METHOD AND DEVICE FOR MEASURING VENOUS BLOOD OXYGENATION

• US 20150351675A1
• Filed: 02/13/2014
• Published: 12/10/2015
• Est. Priority Date: 02/13/2013
• Status: Active Grant

• Current Assignee: Mespere LifeSciences Inc.
• Original Assignee: Mespere LifeSciences Inc.
• Inventors: CHENG, Xuefeng
• Granted Patent: US 10,398,364 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0261 using hydrostatic pressure
• CPC Class Codes: A61B 2562/0233 Special features of optical sensors or probes classified in A61B5/00
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02116 of pulse wave amplitude A61B5/02225 takes precedence
• CPC Class Codes: A61B 5/02141 Details of apparatus construction, e.g. pump units or housings therefor, cuff pressurising systems, arrangements of fluid conduits or circuits A61B5/02233, A61B5/0235 take precedence
• CPC Class Codes: A61B 5/02427 Details of sensor
• CPC Class Codes: A61B 5/02433 for infrared radiation
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/029 Measuring or recording blood output from the heart, e.g. minute volume A61B8/065 takes precedence
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/6822 Neck

Abstract

A device for non-invasively measuring at least one parameter of a cardiac blood vessel in a patient comprises at least one light source that directs light at a tissue site on the patient; at least one photodetector adapted to receive light emitted by the light source and generate an output based on the received light, the output of said photodetector being correlated with a parameter of the blood vessel; and at least one probe for facilitating delivery of light from the light source to the tissue site, and receipt of light by the photodetector. The device may include a height sensor to adapt it for use to determine central venous pressure, or the configuration of light source(s) and photodetector(s) may be adapted to permit the device to provide attenuation correction in the determination of venous blood oxygenation.

Claims

1. A device comprising:

at least one light source adapted to emit light in the 400 nm to 1000 nm wavelength range;

at least one photodetector adapted to receive light emitted by the light source and translate said light into a recordable output wherein said light is reflected from or transmitted through tissue of the patient;

at least one probe which facilitates delivery of light from the light source to an external tissue site on the patient in the proximity of the jugular vein and receipt of light reflected from or transmitted through said patient site by the photodetector; and

a height sensor for mounting on the probe, said height sensor comprising a pressure sensor connected to a reference patch via a tube, wherein the tube is suitable to contain a liquid.

2. The device as defined in claim 1, wherein said light source and said photodetector are embedded in said probe.

3. The device as defined in claim 1, comprising a plurality of photodetectors.

4. The device as defined in claim 3, comprising a plurality of light sources, wherein each light source emits light that is received by a corresponding photodetector of said plurality of photodetectors.

5. The device as defined in claim 1, comprising a plurality of probes, wherein each probe comprises at least one light source and at least one photodetector.

6. The device as defined in claim 1, wherein said probe is compatible for placement on the skin of a patient.

7. The device as defined in claim 1, wherein the recordable output is current or voltage.

8. A system comprising a device as defined in claim 1 in communication with a signal processing means.

9. A device comprising:

one or more light sources to emit at least two different wavelengths of light, wavelength 1 and wavelength 2, in the 400 nm to 1000 nm wavelength range;

one or more photodetectors to receive wavelength 1 and wavelength 2 of light emitted by the one or more light sources and translate said light into a recordable output wherein said light is reflected from or transmitted through tissue of the patient, wherein the distance between the light source and photodetector that emit and receive light of wavelength 1 is different from the distance between light source and photodetector that emit and receive light of wavelength 2; and

at least one probe which facilitates delivery of light from the light source to an external tissue site on the patient in the proximity of the jugular vein and receipt of light reflected from or transmitted through said patient site by the photodetector.

10. The device of claim 9, comprising at least two light sources.

11. The device of claim 9, comprising at least two photodetectors.

12. The device of claim 9, comprising two light sources and two photodetectors.

13. The device as defined in claim 9, wherein said light source and said photodetector are embedded in said probe.

14. The device as defined in claim 9, wherein said probe is compatible for placement on the skin of a patient.

15. The device as defined in claim 9, wherein the difference in the distance between the light source and photodetector that emit and receive light of wavelength 1 and the distance between light source and photodetector that emit and receive light of wavelength is at least about 1 mm.

16. The device as defined in claim 9, wherein the distance between each light source and each photodetector ranges between about 0.5 cm to about 10 cm.

17. The device as defined in claim 9, wherein the wavelength 1 is 660, nm, and wavelength 2 is selected from 880 nm, 905 nm and 940 nm.

18. A system comprising a second device as defined in claim 9 in communication with a signal processing means.

19. A method of determining venous blood oxygenation comprising:

directing light from one or more light sources having first and second wavelengths which are different, selected from a wavelength in the range of 400-1000 nm, at the external tissue site on the patient in the proximity of the internal or external jugular vein;

detecting light reflected from the tissue or transmitted through the tissue at the first and second wavelengths using one or more photodetectors and translating the detected light into an output current for the first and second wavelengths, wherein the distance between the light source and photodetector that emit and receive light of wavelength 1 is different from the distance between light source and photodetector that emit and receive light of wavelength 2; and

determining using a processor the attenuation correction at the external tissue site on the patient based on the optical attenuation at each wavelength, and the venous blood oxygenation by applying the attenuation correction to the measured venous blood oxygenation.