CHROMATIC TEMPERATURE INDICATOR
First Claim
2. placing the coated material on an object the temperature of which is to be sensed, and
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Abstract
A fever indicator which can be visually monitored by observation of a temperature-dependent color-changing characteristic thereof. Said indicator is advantageously formed of a mixture of liquid crystals, e.g., a mixture formed of cholesteryl pelargonate and cholesteryl oleyl carbonate and maintained in contact with a porous and inert, but translucent, material. The mixture is incorporated into an apparatus comprising a reservoir, which can be formed of the porous inert material, and normally includes a fastening means for holding said reservoir in close contact with the body of a patient. Where a black background is required to aid the visibility of the color change, graphite-type carbon powders have been found most advantageous for use.
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Citations
22 Claims
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2. placing the coated material on an object the temperature of which is to be sensed, and
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3. means for fastening said reservoir to a body.
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4. A temperature-sensing apparatus as defined in claim 3 wherein said foam is a glass foam.
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5. A temperature-sensing apparatus as defined in claim 3 wherein said foam is a plastic foam.
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6. Apparatus as described in claim 1 wherein said mixture comprises, in addition from about 0.3 to about 20 percent by weight of particulate graphitized carbon or graphite powder.
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7. A temperature-sensing apparatus as defined in claim 6 wherein said mixture of liquid crystals comprises at least 50 percent cholesteryl pelargonate and the balance comprises cholesteryl oleyl carbonate.
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8. Apparatus as defined in claim 1 comprising a plurality of said mixtures, each adapted to change color at a different temperature.
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9. Apparatus as defined in claim 1 wherein said cholesteric liquid crystal mixture is formed of cholesteryl pelargonate and cholesteryl oleyl carbonate, the former forming at least 50 percent by weight of said composition.
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10. A temperature-sensing apparatus as defined in claim 1 wherein said mass is fused together to form a reticulated structure.
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11. A temperature-sensing apparatus comprising a reservoir containing therein a mixture of cholesteric liquid crystals, said reservoir being formed of a translucent foam.
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12. A temperature-sensing apparatus formed of a reservoir comprising a mixture of cholesteric liquid, said reservoir being formed of a translucent plastic foam having an average pore diameter of less than about 10 millimeters.
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13. Apparatus as defined in claim 1 wherein said translucent mass is composed of transparent beads having an average diameter between about 0.01 millimeters and about 10 millimeters.
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14. A thermally responsive, temperature-indicating mixture comprising a mixture of cholesteric liquid crystals and translucent particles.
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15. A mixture as defined in claim 14 comprising, additionally, from about 0.3 to about 20 percent by weight, based on the cholesteric liquid crystals, of a graphitized carbon powder.
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16. A mixture as defined in claim 14 wherein said cholesteric liquid crystals mixture is formed of cholesteryl pelargonate and cholesteryl oleyl carbonate, the former forming at least 50 percent of said composition.
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17. A thermally responsive, temperature-indicating mixture as defined in claim 14 wherein said particles are between 0.01 millimeters and about 10 millimeters in mean diameter.
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18. An improved process for visually sensing a temperature by use of thermally sensitive, color-responsive chemicals comprising the steps of
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19. A process as defined in claim 18 wherein some graphitic carbon powder is included in said mixture.
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20. A process as defined in claim 18 wherein the liquid crystals are cholesteryl pelargonate and cholesteryl oleyl carbonate, the former forming at least 50 percent by weight of the liquid crystals in the mixture.
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21. A process as defined in claim 18 wherein said porous material is formed of a mass of translucent particles.
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22. A process as defined in claim 18 wherein said porous material is a reticulated foam formed of a translucent material.
Specification