Testing device using a thermochromic display and method of using same
First Claim
1. A testing device for use in determination of a particular characteristic of a fluid, comprising a sensing element for contacting the fluid and producing a response indicative of the characteristic to be determined, electronic means for processing the response to produce an electrical signal of magnitude indicative of the characteristic, and a display device comprising a conductive track for passing a current the magnitude of which is dependent on the magnitude of the electrical signal produced by the electronic means and a thermochromic layer overlying the conductive track for changing color to a dimensional extent dependent on the magnitude of current passing in the conductive track.
7 Assignments
0 Petitions
Accused Products
Abstract
A testing device for qualitatively or quantitatively sensing an electrochemical or analogous reaction at the surface of a test strip (46), the current flowing or charge accumulated at the test strip being processed by electronics (50) to generate a current signal suitable for activating a display (52) typically in the form of a thermochromic layer.
278 Citations
12 Claims
- 1. A testing device for use in determination of a particular characteristic of a fluid, comprising a sensing element for contacting the fluid and producing a response indicative of the characteristic to be determined, electronic means for processing the response to produce an electrical signal of magnitude indicative of the characteristic, and a display device comprising a conductive track for passing a current the magnitude of which is dependent on the magnitude of the electrical signal produced by the electronic means and a thermochromic layer overlying the conductive track for changing color to a dimensional extent dependent on the magnitude of current passing in the conductive track.
- 10. A method of testing a fluid for a particular characteristic thereof using a testing device, comprising the steps of contacting the fluid with the testing device to cause a sensing element to produce a response indicative of the characteristic to be determined, and electronically processing the response to produce an electrical current the magnitude of which is indicative of the characteristic, characterized by the further step of passing the electrical current through a conductive track underlying a thermochromic layer which thereby changes color to a dimensional extent dependent on the magnitude of the current.
-
12. A testing device for use in determination of a particular characteristic of a fluid, comprising a sensing element having electrodes for contacting the fluid, means whereby a current signal is caused to pass between the electrodes when the sensing element is in contact with the fluid, the magnitude of said current signal being representative of the fluid characteristic to be determined, electronic means for processing the current signal to produce a display signal, and a display device for receiving the display signal, whereby to produce a visual indication of the fluid characteristic to be determined, said display device comprising a conductive track for passing the display signal and a thermochromic layer overlying the conductive track for changing color to a dimensional extent dependent on the magnitude of the display signal.
Specification