Chair monitor

A contactless monitoring system comprising:

• (A) a controller for monitoring an individual located within a specified spacing from the controller, said controller comprising
• (1) a single transducer which transmits reflectable pulsed sonic signals toward a monitored individual at intervals and which receives reflected signals from the monitored individual;
• (2) a counter which is coupled with the transducer and which measures the actual return time of each pulsed signal and compares the return time of each pulsed signal with a preset return time range, wherein the preset return time range corresponds directly to at least two boundaries of a three dimensional predetermined space parameter, wherein at least one of the boundaries corresponds to a location beyond which the monitored individual would move when in danger of leaving the seat;
• and
• an alarm generator which is coupled with the counter and which generates an alarm signal when the counter measures a reflected pulsed signal having a return time which is outside the preset return time range, the alarm generator generating the alarm whenever the monitored individual moves outside of any of the monitored boundaries of the three dimensional space.

A method of monitoring a seated individual, comprising:

• mounting a monitoring system at a distance from the individual to be monitored;
• transmitting, from the monitoring system, a series of pulsed signals, wherein the transmitted signals are transmitted toward the monitored individual seated on a seating apparatus so that the pulsed signals are reflected off the monitored individual and back toward said monitoring system;
• receiving the pulsed signals at the monitoring system;
• comparing the return time of each pulsed signal to a threshold return time range which corresponds directly to at least one boundary of a three-dimensional predetermined space parameter that corresponds to a location beyond which the monitored individual would move when in danger of leaving the seat;
• generating an alarm signal only if the return time of a pulsed signal is outside the threshold return time range, thereby indicating that the monitored individual is not within the three-dimensional space parameter, wherein an alarm signal is generated whenever the monitored individual is in danger of leaving the seat.

A contactless monitoring system comprising:

• (A) a controller which is configured to monitor an individual seated in a seat, said controller including
• (1) a transmitter which is configured to transmit a pulsed signal at intervals;
• (2) a receiver which is configured to receive reflected signals from the monitored individual;
• and,
• (3) a circuit which is coupled with the transmitter and with the receiver and which is configured to
• a) measure an intensity-independent characteristic of each pulsed signal that is transmitted from the transmitter, reflected from the monitored individual, and impinged upon the receiver, and
• b) compare the measured characteristic to a range of characteristics having a maximum threshold parameter of the measured characteristic and a minimum threshold parameter of the characteristic, wherein the threshold parameters correspond directly to at least two boundaries of a three-dimensional space parameter, wherein at least one of the boundaries corresponds to a location beyond which the monitored individual would move when in danger of leaving the seat;
• and
• (B) an alarm generator which is coupled with the circuit and which generates an alarm signal when the circuit determines that the measured characteristic of at least one pulsed signal is either less than the minimum threshold parameter or greater than the maximum threshold parameter, and wherein an alarm signal is generated whenever the monitored individual is in danger of leaving the seat.