An example method includes detecting, via a sensor, vibrations originating from a vein of a subject and obtaining an intensity spectrum of the detected vibrations over a range of frequencies. The method further includes using the obtained intensity spectrum to determine a metric selected from a group that includes: a pulmonary capillary wedge pressure (PCWP), a mean pulmonary arterial pressure, a pulmonary artery diastolic pressure, a left ventricular end diastolic pressure, a left ventricular end diastolic volume, a cardiac output, total blood volume, and a volume responsiveness of the subject. An example computing device and an example non-transitory computer readable medium that are related to the method are disclosed as well.
