CONTACT DETECTION DEVICE FOR DETECTING A PHYSICAL CONTACT BETWEEN THE CONTACT DETECTION DEVICE AND AN OBJECT

• US 20120106592A1
• Filed: 07/07/2010
• Published: 05/03/2012
• Est. Priority Date: 07/14/2009
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Klewer, Jasper
• Granted Patent: US 8,602,642 B2
• Time in Patent Office: Days
• US Class Current: 374/45
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure
• CPC Class Codes: G01K 13/20 Clinical contact thermometers for use with humans or animals
• CPC Class Codes: G01K 7/42 Circuits effecting compensation of thermal inertia; Circuits for predicting the stationary value of a temperature

Abstract

The present invention is related to a contact detection device (100) for detecting a contact between the contact detection device (100) and an object (800), a method (400), a diagnostic device and further to a computer program. The invention seeks to improve the reliability of contact sensors. The contact detection device (100) comprises a heater (110) for providing a modulated heat flow (112). A modulated heat signal (122) is generated in dependence of the modulated heat flow (112). A physical contact with an object (800) causes a change in the modulated heat flow (112) that effects the modulated heat signal (122). As the heat flow is modulated, a change in the modulated heat signal (122) is quasi assured. A contact determination unit (130) of the contact detection device (100) derives a contact indication signal (132) indicating at least either the presence or the absence of the physical contact in from the modulated heat (122), preferentially by means of a demodulator (134).

Claims

1. A contact detection device for detecting a physical contact between the contact detection device and an object, the contact detection device comprising:

a heater for providing a modulated heat flow,

a heat signal generation unit being adapted to generate a modulated heat signal in dependence of the modulated heat flow,

a contact determination unit for determining a contact indication signal indicating at least either the presence or the absence of the physical contact depending on the generated modulated heat signal.

2. The contact detection device of claim 1, wherein the heater is realized by a thermal resistor connected to a power source.

3. The contact detection device of claim 2, wherein the power source is adapted to provide a modulated current to the thermal resistor.

4. The contact detection device of claim 2, wherein the power source is adapted to provide a modulated voltage to the thermal resistor.

5. The contact detection device of claim 1, wherein the contact determination unit comprises a demodulator for demodulating the modulated heat signal to generate a demodulated signal and is adapted to determine the contact indication signal depending on the demodulated signal.

6. The contact detection device of claim 5, wherein the demodulator is adapted to demodulate the modulated heat signal in phase with the modulated heat flow.

7. The contact detection device of claim 5, wherein the demodulator comprises:

a first calculation unit being adapted to determine a constant component of the modulated heat signal and to subtract the constant component of the modulated heat signal from the modulated heat signal to generate a first alternating signal,

a multiplier for multiplying the first alternating signal with a second alternating signal to generate an intermediate signal, wherein the second alternating signal is in phase with the modulated heat flow,

an average calculation unit for averaging the intermediate signal to generate the demodulated signal.

8. The contact detection device of claim 5, wherein the contact determination unit comprises a comparator for comparing the demodulated signal with a threshold and is adapted to determine the contact indication signal depending on a result of the comparison.

9. The contact detection device of claim 2, additionally comprising a controller for controlling the heater such that the modulated heat flow provided by the controlled heater seeks to effect a predefined course of temperature of the thermal resistor.

10. The contact detection device of claim 1, wherein the heater is additionally adapted to provide a constant heat flow.

12. A diagnostic device comprising the contact detection device of claim 1.

11. A method of operating a contact detection device for detecting a physical contact between the contact detection device and an object, the method comprising following steps:

providing a modulated heat flow,

generating a modulated heat signal in dependence of the modulated heat flow,

determining a contact indication signal indicating at least either the presence or the absence of the physical contact depending on the modulated heat signal.

13. A computer program for detecting a physical contact between an object and a contact detection device, the computer program comprising program code means for causing the contact detection device to carry out the steps of the method as defined in claim 11, when the computer program is run on a computer controlling the contact detection device.