To Recharge or Not To Recharge

Introduction

Implantable medical devices (IMDs) have revolutionized healthcare by providing effective, long-term solutions for various medical conditions. A wide variety of implantable medical devices are used currently to treat a myriad of conditions, all providing a range of benefits from enhanced quality of life and outcomes for patients to effective treatment with far fewer or zero side effects, unlike pharmacological treatments. Deep brain stimulators, for example, can help patients regain mobility and function, improving their overall independence, while implantable cardioverter-defibrillators (ICDs), can deliver life-saving interventions in emergencies. 

Designed to monitor, support, or replace physiological functions, active implantable medical devices (AIMDs) are surgically implanted in the patient's body and depend on an energy source such as a battery and/or external power to run. AIMDs can significantly enhance the quality of life for patients with chronic conditions, for example, pacemakers can regulate heart rhythms, while cochlear implants can restore hearing. But when their batteries run out, patients need an invasive surgery. For active implantable devices that don’t require battery replacement surgeries, like LVADs, power cables that go through the patient's abdomen are used to power the device into the body. These cables cause infections and deaths. Yet battery replacement surgeries also add risk and cost, burdening our healthcare system, care providers, and patients. 

A History of Recharging

To solve these challenges, implantable medical device makers started designing rechargeable implantable medical devices. Rechargeable implantable medical devices have been in development and use for several decades, with notable advancements occurring over time. These include:

Cardiac Pacemakers: Rechargeable cardiac pacemakers started to emerge in the 1970s. The introduction of rechargeable pacemakers extended the lifespan of the device and reduced the need for frequent surgical interventions. However, rechargeable pacemakers never became mainstream and most pacemakers today rely on primary cell batteries that require battery replacement surgeries. Back in 2014, The Atlantic wrote about potential reasons why.

Neurostimulators: Implantable neurostimulators are used for conditions like chronic pain management and deep brain stimulation to restore motor function, manage epilepsy, and more. Most neurostimulators are rechargeable or are available in rechargeable options. Neurostimulators have become more common in recent years, providing longer-lasting, often highly effective therapy and reducing the need for battery replacements. They also provide an alternative to opioids and other pharmacological treatments that come with significant risks and side effects. 

Cochlear Implants: Rechargeable cochlear implants have been developed to enhance the longevity and usability of these devices for individuals with hearing loss. These advancements have helped improve the overall experience for users.

Implantable Defibrillators: Some implantable cardioverter-defibrillators (ICDs) have rechargeable batteries, allowing for extended device life and fewer or no battery replacement surgeries, which improves patient outcomes.

These are just a few examples of rechargeable implantable medical devices. The adoption of rechargeable technology in implantable medical devices has been driven by the desire to reduce the inconvenience and risks associated with battery replacement surgeries and to improve the overall quality of life for patients. And there are other benefits of rechargeable implantable medical devices.

Benefits of Rechargeable Implantable Medical Devices

1. No Battery Replacement Surgeries: Since rechargeable IMDs can last longer, they often require few to no surgical procedures for device replacement. This reduces the risk of complications associated with surgery, improves outcomes for patients, and substantially lowers healthcare costs.

2. Customizable Therapy: Some rechargeable IMDs allow for adjustments in therapy parameters, such as stimulation intensity or drug delivery rates, which can be tailored to the patient's specific needs over time. This, in turn, increases effectiveness and improves patient outcomes. As personalized healthcare and precision science advance, implantable medical devices will have to be rechargeable to support the increased power and energy demands that come with this closed loop mode of operation. Smarter devices that adapt to the patient’s needs rely on continuous wireless power for two-way communication, data transfer, and therapy delivery.

3. Remote Monitoring and Programming: Rechargeable implantable medical devices can support remote monitoring and programming, enabling healthcare providers to make adjustments without requiring in-person visits and enabling patients to receive quality care from their home. This method of remote care delivery is also known as Hospital at Home and has become increasingly popular since the COVID-19 pandemic and due to ever increasing demand on our healthcare system from an aging population. Hospital at Home, and remote monitoring and care delivery more broadly, allow patients to receive acute care from the comfort of their homes, improving patient outcomes, lowering costs, and reducing healthcare system burden.

4. Smaller Devices: Non-rechargeable devices rely on larger batteries to provide the energy needed to run the device. As new devices are introduced targeting previously untreated therapies, including in body locations and types where larger devices couldn’t be implanted previously, rechargeability is required to make the new device – and treatment – possible.

5. Longer Lifespan: Rechargeable implantable medical devices typically have a longer lifespan compared to non-rechargeable devices. They can be recharged multiple times, extending their usability and eliminating the need for device replacement.‍
6. Manufacturing Advantages: Rechargeable medical devices have some manufacturing advantages for medical device companies. Implant batteries can be smaller and in some cases, be removed completely, with continuous wireless power and/or easy recharging. In addition, Resonant Link’s wireless charging systems use the wireless power link and RF or radio frequency to send data and communications between the external hub and implanted medical device, so no Bluetooth antenna is necessary. This makes devices more secure by eliminating Bluetooth pairing issues and risks, and smaller by removing the antenna.

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Benefits of Non-Rechargeable Implantable Medical Devices

Although the vast majority of implantable medical devices would see improved outcomes and be accessible to a larger patient population if they were rechargeable, or offered a rechargeable option, there are use cases in which non-rechargeable implantable medical devices make sense. Non-rechargeable implantable medical devices, also known as primary cell devices or disposable devices, offer some benefits when compared to rechargeable alternatives in specific medical scenarios.

1. Simplicity: Non-rechargeable implantable medical devices can be simpler in design and more notably, simpler in how they’re used. They do not require patients to engage in regular recharging routines or even engage at all for some devices, outside of getting the device setup and replacing it when needed. This can be beneficial for patients who may have difficulty with device management, such as older patients and patients with limited motor function.

2. Lower Initial Cost: Non-rechargeable devices may have a lower upfront cost compared to rechargeable alternatives, which can be financially advantageous for some healthcare systems and patients. However, when the total burden of care is considered, rechargeable devices are actually more economical as they reduce healthcare costs by eliminating surgeries, improving patient outcomes, and making it possible for patients to live with the same device for much longer.

3. Less Frequent Follow-Up: Since non-rechargeable implantable medical devices have a limited lifespan, they may require less frequent follow-up appointments compared to rechargeable devices, reducing the burden on healthcare resources. This problem is solved, however, with care-at-home, also known as Hospital-at-Home, which many now recognize as necessary given the challenges and opportunities of the COVID-19 pandemic.

4. Suitable for Certain Applications: In cases where the expected duration of treatment is relatively short, non-rechargeable devices may be a more practical choice. They can be well-suited for temporary or short-term medical needs. A caution is that bridge treatments whose use is extended for longer and longer periods should be viewed as more permanent than they are at times, such as Left Ventricular Assist Devices, which patients can end up using longer than expected.

To Recharge or Not to Recharge?

The choice between rechargeable and non-rechargeable implantable medical devices depends on the patient's specific needs, medical condition, and preferences, as well as the intended use case for the device. In most cases, not having a rechargeable option limits the quality of care. Patients deserve the choice and with rechargeable devices offering additional capabilities that are simply not possible or practical with non-rechargeable devices, it also makes business sense for medical device makers to invest in rechargeable options. 

Interested in discussing your device? Contact us today to see what’s possible.