OPTO-PHYSIOLOGICAL SENSOR AND METHOD OF ASSEMBLY

• US 20160278646A1
• Filed: 10/15/2014
• Published: 09/29/2016
• Est. Priority Date: 10/17/2013
• Status: Active Grant

• Current Assignee: Carelight Limited
• Original Assignee: Loughborough University
• Inventors: HU, Sijung, AZORIN-PERIS, Vicente
• Granted Patent: US 10,327,652 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2562/0242 for varying or adjusting the optical path length in the tissue
• CPC Class Codes: A61B 2562/12 Manufacturing methods specially adapted for producing sensors for in-vivo measurements
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/0015 characterised by features of the telemetry system
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/02427 Details of sensor
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 5/7475 User input or interface means, e.g. keyboard, pointing device, joystick
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders

Abstract

A method of assembling an opto-physiological (OP) sensor comprises: (i) modelling the opto-physiological properties of at least one body tissue type to be monitored; (ii) determining, through application of the model, an optimal optical design for an opto-physiological (OP) sensor operable to monitor the opto-physiological properties of the at least one body tissue type; and (iii) making the OP sensor to the determined optical design. The optimal optical design for the OP sensor comprises: (i) determining the optimum separation of each of a plurality of light sources from a photodetector, based on modelled optical path lengths for light travelling from each light source, through the body tissue type to be monitored, to the photodetector; and (ii) locating light sources of different wavelengths at different distances from the photodetector.

Claims

1. A method of assembling an opto-physiological sensor comprising:

modelling the opto-physiological properties of at least one body tissue type to be monitored;

determining, through application of the model, an optical design for an opto-physiological sensor operable to monitor the opto-physiological properties of the at least one body tissue type; and

making the opto-physiological sensor to the determined optical design;

wherein the optical design for the opto-physiological sensor comprises;

determining separation of each of a plurality of light sources from a photodetector, based on modelled optical path lengths (24) for light travelling from each light source, through the body tissue type to be monitored, to the photodetector; and

locating a first array of the plurality of light sources having a first wavelength on a circumference of a first circle, the first circle being centered on the photodetector and having a radius determined based on the first wavelength,

locating a second array of the plurality of light sources of having a second wavelength on a circumference of a second circle, the second circle being centered on the photodetector and having a radius determined based on the second wavelength,

wherein each of the first and second arrays comprises at least four light sources.

2. The method according to claim 1, wherein the optical design for the opto-physiological sensor comprises use of multiple light sources configured to generate light at the same wavelength or waveband and wherein the sensor is configured to select one or more of said multiple light sources for use in an opto-physiological measurement based on captured radiation quality at the photodetector.

3. The method according to claim 1, wherein the at least one body tissue type comprises one or more of:

a tissue site, a tissue color, a tissue thickness, a tissue age and a tissue condition; and

the opto-physiological properties of the at least one body tissue type comprise one or more of;

a coefficient of absorption, a coefficient of scattering, a refractive index and optical density.

4. An opto-physiological sensor comprising:

a plurality of light sources; and

at least one photodetector configured to capture radiation originating from one or more of said light sources, after light from said light source has travelled through a body tissue type to be monitored,

wherein the plurality of light sources are located relative to the photodetector at positions determined by a model of the opto-physiological properties of the body tissue type to be monitored,

wherein the separation of each light source from the photodetector is based on modelled optical path lengths for light travelling from each light source, through the body tissue type to be monitored, to the photodetector; and

wherein a plurality of light sources of a first wavelength are positioned in a first array on the circumference of a first circle, the first circle being centered on the photodetector and having a radius determined based on the first wavelength,

wherein a plurality of light sources of a second wavelength are positioned in a second array on the circumference of a second circle, the second circle being centered on the photodetector and having a radius determined based on the second wavelength,

wherein each of the first and second arrays comprises at least four light sources.

5. The opto-physiological sensor according to claim 4 wherein multiple light sources are configured to generate light at the same wavelength or waveband and the sensor is operable to select one or more of said multiple light sources for use in an opto-physiological measurement based on the captured radiation quality.

6. The opto-physiological sensor according to claim 4, further comprising a controller operable to activate and deactivate the plurality of light sources based on a measured signal from the photodetector.

7. An opto-physiological system comprising:

an opto-physiological sensor according to claim 4; and

an analyser configured to analyse a signal measured by the photodetector to determine at least one physiological parameter therefrom.