# US 2014/0155764 A1 · Automated process for assessing cardiac filling pressure non-invasively > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0155764 A1 - Document ID: US20140155764A1 - Status: Published application - Kind: A1 - Application number: 14/117,079 - Filed: 2012-05-14 - Published: 2014-06-05 - Earliest claimed: 2011-05-12 - Assignees: The Johns Hopkins University - Inventors: Harry A. Silber - Web page: https://patentgrep.com/patent/US20140155764A1 ## CPC - A61B 5/0205: Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition - A61B 5/02028: {Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction} - A61B 5/02116: {of pulse wave amplitude (A61B5/02225 takes precedence)} - A61B 5/03: Measuring fluid pressure within the body other than blood pressure, e.g. cerebral pressure {; Measuring pressure in body tissues or organs (determining bladder or urethral pressure A61B5/205)} - A61B 5/0873: {using optical means} - A61B 5/7221: {Determining signal validity, reliability or quality (preventing, reducing or removing noise induced by motion artefacts A61B5/7207; noise originating from a therapeutic or surgical apparatus A61B5/7217)} - A61B 5/08: Measuring devices for evaluating the respiratory organs - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract An embodiment in accordance with the present invention provides an automated device and method for determining cardiac filling pressure non-invasively. The device includes a computer readable medium programmed to analyze a photoplethysmography signal having a pulse amplitude. The analysis is done to determine a point in time that the pulse amplitude of the photoplethysmography signal does not vary by a predetermined amount over a first predetermined time period. The method also includes displaying instructions for the user to prepare for and begin an expiratory effort. The expiratory effort of the user is compared to a predetermined goal range for expiratory effort, and an indicator of the user's expiratory effort relative to the predetermined goal range is displayed on the user interface. ## Claims ### Claim 1 A method for automating a process for determining cardiac filling pressure non-invasively, comprising: analyzing a photoplethysmography signal having a pulse amplitude, said analyzing being done to determine a point in time that the pulse amplitude of the photoplethysmography signal does not vary by a predetermined amount over a first predetermined time period; displaying a first instruction on a user interface to inform a user that a second instruction to initiate an expiratory effort will be displayed; displaying the second instruction on the user interface informing the user to begin an expiratory effort; comparing the expiratory effort of the user to a predetermined goal range for expiratory effort; and displaying an indicator of the user's expiratory effort relative to the predetermined goal range on the user interface. ### Claim 2 (depends on 1) The method of claim 1 further comprising instructing the user to sustain the expiratory effort for a second predetermined period of time. ### Claim 3 (depends on 2) The method of claim 2 further comprising displaying an elapsed time for the expiratory effort as well as a time remaining in the second predetermined period of time. ### Claim 4 (depends on 1) The method of claim 1 further comprising indicating to the user that the data acquisition sequence is invalid when the expiratory effort does not meet the predetermined goal range within a third predetermined period of time. ### Claim 5 (depends on 1) The method of claim 1 further comprising indicating to the user that the data acquisition sequence is invalid when the expiratory effort exceeds the predetermined range for expiratory effort. ### Claim 6 (depends on 1) The method of claim 1 further comprising displaying that the user can cease the expiratory effort. ### Claim 7 (depends on 1) The method of claim 1 further comprising calculating a first average of the pulse amplitude of the photoplethysmography signal for a fourth predetermined period of time before the user ceases the expiratory effort. ### Claim 8 (depends on 7) The method of claim 7 further comprising calculating a second average of the pulse amplitude of the photoplethysmography signal for a fifth period of time before an initiation of the expiratory effort. ### Claim 9 (depends on 8) The method of claim 8 further comprising calculating a pulse amplitude ratio of the first average of the pulse amplitude to the second average of the pulse amplitude. ### Claim 10 A method for automating a process for determining cardiac filling pressure non-invasively, comprising: programming a computer readable medium to execute steps comprising: analyzing a photoplethysmography signal having a pulse amplitude, said analyzing being done to determine a point in time that the pulse amplitude of the photoplethysmography signal does not vary by a predetermined amount over a first predetermined time period; transmitting a first instruction to be displayed on a user interface, said first instruction informing a user that a second instruction to initiate an expiratory effort will be displayed; transmitting the second instruction to be displayed on the user interface, said second instruction informing the user to begin an expiratory effort; comparing the expiratory effort of the user to a predetermined goal range for expiratory effort; and transmitting a third instruction to be displayed on the user interface, said third instruction indicating the user's expiratory effort relative to the predetermined goal range on the user interface. ### Claim 11 (depends on 10) The method of claim 10 further comprising instructing the user to sustain the expiratory effort for a second predetermined period of time. ### Claim 12 (depends on 11) The method of claim 11 further comprising displaying an elapsed time for the expiratory effort as well as a time remaining in the second predetermined period of time. ### Claim 13 (depends on 10) The method of claim 10 further comprising indicating to the user that the data acquisition sequence is invalid when the expiratory effort does not meet the predetermined goal range within a third predetermined period of time. ### Claim 14 (depends on 10) The method of claim 10 further comprising indicating to the user that the data acquisition sequence is invalid when the expiratory effort exceeds the predetermined range for expiratory effort. ### Claim 15 (depends on 10) The method of claim 10 further comprising displaying that the user can cease the expiratory effort. ### Claim 16 (depends on 10) The method of claim 10 further comprising calculating a first average of the pulse amplitude of the photoplethysmography signal for a fourth predetermined period of time before the user ceases the expiratory effort. ### Claim 17 (depends on 16) The method of claim 16 further comprising calculating a second average of the pulse amplitude of the photoplethysmography signal for a fifth period of time before an initiation of the expiratory effort. ### Claim 18 (depends on 17) The method of claim 17 further comprising calculating a pulse amplitude ratio of the first average of the pulse amplitude to the second average of the pulse amplitude. ### Claim 19 An apparatus for automating a process for determining cardiac filling pressure non-invasively, comprising: a device including a housing, said device including a user interface disposed within said housing, an expiratory effort reception apparatus being coupled to said housing, a photoplethysmograph, and a computer readable medium, wherein said computer readable medium is programmed with steps comprising: analyzing a signal from the photoplethysmograph, said signal having a pulse amplitude, said analyzing being done to determine a point in time that the pulse amplitude of the signal does not vary by a predetermined amount over a first predetermined time period; transmitting a first instruction to be displayed on a user interface, said first instruction informing a user that a second instruction to initiate an expiratory effort will be displayed; transmitting the second instruction to be displayed on the user interface, said second instruction informing the user to begin an expiratory effort; comparing the expiratory effort of the user to a predetermined goal range for expiratory effort; and transmitting a third instruction to be displayed on the user interface, said third instruction indicating the user's expiratory effort relative to the predetermined goal range on the user interface. ### Claim 20 (depends on 19) The device of claim 19 further comprising said computer readable medium being disposed within the housing of the device.