Pressure switches, transmitters, systems, and methods for monitoring a pressure at a tissue site
Apparatuses, systems, and methods for monitoring a pressure exerted on a tissue site are provided. In one embodiment, an apparatus includes a pressure switch adapted for placement adjacent the tissue site. The pressure switch includes an antenna operable to receive a first signal, a diode disposed adjacent the antenna, and a membrane covering the antenna and the diode. The membrane is movable from an unpressed position to a pressed position when a force is exerted on the membrane to cause electrical communication between the antenna and the diode. The antenna is operable to send a second signal when the membrane is in the pressed position. The apparatus may also include a transmitter operable to emit the first signal to the antenna. The transmitter may output an alert when the transmitter receives the second signal.
1. A system for monitoring a pressure exerted on a tissue site, the system comprising:
a transmitter operable to propagate a first signal, the first signal being a radio frequency signal, and emitting an alert when the transmitter receives a second signal in response to the first signal; and
a pressure switch adapted for placement adjacent the tissue site and to be responsive to a force applied at the tissue site, the pressure switch comprising:
an antenna operable to receive the first signal and propagate the second signal;
a diode disposed adjacent the antenna and electrically connected to the antenna to rectify the second signal;
a switch electrically connected to the antenna and the diode for completing a circuit when closed; and
a membrane covering the antenna and the diode, the membrane movable from an unpressed position to a pressed position when the force is exerted on the membrane to close the switch;
whereby the antenna propagates the second signal when the membrane is in the pressed position.
2. The system of claim 1 , wherein the transmitter vibrates when the transmitter receives the second signal.
3. The system of claim 1 , wherein the antenna is formed from a conducting conduit, and wherein the conducting conduit forms a spiral.
4. The system of claim 1 , wherein the switch comprises a gap between the antenna and the diode, and a conductive material on an antenna-facing side of the membrane to electrically close the gap when the membrane is in the pressed position.
5. The system of claim 1 , wherein the membrane moves from the pressed position to the unpressed position when at least a portion of the force is removed from the membrane.
6. The system of claim 1 , wherein the membrane is shaped to form a dome.
7. The system of claim 1 , wherein the pressure switch is a passive device.
8. The system of claim 1 , wherein the pressure switch further comprises:
an adhesive layer adapted to adhere the pressure switch adjacent the tissue site, and
wherein the antenna is disposed between the adhesive layer and the membrane.
9. The system of claim 1 , wherein the pressure switch further comprises:
an adhesive layer adapted to adhere the pressure switch to the tissue site, and
wherein the antenna is disposed between the adhesive layer and the membrane.
10. The system of claim 1 , wherein the pressure switch further comprises:
a padding layer, and
wherein the antenna and the diode are disposed between the padding layer and the membrane.
11. The system of claim 1 , wherein the pressure switch further comprises:
a padding layer formed from a gel, and
wherein the antenna and the diode are disposed between the padding layer and the membrane.
12. The system of claim 1 , wherein the pressure switch further comprises:
an adhesive layer adapted to adhere the pressure switch adjacent the tissue site, wherein the antenna is disposed between the adhesive layer and the membrane; and
a padding layer disposed between the adhesive layer and the antenna.
13. The system of claim 1 , wherein:
the antenna is formed from a conducting conduit,
the conducting conduit forms a spiral,
the switch includes a gap between the antenna and the diode, and a conductive material on an antenna-facing side of the membrane, and
the pressure switch further comprises:
an adhesive layer adapted to adhere the pressure switch adjacent the tissue site, wherein the antenna is disposed between the adhesive layer and the membrane; and
a padding layer disposed between the adhesive layer and the antenna.
14. A pressure switch for monitoring a pressure exerted on a tissue site and adapted for placement adjacent the tissue site and to be responsive to a force applied at the tissue site, the pressure switch comprising:
an antenna operable to receive a first radio frequency signal and propagate a second radio frequency signal in response to the first radio frequency signal;
a diode disposed adjacent the antenna and electrically connected to the antenna to rectify the second radio frequency signal;
a switch electrically connected to the antenna and the diode for completing a circuit when closed; and
a membrane covering the antenna and the diode, the membrane movable from an unpressed position to a pressed position when the force is exerted on the membrane to close the switch;
whereby the antenna propagates the second radio frequency signal when the membrane is in the pressed position.
15. The pressure switch apparatus of claim 14 further comprising:
a tactile feedback device operable to output a tactile alert to a patient when the second radio frequency signal is received;
wherein the tactile feedback device is adjacent the pressure switch.
16. The pressure switch of claim 15 , wherein the tactile feedback device is coupled to the pressure switch.
17. The pressure switch of claim 15 , wherein the tactile feedback device and the pressure switch are located in an off-loading boot.
18. The pressure switch of claim 15 , wherein the tactile alert is vibration.
19. The pressure switch of claim 15 , wherein the tactile alert is electrical stimulation.