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Povzetek. Spremenljivost frekvence sr?nega utripa je izmerljiva na podlagi meritev frekvence sr?nega utripa ter velja za enega izmed najobetavnejsih kazalcev aktivnosti avtonomnega ziv?nega sistema. Za potrebe pridobivanja parametra se trenutno uporabljata konvencionalni kontaktni metodi (elektrokardiogram ter opti?na pletizmografija). Metodi sta zanesljivi, vendar omejeni s potrebo po stalnem fizi?nem kontaktu med merilno elektrodo in kozo merjenca. V literaturi so objavljene obetavne resitve za brezkontakten pristop k merjenju. Temeljijo na merjenju parametrov, ki so posredno ali neposredno odvisni od delovanja srca. Merilne metode merijo glasnost bitja srca z mikrofonom, miniaturne premike na povrsini prsnega kosa zaradi bitja srca z radarjem, spremembe temperature v blizini ve?je povrsinske zile zaradi pretoka krvi s toplotno kamero, volumetri?ne spremembe zil zaradi pretoka krvi prek odboja ambientalne svetlobe z RGB-kamero ter spremembe v elektri?nem polju v blizini opazovane osebe zaradi elektromagnetne aktivnosti srca s pomo?jo kapacitivnega senzorja. Izbrali smo stiri metode, za katere smo izdelali senzorje, jih so?asno preizkusili na enaki razdalji ter primerjali z referen?no kontaktno metodo. Namen ?lanka so opisati glavne zna?ilnosti omenjenih metod, kratka predstavitev izvedenih so?asnih meritev z narejenimi senzorji ter njihova analiza.
Klju?ne besede: brezkontaktno merjenje, spremenljivost frekvence sr?nega utripa, Dopplerjev pojav, radar, mikrofon
Non-contact measurement of the heart rate and the heart rate variability
The heart-rate variability (HRV) is determined by measuring the heart rate (HR). HR is the basic physiological parameter measured in the clinical practice and the HRV has been recognized as a promising quantitative marker of the autonomic activity. Currently, the parameters are obtained by the two conventional measuring methods, i.e. electrocardiography and optical plethysmography. The two methods are considered to be reliable but limited by the need of the constant physical contact between the measuring electrodes and the skin. The literature provides examples of the non-contact measurement of HR and HRV based on measuring different phenomena, such as the sound of the heart with a microphone, minute displacement of the chest due to the heartbeat with a radar, changes in temperature in proximity of superficial arteries due to the blood flow with a thermal camera, absorbance of light due to the volumetric changes in the vessels during the blood flow with an RGB camera and changes in the electromagnetic field in the proximity of the subject with a capacitance-based sensor. Four...