Storing Health Data in JPEG: Looking at Exif Area Capacity Limits

Formats for data storage in personal computers vary according to manufacturer and models for personal health-monitoring devices such as blood-pressure and body-composition meters. In contrast, the data format of images from digital cameras is unified into a JPEG format with an Exif area and is already familiar to many users. We have devised a method that can contain health data as a JPEG file. Health data is stored in the Exif area in JPEG in a HL7 format. There is, however, a capacity limit of 64 KB for the Exif area. The aim of this study is to examine how much health data can actually be stored in the Exif area. We found that even with combined data from multiple devices, it was possible to store over a month of health data in a JPEG file, and using multiple JPEG files simply overcomes this limit. We believe that this method will help people to more easily handle health data regardless of the various device modelsthey use.