Non-invasive methods and systems for assessing cardiac filling pressure

Patent metadata

Field	Value
Publication number	US-9549678-B2
Application number	US-200913003076-A
Country	US
Kind code	B2
Filing date	Jul 1, 2009
Priority date	Jul 8, 2008
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

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.

First claim

What is claimed is:

1. A method, comprising:
displaying to the user (1) a target expiratory pressure for the user, (2) a target time period for maintaining by the user the target expiratory pressure, and (3) a representation of a target location for the user to place an optical pulse volume sensing device;
sensing a change in pulse volume using the optical pulse volume sensing device coupled to a finger of the user, the optical pulse volume sensing device including a photoplethysmography (PPG) transducer, the optical pulse volume sensing device configured to sense a change in volume caused by a volume pulse by illuminating skin with light from a light emitting diode (LED), and is configured to provide an output of a pulse pressure signal of cardiac circulatory flow;
measuring an expiratory pressure for a predetermined period of time using a pressure transducer fluidly coupled to a mouth;
determining a pulse amplitude ratio, which is a ratio of the pulse amplitude near an end of the predetermined period of time and a baseline pulse amplitude; and
assessing the determined pulse amplitude ratio based on a correlation to determine a filling pressure condition of a heart, the correlation being associated with a graphical plot of a plurality of left ventricular end diastolic pressure (LVEDP) measurements of a plurality of patients using a catheter, and a graphical plot of the plurality of LVEDP measurements against a plurality of pulse amplitude ratios of the plurality of patients.

2. The method of claim 1 , wherein the pressure transducer is disposed in one of a mouth piece or a tubing so the pressure transducer is located remote from the mouth.

3. The method of claim 1 , further comprising:
communicatively coupling a microprocessor to each of the pressure transducer and the optical pulse volume sensing device; and
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.

4. The method of claim 3 , wherein the microprocessor includes an applications program including program segments and instructions and criteria for determining the pulse amplitude ratio from the output signals from the pressure transducer and the optical pulse volume sensing device.

5. The method of claim 4 , wherein the applications program includes program segments and instructions and criteria for periodically deter mining the pulse amplitude ratio.

6. The method of claim 4 , further comprising:
storing in a storage device operably coupled to said microprocessor the determined pulse amplitude ratios, a pulse volume near the end of the predetermined period of time, the baseline pulse volume and measured pressures during the predetermined period of time.

7. The method of claim 3 , further comprising:
printing data associated with the determined pulse amplitude ratios using a printing device operably coupled to said microprocessor.

8. The method of claim 6 , further comprising:
disposing the microprocessor and storage device in an enclosure of a device.

9. The method of claim 8 , wherein the device further includes one of a display device or a printing device; and wherein said method further includes one of displaying determined information using the display device or outputting a hard copy of the determined information.

10. The method of claim 8 , wherein the device microprocessor is communicatively coupled to each of the optical pulse volume sensing device and the pressure transducer.

11. The method of claim 1 , wherein:
the optical pulse volume sensing device further includes a communication interface module that is configured to form a communication link with a communications system that is external to said device and to output signals to the communications system that are appropriate for transmission over the communications system.

12. The method of claim 11 , further comprising communicating information acquired by the optical pulse volume sensing device to one of a practitioner or a monitoring apparatus.

13. A system for assessing cardiac filling pressure non-invasively, said system comprising:
a display module configured to display to a user (1) a target expiratory pressure for the user, (2) a target time period for maintaining by the user the target expiratory pressure, and (3) a representation of a target location for the user to place an optical pulse volume sensing device;
the optical pulse volume sensing device including a photoplethysmography (PPG) transducer, the optical pulse volume sensing device configured to be located on a finger or digit of the user such that the optical pulse volume sensing device senses a change in volume caused by a pressure pulse by illuminating skin with light from a light emitting diode (LED), the optical pulse volume sensing device configured to provide an output of a pulse pressure signal of cardiac circulatory flow;
a pressure transducer configured to be fluidly coupled to a mouth such that the pressure transducer measures expiratory pressure during a predetermined period of time; and
a processor configured to determine a pulse amplitude ratio, which is a ratio of the pulse pressure near an end of the predetermined period of time and a baseline pulse pressure; and
an output device configured to display the pulse amplitude ratio based on the correlation to determine a filling pressure condition for a heart, the correlation being associated with a graphical plot of a plurality of left ventricular end diastolic pressure (LVEDP) measurements of a plurality of patients using a catheter, and a graphical plot of the plurality of LVEDP measurements against a plurality of pulse amplitude ratios of the plurality of patients.

14. A device for assessing cardiac filling pressure non-invasively, said device comprising:
an optical pulse volume sensing device including a photoplethysmography (PPG) transducer, the optical pulse volume sensing device configured to be located on a finger or digit such that the optical pulse volume sensing device senses a change in volume caused by a pressure pulse by illuminating skin of the finger or digit with light from a light emitting diode (LED), the optical pulse volume sensing device configured to provide an output of a pulse pressure signal of cardiac circulatory flow;
a microprocessor configured to be communicatively coupled to the optical pulse volume sensing device and to a pressure transducer that is fluidly coupled to a mouth such that the pressure transducer measures expiratory pressure during a predetermined period of time, the pressure transducer operatively coupled to a display module configured to display to a user (1) a target expiratory pressure for the user, (2) a target time period for maintaining by the user the target expiratory pressure, and (3) a representation of a target location for the user to place the optical pulse volume sensing device; 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, which is a ratio of the pulse volume near an end of the predetermined period of time and a baseline pulse volume; and for determining a correlation between the pulse amplitude ratio and left ventricular end diastolic pressure (LVEDP) based on a graphical plot of a plurality of LVEDP measurements of a plurality of patients using a catheter and a graphical plot of the plurality of LVEDP measurements against a plurality of pulse amplitude ratios of the plurality of patients; and
for assessing the determined pul

Assignees

• Silber Harry A
• Univ Johns Hopkins

Inventors

• Silber Harry A

Classifications

• A61B5/0261

  using optical means, e.g. infrared light · CPC title

• A61B5/682

  Mouth, e.g., oral cavity; tongue; Lips; Teeth · CPC title

• A61B5/0205

  Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition · CPC title

• A61B5/02416

  using photoplethysmograph signals, e.g. generated by infrared radiation (A61B5/14552 takes precedence) · CPC title

• A61B5/0215

  by means inserted into the body · CPC title