Contents
In Electrocardiography (ECG) recorder five leads from the patient are connected to the ECG recorder through a selector switch to obtain 12 lead configurations as illustrated below:
A standard voltage of 1 mV is used to calibrate the recorder. The output from the lead selector switch is amplified using a differential amplifier with a high common mode rejection ratio. It is called a preamplifier. The output of the preamplifier goes to a DC amplifier which is called the pen amplifier as it provides the power to drive the pen motor that records the ECG trace.
ECG recorder employs heat sensitive paper as the recording paper. The pen is actually an electrically heated stylus which is called recording stylus. The recorder also has a marking stylus to mark a code indication of the standard lead configuration on the trace. The paper speed is kept at 25 m/s or 50 m/s.
Related: Electrocardiogram (ECG)
The common types of ECG recorder are discussed as follows:
This is the most frequently used type of ECG recorder and it is portable. As the name suggests, the output of one out of 12 standard lead configurations is traced at a time. Twelve traces are therefore recorded on a paper of length 3 to 6 feet. Hence it is inconvenient to read and store.
The recorder records the output of three leads simultaneously. It can also switch automatically to the next group of three leads to carry out the recording. The time required for recording 12 traces is considerably reduced.
Find out more about: Fingertip Pulse Oximeter Blood Oxygen Saturation Monitor
This recorder presents an image of both the magnitude and the spatial orientation of the heart vector.
This method requires that the ECG signals from the standard leads be transmitted sequentially to the computer using some appropriate means together with all the information regarding the patient.
Typically ECG represents a brief recording of the cardiac activity. However, arrhythmia may occur under certain conditions at any unspecified time. Hence, continuous recording that was introduced by physician Holter to capture ECG at the time of arrhythmia. In this case, a small device like magnetic tape recorder which can be worn in a shirt pocket is used and it allows the recording of the ECG continuously for 24 hrs. The recorded tape is analyzed using a special scanning device.
Get Access to Our Premium Articles & Resources Learn More
You can also read: Biomedical Signals Acquisition Instruments
Confocal Microscopy Technique In conventional microscopy, the specimen is usually mounted on a glass slide…
A cardiac pacemaker is normally used to produce pulses that force the heart to beat…
Electroporation is a technique that utilizes intense pulses of electricity to ‘punch’ holes in cell…
Single Photon Emission Tomography (SPECT) is a technique for producing 3D images from 2D images…
Polarographic electrodes differ from the typical pH and ion specific cells in that a polarographic…
Scintillation counters are basically made up of the following main components: a scintillation material (crystal),…
View Comments