Biotelemetry and How it is Applied in Medical Field

Biotelemetry is the process which the measurement of biological parameters is done over a distance. This involves transmitting the bioelectrical and physiological data from the point of generation i.e. a patient located away from the hospital to the point of reception (hospital). The biological data are put in a suitable form to be transmitted by radio transmission and this process is referred as Telemetry.

Telemetry involves some type of modulation of radio frequency carriers by physiological signals so that the modulated carriers with patient data can be transmitted. At a distance place (hospital), the transmitted signals are received and demodulated to recover the information.

Components of a Biotelemetry System

A biotelemetry system consists of a transmitter and receiver system as shown in the diagrams below:

The physiological signals are obtained by a suitable transducer and are amplified and then are used to modulate the carrier waves for transmission. The receiver receives the transmission and demodulates it to separate the signals from the carrier waves so that to display or record the signals.

Applications of Telemetry in Medical field

Biotelemetry can be applied to the following measurements:

1. Bioelectrical variables such as ECG, EEG, and EMG
2. Physical variables that need transducers for conversion into electrical outputs e.g. blood flow, blood pressure, temperature etc.

In bioelectrical variables, the signals are in electrical form, hence they are directly amplified or process before they are transmitted by biotelemetry. In physiological variables, the parameters are eventually measured as variations of resistances, inductions or capacitance. The differential outputs obtained from these 3 electrical elements can be calibrated to represent pressure, blood flow, temperature or any other measurement where some physical relationship exists.

In biotelemetry, the appropriate analog signal (voltage or current) is first converted in some form of code which is capable of being transmitted. The transmitted signal is decoded at the receiving end where it is converted into its original form.

In medicine, telemetry is carried out in the transmission of the electrocardiogram (ECG) from an Ambulance and the site of an emergency to the hospital. Telemetry is also used for obtaining exercise electrocardiogram i.e. Treadmill test (TMT test) and monitoring of heart patients at home or on job. It also used for monitoring of athletes when they are trying to improve their performance.

Telemetry is used for the transmission of the electromyogram for the:

• Studies of muscle damage
• Partial paralysis problems
• Human performance studies

Telemetry can be used to send electrical impulse to cause a dead nerve to function as it once did. Telemetry is also used in the treatment of drop foot i.e. the inability of a patient to lift his foot.

Telemetry is used in the study of:

• Blood pressure
• Heart rate
• Blood flow

It is used in monitoring of skin temperature or systematic body temperature. Telemetry is also used in the form of ‘’Radio pills” to monitor stomach pressure or PH.

Related: Key Features and Applications of Telemedicine