Medical software development

Rationale

The SmarTest® series is a product family of Immundiagnostik AG in conjunction with Preventis GmbH. It defines the next generation of point-of-care diagnostics. The focus is on delivering quantitative lab-comparable results. Besides the fact that delivering quantitative results has the edge for long-term health monitoring in comparison with semi-quantitative and qualitative, digitising rapid tests also offers new possibilities for integrations, telemedicine and analytics. With a keen eye for the ease of use, an implemented well-thought-through user guidance enables lay users to perform such tests at home and let their therapy adjusted remotely.

Image of different lateral flow test cassettes

Challenges

First and most importantly, we were in need of establishing a consistent user-flow from the process of setting up the app over test execution guidance to the final result interpretation.
Second, as the software in combination with the hardware needs to be certified as medical product (IVDD/IVDR) and we were going to reuse modular components in every app, a modular documentation had to be created accordingly.
Finally, handling different test-cassette types in combination with the dynamic of smartphones due to the fragmentation of the Android market (different configurations) needed to be considered as well.

Implementation

Right from the start we have received one major requirement from our partner, that each medical product as the symbiosis of hardware (a rapid test) and software (our part) should have its own app. Primarily to ease up documentation w.r.t. the intended use.

Hence, our idea was to build modular components which could be used in different apps. Due to the nature of a product family, we ended up implementing feature toggles so that each product is basically the same besides its feature toggles. An advantage is, that every improvement and bug fixes are added to all products using the feature simultaneously. The actual release depends on the internal release cycles as it is a medical product in the end. A disadvantage is for obvious reasons, that if we introduce a bug and it does not get detected early on, it may will be shipped to other apps as well.

Over the course of time and due to the improvements of Kotlin/Native and the engagement of JetBrains, we decided to stick to Kotlin to build cross-platform usable so-called multiplatform frameworks. This helped us to reduce code duplication of business logic and to develop apps even faster and safer. Summarising we separated the business logic from each native app implementation and created small modules which can be used in all the apps of the SmarTest® family and across all platforms.

A second requirement was to build a consistent user-flow in the apps which should support both application types, home-use (by lay-users) as well as prof-use (by medical staff only). So, we came up with an animated guidance for lay-users that can be skipped by professionals. Besides textual components, most of the app remains the same for both groups.

Outcome

The final solution can be imagined as a shell used to instantiate and quickly roll out all kinds of medical apps in this SmarTest® series setting for different parameters/analytes.
Integration of QuantOn Technology® in smartphone apps certified as medical product (IVD) enables real POCT diagnostic with a quantitative value and potential integration of telemedicine.
Exceptional consistent user-flow across all individual products with animated instructions to be provide guidance while performing a rapid test.
Modular apps with easy to enable features (basically by ticking the boxes).
Adaptions to new rapid test types or parameters can be done within a few days.
Technical documentation according to ISO 62304 and ISO 62366 was created and as of today, 10 apps (5 products multiplied with two platforms, Android and iOS) are published as a medical device.