Limitless possibilities ahead for defibrillators

From wearable defibrillators to AI-powered devices, the defibrillator technology has come a long way in improving the survival rate of individuals suffering from cardiac arrest.

Even with improvements in cardiovascular disease prevention and treatment, sudden cardiac death (SCD) continues to be a major cause of death. Although the prognosis following sudden cardiac arrest (SCA) varies considerably and is largely dependent on the underlying cause as well as the speed and effectiveness of resuscitation, the prognosis for the majority of patients remains poor. Recent advancements in cardiovascular electronics have, however, completely changed how patients with heart failure with low ejection fraction are treated. Every few years, new device generations are introduced, with the hope that they will improve patient management and outcomes while still being affordable. These devices are incrementally improved in terms of performance and safety. As a result, today’s defibrillator devices are quite different from the pioneering but often bulky devices of the late 20th century.

Defibrillators have significantly improved over time, becoming more efficient and user-friendly. In this article, some of the most recent developments in defibrillator technology will be covered, along with how they are enhancing patient outcomes.

Technology trends
AEDs. Automated external defibrillators (AEDs) are portable devices that are designed for use by laypersons, with minimal training. In the past, using an AED was a complex process, requiring extensive knowledge of defibrillation. However, recent advancements in AED technology have made the devices much more user-friendly, with automated voice instructions guiding the user through the process. The new AEDs are also smaller and more lightweight, making them easier to carry and store.

Maintenance is a significant challenge in both public and private access to AEDs. Without regular maintenance, including testing, software updates, and replacement of components like electrode pads and batteries, an AED may not work properly in an emergency. It is the responsibility of the staff and owners to keep the AED in good condition.

A new technology that could address this challenge is the single-use, multi-shock AED. This type of AED would only be used once before being recycled, eliminating the need for maintenance. In the past, this option was too expensive, but now MedTech companies are making progress in creating affordable single-use AEDs that are easy to maintain. Every improvement in AED accessibility increases the chances of saving lives.

The user interface and instructions for AEDs have remained largely unchanged despite the advancements in technology. AEDs are designed for anyone, including children, to use in an emergency, but there is room for improvement. The integration of cutting-edge technology into AEDs, such as connecting to emergency services and GPS, could empower individuals to save lives more effectively. An AED that provides accurate information and answers, while a patient is being treated, would give bystanders more confidence to act in any situation.

ICDs. One of the major advancements in defibrillator technology is the development of wearable defibrillators. These devices, also known as implantable cardioverter defibrillators (ICDs), are small, battery-powered devices that are implanted under the skin and continuously monitor the heart’s rhythm. If a life-threatening arrhythmia is detected, the ICD delivers a shock to restore a normal rhythm. This type of defibrillator has been proven to significantly increase the survival rate of individuals suffering from cardiac arrest, and it is recommended for individuals at high risk of sudden cardiac death.

Recent advancements in implantable defibrillator technology have resulted in devices that are smaller and more compact, making the procedure less invasive and reducing the recovery time for patients.

Newer-generation ICD and CRT-D devices incorporate algorithms promising fewer inappropriate shocks, more efficient CRT delivery with personalized programming, greater longevity, more reliable and less energy consuming remote capability, and more patient and carer involvement in their therapy and disease management. The availability and daily utility of these features is likely to vary across manufacturers, patients, and healthcare environments, and will need to be monitored through clinical studies, but each comes with the potential of improved outcomes and greater efficiency at a particularly demanding time in healthcare. Awareness of the increasing variety of options is essential to personalize the device prescription to the patient.

There have been several new device introductions to the market in the past couple of years. The biggest trends in ICDs have been smaller devices, simplified implantation, reducing or eliminating leads implanted in the veins or the heart, and a movement toward MRI-conditional labeling.

S-ICD. Subcutaneous ICD (S-ICD). It is well known that one of the major drawbacks of the ICD is the presence of an endovenous lead, with a subsequent risk of fracture, or a potential risk for infection. When indicated, the extraction of endovenous leads is associated with a significant risk of morbidity, and even mortality. To overcome these difficulties, an entirely subcutaneous ICD (S-ICD) has been designed. These devices have the advantages to avoid any risk of device-related endocarditis, and all the problems inherent to the presence of an endovenous lead. The main disadvantage is the current impossibility to deliver anti-tachycardia-pacing (ATP) and long-term conventional pacing. Nevertheless, these systems will be coupled with leadless pacemakers in the near future to overcome this specific, but important, issue.

