STRESS TESTING

THE PROPOSED SYSTEM CONSISTS OF A SMALL, LIGHT-WEIGHT, BATTERY OPERATED RADIO TRANSMITTER, ATTACHED TO THE PATIENT UNDER OBSERVATION,AND A RECEIVER, LOCATED NOT MORE THAN 100 METERS AWAY. THE 11 LEADS FROM THE ELECTRODES ON THE PATIENTS BODY ARE CONNECTED TO THE TRANSMITTER WHICH AMPLIFIES AND PROCESSES THESE ANALOG ECG SIGNALS AND FREQUENCY MODULATES 10 INDEPENDENT SUBCARRIERS. THE SUBCARRIERS ARE COMBINED TO FREQUENCY MODULATE A RADIO FREQUENCY (RF) CARRIER. THE OPERATING FREQUENCY IS IN THE RANGE OF 174 TO 216 MHZ AND OCCUPIES LESS THAN 200 KHZ BANDWIDTH. FCC LICENS IS NOT REQUIRED FOR THE OPERATION AT THESE FREQUENCIES. THE RECEIVER STATION OBTAINS THE RF SIGNAL FROM AN APPROPRIATELY POSITIONED ANTENNA AND TRANSFORMS IT BACK TO A 12-LEAD ECG SIGNAL. THE ANALOG ECG SIGNAL IS DIGI TALIZED FOR TEMPORARY STORAGE IN A MICROPROCESSOR CONTROLLED DISPLAY PROCESSOR. THE DIGITALIZED SIGNAL IS AVAILABLE FOR COMPUTER STORAGE OR PROCESSING. THE DISPLAY PROCESSOR ENABLES THE OPERATOR TO VIEW THE LAST 8 SECONDS OF ECG TRACE ON A CRT DISPLAY AS A MOVING TRACE. THE TRACE CAN BE "FROZEN" FOR EXAMINATION OR PUT ON STRIP-CHART RECORDING.