Microprocessor controlled apparatus for the noninvasive determination of peripheral outflow and flow disturbances
First Claim
1. A measurement apparatus for the noninvasive determination of peripheral blood outflow and flow disturbances in veins of human beings, said apparatus including at least one light transmitter and one light receiver for directing and receiving reflected light from an extremity of said being, an evaluation and read-out circuit to ascertain blood outflow and inflow in the veins by means of measuring the change in light reflection, said evaluation and read-out circuit including means to raise, prior to said measuring, the current flowing through the light transmitter until the signal-to-noise ratio of the receiver has attained a specific value.
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Accused Products
Abstract
A measuring apparatus for the noninvasive determination of peripheral outflow and flow disturbances in the extremities of human beings includes at least one light transmitter for directing light onto the skin of a human subject and at least one light receiver for receiving reflected light as well as an evaluation and read-out circuit to ascertain the temporal course of blood outflow or inflow in the veins by measuring the changes in the reflected light. The evaluation and read-out circuit calibrates itself prior to measuring by raising the current flowing through the light transmitter or transmitters until the signal-to-noise ratio of the receiver has attained a specific value.
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Citations
12 Claims
- 1. A measurement apparatus for the noninvasive determination of peripheral blood outflow and flow disturbances in veins of human beings, said apparatus including at least one light transmitter and one light receiver for directing and receiving reflected light from an extremity of said being, an evaluation and read-out circuit to ascertain blood outflow and inflow in the veins by means of measuring the change in light reflection, said evaluation and read-out circuit including means to raise, prior to said measuring, the current flowing through the light transmitter until the signal-to-noise ratio of the receiver has attained a specific value.
Specification