
It’s been almost a century since the first use of electroencephalography (EEG) to record the electrical activity of the brain, and in that time, the evolution of electronics for monitoring and treating health conditions has been astounding. Today, as much as 10% of the US population relies on implantable medical electronics (IMEs), thanks to huge advances in miniaturisation, battery design and more.
IMEs save lives daily. Millions of people worldwide rely on cardiac pacemakers to deliver electrical pulses to stimulate a regular heartbeat, even as implantable cardioverter-defibrillators are increasingly common too.
But IMEs are not limited to the treatment of cardiac conditions, and are equally popular in young patients as among the elderly. State-of-art technologies that monitor biological signals like pulses or temperature are becoming key pillars of clinical research and personalised healthcare. Wearable glucose monitors revolutionising the treatment of diabetes, and innovative work by the likes of MIT on ingestible sensors to diagnose gastrointestinal diseases, are among many examples here.
“Recent innovations include several breakthroughs that hold great promise for enhancing medical treatments and patient outcomes,” says Dr Thomas Dietrich, CEO at IVAM Microtechnology Network, a trade organisation that has done extensive work on both wearable and hybrid organic electronics. “Closed-loop systems for diabetes management – which integrate continuous glucose monitors with insulin pumps, automate insulin delivery based on real-time glucose readings – provide more precise glucose control.”
Dietrich also points to advances in bioelectronic medicine – using electrical impulses to modulate the body’s nervous system – which has shown promising results in treating rheumatoid arthritis, Crohn’s disease and heart failure, among other conditions. Flexible and stretchable electronics also allow implantable devices to conform more naturally to the body’s tissues, reducing discomfort and improving integration and function.

“Advanced neuroprosthetics, particularly brain-machine interfaces, have seen significant improvements in electrode technology, signal processing algorithms, and wireless communication, providing greater independence for individuals with paralysis or limb loss,” Dietrich adds. “Innovative implantable drug delivery systems, including bioresorbable implants, offer controlled, long-term medication release, improving adherence to treatment regimens.”
One tangible example comes from SetPoint Medical in California, which has been developing a bioelectronic therapy for inflammatory diseases. Its pilot studies have shown positive results in patients with Crohn’s symptoms. The study involved eight patients with severe Crohn’s disease not responsive to tumour necrosis factor (TNF) antagonist drugs, who received an implant in their necks to deliver electrical stimulation to the vagus nerve.
Then there’s the field of optogenetics, which uses light to control cells within living tissue. This has opened up new avenues for the treatment of neurological disorders. Biodegradable electronics, which degrade naturally within the body, address major concerns around device removal and long-term biocompatibility.
1.16m
The number of pacemakers fi tted globally in 2016. The number was estimated to reach 1.43m in 2023.
Statista
Spoilt for choice
With the growing incidence of chronic disease around the globe – dovetailed with rapid technological advancement, increased government funding and improvement in materials science – the possibilities for therapeutic applications seem endless.
Yet if the sector could reach more than $270bn by 2032, it’s in the cardiac arena that IMEs have arguably found their blockbuster application.
“I have been working in this field for 38 years, and the technological developments have been so spectacular I could never have guessed what the future would hold,” says Dr Kenneth Ellenbogen, president of the Heart Rhythm Society and a professor of cardiology at VCU School of Medicine in Richmond, Virginia. “Looking ahead 20 years from now, we might see biological pacemakers, not implantable devices, because there will be some kind of gene that restores heart function.
“For now, there is tremendous development in the technology of placing devices without putting leads in their heart or batteries under the skin,” Ellenbogen continues. “When I started, defibrillators used patches on the heart, but now they can be transvenous or subcutaneous, and they used to last two years, but now can last 15 years because of improvement in battery systems.”
$112.5bn
The amount the market for implantable medical devices exceeded in revenue in 2022.
It is expected to grow at a CAGR of 9% between 2023 and 2032.
Recent clinical trials have demonstrated improvement in the safety and efficacy of cardiac IMEs, including complex stimulation systems, technical improvements in pacemakers, and subcutaneous implantable cardioverter defibrillators (S-ICDs). The mCRM System from Boston Scientific, which is the first modular cardiac rhythm management system and comprises an S-ICD system and a leadless pacemaker, has performed well in trials, with minimal complications and a high rate of communication success between components.
Those results are significant because they indicate a potential upgrade pathway for patients currently using implanted S-ICDs – but who may develop a need for ATP or pacing.
