Applying Usability Test to Find the Interface Design Principle of HRV Device for Senior Users

Home use medical device industry prospers due to the ageing society. In both physiological and psychological domain, home use medical devices have received much attention in recent years. Seniors usually feel depressed or anxious because of losing health and living abilities. They can use the heart rate variability (HRV) device in analyzing their emotional response, however the interface of commercial HRV devices are not easy for them to operate. Therefore, the usability test of these devices was introduced for the senior users. Five senior user were recruited to conduct usability test of the two commercial HRV devices: ANSWatch (Taiwan Scientific Corp.) and CheckMyHeart Handheld HRV (DailyCare BioMedical Inc.) follow the typical operation task. Then the in-depth interview were conducted to find operational failure factors. All of senior users indicated that the serious failure factors are: “unable to understand English instructions” and “unable to determine the meaning of illustration”. Four of them indicated that the minor ones are: “no appropriate guide”; “text is too small”; and “layout is not appropriate”. Three of them indicated that “illustration surface reflection” is another problem. Therefore, we suggests that the home use HRV device interface design should consider principles such as (1) the language and icon properties, (2) step guides and text properties, (3) consistency of interface configuration, (4) color scheme to improve the operational satisfaction for the senior users.