Can a mobile phone be used as a pedometer in an outpatient cardiac rehabilitation program?

Our aim is to evaluate the use of a mobile phone as a step counter in cardiovascular disease patients, to measure daily walking activity through the course of an outpatient cardiac rehabilitation program. A conventional Omron pedometer (HJ-7201TE) and a mobile phone inbuilt step counter (Nokia StepCounter Beta V0.26) were used in the study. Firstly, we conducted a laboratory trial with 11 normal healthy subjects to investigate the performance of the two devices over different step rates during walking. Secondly, we collected and analysed 141 daily step count records from 18 patients wearing the two devices during a clinical trial. The laboratory study revealed that both devices maintain an accuracy of less than 2% error rate within step rates of between 85 and 125 steps/min but tend to degrade outside this step rate range. During the clinical trial, patients carried the mobile phone as well as the Omron pedometer in a free living environment. The results of this study showed that despite the underperformance of these devices during the slow walk, the reliability of the mobile phone ((error 10%+/-30%) was better than the Omron pedometer (20.5%+/30% error) and accounted reliable assessment of 84% of the patients. This demonstrates the feasibility of using the inbuilt step counter as an integral solution of the mobile phone for delivery an ICT-based home care CR program.