Designing an IoT-Based Cardiac Arrest Monitoring System

Role

Product &
UX Designer

Duration

5 Months

Scope

UX Research
Product Design
Interaction Design
Hardware-Integrated UX

*The initial IoT prototype was developed and published as a research project.

*The product redesign was completed independently to explore how such a system could work in real-world use.

Open booklet showing line drawings of the clip-on cardiac monitor and its parts

As cardiac monitoring systems increasingly rely on smartphones and smartwatches, they remain inaccessible to many elderly users especially in low-access environments where digital literacy is limited.

After developing an IoT prototype and publishing our research, I designed the product experience that makes the system usable for real-time cardiac monitoring transforming it into a standalone wearable built around simplicity, familiarity, and reliable emergency response.

Research → Published system

Published in IEEE, validating real-time cardiac detection

Read full IEEE paper

IEEE publication validating system architecture and detection model

Tablet showing the published IEEE paper on IoT cardiac arrest monitoring
System architecture diagram: heart rate sensor, amplifier and buzzer connect to a microcontroller with battery, GPS and an MQTT app

A system-level architecture showing how sensor data flows through detection and emergency response.

Hardware Prototype

A functional prototype used to validate sensor behavior and real-time detection.

Prototype LCD showing pulse and BPM readings Breadboard prototype with sensor, microcontroller and wiring

Adapted from my IEEE publication to illustrate system design and implementation

While technically sound, the system’s reliance on a smartwatch limited accessibility and real-world usability.

The Problem

Who is affected

Older adults at high risk of cardiac arrest who need reliable, continuous monitoring while traveling or living in remote areas.

What isn’t working

The monitoring system was built as a rough prototype and relied on a smartwatch for real‑time data collection and alerts.

Why that’s a problem

Elderly users often avoid complex technology; they do not consistently wear or manage smartwatches and are unfamiliar with them, leading to missed data and alerts and making the system unusable in real‑world use.

Design considerations

Design Goal:

Encourage consistent use
by leveraging existing habits.

Design Feature:

Device clips on to user’s watch and builds on watch wearing habit.

Design Goal:

Aesthetically appealing and always ready to operate.

Design Feature:

Non-intrusive design fits into watch strap of user’s preference.

Efficient wireless charging ensures consistent readiness.

Design Goal:

Reliable early detection of cardiac arrest.

Design Feature:

Reliable IOT sensors combined with Fourier transform and machine learning technologies.

Design Goal:

Family and emergency responders.

Design Feature:

Immediate notification when cardiac malfunction detected.

Design Goal:

Easy location of user during emergency.

Design Feature:

Notification through mobile phone.

GPS tracking with mapping.

"Send Help" option, prompting nearby emergency services for a rapid response.

Design Goal:

Bystanders - Clear notification to prompt action.

Design Feature:

Loud built-in buzzer to attract attention.

Voice notification that the wearer is suffering a cardiac arrest.

Voice instruction to please call an ambulance.

Insight

Less screen.
More familiarity.

Elderly users avoid complex technology.

Design must fit into existing habits, not introduce new ones.

Storyboard

  1. 1. The clip-on monitor charges on its case by the bed
  2. 2. The user clips the module onto their watch strap
  3. 3. The module sits on the wrist like a normal watch
  4. 4. The user goes about the day, riding a scooter
  5. 5. The device detects a cardiac event and sounds its alarm
  6. 6. A bystander hears the voice alert: Oh my! He needs help!
  7. 7. A family member receives the alert on their phone
  8. 8. The phone shows an emergency screen with location and a Send help button
  9. 9. An ambulance is dispatched to the location
  10. 10. The user recovers in hospital with family

Design direction: Screenless interaction

Product idea

Creating a mesh watch strap with the cardiac arrest monitoring system.

Clip-on mesh
designed to fit
any strap

Line drawings of the clip-on mesh in three views
Line drawings of the clip-on module on the mesh strap

Clip-on module
seamlessly integrated
into the mesh strap

Watch with the module attached, components numbered 1 to 6
Exploded view of the module, strap and charging case

Components:

  1. Micro Controller
  2. Heart Rate Sensor
  3. GPS
  4. Buzzer
  5. Button to control the buzzer
  6. Battery
Line drawings of the separate charging case from several angles

Simplifying Charging:

Early designs integrated charging into the strap, but this added bulk and complexity. I redesigned it as a separate, intuitive charging case that prioritizes simplicity and comfort.

Building on this concept, the final system integrates these ideas into a cohesive, real-world solution.

Proposed Solution

A screenless, wearable system designed to fit into existing habits while enabling reliable real-time cardiac monitoring.

The solution combines a familiar watch form, embedded sensors, and a simple alert system to ensure accessibility, comfort, and timely response.

Core Features

  1. Screenless interaction for ease of use

  2. Continuous monitoring through integrated sensors

  3. Immediate alerts via buzzer and voice guidance

  4. GPS-enabled emergency response system

Sketches of the final wearable in round and square watch styles

Impact

By removing complexity and designing around familiarity, the system improves accessibility and ensures critical health monitoring is usable in real-world conditions.