Signal transmission telemetry

Some type of signal transmission is required for all measuring systems that have a display (indicator, recorder) remote from the measuring element and transmitter. In many instances, measurements may be required of temperatures, flows, pressures, 

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Telemetry involves the transmission of sensor data such as fire alarms, emissions, access, etc., to a distant or central monitoring station. This application generally involves one-way transmission and requires only one fiber. Certain types of telemetry, however, may be interactive. Correction signals, based on received data or signals, may be sent to the transmit locations. These applications would employ two fibers, one for transmit and one for receive. 

A simplex telemetry system is employed for the transmission using straightforward modulation schemes such as amplitude modulation, on-off keying, amplitude-shift keying, and phase-shift keying [101-103]. Because the physiological signals vary slowly, such modulation schemes are preferable for miniaturized and low-power wireless biosensors. 

Due to patient s physical restrictions when connected to cables and machines, Taylor,ef fl/.,[2]had designed wireless transducers for cardiotocography via radio frequency (RF) telemetry, where there was no wire connection between the transmitter and the receiver. Thus, patients feel more confortable and at ease to move. There are also many other existing researches regarding wireless transmission of ECG signals, and the transmission is always to a laptop or a personal computer (PC)[3-4]. 

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