Publication

Multi-Analyte Calibration and Verification of a Multi-Parameter Laser-Based Pulse Oximeter


Patents (or Patents Pending)

US 10,863,937, Ex Vivo Calibration of a Photoplethysmographic Device

US 10,405,782, Photoplethysmographic Device with Mechanically-Protected Sensor Connector

EP 2,725,979, Homogenizing Light Sources in Photoplethysmography

EP 2,706,915, Anti-Reflective Launch Optics for Laser-Based Photoplethysmography

US 8,632,262, Laser to Fiber Optical Coupling in Photoplethysmograpic

US 8,498,507, Anti-Reflective Launch Optics for Laser to Fiber Coupling in a Photoplethysmograpic Device

US 8,078,251, Spring Wing Assembly for Photoplethysmographic Sensor

US 7,430,444, Photoplethysmographic Device with Species Specific Calibration

US 6,754,515, Stabilization Of Noisy Optical Sources in Photoplethysmography

US 6,647,279, Hybrid Optical Delivery System for Photoplethysmography

Pending Patent Applications

White Papers

The following papers require a PDF reader. Click on the link to the right to get Adobe PDF Reader.

Pulse Oximetry - Where it Came From and Where it is Going

Laboratory CO-Oximetry and the Value of the Radiometer OSM3

Radiometer OSM3 Storage, Shipping, and Handling Tips

Radiometer OSM3 Hemoximeter Calibration Verification



 

US 10,863,937 B2

EX VIVO CALIBRATION OF A PHOTOPLETHYSMOGRAPHIC DEVICE

ABSTRACT
A method for calibration of a photoplethysmographic device including the steps of providing a fluid circuit (305) for blood or other liquid, a pump mechanism (310) to generate pulsatile flow of blood through the fluid circuit, a sample of excised tissue (315) in the fluid circuit through which the blood flows, and a photoplethysmographic device including an emitter and a photodetector (330) positioned on the tissue (335, 340) so that a portion of the light output by the emitter passes through the tissue and is incident on the photodetector. The method further includes the steps of energizing the pump mechanism (420) to move the blood through the tissue, energizing the emitter (425) to output light, collecting paired data from the photodetector and from one or more reference measurements (430), and processing the paired data to calibrate the photoplethysmographic device (435).




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US 10,405,782 B2

PHOTOPLETHYSMOGRAPHIC DEVICE WITH MECHANICALLY-PROTECTED SENSOR CONNECTOR

ABSTRACT
A photoplethysmographic device including at least one laser light source and further including a protective sensor connector that has a protective flap (350), a mechanism (340) for controlling movement of the protective flap, and a plurality of interconnections, at least one of which is an optical connection (240). The movement of the protective flap designed to provide at least a substantially open position and a substantially closed position.




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European Patent No. 2725979 (France, Germany, and UK)

HOMOGENIZING LIGHT SOURCES IN PHOTOPLETHYSMOGRAPHY

ABSTRACT
In accordance with one embodiment a light homogenizing apparatus for a photoplethysmographic device comprises one or more light guides conducting light from at least one laser wherein the light exiting the light guides is incident on a light mixing element. The light mixing element comprises a plurality of one or more light sources incident upon a diffusing element followed by an internally reflective light guide. Accordingly, several advantages of one or more aspects are as follows: that light exiting the light mixing element is a substantially homogeneous mixture of the light that was incident on the light homogenizing apparatus; and that the apparatus provides a high optical throughput. The combination of these advantages contributes to accurate, high-resolution photoplethysmographic measurement.




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European Patent No. 2706915 (France, Germany, and UK)

ANTI-REFLECTIVE LAUNCH OPTICS FOR LASER-BASED PHOTOPLETHYSMOGRAPHY

ABSTRACT
An embodiment of a light launching portion of a photoplethysmographic device having a laser (20) light source and a light guide (40). The coupled end of the light guide (40) includes an anti-reflection coating (30a) to prevent or minimize the back reflection of light emitted by the laser (20). This minimizes the extent to which back reflected light can re-enter the laser and adversely alter the optical output properties of the laser (20) and additionally minimizes the associated light loss thus helping to maximize the optical coupling efficiency. Other embodiments are described and shown.




