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 users expiratory effort relative to the predetermined goal range is displayed on the user interface.
