I bought an Apple Watch six months ago. This was no casual purchase. As an Apple fan, a watch collector and with more than 20 years of experience in the design innovation space, I had extremely high expectations of the purchase. While I have enjoyed the stylish Apple Watch’s features and functions, I have occasionally felt frustrated with the overall experience, for two, admittedly personal, reasons.

First, the Apple Watch won’t continuously monitor my heart rate. Because of a history of heart disease in my family, I keep a close eye on my health. Tracking my heart rate over the course of days and weeks would provide me with beneficial longitudinal data. The Apple Watch is designed to measure a user’s heart rate whenever the Workout App is launched, but otherwise won’t record it when one moves, which is exactly when I want to measure it (I realize this saves battery life, but I’d be happy to recharge throughout the day to have this functionality).

Second, it’s hard to fit the Apple Watch into my aesthetic life. As a guy who has collected watches for more than 20 years, I was disappointed that wearing my Apple Watch meant not wearing my other timepieces. I’ve tried to wear both the Apple Watch and a watch from my collection simultaneously, one on each wrist, but it was uncomfortable…and I felt like a tech nerd (no offense to tech nerds — I am one, but sometimes I try to hide it).

So I saw this as an interesting design challenge, similar to the kind I frequently face in my day-to-day work. This time, however, I was both the designer and the consumer. Could I find a way to wear the Apple Watch daily, gather continuous heart rate information and still wear my other watches? I’ve had significant experience designing both medical devices and consumer products, so I was hoping to employ this knowledge in creating my solution.

My first thought: The body of the Apple Watch can be separated from its band. That might be the kernel of a solution. This watch body “engine” module could potentially be relocated on the body without the use of the watchbands.

Next came a four-step design process:

Step 1: Determine if the Apple Watch’s heart rate monitor would work when worn on other parts of the body. I created a series of quick hack models to see what would happen if I wore the watch on my ankle, shoulder, forearm and abdomen while running. The Apple Watch successfully monitored my heart rate when worn on my ankle, shoulder and forearm — but not my abdomen. This is likely because Apple’s photoplethysmography process relies on reading the flow of blood, and there is insufficient “visible” blood flow around the abdomen.

Step 2: Figure out where on my body to wear the watch engine. I quickly saw that there weren’t many options…especially because I wanted to be able to view the watch screen at all times. My ankle and shoulder had inherent visibility — and screen-access challenges. I settled on my upper forearm. In this location, I could wear the watch engine discretely, underneath a long-sleeved shirt. It would be invisible with sleeves rolled down, yet accessible when needed.

Step 3: Devise a process for attaching the Apple Watch to the forearm. There was no easy way to attach it to my forearm. The Apple Watch bands weren’t long enough to encircle the forearm, and even if they were, the screen was improperly oriented for viewing. This meant that the Apple Watch band connection points probably couldn’t be used to hold it to the forearm.

Step 4: Prototype. Knowing that the Apple Watch body module would effectively read my heart rate on my forearm, I began creating wearable prototypes that would hold the watch to my forearm. In the end, I built four prototypes.

First prototype: clear patch

A skin-safe clear adhesive leveraged from medical products (Tegaderm) covers the watch body. The advantages are that it’s easy to apply and it holds well to the arm. The disadvantages are that the adhesive looks creepy on the skin and the Apple Watch screen is a little hard to see through the adhesive.

Second prototype: frame and band

The watch body is held under clear film pocket in a plastic frame and a flexible fabric strap is added to secure the watch body to the forearm. The strap worked well and the watch body can easily be inserted and removed, but it looks over-designed and bulky on the arm.

Third prototype: case and band

A clear watch body case is attached to a flexible strap (brought forward from the second prototype). The Apple Watch snaps into the case and it holds the watch body in the proper orientation. This provides a more traditional look — like a smartphone-holding exercise strap — and it’s comfortable and easy/quick to put on and take off. However, this configuration limits use to only the forearm (and maybe ankle); ideally I’d like a solution I could wear on other parts of my body.

Fourth prototype: adhesive patch

A clear watch body case is attached to a flexible fabric patch. A medical skin-safe adhesive (from the first prototype) is applied to the underside of the patch. The watch body snaps into the clear case. The advantages are that it’s easy to apply, holds well to the arm and can be used in multiple locations on the body. There are no disadvantages.

Working in the design industry, we regularly do what we call Resonance Testing: giving our prototypes to consumers to understand which target attributes resonate with them. This testing process isn’t about finding a statistical winner. Rather, it focuses on concept evolution — carrying forward only the most successful aspects of each idea. Although this test of the Apple Watch engine was an N of 1, I followed a similar approach, evolving each concept and brining the best attributes to the subsequent concepts.

In the end, the fourth prototype, the Apple Patch, most effectively fit my life. What was it about the Apple Patch?

The watch body, which was held in place by a clear plastic case attached to a skin-safe adhesive patch, allowed me to wear it unobtrusively while also wearing one of my favorite watches from my collection. It also allowed the flexibility to wear it in different locations on my body. The patch could also be customized with various colors and patterns. So this redesign allowed the Apple Watch to continuously feed me information about my heart rate, just as I desired. In fact, I’m rolling up my sleeve and looking down at my Apple Watch as I type this, and can report that my heart rate is 58.

The Apple Watch hack provided two good lessons:

Prototype to learn. Although experiential prototyping and testing is core to any designer’s approach, I was excited by how quickly I was able to evolve and improve the design by creating informal testing models. It made me further appreciate the importance of this agile-like approach to innovation and failing forward fast.

Every innovation can be customized and improved. Consumers have unique needs and companies should support and encourage customization in the products and services they create. As the maker movement and at-home 3D printing grows, it will be even more important to empower consumers to be part of the design and innovation process.