Nowadays personal health monitoring is a perspective branch in medicine. Because of very quick rhythm of life it’s easier to test yourself at home. More and more medical companies develop easy-to-use tests and devices that allow getting quick information about your health. Devices are developed in a user-friendly way, that’s why medical education is not necessary to understand the vital signs of your body.
Pulse wave (PW) is a physiological event, observable and measurable in the arterial system during blood circulation. One of characteristics that can be determined from a PW record is heart rate variability (HRV), an indication of beat-to-beat alterations in the heart rate. HRV is an accurate and reliable reflection of several physiological factors modulating the normal rhythm of the heart. HRV has escalated in use as an important diagnostic tool which indicates the balance between sympathetic and parasympathetic branches of the autonomous nervous system (ANS) and the synchronization between them. HRV patterns are also sensitive to changes in emotional state and can be used to distinguish positive and negative emotions. However, HRV is just one of characteristics that can be extracted from a good quality pulse wave record. Other characteristics of the PW in the time and frequency domains can serve as an indication of the status of a cardio-vascular system.
Modern personal health monitoring tools, which use data processing capability of smartphones and personal computers, make daily or even continuous HRV analysis available for users who are affected by sedentary life style, high stress, and fatigue. The practical application of the PW monitoring requires, besides software and electronic, selection of clinically meaningful characteristics of the pulse wave and communicating them to a non-medical user. For this purpose, it is proposed to use, in addition to HRV, duration of the four phases of the pulse wave (which are related to tonicity and strength of the heart muscle) and position of the reflected wave (which is related to elasticity of blood vessels), and compare them with the baseline level obtained for the same user under non-stressed conditions. Deviations from the baseline are presented to the user. Correlation of these readings with objective parameters of the cardio-vascular system is supported by clinical data. Key words: heart rate variability, pulse wave characteristics, personal health monitoring