Patent ID: 8295920
Filing Date: 2012-10-23
Classification: A61B,A61M

Abstract:
1. A sensor device for detecting a change in the level of fluid within tissue of a body, the sensor device comprising: a housing having a plurality of bridge segments, the bridge segments connecting at intersections and being arranged to circumscribe an opening defined by the housing; and a plurality of antenna elements at least partially seated within the housing at intersections of the bridge segments, each of the plurality of antenna elements comprising a generally planar antenna mounted to a substrate material at a base of the planar antenna, an outer surface of the planar antenna facing away from the substrate, each of the plurality of antenna elements further comprising an electrical shield surrounding the substrate, wherein the each of the plurality of antenna elements comprises at least a first antenna element pair and a second antenna element pair, the first antenna element pair comprising a first transmitting antenna element, a first receiving antenna element, and a first bridging segment, the second antenna element pair comprising a second transmitting antenna element, a second receiving antenna element and a second bridging segment, wherein a first high sensitivity zone is formed between the first transmitting antenna element and the first receiving antenna element and a second high sensitivity zone is formed between the second transmitting antenna element and the second receiving antenna element wherein the first antenna element pair and the second antenna element pair are spaced from each other to create an area of reduced sensitivity between the first high sensitivity zone and the second high sensitivity zone, wherein the space between the first antenna element pair and the second antenna element pair is set so that the sensor is insensitive to fluid changes of a predetermined volume within the area of reduced sensitivity.