How would you build a monitoring device for elderly people?

In this question, the interviewer is interested in understanding your design thinking process, practical capabilities, and how aware you are about the needs of a unique user group (the elderly). To answer it, you need to:

1. Identify and clearly define the problem you are trying to solve.
2. Understand the unique needs and limitations associated with the elderly.
3. Conceptualize a product that fits their needs while solving the problem.
4. Think about the practicality of building the device considering factors like materials, technology, cost, safety, and approval processes.
5. Discuss how you would include the elderly or their caretakers in the design process, to ensure the solution meets their needs.

You should provide a clear, step-by-step plan, detailing each stage of the process, from conceptualization to the final product.

Problem identification: The key problem to solve is ensuring the safety and well-being of the elderly, as they are often prone to medical emergencies, falls or forgetting to take medications.

User analysis: Elderly people may have limited mobility, poor eyesight, and hearing, or forgetfulness. Therefore, the device needs to be user-friendly, accessible, visually clear, has audible alerts, and non-intrusive.

Design: Considering these factors, I would propose a wearable device, lightweight, with a simple interface. The device would have sensors to detect falls or abnormal heart rates, a medication reminder system, and a panic button to alert emergency contacts or medical services.

Practical considerations: The device would utilise technologies like GPS for location tracking, accelerometer for fall detection, and connectivity options for emergency alert transmission. For material, I'd choose lightweight, hypoallergenic materials to make it comfortable and safe.

Inclusion in design: Finally, it's important that we include the elderly or their caretakers in the design and testing process to ensure it meets their needs and is comfortable and easy to use.

To address the problem of monitoring elderly people, I would design an in-home system instead of a wearable device.

Defining users: Elderly people living alone, or with limited support, may need a comprehensive monitoring system rather than a wearable device they might forget to wear.

Design: The system would include sensors placed throughout the home to detect excessive periods of inactivity or falls, cameras to allow remote visual check-ins if consent is provided, and a speaker system for easy two-way communication.

Practical considerations: Technologies like motion detection sensors, video cameras, microphones, and speakers would be included. The system would require a robust data backend to analyze and predict potentially dangerous situations based on motion tracking.

User involvement: The elderly or their caregivers should be involved in the design process to determine locations for sensor placements, privacy concerns with cameras, and the practicability of speaker-based communication. Also, they should find the setup non-invasive and comfortable to live with.

In both examples, the goal is to design a system that respects elderly users' autonomy and privacy while ensuring their safety and well-being. It's also vital to utilize robust technologies that can be relied upon in any emergency.