Blood flow monitor apparatus
First Claim
1. A blood flow monitor apparatus comprising a transducer having a face for application to the skin, a photoelectric detector, first light guide means extending between said detector and said face, a light source, second light guide means extending between said source and said face to terminate in an array surrounding said first light guide means, means for providing a first signal representing the rate of change with time of the output from said detector, and means for providing a second signal representing the ratio between the maximum and minimum values of said first signal.
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Accused Products
Abstract
Blood flow monitor apparatus includes a transducer having a skin-engaging face from which first and second light guides respectively lead to a photodetector and light source, the second light guide forming an array surrounding the first at said face. There can be a plurality of second light guides leading to respective individual sources or, by bundling guides of fibre optic form, to a single source. In the latter case the source can be remotely connected by a fibre optic cable to a separate skin probe. Infra-red operation is preferred. The apparatus will also normally involve a visual display of, and an alarm responsive to attainment of a preset level for, at least one characteristic of the detector output. The first time differential is a characteristic of particular interest, and a presently preferred characteristic is the ratio between the maximum and minimum values of this differential.
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Citations
8 Claims
- 1. A blood flow monitor apparatus comprising a transducer having a face for application to the skin, a photoelectric detector, first light guide means extending between said detector and said face, a light source, second light guide means extending between said source and said face to terminate in an array surrounding said first light guide means, means for providing a first signal representing the rate of change with time of the output from said detector, and means for providing a second signal representing the ratio between the maximum and minimum values of said first signal.
Specification