages, each stage is as following: The basic structure of the heart is shown on Figure 2. Measuring at different region of the heart will retrieve different biopotential.
And, so that it will generate different ECG waveforms. The ECG generated by each cardiac cycle is summarized on Table 1.
Duration at 75 bpm 0. Blood pumped into aorta and pulmonary artery.
The ECG is converted into electrical voltage by electrodes. The cardiac mechanism of ECG is shown on Figure 4. In the top figure, the electrocardiogram ECG initiates the cardiac cycle.
The datashret sounds are also shown. The bottom figure shows that ejection occurs when the pressure in the left ventricle exceeds that in the arteries.
Ad6244 the electrodes convert the ECG into electrical voltage, these voltage can be fed into an instrumentation amplifier, and then be processed.
We measure the ECG by connecting two electrodes on the right and left chest respectively, as shown on Figure 5. The body should be connected to ground of the circuits, so that we connect the leg to the ground.
If the body is datasyeet grounded, no signal would be obtained. Circuits of the ECG system.
View ad624 datasheet:
The ECG circuit diagram is shown on Figure 6. Some important features of the AD are listed on Table 2. The small ac signal voltage datasheeg than 5 mV detected by the sensor on the electrodes will be accompanied by a large ac common-mode component up to 1. The equation of the CMRR: The is connected as a source follower. The output DC voltage of the AD is adjusted to 3V, which is an optimal value after many try and errors.
The data sheet of ST Op Amp is on . In general, components of the signal of interest will reside in the 0. We take the suggestion by the book of John Webster  to have the bandpass filter the frequency range of 0. The filter is implemented by cascading a low-pass filter and a high-pass filter. The data of low-pass and high-pass filter are implemented by simple RC components, as shown on Table 3.
The measured transfer function of the bandpass filter is on Figure 8. The ECG circuit is shown on Figure 9. The three measured ECG signals, on Figure 10, are respectively from the Instrumentation Amp, opto-coupler, and filter.
The circuits function very well so that the three signals are almost identical to each other. Measuring different region of the heart will obtain different ECG signals. Atrial diastole Ventricular diastole. Atrial systole Ventricular diastole. Atrial diastole Ventricular systole.