US 5,748,103 A · Two-way TDMA telemetry system with power conservation features

Abstract

A two-way medical telemetry system is provided for displaying and monitoring, at a central location, physiologic and other patient data of multiple, remotely-located patients. The system comprises multiple battery-powered remote telemeters, each of which is worn by a respective patient, and a central station which receives, displays and monitors the patient data received (via RF) from the remote telemeters. The telemeters communicate with the central station using a two-way TDMA protocol which permits the time sharing of timeslots, and which uses a contention slot to permit telemeters to transmit service requests to the central station. Two-way spacial diversity is provided using only one antenna and one transceiver on each remote telemeter. The remote telemeters include circuitry for turning off the active transceiver components thereof when not in use (to conserve battery power), and include circuitry for performing a rapid, low-power frequency lock cycle upon power-up. The system has multiple modes of operation, including a frequency hopping (spread spectrum) mode and a fixed frequency mode, both of which preferably make use of the 902-928 MHz ISM band. Patient locators are provided to allow the clinician to track the location of each patient.

Claims24

Dependent claims

In a two-way TDMA telemetry system in which a plurality of remote telemeters transmit telemetry data, including real-time waveform data, to a data receiving station during respective telemetry timeslots of a TDMA frame, and in which the data receiving station transmits control data to the telemeters during at least one control timeslot of the TDMA frame, a method of extending the battery life of a first remote telemeter that transmits continuous real-time waveform data to the data receiving station, the method comprising, during the TDMA frame:

(a) providing battery power to active transmitter components of the first remote telemeter during a first telemetry timeslot which corresponds to the remote telemeter, to thereby allow the first remote telemeter to transmit telemetry data, including the continuous real-time waveform data, to the data receiving station during said first telemetry timeslot;
(b) providing battery power to at least one active receiver component of the first remote telemeter during said at least one control timeslot, to thereby allow the remote telemeter to receive control information from the data receiving station;
and
(c) maintaining said active transmitter and receiver components in respective low-power states during a plurality of telemetry timeslots which correspond to other remote telemeters of the system;
the method thereby conserving battery power during timeslots for which the remote telemeter is neither transmitting nor receiving data.

2 more elements

A remote telemeter for use in an ambulatory TDMA medical telemetry system which includes a data receiving station and a plurality of remote telemeters, the data receiving station and telemeters configured to communicate bi-directionally using a TDMA protocol in which the telemeters transmit physiologic data, including real-time ECG waveform data, on uniquely-corresponding telemetry timeslots, and in which the data receiving station transmits control information to the remote telemeters during control timeslots, the remote telemeter comprising:

sensor circuitry for sensing the physiologic data of a patient;
a processor coupled to said sensor circuitry;
a battery-powered transceiver responsive to said processor to transmit the physiologic data of the patient, including real-time ECG waveform data of the patient, to the data receiving station during telemetry timeslots which correspond to the remote telemeter, and to receive control information from the data receiving station during control timeslots, said transceiver comprising active transmitter and receiver components which are coupled to said processor such that said processor selectively switches said active components between respective low-power and operational states to conserve battery power;
and
a control program executed by said processor to implement said TDMA protocol, said control program configured to maintain said active transmitter and receiver components in said respective low power states during telemetry timeslots which do not corresponds to the remote telemeter, thereby conserving battery power during timeslots for which the remote telemeter is neither transmitting nor receiving data.

2 more elements

Dependencies are inferred from the claim text.

Two-way TDMA telemetry system with power conservation features

Life of this patent

Two-way TDMA telemetry system with power conservation features

Life of this patent

Abstract

Claims24