Claims
- 1. A modular apparatus for monitoring the presence of a person within a predefined space on a bed, said bed having a mattress, said apparatus comprising:
a mattress cover having at least one flexible capacitance sensor, said at least one flexible capacitance sensor comprising a plurality of coplanar conductive elements positioned in spaced relation to one another, said mattress cover being adapted for overfitting the mattress such that a person may overlie said plurality of coplanar conductive elements when resting on the bed; a driver/sensor circuit electrically connected to said flexible capacitance sensor for supplying a voltage between said plurality of conductive elements, detecting a change in capacitance associated with said flexible capacitance sensor in response to a change in position of a person with respect to said flexible capacitance sensor, and generating an output signal having frequency variations representative of said change in capacitance, said driver/sensor circuit being positioned adjacent said plurality of conductive elements to minimize interference from external electromagnetic fields; and a control/monitor module electrically connected to said driver/sensor circuit for receiving said output signal from said driver/sensor circuit, analyzing said output signal to make a determination of whether said output signal is representative of a change in presence of a person within a predefined space, and generating an alarm signal if said determination is affirmative.
- 2. The apparatus of claim 1 wherein said mattress cover has an underside and said plurality of coplanar conductive elements is disposed on said underside of said mattress cover.
- 3. The apparatus of claim 1 wherein said plurality of coplanar conductive elements comprises bands of conductive ink deposited on said mattress cover.
- 4. The apparatus of claim 1 wherein said plurality of coplanar conductive elements comprises a pair of bands spanning the width of said mattress cover.
- 5. The apparatus of claim 1 wherein said mattress cover has an underside and wherein said plurality of coplanar conductive elements comprises a pair of bands of conductive ink deposited on said underside of said mattress cover, said pair of bands spanning the width of said mattress cover.
- 6. The apparatus of claim 1 wherein said plurality of coplanar conductive elements comprises bands of conductive threads woven into said mattress cover.
RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of co-pending U.S. patent application Ser. No. 09/401,482, filed Sep. 22, 1999, now U.S. Pat. No. 6,297,738 issued Oct. 2, 2001, which is a continuation-in-part of U.S. patent application Ser. No. 08/708,397, filed Sep. 4, 1996, the disclosures of which are incorporated herein by reference.
Continuation in Parts (2)
|
Number |
Date |
Country |
Parent |
09401482 |
Sep 1999 |
US |
Child |
09969497 |
Oct 2001 |
US |
Parent |
08708397 |
Sep 1996 |
US |
Child |
09401482 |
Sep 1999 |
US |