NON-INVASIVE METHODS AND SYSTEMS FOR ASSESSING CARDIAC FILING PRESSURE

• US 20110245691A1
• Filed: 07/01/2009
• Published: 10/06/2011
• Est. Priority Date: 07/08/2008
• Status: Active Grant

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Silber, Harry A.
• Granted Patent: US 9,549,678 B2
• Time in Patent Office: Days
• US Class Current: 600/485
• 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 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02116 of pulse wave amplitude A61B5/02225 takes precedence
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/682 Mouth, e.g., oral cavity; tongue; Lips; Teeth
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6838 Clamps or clips

Abstract

Featured are methods and systems for assessing cardiac filing pressure non-invasively. Such methods include, inter alia, arranging a photoplethysmography (PPG) transducer on a finger of a patient and fluidly coupling a pressure transducer to the patient'"'"'s mouth so that the pressure transducer measures expiratory pressure. The PPG transducer provides an output of a pulse volume signal of cardiac circulatory flow. Such methods also including determining a pulse amplitude ratio, using the pulse volume near the end of the expiratory effort and a baseline pulse volume, and assessing the pulse amplitude ratio so as to determine a filing pressure condition for the heart of the patient.

Claims

1. A method for assessing cardiac filing pressure of a patient or subject non-invasively;

said method comprising the steps of;

providing an optical pulse volume sensing device and arranging it on a finger or digit of a patient or subject so that the optical pulse volume sensing device senses a change in volume cause by the pressure pulse;

fluidly coupling a pressure transducer to the patient'"'"'s mouth so that the pressure transducer measures expiratory pressure;

determining a pulse amplitude ratio, using the pulse amplitude near the end of the expiratory effort and a baseline pulse amplitude; and

assessing the determined pulse amplitude ratio so as to determine a filing pressure condition for the heart of the patient.

2. The method of claim 1, wherein the provided optical pulse volume sensing device senses a change in volume cause by the volume pulse by illuminating the skin with light from an LED, and provides an output of a pulse pressure signal of cardiac circulatory flow.

3. The method of claim 2, wherein the provided optical pulse volume sensing device is a photoplethysmography (PPG) transducer

4. The method of claim 1, wherein said fluidly coupling includes providing a mouth piece and/or tubing one end of which is fluidly coupled to the patient'"'"'s mouth, wherein the pressure transducer is disposed in one of the mouth piece or tubing so the pressure transducer is located remote from the mouth.

5. The method of claim 1, further comprising the steps of:

providing a microprocessor or a computer including such a microprocessor;

communicatively coupling the microprocessor to each of the pressure transducer and the optical pulse volume sensing device; and

wherein said determining the pulse amplitude ratio includes determining the pulse amplitude ratio using the microprocessor and output signals from the pressure transducer and the optical pulse volume sensing device.

6. The method of claim 5, wherein providing a microprocessor or a computer further includes providing an applications program including program segments and instructions and criteria for carrying out said determining the pulse amplitude ratio from the output signals from the pressure transducer and the optical pulse volume sensing device.

7. The method of claim 6, wherein the provided applications program including program segments and instructions and criteria for periodically determining the pulse amplitude ratio.

8. The method of claim 6, wherein:

said providing a microprocessor or a computer includes providing a storage device operably coupled to said microprocessor; and

said provided applications program including program segments and instructions and criteria for causing the determined pulse amplitude ratios and other data including the pulse volume near the end of the expiratory effort, the baseline pulse volume and measured expiratory pressures to be stored in the storage device.

9. The method of claim 5, further comprising the steps of:

providing a printing device for printing of information; and

operably coupling the printing device to said microprocessor.

10. The method of claim 8, further comprising the steps of:

providing a device including an enclosure; and

disposing the provided microprocessor and storage device in the enclosure.

11. The method of claim 10, wherein the provided device further includes one of a display device or a printing device;

and wherein said method further includes one of displaying determined information to the user using the display device or outputting a hard copy of the determined information to the user.

12. The method of claim 10, wherein the provided device includes means for communicatively coupling the device microprocessor to each of the optical pulse volume sensing device and the pressure transducer.

13. The method of claim 1, further comprising the steps of:

providing a real-time pressure display operably coupled to the pressure transducer;

directing the patient to control the expiration pressure being displayed to be at or about a given value.

15. The method of claim 13, wherein said directing includes directing the patient to maintain the expiration pressure at a given value that is one of about 20 mmHg, at least 20 mmHg, in the range of from about 20 mmHg to about 35 mmHg, or in the range of from about 10 mmHg to about 50 mmHg.

16. The method of claim 13, wherein said obtaining a pulse amplitude ratio further includes obtaining a plurality of pulse amplitude ratios, where at least one of the plurality pulse amplitude ratios is determined under a different expiratory pressure.

14. (canceled)

17. (canceled)

18. The method of claim 17, wherein:

the optical pulse volume sensing device further includes a communication interface module that is configured and arranged so as to form a communication link with communications system that is external to said device and so as to output signals to the communications system that are appropriate for transmission over the communications system; and

said method further includes the step of operably coupling the communications interface to the communication system.

20. The method of claim 18, further comprising the step of communicating information acquired by the provided optical pulse volume sensing device to one of a practitioner or a monitoring apparatus.

19. (canceled)

21. (canceled)

22. A system for assessing cardiac filing pressure of a patient or subject non-invasively;

said system comprising;

an optical pulse volume sensing device, configured and arranging so as to be located on a finger or digit of a patient or subject and so that the optical pulse volume sensing device senses a change in volume cause by the pressure pulse;

a pressure transducer that is configure and arranged so as to fluidly coupled to a mouth of the patient and so that the pressure transducer measures expiratory pressure;

a means for determining a pulse amplitude ratio, using the pulse pressure near the end of the expiratory effort and a baseline pulse pressure; and

means for assessing the determined pulse amplitude ratio so as to determine a filing pressure condition for the heart of the patient.

23-36. -36. (canceled)

37. A device for assessing cardiac filing pressure of a patient or subject non-invasively;

said device comprising;

an optical pulse volume sensing device, configured and arranging so as to be located on a finger or digit of a patient or subject and so that the optical pulse volume sensing device senses a change in volume cause by the pressure pulse;

a microprocessor;

means for communicatively coupling the microprocessor to the optical pulse volume sensing device and to a pressure transducer that is fluidly coupled to a mouth of the patient so that the pressure transducer measures expiratory pressure; and

an applications program for execution on the microprocessor, the applications program including program segments and instructions and criteria for determining a pulse amplitude ratio, using the pulse volume near the end of the expiratory effort and a baseline pulse volume; and

for assessing the determined pulse amplitude ratio so as to determine a filing pressure condition for the heart of the patient.

38-40. -40. (canceled)

41. A method for assessing cardiac filing pressure of a patient or subject non-invasively;

said method comprising the steps of;

providing an optical pulse volume sensing device and arranging it on a finger or digit of a patient or subject so that the optical pulse volume sensing device senses a change in volume cause by the pressure pulse;

providing a positive pressure delivery device

fluidly coupling a pressure transducer to the patient'"'"'s mouth;

selectively fluidly coupling the positive pressure delivery device to the patient'"'"'s mouth so as to deliver a positive inspiratory pressure breathing mixture to the patient and measuring such positive pressure using the pressure transducer;

determining a pulse amplitude ratio, using the pulse amplitude near the end of the delivery of the pressurized breathing mixture effort and a baseline pulse amplitude; and

assessing the determined pulse amplitude ratio so as to determine a filing pressure condition for the heart of the patient.

42. (canceled)