Direct light differential measurement system
First Claim
1. A measurement system for measuring blood characteristics, comprising:
- an emitter emitting light at a plurality of wavelengths from a first side of a blood flow channel to a second side of the blood flow channel;
a sensor on the second side of the blood flow channel;
a reference sensor on the first side of the blood flow channel positioned to receive the light directly from the emitter, the reference sensor located proximate to and in line of sight of the emitter;
a mask on the first side of the blood flow channel positioned to;
block light from external and externally reflected sources to the reference sensor, the blocked light including reflected light of the emitter, andallow the light directly from the emitter to the reference sensor; and
a controller configured to compensate measurements of light by the sensor based upon measurements of light by the reference sensor.
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Accused Products
Abstract
A measurement system for measuring blood characteristics includes a controller, an emitter, a sensor, a reference photo sensor, and a mask. The emitter emits light at a plurality of wavelengths from a first side of a blood flow channel to a second side of the blood flow channel. The sensor is provided on the second side of the blood flow channel. The reference photo sensor is provided on the first side of the blood flow channel. The mask is provided on the first side blocking reflected light other than from the light from the emitter to enter the reference photo sensor. The controller compensates measurements from the sensor based upon measurements from the reference photo sensor.
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Citations
20 Claims
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1. A measurement system for measuring blood characteristics, comprising:
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an emitter emitting light at a plurality of wavelengths from a first side of a blood flow channel to a second side of the blood flow channel; a sensor on the second side of the blood flow channel; a reference sensor on the first side of the blood flow channel positioned to receive the light directly from the emitter, the reference sensor located proximate to and in line of sight of the emitter; a mask on the first side of the blood flow channel positioned to; block light from external and externally reflected sources to the reference sensor, the blocked light including reflected light of the emitter, and allow the light directly from the emitter to the reference sensor; and a controller configured to compensate measurements of light by the sensor based upon measurements of light by the reference sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A measurement method for measuring blood characteristics, the method comprising:
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emitting, by an emitter, light from a first side of a blood flow channel to a second side of the blood flow channel; blocking, by a mask on the first side, receipt of light sourced other than directly from the emitter by a reference sensor positioned on the first side of the blood flow channel with the emitter, wherein the reference sensor is proximate to and in line of sight of the emitter and wherein the blocked light includes reflected light of the emitter; measuring, at a sensor on the second side of the blood flow channel, characteristics of light received from the emitter after the light has passed through blood flowing through the blood flow channel; measuring, at the reference sensor, characteristics of light received from the emitter without the light passing through the blood flowing through the blood flow chamber; and compensating, by a controller, for effects on measurements taken from the measuring of the characteristics of the light by the sensor caused by changes of the light at the emitter using the measuring of light by the reference sensor. - View Dependent Claims (12, 13, 14)
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15. A measurement method for calibrating measurements of blood characteristics, comprising:
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emitting, by an emitter, light at a plurality of wavelengths from a first side of a blood flow channel to a second side of the blood flow channel; measuring, at a reference sensor on the first side of the blood flow channel, quantifiable characteristics of light received directly from the emitter, while excluding reflected light of the emitter with a mask, wherein the reference sensor is proximate to and in line of sight of the emitter light; measuring, at a sensor on the second side of the blood flow channel and while no blood chamber is disposed within the blood flow channel, quantifiable characteristics of light received from the emitter; determining, by a controller, a calibration ratio between the measurements from the reference sensor and the measurements from the sensor; measuring, at the sensor and while an empty blood chamber is disposed within the blood flow channel, quantifiable characteristics of light received from the emitter; determining, by the controller, a profile of light loss as a function of the calibration ratio, the measurements from the reference detector, and the measurements from the sensor; measuring, at the sensor while blood is flowing within a blood chamber disposed in the blood flow channel, quantifiable characteristics of light received from the emitter; and determining, by the controller and while the blood is flowing within the blood chamber disposed in the blood flow channel, a profile of blood characteristics as a function of the profile of light loss, the calibration ratio, the measurements from the reference sensor, and the measurements from the sensor. - View Dependent Claims (16, 17)
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18. A dialysis system for filtering blood of a patient, the system comprising:
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arterial extracorporeal tubing for transporting blood from the patient; a dialyzer, for receiving patient blood via the arterial tubing and filtering the patient blood; venous extracorporeal tubing for transporting cleaned blood from the dialyzer to the patient; a pump for causing the patient blood to be circulated through the arterial tubing, dialyzer, and venous tubing; and a blood measurement system for measuring characteristics of blood in the dialysis system, the blood measurement system comprising; an emitter emitting light into a blood flow channel; a sensor for receiving the light after it has passed through the blood flow channel; a reference sensor receiving light from the emitter without the light passing through the blood flow channel, the reference sensor located proximate to and in line of sight of the emitter; a mask blocking light sourcing other than directly from the emitter to the reference sensor, the mask blocking reflected light of the emitter from reaching the reference sensor; and a controller configured to compensate measurements from the sensor based upon measurements from the reference sensor. - View Dependent Claims (19, 20)
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Specification