System and method for measuring blood parameters
Inventors
Weinstein, Aharon • Gandelman, Yosef
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-9913602-B2
Publication Date
2018-03-13
Expiration Date
Abstract
The present invention provides techniques for measuring one or more parameters of a subject using a probe having an optical assembly configured and operable for applying optical measurements to a measurement location in a subject and generating optical measured data indicative thereof comprising at least one of pulsatile and occlusion measurements, a pressure system configured and operable for controllably applying pressure to the subject in the vicinity of the measurement location and measuring pressure inside the pressure system and generating pressure data indicative thereof, and a control system configured and operable for receiving and processing the pressure data to identify whether the optical measured data is valid, and for processing the valid optical measured data and determining at least one relation between the valid optical measured data and the corresponding pressure data indicative of at least one parameter of the subject.
Core Innovation
The patent describes a non-invasive system for measuring level of at least one analyte of a subject by combining optical measurements and pressure measurements at a measurement location. The optical measurements are taken from the measurement location in at least one of pulsatile and occlusive blood states and generate optical measured data indicative of the response. In parallel, an auxiliary pressure system controllably applies pressure to the subject in the vicinity of the measurement location to affect the pulsatile and occlusive blood states.
The system includes a pressure sensor system in fluid connection with the pressure system for measuring changes of pressure inside the pressure system during pressure application, generating pressure data indicative of pressure changes caused by volumetric changes at the measurement location. A control system receives and processes the pressure data and the optical measured data to determine at least one relation between them. The processor analyzes the relation for determining the at least one analyte of the subject.
The tissue-based implementation applies an expandable element to permit a pulsatile blood state in an unexpanded state and to apply an occlusive blood state in an expanded state, while an optical assembly detects light response of the measurement location in at least one of the pulsatile and occlusive blood states. A pressure sensor generates pressure measurement data indicative of pressure applied to the expandable element from the tissue in those blood states.
The processor validates at least one of the optical and pressure measurement data based on the measured data and, whenever it is determined that the data is valid, calculates at least one relation between optical and pressure measurement data indicative of the analyte of the examined tissue. The patent further describes deriving relations using data processing constructs such as an AC/DC ratio and a parametric slope, including a volumetric parametric slope, and provides environmental compensation options using barometric pressure sensing and temperature sensing as part of the measurement context.
Claims Coverage
The independent claims cover three inventive features: a system that jointly acquires optical and pressure data during pulsatile and occlusive blood states to determine an analyte, a tissue implementation using an expandable element with validated optical/pressure relations, and a computerized-device method that performs pressure/optical acquisition during pulsatile/occlusive states and determines an analyte from a relation between optical and pressure data.
Optical measurements during pulsatile and occlusive blood states
The optical assembly is configured and operable for applying optical measurements to a measurement location in the subject and generating optical measured data, the optical measurements comprising measurements taken from the measurement location in at least one of pulsatile and occlusive blood states.
Controllably applied pressure producing pressure data indicative of volumetric changes
An auxiliary system comprises a pressure system configured and operable for controllably applying pressure to the subject in the vicinity of the measurement location and affecting at least one of said pulsatile and occlusive blood states, and a pressure sensor system in fluid connection with the pressure system for measuring changes of pressure inside the pressure system during the application of said pressure and generating pressure data indicative of the pressure changes caused by volumetric changes in the measurement location.
Processor determining a relation between optical and pressure data to determine an analyte
A control system is configured and operable for receiving and processing the pressure data and the optical measured data, determining at least one relation between the optical measured data and the corresponding pressure data, and analyzing said at least one relation for determining the at least one analyte.
Expandable element alternating pulsatile and occlusive blood states in examined tissue
At least one expandable element is configured and operable to apply pressure to a vicinity of a measurement location on the tissue, to permit a pulsatile blood state in said tissue in an unexpanded state of the expandable element, and to apply an occlusive blood state in said tissue in an expanded state thereof.
Optical assembly detecting light response and generating optical measurement data in both blood states
An optical assembly is configured to detect light response of the measurement location to incident light and generate optical measurement data indicative of the detected light response, while the examined tissue is in at least one of said pulsatile and occlusive blood states.
Pressure sensor fluidly coupled to expandable element generating pressure measurement data
A pressure sensor is fluidly coupled to said at least one expandable element and is configured and operable to generate pressure measurement data indicative of pressure applied to said at least one expandable element from said tissue being in at least one of said pulsatile and occlusive blood states.
Processor validating optical and pressure data and computing relation indicative of analyte
A processor is configured to process said pressure and optical measurement data, validate at least one of said optical and pressure measurement data based on at least one of the measurements data, and whenever it is determined that said data is valid calculate at least one relation between the optical and the pressure measurement data, said at least one relation being indicative of said at least one analyte of the examined tissue.
Computerized-device method for pressure and optical acquisition and relation-based analyte determination
A method for measuring by a computerized device level of at least one analyte, wherein the computerized device operates a pressure system to apply pressure affecting pulsatile and occlusive blood states, receives optical measured data from the measurement location while in the pulsatile and occlusive blood states, receives pressure data indicative of pressure changes inside the pressure system due to vascular volumetric changes in the measurement location while optical data is obtained, processes optical and pressure data to determine at least one relation between optical measured data and pressure data, and determining said at least one analyte based on said at least one relation.
Overall, the independent claims require a pressure-coupled measurement approach that produces pressure data indicative of vascular volumetric changes during optical measurements in pulsatile and occlusive blood states, and a processing function that validates optical and pressure data and determines analyte level from a relation between the optical measured data and the pressure data.
Stated Advantages
Improved signal-to-noise compared with conventional pulse oximetry, particularly in low perfusion.
Reduced motion artifacts compared with conventional pulse oximetry.
Documented Applications
In vivo clinical performance study for hemoglobin (Hb) reporting bias, accuracy, and correlation/scatter-plot results based on the described measurement system.
Interested in licensing this patent?