Smart defibrillators. Smart defibrillators are devices that are equipped with advanced technology, allowing them to communicate with other medical devices and provide real-time data to healthcare providers. This information can be used to monitor the patient’s condition and make more informed treatment decisions. Additionally, smart defibrillators can also be connected to remote monitoring systems, allowing healthcare providers to monitor the patient’s condition even when they are not in the hospital.

In addition, these smart defibrillators are integrating smart sensors. These sensors allow the device to automatically diagnose the cause of the cardiac arrest and determine the appropriate therapy. This helps ensure that the patient receives the correct treatment, leading to improved outcomes. Additionally, smart sensors also allow the defibrillator to provide real-time feedback to the user, ensuring that the device is used correctly and effectively.

Improved electrodes. One of the most significant advancements in defibrillator technology has been the improvement of defibrillation electrodes. In the past, defibrillation electrodes were large and often caused skin irritation. However, recent advancements have resulted in electrodes that are smaller, more comfortable to use, and less likely to cause skin irritation. These improved electrodes also have a longer shelf life, reducing the need for frequent replacement.

Advanced batteries. Another important advancement in defibrillator technology has been the development of advanced batteries. Battery longevity has long been an issue with ICDs. As patients live longer, they may need to undergo surgical procedures every few years for regular battery replacements. Increased device longevity can reduce the risk of infection and other complications due to repeat replacement procedures, and help minimize out-of-pocket patient expenses for avoidable replacement procedures. In the past, defibrillators were powered by bulky lead-acid batteries that had a limited lifespan. However, recent advancements in battery technology have resulted in lighter, more compact, and longer-lasting batteries that are better suited for use in defibrillators.

Artificial intelligence. The use of artificial intelligence (AI) in defibrillator technology has also made significant strides. AI-powered defibrillators can analyze the patient’s heart rhythm in real time and provide accurate information to the user. This technology allows the device to make more informed decisions, such as adjusting the energy of the shock to ensure the best possible outcome. Moreover, AI can also be used to diagnose the causes of heart attacks, classify heart rhythms without interrupting cardiopulmonary resuscitation (CPR), and predict the success of defibrillation.

While the success rate has improved, concerns around cost and high processing power remain a challenge.

How machine learning is implemented in medical applications has evolved over recent years. Currently, supervised machine learning models are still necessary for defibrillator applications. Deep learning replicates the brain’s neural networks with artificial neural networks (ANN), which contain layers of nodes that process input data.

AI can be leveraged for standard ECG analysis. Convolutional neural networks (CNNs) are a sub-category of ANN, which uses high-level features from the raw data. This method has been used in medical imaging and ECG analysis but can also be used to evaluate multiple dimensions in data sets. In one model, ECG interpretation by CNN was more accurate than by human cardiologists, but automated ECG analysis is still not used extensively.

Smart watches, like the Apple Watch, and other wearable technology has become more widely used, especially with the capability to conduct automated single-lead ECGs to detect atrial fibrillation.

In one study, the Kardia Band (KB) algorithm, used in Apple watches, was not as accurate as clinicians’ diagnosis. The algorithm was not able to interpret more than half the ECG and KB recordings. Physician oversight is still necessary for the most accurate diagnosis.

In addition, AI can be used as a screen for early pulmonary hypertension and asymptomatic left ventricular dysfunction. Mayo Clinic used data from almost 45,000 patients to teach a CNN to identify asymptomatic left ventricular dysfunction. The results were promising, showing a positive AI screen predicted a four times greater risk of developing ventricular dysfunction than the patients who did not use the screen.

AI can also evaluate when to stop CPR and optimize shock delivery. It can also reduce the number of unnecessary shocks, which will improve the patient’s quality of life. Future plans include creating a robust dataset of ECGs for building and testing algorithms to compare technologies.

Wireless connectivity. One of the important advancements in defibrillator technology is the use of wireless connectivity. Wireless connectivity allows defibrillators to communicate with other medical devices, such as heart monitors and pacemakers, and transfer important patient data in real time. This allows healthcare providers to monitor the patient’s condition remotely, reducing the risk of complications and improving patient outcomes. Additionally, wireless connectivity also enables defibrillators to be remotely programmed and updated, making it easier for healthcare providers to ensure that their patients receive the best possible care.

Outlook
In conclusion, recent advancements in defibrillator technology have led to more effective and user-friendly devices. From wearable defibrillators to AI-powered devices, the technology has come a long way in improving the survival rate of individuals suffering from cardiac arrest. The continued evolution of defibrillator technology will likely lead to even more advanced and effective devices in the future, helping to save countless lives. Imagination of researchers and device companies seems to be limitless.