Asthma Controller App for Northwestern Medicine: Capmedic BLE, Spirometry Guidance, and Zone-Based Lung Monitoring

The Challenge: Clinical-Grade IoT Software for a Major US Health Institution, Built at Startup Speed

Building a Bluetooth Low Energy connected asthma controller app for clinical deployment at a major US healthcare institution required the reliability and UX standards of a patient-facing medical tool, delivered in two months. The Asthma Controller Android tablet app had to integrate with the Capmedic device over BLE, provide clear inhaler usage instructions, guide patients through spirometry testing, display lung function test results, and present zone-based health status indicators (Red for danger, Yellow for caution, Green for stable) to patients across a wide range of ages and technical comfort levels. The complete Android tablet app was built from scratch in two months, for a consultant developing the product for Northwestern Medicine, targeting 100,000 potential patients.

What AppMatic Tech Engineered for the Northwestern Medicine Asthma Controller

AppMatic Tech delivered the full Android tablet app from scratch in two months: Capmedic BLE device integration, inhaler instruction flows, spirometry guidance, lung function testing, zone-based health monitoring, adherence tracking, and clinical API sync.

Inhaler Usage Instructions

AppMatic Tech built the step-by-step inhaler instruction module within the Asthma Controller Android tablet app, guiding patients through the correct technique for using the Capmedic inhaler device. Instruction screens were designed for clinical clarity, with large text, simple iconography, and step confirmation, to be usable by patients across all age groups including those with limited digital experience.

Spirometry Guidance

AppMatic Tech implemented the spirometry guidance module, walking patients through how to correctly perform a spirometry test using the Capmedic device. The module covers patient positioning, breathing technique, test initiation, and result capture, ensuring consistent spirometry execution that meets the data quality standard required for clinical lung function assessment.

Lung Function Test

AppMatic Tech built the lung function testing feature, the primary clinical measurement captured by the Capmedic device, presenting test results to patients in a clear, accessible format alongside historical trend data. Lung function test results feed directly into the zone indicator system and sync to the clinical API for provider review.

Zone-Based Health Monitoring (Red, Yellow, Green)

AppMatic Tech implemented the zone-based health status indicator system: Red (danger), Yellow (caution), and Green (stable). Zone status is calculated from the patient's lung function test results and displayed prominently on the app dashboard so patients can immediately understand their current health status without interpreting raw clinical numbers. Zone thresholds were defined by the clinical team and configured via the admin layer.

Capmedic BLE Device Integration

AppMatic Tech implemented the device integration layer connecting the Android tablet app to the Capmedic asthma controller over Bluetooth Low Energy, handling device discovery, pairing, inhaler event data reception, and reliable logging of each usage event. Every medication event captured by the Capmedic device was accurately synced to the patient's adherence record without data loss.

Clinical API Sync and Adherence Tracking

AppMatic Tech integrated the clinical API to sync patient lung function results, zone status history, and inhaler adherence data with Northwestern Medicine's systems, enabling healthcare providers to access patient data alongside other clinical records. Adherence tracking presented usage frequency and zone trend data to patients within the app.

Asthma Controller Project Outcomes

Asthma Controller Tech Stack

Kotlin

Native Android tablet development

Android

Primary app platform

Firebase

Push notifications and adherence reminders

BLE

Capmedic BLE

Bluetooth Low Energy device integration

API

Healthcare API

Clinical data sync and provider records

Mobile-Layer Security on the Asthma Controller

• BLE Session Isolation

  AppMatic Tech implemented BLE session scoping ensuring each inhaler usage and lung function test session was bound to the authenticated patient's device pairing. The Capmedic BLE connection could not log events or zone data to an unverified or cross-patient session.

• Token-Based Session Management

  Patient authentication used token-based sessions ensuring adherence records, lung function history, and zone status data were scoped to the verified patient account only, with session termination enforced after inactivity.

• API Credential Handling

  Backend API credentials used for clinical data sync were not stored in the Android app binary. API calls used authenticated request headers managed at the session layer with no hardcoded credentials in source.

• Minimal On-Device Health Data Storage

  AppMatic Tech implemented the Android tablet app to minimise on-device health data persistence. Lung function results and zone history were synced to the backend immediately and only cached locally where required for offline resilience.

• Push Notification Scoping

  Medication reminder and zone alert push notifications were scoped to the device registered to the authenticated patient account, ensuring alerts were not delivered to unintended devices in a shared clinical or household environment.