• Bio telemetry is the measurement of biological parameters over a distance.
• Bio-telemetry involves some type of modulation of a radio frequency carrier and is often referred to us radio telemetry.
• The telemetering system should be selected to transmit the bio-electric signals with maximum fidelity and simplicity and directivity .
• In a single channel telemetry system the physiological variables from a single patient is measured using suitable electrodes and sensors and fed to the radio transmitter after suitable signal conditioning.
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| Biotelemetry Summary |
• The receiver consists of a tuner, demodulator, and a display unit.
• The temperature telemetry system normally uses a thermistor in order to measure temperature.
• In a biotelemetry transmitter, the measured variables are suitably amplified and processed and given to the modulator circuit
• The multi channel systems permits the transmission of the parameters such as ECG, heart rate, respiration rate, temperature, blood pressure etc. simultaneously from different patients (channels) and hence called multichannel telemetry system.
• There are two basic multiplexing methods used in bio-telemetry system-Frequency Division Multiplexing and Time Division Multiplexing.
• In FDM system we use the principle of frequency division multiplexing where each signal is frequency modulated on a sub carrier frequency.
• We can use time division multiplex system by the time sharing scheme where the transmission channel is connected to each single channel input for a short period of time to sample and transmit the signal.
• Obsterical telemetry system provides greater freedom of movement to patients during labour, and under all conditions the patient is continuously monitored through a wireless link.
• Sometimes it is desirable to implant the telemetry or receiver subcutaneously. Implantable telemetry systems allow the measurement of physiological variables over long periods of time.
• An advantage of biotelemetry systems is that time of measurement can be saved. This is because bio-telemetry helps us to record the bio signals over long periods and it can be done while the patient is engaged in his normal activities. ,
• A major disadvantage of radio biotelemetry system is that if the patient moves beyond the range of the system, the measurements cannot be transmitted effectively.
• Applications of telemetry in patient care such as telemetry of ECGs from extended coronary care patients, telemetry of ECG measurements during exercise.
Author Bio: The Author of this article, Sreejith is writing articles on Biotelemetry Applications and Advantages Electronics and Communications
