Monitoring a vital parameter of a patient with “in-situ” modulation scheme to avoid interference
First Claim
1. A method of monitoring a vital parameter of a patient by measuring attenuation of light emitted onto tissue of the patient, comprising:
- modulating light according to a modulation mode;
emitting the modulated light onto the tissue of the patient;
collecting ambient light and light which is transmitted through the tissue and reflected from the tissue;
demodulating the collected light according to the modulation mode;
analyzing the demodulated collected light with regard to a contribution of the ambient light;
determining a modulation mode for which the contribution of the ambient light is minimized or falls under a predefined threshold; and
setting the modulation mode for modulating the light according to the determined modulation mode for which the contribution of the ambient light is minimized or falls under a predefined threshold.
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Accused Products
Abstract
The invention relates to a method of monitoring a vital parameter of a patient by measuring attenuation of light emitted onto tissue of the patient, comprising the following steps: modulating the light with a modulation frequency or/and a modulation code; emitting the modulated light onto the tissue of the patient; collecting light which is transmitted through the tissue or/and which is reflected from the tissue; demodulating the collected light; analyzing the demodulated collected light with regard to interference with ambient light; determining a modulation frequency or/and a modulation code for which interference with the ambient light is minimized or falls under a predefined threshold; and setting the modulation frequency or/and the modulation code for modulating the light according to the determined modulation frequency or/and a modulation code for which interference with the ambient light is minimized or falls under a predefined threshold. In this way a versatile and reliable possibility of monitoring a vital parameter of a patient with a high signal-to-interference ratio is provided.
9 Citations
20 Claims
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1. A method of monitoring a vital parameter of a patient by measuring attenuation of light emitted onto tissue of the patient, comprising:
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modulating light according to a modulation mode; emitting the modulated light onto the tissue of the patient; collecting ambient light and light which is transmitted through the tissue and reflected from the tissue; demodulating the collected light according to the modulation mode; analyzing the demodulated collected light with regard to a contribution of the ambient light; determining a modulation mode for which the contribution of the ambient light is minimized or falls under a predefined threshold; and setting the modulation mode for modulating the light according to the determined modulation mode for which the contribution of the ambient light is minimized or falls under a predefined threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A device for monitoring a vital parameter of a patient by measuring attenuation of light emitted onto tissue of the patient, the device comprising:
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a light modulator configured to modulate the light according to a modulation mode; a light emitter configured to emit the modulated light onto the tissue of the patient; a light detector configured to detect ambient light and light which is transmitted through the tissue and reflected from the tissue; a light demodulator configured to demodulate the collected light according to the modulation mode; an interference analyzer configured to analyze the demodulated collected light with regard to the contribution of the ambient light; and a processing unit configured to determine a modulation mode for which the contribution of the ambient light is minimized or falls under a predefined threshold and set the modulation mode for modulating the light according to the determined modulation mode for which the contribution of the ambient light is minimized or falls under a predefined threshold. - View Dependent Claims (15, 16)
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17. An apparatus for monitoring a vital parameter of a patient, the apparatus comprising:
one or more processor configured to; control a light modulator to modulate the light according to a modulation mode; control a light emitter to emit the modulated light onto the tissue of the patient; control a light detector to detect ambient light and light which is transmitted through the tissue and reflected from the tissue; control a light demodulator to demodulate the collected light according to the modulation mode; control an interference analyzer to analyze the demodulated collected light with regard to the contribution of the ambient light; and determine a modulation mode for which the contribution of the ambient light is minimized or falls under a predefined threshold and set the modulation mode for modulating the light according to the determined modulation mode for which the contribution of the ambient light is minimized or falls under a predefined threshold. - View Dependent Claims (18, 19, 20)
Specification