Background & Aim: In research and clinical medicine the interest in the heart rate variability (HRV) has increased in the recent past. With the variety of the measuring methods attention should he paid that all methods conform to the quality criteria's according the guideline of the DGAUM (DGAUM 2006). Heart-rate watch monitors have high failure rates when recording the heart rate in areas with electromagnetic interferences (Hottenrott, 2007) or inside of vehicles (Sammito, 2008). The aim of our study was the validation of a radio-less memory belt (Suunto Memory Belt [SMB]) for HRV recording under laboratory conditions and inside vehicles (medical ambulance vehicle [RTW] and an armoured military vehicle [MTW]) vs. a wire-lead transferring system (Schiller MT-101). Methods: 27 volunteers without cardiac diseases (19 male, 8 female, age: 24.1 ± 4.1 years) took part in an examination over 40 minutes under laboratory conditions and/or in a medical ambulance vehicle and/or in an armoured military vehicle. In every examination the volunteers carried both recording systems. In the examinations inside the vehicles (RTW or MTW) the motor was turned on after 20 of the 40 minutes. Results: Interbeat-intervals were recorded in total 57 examinations (21 x laboratory, 21 x RTW. 15 x MTW). The radio-less memory belt showed only a low failure rate (0.55 % of all heart rates). The medial difference of the interbeat-intervals between the SMB and the Schiller-EKG after manual synchronization was 0.03 ms ±12.60 ms (0.004 %). The limit of agreement (LoA) was 98.19 %. There was no interference by the motor. The HRV parameters (MeanRR, SDNN, RMSSD, LF, HF. LF/HF, SD1, SD2) have a LoA of 91.23-94.74 %. Conclusion: This study showed for the first time the validity of a radio-less memory belt for recording Interbeat-intervals in vehicles. The conformity with a wire-lead transferring system was very high. Also, the HRV parameters showed acceptable correspondence. For scientific questions the radio-less memory belt is an alternative for field trials. Further studies have to demonstrate the validity of the HRV parameters under higher physical train.
© Copyright 2011 Herzfrequenzvariabilität: Gesundheitsförderung - Trainingssteuerung - Biofeedback. Internationales Symposium am 29. und 30. Oktober.. Veröffentlicht von Feldhaus, Ed. Czwalina. Alle Rechte vorbehalten.