SOME PROBLEMS IN PREVENTING MOTION INTERFERENCES DURING PROLONGED EKG INVESTIGATIONS,

Experiments were performed to investigate the possibilities of using the synchronous cumulation method for isolating EKG recordings from interferences caused by movements of the subject. A specialized medical data-processing computer, the ATAS-401 Nihon Konden Kogyo Co., Ltd., Tokyo, Japan which accomplishes synchronous cumulation was used in the experiments. A schematic diagram showing the connection of the devices used is shown. Use of the synchronous cumulation method greatly improved the structure of EKG curves recorded during various movements of the subject. Results of three cumulated EKG recordings indicated that interferences produced by movements are rarely characterized as a stationary random process. In a majority of cases, the character depends on the time factor. Selection of the number of cumulation cycles is discussed. Successful use of the synchronous cumulation method depends on the periodicity of the cumulated signal. Problems in recording signal changes and a method of automatic regulation are discussed. The synchronous cumulation method with automatic regulation of cumulation time depending on the interference level is now being clinically tested in a new variant of the device for recording oxygen starvation of the human cardiac muscle. Author