Apparatus for detecting probe dislodgement
First Claim
Patent Images
1. Apparatus for indicating the dislodgement of an article from a body, said apparatus comprising:
- a temperature responsive element having a characteristic which varies as a function of its temperature, said element adapted for contact with a body for sensing the proximity of said element to said body;
means for periodically heating said temperature responsive element and for developing a control signal which varies in accordance wih said characteristic of said temperature responsive element and is representative of the heating of said element and the heat dissipated from said element;
and means responsive to said control signal for developing an indication of said proximity of said temperature responsive element to said body.
1 Assignment
0 Petitions
Accused Products
Abstract
A loose probe alarm in which a temperature responsive element (14) arranged for attachment to a body is periodically heated (20, 22, 26) and the effects of self-heating of the temperature responsive element are monitored (32, 36, 38) to determine whether the temperature responsive element has been dislodged from the body. The alarm is arranged to sense the difference in the amount of heat dissipated by the temperature responsive element when it remains in contact with the body to which it has been attached and when it has been dislodged from this body.
-
Citations
12 Claims
-
1. Apparatus for indicating the dislodgement of an article from a body, said apparatus comprising:
-
a temperature responsive element having a characteristic which varies as a function of its temperature, said element adapted for contact with a body for sensing the proximity of said element to said body; means for periodically heating said temperature responsive element and for developing a control signal which varies in accordance wih said characteristic of said temperature responsive element and is representative of the heating of said element and the heat dissipated from said element; and means responsive to said control signal for developing an indication of said proximity of said temperature responsive element to said body. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. Apparatus for sensing body temperature comprising:
-
a probe housing having a contact surface adapted for contact with a body; a thermistor having an electrical resistance which varies as a function of its temperature, said thermistor positioned within said contact surface of said probe housing for sensing the temperature of said body and for sensing the proximity of said thermistor to said body; a source of fixed voltage; means for coupling said voltage source to said thermistor to develop across said thermistor a first signal component representative of said temperature of said body; a source of pulse signals; means for coupling said pulse signals source to said thermistor to periodically heat said thermistor and to develop across said thermistor a second signal component which varies in accordance with said electrical resistance of said thermistor and is representative of the heating of said thermistor and the heat dissipated from said thermistor; means coupled to said thermistor for separating said first and said second signal components; means coupled to said separating means and responsive to said first signal component for developing an indication of said temperature of said body; and means coupled to said separating means and responsive to said second signal component for developing an indication of said proximity of said thermistor to said body. - View Dependent Claims (10, 11)
-
-
12. Apparatus for sensing body temperature comprising:
-
a probe housing having a contact surface adapted for contact with a body; a thermistor having an electrical resistance which varies as a function of its temperature, said thermistor positioned within said contact surface of said probe housing for sensing the temperature of said body and for sensing the proximity of said thermistor to said body; a source of fixed voltage; means for coupling said voltage source to said thermistor to develop across said thermistor a first signal component representative of said temperature of said body; a source of pulse signals; means for coupling said pulse signals source to said thermistor to periodically heat said thermistor and to develop across said thermistor a second signal component which varies in accordance with said electrical resistance of said thermistor and is representative of the heating of said thermistor and the heat dissipated from said thermistor; means responsive to said first signal component for developing an indication of said temperature of said body; and means responsive to said second signal component for developing an indication of said proximity of said thermistor to said body.
-
Specification