Patent ID: 8244078

Claim:
A sensor probe for detecting an environmental state within a bodily lumen, the sensor probe comprising: an elongated body comprising an optical guide having an outcoupling surface, which is part of an end surface of the elongated body, facing a reflective surface of an overhanging part; a photodetector which detects a property of light which is composed of light in the optical guide that is reflected from the outcoupling surface of the optical guide and of light in the optical guide that is reflected from the overhanging part; and a hydrogel material of which a property changes when at least one of getting into contact with an environmental material and detecting an environmental change, and which is provided between the end surface of the elongated body and the overhanging part, wherein the overhanging part has a first portion connected to a rigid support mounted on the end surface and a second portion connected to the hydrogel material so that the overhanging part is configured to pivot at the rigid support for tilting when a volume of the hydrogel material increases in response to the at least one of the contact with the environmental material and the detecting the environmental change.