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US 12,588,842 B2Granted
Systems and methods for measuring oxygen in a patient's bloodstream
AssigneeAnalog Devices International Unlimited Company
InventorsJohn Jude O'Donnell, Colin G. Lyden, Michael C.W. Coln
Life of this patent
Estimating the term…
Abstract
A photometry device can include a first LED to emit light to a target in response to a first current through the first LED, a second LED to emit light to the target in response to a second current through the second LED, and an inductor, coupled to the first and second LEDs, to store energy associated with at least one of the first and second currents.
Claims18
A photometry circuit for measuring a characteristic of a target, comprising:
- a pulse sub-circuit configured to generate a first variable amplitude current pulse;
- a first light source electrically coupled to the pulse sub-circuit, the first light source configured to receive the first variable amplitude current pulse from the pulse sub-circuit and emit first emitted light towards the target, the first emitted light being based on an amount of charge provided to the first light source by the first variable amplitude current pulse;
- a first charge storage element electrically coupled to the first light source, the first charge storage element configured to store a stored amount of charge received from the first light source, the stored amount of charge being based on the amount of charge provided to the first light source by the first variable amplitude current pulse;
- a photosensor positioned to detect first received light received from at least a portion of the target in response to the first emitted light;
- an integrator configured to integrate a current associated with the first received light to generate a first integrated current indicating an amount of charge corresponding to the first received light;
- a second light source;
- a switch positioned to, when actuated, release the stored amount of charge stored at the first charge storage element to provide a second variable amplitude current pulse to the second light source, wherein the second light source is configured to emit second emitted light towards the target using the second variable amplitude current pulse;
- and
- a hardware control circuit configured to determine a characteristic of the target based at least in part on the first integrated current and the stored amount of charge.
6 more elements
A photometry method for measuring a characteristic of a target, the method comprising:
- generating a first variable amplitude current pulse;
- emitting first emitted light towards the target using a first light source and the first variable amplitude current pulse;
- storing a stored amount of charge at a first charge storage element electrically coupled to the first light source, the stored amount of charge being received from the first light source and based on an amount of charge provided to the first light source by the first variable amplitude current pulse;
- detecting, using a photosensor, first received light received from at least a portion of the target in response to the first emitted light;
- integrating a current associated with the first received light to generate a first integrated current indicating an amount of charge corresponding to the first received light;
- actuating, using a hardware control circuit, a switch to release the stored amount of charge stored at the first charge storage element, wherein the releasing generates a second variable amplitude current pulse;
- emitting second emitted light towards the target using the second variable amplitude current pulse and a second light source;
- and
- determining, using the hardware control circuit, a characteristic of the target based at least in part on the first integrated current and the stored amount of charge.
6 more elements
A photometry system for measuring a characteristic of a target, the photometry system comprising:
- means for generating a first variable amplitude current pulse;
- means for emitting first emitted light towards the target using the first variable amplitude current pulse;
- means for storing a stored amount of charge, the stored amount of charge being received from the means for emitting first emitted light and based on an amount of charge provided to the means for emitting the first emitted light by the first variable amplitude current pulse;
- means for detecting first received light received from at least a portion of the target in response to the first emitted light;
- means for integrating a current associated with the first received light to generate a first integrated current indicating an amount of charge corresponding to the first received light;
- means for releasing the stored amount of charge stored at the means for storing the amount of charge, wherein the releasing generates a second variable amplitude current pulse;
- means for emitting second emitted light towards the target using the second variable amplitude current pulse;
- and
- means for determining a characteristic of the target based at least in part on the first integrated current and the stored amount of charge.
6 more elements
Dependencies are inferred from the claim text.