Think it is hard these days to create an implantable medical device? Try having the FDA tell you that microcontrollers are verboten, or sorting through capacitors that only work 40% of the time, or asking Honeywell if it might shrink one of its high-performance rocket batteries.

That is exactly what Mir Imran went through in the early 1980s as he worked on what became the first implantable cardioverter-defibrillator, or ICD.

Imran, who has a master's degree in biomedical engineering from Rutgers University, left after three years of medical school to work on the pioneering device with what was then Intec Systems--later acquired by Eli Lilly, spun out as Guidant and eventually acquired again as Boston Scientific.

The work involved a team that also included Stephen Heilman, Alois Langer, Jack Lattuca, Morton Mower, and Michel Mirowski.

Imran acknowledges device designers also had some advantages in the early 1980s, especially because the FDA at the time gave developers more leeway in designing cutting edge technologies.

And yet Imran and his colleagues faced design challenges that seem mind-boggling today. Imran recalled that when he was a child in India, an uncle would visit in a Model-T Ford, and Imran would have to help crank the car so his uncle could leave.

"The defibrillator story I'm telling you is like the Model-T hand-crank starter," says Imran, who is presently founder, CEO, and chairman of San Jose, CA-based InCube Labs.

Here are three lessons Imran learned from the experience:

1. If you hit a roadblock, drive around it.

Imran and his colleagues faced plenty of challenges to engineer around. For example, the FDA at the time had never approved a software-operated implantable device.

"They thought it would be dangerous. They thought there would be no way to test the reliability of the code," Imran says.

The first-generation implant, then, was engineered to be almost completely analog. "We had a very simple, analog telemetry system," Imran says.

They even had to develop an analog custom chip where they scaled the geometry of CMOS transistors to get low-noise ultra-low-power amplifiers for the ICD detection circuit.

"That was another first, using implantable CMOS in defibrillators," Imran says.

The first-generation device also used a 360-volt capacitor from a photoflash. "That was the highest voltage capacitor that was available," Imran says.

Because they were commercial grade, they employed quality control checks that weeded out 60% of the capacitors in the process. "We developed new tests to find leakage of currents and how they formed," Imran says.

2. Never give up on what you are passionate about.

There were plenty of huge challenges. But Imran suspects it was the team's passion for the project that kept them going.

"I think what was driving us was the importance of this potential new therapy, that it could become a life saving therapy for millions of people. And it has," Imran says.

"We had that recognition back then. That's what drove us to extreme efforts to develop it and put it in human patients."

The group's passion likely helped talk other companies into helping with the project.

For example, they needed a battery with a 1 amp current. The only battery available was one Honeywell produced for guided missiles. It was a size of a Coke can, and Imran and team had to persuade Honeywell to produce a battery that was half an inch thick.

Stack two on top of each other, and it was a 1-inch-thick battery going into a device the size of a king-sized pack of cigarettes implanted in the abdomen, with leads strung up to the heart.

3. Don't worry about whether it's possible until it's too late.

Imran acknowledges that the design team may have not even pursued an implantable ICD had they known the numerous challenges they would face.

"We also didn't know we couldn't do it. We didn't know it couldn't get done. We thought we could solve any problem," Imran says.

As is often the case in massive endeavors, the team only realized the huge scale of the obstacles until they were in the thick of the project.

"You are already up to your eyeballs in it, so you have to take it to the end," Imran says.

Imran suspects not giving up can also be a failing. "But it's also what allows me to go after big problems that would take a long time to solve or bring to market."

Chris Newmarker is senior editor of MPMN and Qmed. Follow him on Twitter at @newmarker.