Personal Health Device Implementation Guide 0.3.0 - STU 1 (2nd ballot)

Personal Health Device Implementation Guide, published by Health Level Seven International (Health Care Devices Work Group). This is not an authorized publication; it is the continuous build for version 0.3.0). This version is based on the current content of https://github.com/HL7/PHD/ and changes regularly. See the Directory of published versions

Non 11073 20601 Devices

Not all Continua PHDs are based upon the 11073-20601 standard. Continua also supports Bluetooth Low Energy devices that follow the various Bluetooth Low Energy health device profiles and services. However, Continua requires that the information provided by the device can be mapped to 11073 20601 MDS and Metric objects by the PHG as specified in the transcoding white paper (the various versions can be found here) if the measurements are going to be propagated downstream by Continua transactions. The requirement does not mandate that the PHG actually create these objects, but the resulting downstream messages have to be composed as if they had come from a compliant 11073 20601 device supporting the same type of measurement.

The transcoding requirements put further demands on the Bluetooth Low Energy device over and above that specified in the Bluetooth Low Energy health profile specifications. For example, the Bluetooth Low Energy Health Thermometer Profile does not require that a thermometer is able to report its sense of current time even if it reports time stamps in the measurements. Continua requires that all measurements that have time stamps also be able to report their sense of current time. The reason is that PHDs often have unreliable time clocks that the PHG can correct if the PHG is able to obtain the PHD’s sense of current time.

Bluetooth Low Energy devices use an exchange protocol that is not generically extensible. Special implementation code is needed for every health device profile and service. The non-generic extensibility means that PHDs supporting a new Bluetooth Low Energy health device specification will not interoperate with any PHGs that do not have pre-coded knowledge of that new health device specification. The future interoperability designed into this guide will not work for Bluetooth Low Energy devices.

In addition to Continua Bluetooth Low Energy PHDs, there are numerous proprietary medical devices on the market. It may be possible to map the measurements coming from these devices to the PHD profiles, but that mapping would require that the resulting downstream resources be created and populated as if they had come from a compliant 11073 20601 device. The writers of this guide have performed this task for a number of proprietary Serial Port Protocol (SPP) and Bluetooth Low Energy devices.

In this Implementation Guide, the PHD is treated as a 11073 20601 compliant device. When working with other device types, it is the responsibility of the FHIR encoder to ‘virtually’ map the data from the non-11073 20601 device to the 11073 20601 model before generating the PHD FHIR resources.

In general, if a PHD provides timestamps with its measurements, it needs to provide a means for the PHG to get its sense of current time. If it does, one can likely use this implementation guide with that device.