Direct-to-Cloud-Constrained Devices - Detailed Proposal

1. Proposed Work Item: Direct-to-Cloud-Constrained Devices

• Proposal Editor: Michael J. Kirwan
• Proposal Contributors: Tim Frost, Thom Erickson, Horst Merkle, Erik Moll, Jacob Andersen, Barry Reinhold, Michael J. Kirwan
• Profile Editor: Tim Frost
• Profile Contributors: Thom Erickson, Horst Merkle, Tim Frost, Jacob Andersen, Erik Moll, Barry Reinhold, Michael J. Kirwan
• Domain: DEVices

Summary

To simplify and improve the remote patient monitoring user experience, it is desirable to enable medical sensor to communicate directly to a health server in the cloud. The use of a gateway device is not practical in many scenarios. The D2C solution leverages to the maximum extend practical existing industry standards covering cellular Internet of Things communications, IEEE Personal Health Devices, FHIR and transport security. Uniform implementation of these standards are essential to achieve interoperability. A simplified protocol is required to accommodate the compute and power limitations of such sensors. It is envisioned that the actors defined in the POU profile would be employed. However, the transactions would be materially different and therefore warrant a separate Implementation Guide. The COVID-19 pandemic has been the global defining event that has thrust remote patient monitoring into the minds of mainstream users. This IG will enable a collection of companies large and small from all corners of the globe to bring to market the billions of devices that must communicate universally understood health data critical to treating patients of pandemics. IHE Devices Domain expertise is uniquely suited to guide medical device manufacturers and Healthcare & Life Sciences software vendors leverage Patient Generated Health Data that is provided directly from a health sensor to health information system via cellular Internet of Things where WiFi may not be available.

2. The Problem

With WiFi and Bluetooth connectivity the end-user is either restricted to transferring data wherever a hub is located, or would need to carry a hub device wherever they go. Furthermore, pairing and configuration is an additional obstacle. It is desired that medical sensors are small and long-life battery powered - which puts “constraints” on their communication capability, requiring the data communicated to be lightweight to reduce on-time of the device. Therefore it is desired to define a lightweight approach for secure direct data transfer from such a constrained device to cloud.

3. Key Use Case

Sarah has tested positive for Covid-19. While in quarantine, her physician suggests she monitor her temperature and blood saturation. The device provided to Sarah is a wearable sensor(s). Sarah's has no fixed broadband connectivity in her home; however, her wide area connectivity (a.k.a. cellular) is good, which means that her physician can receive and monitor her condition while she is at home without any extra work for Sarah or her physician as long as the devices Sarah is using have connectivity.

Johnny is in the 6th grade and a child with Type 1 diabetes. He is required to monitor his glucose levels continuously. The device provided to Johnny is a wearable continuous glucose monitoring (CGM) sensor. It is not feasible/convenient to expect Johnny to be carrying/managing a secondary hub device with him. The wide area connectivity (a.k.a. cellular) allows Johnny's caregivers (e.g. parents, school nurse) to monitor Johnny's glucose levels and receive alerts (e.g. approaching hypoglycemic events) throughout his school day for fast intervention when needed.

4. Standards & Systems

Mobile Communications

It is intended that the recommended communication protocol and protocol stack, by which DOR communicates with DOC, is applicable for transfer via 3GPP LPWA (Low Power Wide Area) technologies such NB-IoT and eMTC. 3GPP: The 3rd Generation Partnership Project (3GPP) unites [Seven] telecommunications standard development organizations (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC), known as “Organizational Partners” to produce the Reports and Specifications that define 3GPP technologies covering all components of the mobile telecommunications system.

(SDOs). 

NB-IoT: NarrowBand-Internet of Things (NB-IoT) is a technology standardised by 3GPP in their Release 13 specification. NB-IoT is a low power wide area (LPWA) technology which supports IoT through lower device complexity, and providing extended coverage, and long battery life, whilst leveraging a mobile carrier’s licensed spectrum and sites. eMTC: eMTC (enhanced Machine Type Communication) is a technology standardised by 3GPP in their Release 13 specification. eMTC is a low power wide area (LPWA) technology which supports IoT through lower device complexity, providing extended coverage, and long battery life, whilst leveraging a mobile carrier’s licensed spectrum and sites.

Healthcare Interoperability Standards

IEEE 11073-10206 Personal Health Devices - Health informatics - Device interoperability - Personal health device communication -- Domain information model. It is intended to use the information model in this standard as a basis for defining a communication protocol to transfer the healthcare device data extracted from that information model from DOR to DOC. HL7 FHIR: FHIR stands for Fast Healthcare Interoperability Resources. Developed by Health Level Seven International (commonly known as HL7), it's an interoperability specification for the exchange of healthcare information electronically. It is intended for the DOC to translate received healthcare device data into a FHIR Resource.

Transport and Transport Security Standards

In recommending a transport protocol stack over which to carry the healthcare data, at least the following standards will be considered: CoAP (Constrained Application Protocol) as defined in IETF RFC 7252. UDP (User Datagram Protocol) as defined in IETF RFC 768. IPv4 as defined in IETF RFC 791. DTLS (Datagram Transport Layer Security) with version 2 as defined in IETF RFC 6347 OSCORE (Object Security for Constrained RESTful Environments) as defined in IETF RFC 8613.

5. Technical Approach

<This section describes the technical scope of the work and the proposed approach to solve the problems in the Use Cases. The Technical Committee will be responsible for the full design and may choose to take a different approach, but a sample design is a good indication of feasibility. The Technical Committee may revise/expand this section when doing the effort estimation.>

<If any context or "big picture" is needed to understand the transaction, actor and profile discussion below, that can be put here>

<If a phased approach would make sense indicate some logical phases. This may be because standards are evolving, because the problem is too big to solve at once, or because there are unknowns that won’t be resolved soon.>

<The material below also serves as the breakdown of tasks that the technical committee will use to estimate the effort required to design, review and implement the profile. It helps a lot if it is reasonably complete/realistic.>

<READ PROPOSER HOMEWORK IN Proposal Effort Evaluation FOR GUIDANCE ON POPULATING THE FOLLOWING SECTIONS >

Actors

• (NEW) <List possible new actors>
• <List existing actors that may be given requirements in the Profile.>

Transactions

• (NEW) <List possible new transactions (indicating what standards would likely be used for each. Transaction diagrams are very helpful here. Feel free to go into as much detail as seems useful.>
• <List existing transactions that may be used and which might need modification/extension.>

Profile

• <Describe the main new profile chunks that will need to be written.>
• <List existing profiles that may need to be modified.>

Decisions/Topics/Uncertainties

• <List key decisions that will need to be made, open issues, design problems, topics to discuss, and other potential areas of uncertainty>
• <Credibility point: A proposal for a profile with any degree of novelty should have items listed here. If there is nothing here, it is usually a sign that the proposal analysis and discussion has been incomplete.>

6. Support & Resources

<List groups that have expressed support for the proposal and resources that would be available to accomplish the tasks listed above.>

<Identify anyone who has indicated an interest in implementing/prototyping the Profile if it is published this cycle.>

7. Risks

<List real-world practical or political risks that could impede successfully fielding the profile.>

<Technical risks should be noted above under Uncertainties.>

8. Tech Cmte Evaluation

<The technical committee will use this area to record details of the effort estimation, etc.>

Effort Evaluation (as a % of Tech Cmte Bandwidth):

• xx% for MUE
• yy% for MUE + optional

Editor:

TBA

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