One lead data logger system on heart signal

The heart is a primary organ inside the human body. Therefore, it is necessary to take care of their health. One way to find out his health is by monitoring the heart itself. In monitoring the heart, it is very necessary to store monitoring results to facilitate the medical team or doctors in conducting patient examinations. Therefore, a research was conducted to design or create a heart signal data logger system as a modification of an electrocardiograph commonly known as a holter monitor. From the results of measuring the amplitude of the R wave height on the holter monitor and the original ECG with phantom input, the average relative error is 3.67% and the length of the R to R distance is -23.8%. Then from the results of measuring the amplitude of the R wave height on the Holter monitor and the original ECG with the same input from the same patient in four different positions. The lying position has a relative error value of -73,3%, sitting position -53.8%, standing position -45.2%, and walking position -56.6%. Whilst, for the length of the distance from R to R, the lying position has a relative error value of 10.3%, the sitting position is 33.3%, the standing position is -10%, and the walking position is 29.4%.