Indivo iOS FrameworkPascal B PfiffnerKenneth D MandlIntelligent Health LaboratoryChildren's Hospital Informatics ProgramBoston Children's HospitalHarvard Medical School

Writing medical apps

Medical Data

Connecting medical apps

• To some sources you just can’t connect – EHRs

• To other sources you can – but it’s a ton of work

• What we need is low hacktivation energy

➔ Frameworks

IndivoPersonally Controlled Health Record

Indivo PCHR

• Full-featured backend for personally controlled health record (PCHR) data

• App platform with an extensive API

• Comes with a substitutable front end

• Open Source (github.com/chb)

➔ Patient portal for research projects

Why a patient portal?

• Key technology for engaging patients

• Valuable source of data for phenotype and outcomes

• A channel for providing value back to the patient, to facilitate recruitment and retention

• Efficient method for obtaining low-cost, timely data

• A means for patients to manage their own consents for research

Indivo deployments

• Boston Children’s Hospital – genomics research

• CARRAnet – rheumatologic childhood diseases

• Harvard IBD network – intestinal bowel disease

• TuAnalyze – diabetes network

• Wake Forest School of Medicine – DICOM sharing

Why Mobile?

bdconf Dallas, Sep 2012

Mobile

• 35% of Americans have no internet access at home

• hispanic: 49%, blacks: 51%, w/ disabilities: 59%

• 20% have no desktop internet access at all

• hispanic: 32%, blacks: 29%, w/ disabilities: 46%, w/o diploma: 57%

• Mobile internet use: 31% (2009) ➔ 55% (2012)

• 31% of all Americans only or mostly use the internet on their phones

If your services are not available on mobile devices, they

do not existfor those people

“

”Karen McGrane

Writing Indivo Apps

All you need to do is…

• Perform an OAuth handshake

• Determine correct REST paths

• Deserialize incoming XML or JSON

• Correctly serialize outgoing XML or JSON

All you need to do is…

• Perform an OAuth handshake

• Determine correct REST paths

• Deserialize incoming XML or JSON

• Correctly serialize outgoing XML or JSON

lather, rinse, repeat

Goals

1. High quality mobile experience for Indivo users

2. Framework for easier development of patient-facing apps

• Python client: web apps

• iOS framework: iOS (mobile)

iOS framework

• Handles authentication (OAuth)

• Knows where an object comes from (REST paths)

• Knows Indivo objects’ anatomy (XML handling)

AuthenticationOAuth

App Developer

selectRecord:

callback is called and "activeRecord" property is ready

User

Taps a connect button

Selects a record

Logs in

Approves app

Framework

request app starting page

receives callback with record id

requests request token

receives access token

displays HTML in embedded web view

receives verifier

receives request token

asks to authorize the token

requests access token

displays HTML in embedded web view

Indivo X

returns HTML for either login screen or a record list

returns record id upon record selection

returns request token

authorizes app and approves request token

returns access token

app previously authorized?

YESNO

Handling OAuth

• Server call class to encapsulate all requests

• All OAuth signing is done transparently

• Knows when user interaction (login and App approval) is needed and provides a UI

➔ Authentication is handled for you

App flow

[indivo selectRecord:^{ }];

indivo.activeRecord

Object HandlingREST paths & serialization

From schema to Cocoa

• The developer should not have to deal with XML serialization/deserialization

➔ Provide Cocoa classes for all Indivo data models

• We have to write Objective-C classes for all types

• Indivo’s data models can be extended, what about those?

➔ Include a generator that creates Cocoa classes from Indivo’s data models

Self-aware objects

• Document objects know their record

• Records know their server

• Framework knows the object actions

➔ REST methods can be inferred for all tasks

Abstract logic into Cocoa objects

Server Record addDocumentOfClass:

fetchReportsOfClass:

selectRecord:

Docspush:

replace:

archive:

...

Integrating Indivo into Existing AppsPediatric Growth Charts

Example: growth data

Example: growth data

Growth charts app

• Standalone iOS growth charts app

• Built modular with extendability in mind, but started with only a local “data source”

➔ Indivo-enable the app

Integrating Indivo

• Select child ➔ call Indivo’s selectRecord: method

• Create child instance with Indivo demographics

• Convert Indivo vitals into app format data sets

Indivo-enabled (read-only)

Growth charts app

• Add Indivo framework

• 2 lines (+credentials) to setup Indivo server instance

• 9 lines to convert Indivo record to app’s child object

• 21 lines to convert Indivo vitals into app’s measurement set objects

SMARTOutlook

iOS framework

• Released with SMART 0.6

• Write apps that run against EHR data

• Same convenience™ as the Indivo framework

• Sister Android framework in the works

The End

pascal.pfiffner@childrens.harvard.edu

github.com/chb/IndivoFramework-ios