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US 8,632,262 B2

LASER TO FIBER OPTICAL COUPLING IN PHOTOPLETHYSMOGRAPHY

ABSTRACT
An embodiment of a laser to fiber coupling apparatus having a substrate that supports a laser mount, to which is affixed a submount and laser die, and an open slot mount, in which a light guide is affixed with an adhesive, such that the light from the laser is coupled into the light guide. The open slot arrangement permits the light guide to be moved in all six translational and rotational degrees of freedom to maximally couple the light from the laser to the light guide.




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US 8,498,507 B2

ANTI-REFLECTIVE LAUNCH OPTICS FOR LASER TO FIBER COUPLING IN A PHOTOPLETHYSMOGRAPHIC DEVICE

ABSTRACT
An embodiment of a light launching portion of a photoplethysmographic device having a laser light source and a light guide. The coupled end of the light guide includes an anti-reflection coating to prevent or minimize the back reflection of light emitted by the laser. This minimizes the extent to which back reflected light can re-enter the laser and adversely alter the optical output properties of the laser and additionally minimizes the associated light loss thus helping to maximize the optical coupling efficiency.




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US 8,078,251 B2

SPRING WING ASSEMBLY FOR PHOTOPLETHYSMOGRAPHIC SENSOR

ABSTRACT
A photoplethysmographic sensor designed for use on the presenting portion of a fetus during labor and delivery. The sensor has a non-deployed state in which the sensor presents a smaller footprint, or cross sectional area, for transvaginal insertion. Once the sensor is applied to the fetal tissue it is moved into the deployed state, which has a larger footprint or cross sectional area, than the sensor does in the non-deployed state. The deployed state optimizes the physical distance between the light emitter and the photodetector to maximize the photoplethysmographic measurement accuracy from the fetal tissue.




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US 7,430,444 B2

PHOTOPLETHYSMOGRAPHIC DEVICE WITH SPECIES-SPECIFIC CALIBRATION

ABSTRACT
A method and apparatus for photoplethysmographic measurements from non-human species is disclosed. The extinction of light by hemoglobin, as a function of wavelength, varies as a function of the species of the subject being monitored. The calibration of a photoplethysmographic device should therefore also vary dependant upon the species of the subject. The photoplethysmographic device of this invention includes calibrations specifically designed to provide accurate readings on non-human subjects.


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US 6,754,515 B1

STABILIZATION OF NOISY OPTICAL SOURCES IN PHOTOPLETHYSMOGRAPHY

ABSTRACT
A method and apparatus for photoplethysmographic measurements is disclosed. In this system light from a plurality of emitters is delivered to the tissue-under-test. A subset of one or more of the emitters is known to be quiet light sources with relatively stable output intensity levels and spectral contents. A second subset of one or more emitters is known to be relatively noisy light sources with output intensity levels that fluctuate over time. The use of noisy light sources may be necessary for the photoplethysmographic measurements due to favorable spectral output characteristics such as narrow spectral bandwidth or desirable center wavelengths for the measurement of the hemodynamic parameters or analytes of interest. This invention utilizes the quiet light sources to enable the use of noisy light sources without the loss in accuracy or precision of analyte measurement that would otherwise typically be associated with the use of noisy light sources in the design and use of a photoplethysmographic instrument.



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US 6,647,279 B2

HYBRID OPTICAL DELIVERY SYSTEM FOR PHOTOPLETHYSMOGRAPHY

ABSTRACT
A hybrid optical system for photoplethysmographic measurements is disclosed. The system delivers light from a plurality of emitters to the tissue-under-test. A set of one or more of the emitters resides in close proximity to the sensor. A second set of one or more emitters resides at some distance from the sensor with the light from this second set of emitters being delivered to the sensor by a light pipe typically consisting of a fiber optic cable. This invention allows the photoplethysmographic instrument designer to use two or more different types of emitters in the same photoplethysmographic device while still generating a technically feasible and cost effective design.



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Pending Patent Applications

Kestrel Labs has additional patents pending with the United States Patent Office (USPTO) and the European Patent Office (EPO). For information on pending patent applications, that have not yet been published, please contact the Company directly.


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