# A smart diaper sensor that tells care staff when it is time to change.

> Wear & Care makes a connected diaper sensor for care homes. The sensor detects when a diaper needs changing and notifies care staff on their phone, so residents are changed when they need it, not on a fixed round.

- URL: https://bon.do/en/work/wear-and-care
- Client: Wear & Care
- Sector: Elderly care and medical IoT
- Platforms: Sensor, web, iOS and Android
- Role: Full build
- Outcome: Live in Danish care homes, with the carer app in the App Store and Google Play.
- Tags: Apps, IoT, MedTech

## Overview

Wear & Care makes a connected diaper sensor for care homes. The sensor detects when a diaper needs changing and notifies care staff on their phone, so residents are changed when they need it, not on a fixed round.

A care home at 3 a.m. is the real test environment. The alert has to reach the right carer, on the right shift, without adding noise. The platform also has to fit the municipality’s identity system and the care home’s existing workflows.

We built the sensor ingress, .NET 10 backend, Angular portal and Flutter carer app as one system. The backend uses PostgreSQL, Wolverine, Redis, Azure Service Bus and NATS JetStream, and runs in Kubernetes. We integrated KOMBIT and NemLog-in/MitID through Keycloak, with role-based access scoped to the care home. Alerts go out by push, SMS and SignalR, and every event is logged.

The platform is live in Danish care homes, with the carer app in the App Store and Google Play. The sensor data, resident, room and shift stay connected, and the ward overview gives staff one place to see who needs attention.

## Results

- **Scope:** 3 layers. Sensor software, cloud backend and carer app, one team.
- **.NET projects:** 7 services. API, worker, ingress, data, clients, auth and view rendering.
- **Automated tests:** 3,200 lines. Added in one September 2026 hardening sprint.

## At a glance

- **Client:** Wear & Care
- **Product:** Smart diaper sensor for care homes
- **Users:** Care staff · care home managers
- **Our role:** Design, backend and frontend
- **Type:** Medical IoT device
- **Stack:** .NET 10 · PostgreSQL · Angular · Flutter · Kubernetes · Keycloak
- **Timeline:** Ongoing product partnership

## What we built

### 01. Device software

Telemetry, battery, pairing and offline behaviour, with a config channel back to the device.

### 02. Cloud backend

Links each sensor to a resident and room, routes alerts to the right shift, and keeps a log of every change.

### 03. Carer app

A ward overview and alerts designed for a busy shift, readable at a glance, at night, with one hand.

## How it ran

### 01. Discover: A night on the ward

How care staff actually work, and what an alert must, and must not, do.

### 02. Design: Flows tested with carers

Prototypes of the ward overview and alerts, tested with care staff.

### 03. Build: Sensor, cloud and app together

Working increments every two weeks, end to end.

### 04. Launch: Live in care homes

Rollout, monitoring and support under a clear agreement.

> Bon.do assisted us all the way from design to finished backend and frontend of a new medical IoT device. They understand both MDR and GDPR as well as hardware interaction.
>
> Jesper Jarmann, CEO, Wear & Care

## Contact

Bon.do ApS · Rantzausmindevej 228, 5700 Svendborg, Denmark · info@bon.do · https://bon.do/en/contact-us