Fiber Optic Pressure Sensors and Catheters
First Claim
1. An intensity modulated fiber optic pressure sensor, comprising:
- at least one multimode optical fiber with a core and cladding surrounding the core;
a diaphragm having a reflective surface and having an outer circumferential edge attached to a cylindrical support element; and
at least one cylindrical housing disposed circumferentially around the diaphragm and the optical fiber, an end face of the cylindrical housing being adhered to the cylindrical support element,the diaphragm having an exterior face exposed to the exterior environment,the diaphragm, the support element, and an end of the optical fiber forming a cavity.
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Accused Products
Abstract
A catheter with many fiber optic pressure sensors. The sensor diaphragm is formed from a wafer with a thin silicon layer and a silicon substrate layer separated by a silicon dioxide layer. A method includes masking and etching channels through the silicon substrate layer in a pattern of concentric circles to form a concentric circular etched channels and cylindrical unetched portions of the silicon substrate layer between the channels, exposing the silicon dioxide in the etched regions, and dissolving the exposed silicon dioxide to expose the crystalline silicon layer in the etched regions. The unetched cylindrical portion of the silicon substrate forms the diaphragm support element and the thin silicon layer forms the diaphragm. After applying a reflective coating to the exposed thin silicon layer, the support element face is adhered to the end face of a tubular housing, and a fiber optic probe is inserted in the tubular housing.
80 Citations
24 Claims
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1. An intensity modulated fiber optic pressure sensor, comprising:
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at least one multimode optical fiber with a core and cladding surrounding the core; a diaphragm having a reflective surface and having an outer circumferential edge attached to a cylindrical support element; and at least one cylindrical housing disposed circumferentially around the diaphragm and the optical fiber, an end face of the cylindrical housing being adhered to the cylindrical support element, the diaphragm having an exterior face exposed to the exterior environment, the diaphragm, the support element, and an end of the optical fiber forming a cavity. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method of forming an optical fiber sensor, comprising:
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providing a wafer with a silicon substrate layer and a thin silicon layer having a thickness less than the thickness of the silicon substrate layer, and a silica layer positioned between the silicon substrate layer and the thin silicon layer; masking and etching a pattern of concentric channels through the silicon substrate layer to form a continuous unetched portion of the silicon substrate layer between the concentric channels, said etching exposing the silica layer in the concentric etched channels; exposing the thin silicon layer in the etched portion; forming a reflective coating on the exposed portion of the thin silicon layer; positioning a first hollow tube with an end face of the tube abutting the flat surface of the continuous unetched portion of the silicon substrate layer and affixing the end face of the first hollow tube to the unetched portion of the silica layer; positioning an optical fiber probe having at least one optical fiber within the tube with an end face of the optical fiber spaced apart from the second silicon layer; and affixing the optical fiber probe within the first hollow tube. - View Dependent Claims (22, 23, 24)
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Specification