$271.5bn
The amount the market for implantable medical devices could be worth by 2032. Global Market Insights
“There is iterative development, then sometimes there is a big step up in technology, like the move from a defibrillator that has two wires to one with three wires,” is how Ellenbogen puts it. “The third can restore near normal cardiac mechanical function, which means we are not just treating electrical problems in the heart, but also treating congestive heart failure.”
IMEs are equally finding a host of new applications beyond cardiac devices. Wound care, for instance, is highly resource-intensive, with around 6.5 million people in the US living with chronic wounds at any given time, resulting in an estimated annual expenditure of more than $25bn.
Managing slow-healing wounds and associated complications is challenging, time-consuming and expensive, and traditional data collection approaches are often clumsy and inaccurate. Yet new hydrogelbased smart wound dressings are integrating drug delivery and sensing modules for blood pH and glucose, which could accelerate the treatment of cutaneous wounds.
The drive for personalised medicine, the development of new sensors and analytical devices – as well as advances in microtechnology and miniaturisation – all enable IMEs to support longterm medication delivery and organ stimulation. IMEs are equally revolutionising neurology, as deep brain stimulators improve treatment for conditions such as Parkinson’s disease and epilepsy. There are also likely to be huge strides forward in pain management using spinal cord stimulators.
Pushing the envelope
Making IMEs smaller, more flexible, more biocompatible, and more robust has underpinned a tidal wave of innovation – yet implantable devices can still be rigid and bulky, particularly when it comes to power supply systems.
Now, however, an intense focus on this problem is leading to some promising breakthroughs, though the hard road to commercialisation and regulatory approval lie ahead. A key area for innovation involves harvesting energy from the body. Living organisms generate energy in many forms, including chemical energy from the reaction of organic molecules, and mechanical energy from muscle movement. This means internal energy-harvesting devices could hold the key to powering IMEs.
Nanogenerators (NGs) can convert mechanical energy into electrical energy through piezoelectric and triboelectric effects. That’s even as biofuel cells can generate energy from glucose oxidation. With this in mind, at any rate, it makes sense that a team in China recently unveiled a proof-of-concept design for an implantable battery that runs on the body’s oxygen supply. The system uses electrodes made of sodium-based alloy and nanoporous gold – encased in a porous polymer film – which chemically react with oxygen to produce an electrical current.
Dr Yunlong Zhao, an associate professor at the Dyson School of Design Engineering at Imperial College London, as well as a nanoelectronics expert at the National Physics Laboratory, focuses on the development of power units for IMEs. He believes that this is the area from which the next gamechanging technologies will emerge.
”Many devices are still quite large, rigid and need large power units, and with long-term use a device may cause an immune response,” Zhao says. “Also, the body may damage the device through movement, so IMEs need to be stable and safe inside the body. We want to power devices using higher energy sources, which normally means using more active materials or bigger batteries, but we want to reduce battery size.”
Rechargeable implantable devices are very new, but they can recharge through body movement, chemical reactions, or – if the device is very close to the skin and light could penetrate – through wireless power sources. Using the body itself is impressive and innovative, and there are many creative projects under way, including work on an enzyme-based fuel cell. The next step is to convince clinicians that they are stable in the body and not toxic.
Rechargeable batteries would certainly go a long way to addressing challenges around battery size. In practice, however, the development of such components is hampered by high cost, stringent regulations, and the potential incidence of post-procedural complications. IMEs have, in the past, seen a relatively high number of recalls. In 2021, to give one example, the FDA announced that pharma giant Abbott was recalling more than 60,000 pacemakers due to a risk of moisture causing electrical shorts.
32m
The number of Americans (around 10% of the population) that will rely on an implanted medical device during their lifetimes.
American Medical Association
Such setbacks, however, seem to do little to stem the tide of innovation, and the use of nanotechnology and microfabrication will no doubt deliver smaller, more efficient components. In the future, smart and adaptive systems will perhaps become more prevalent, incorporating artificial intelligence and machine learning to analyse physiological data in real time, heralding a new era of personalisation.
$10.13bn
The size the global implantable cardiac rhythm management device market was estimated to be in 2023. It is projected to grow at a CAGR of 6.4% from 2024 to 2030.
Grand View Research
“Improvements in biocompatibility and longevity will be driven by the use of advanced materials, such as silicon carbide and graphene, and the development of self-healing materials that can repair minor damages autonomously,” believes Dietrich.
For Zhao, minimally invasive power sources, energy storage devices, rechargeable batteries, human body energy harvesters, and wireless power transfer hold the key. On all fronts, it seems, potentially game-changing technologies lie just beyond the horizon. The challenge, therefore, is not to drive innovation in IMEs, but to match that innovation to the most important clinical needs.