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Introduction
Active implantable medical devices (AIMDs) are medical devices that are implanted inside the body and are battery powered or have an active element such as a microchip to perform specific therapeutic and diagnostic functions. They are an integral part of modern medicine and have helped improve the quality of life for millions of people worldwide.
Cardiac devices
One of the most common types of AIMDs are cardiac devices like pacemakers and implantable cardioverter defibrillators (ICDs). These devices are implanted in patients with significant heart rhythm problems or cardiac arrest to help regulate heartbeat and treat lethal arrhythmias.
Pacemakers are small battery-powered devices implanted under the skin in the chest area and are connected to the heart with insulated wires called leads. They help regulate heartbeat by sending electrical impulses to the heart muscles if the heart’s natural pacemaker, the sinoatrial node, does not coordinate the heart’s contraction properly. Modern pacemakers can sense body activity and adjust pacing rate accordingly. Over 5 million pacemakers have been implanted worldwide since the first implantation in 1958.
ICDs are more sophisticated devices designed to detect life-threatening arrhythmias like ventricular fibrillation and deliver an electric shock to restore normal heart rhythm. In addition to pacing functions, ICDs can terminate an arrhythmia by delivering one or more shocks. They have saved millions of lives from sudden cardiac arrest. However, ICD shocks can be unpleasant for patients if delivered inappropriately.
Neurological devices
AIMDs are also commonly used in the field of neurology to treat neurological diseases and disorders. Deep brain stimulation (DBS) devices help treat movement disorders like Parkinson’s disease by delivering electrical pulses to specific brain areas. Over 150,000 patients worldwide have benefited from DBS therapy for Parkinson’s disease and related tremors.
Vagus nerve stimulation devices are implanted near the neck region and stimulate the vagus nerve to help control seizures in refractory epilepsy. Cochlear implants restore partial hearing in patients with severe to profound hearing loss by bypassing damaged cochlear hair cells and stimulating auditory nerves directly.
Spinal cord stimulators deliver mild electrical pulses to the spinal column for effective relief from chronic pain in conditions like failed back surgery syndrome. Transcutaneous electrical nerve stimulation devices are externally worn and provide pain relief through electrical stimulation of nerve fibers.
Insulin pumps and glucose monitors
For patients with diabetes, insulin pumps and continuous glucose monitoring (CGM) systems are common AIMDs. Insulin pumps are small programmable devices attached to the body with an infusion set and catheter to continuously deliver calculated doses of rapid acting insulin just under the skin. They provide better glycemic control than multiple daily injections.
CGM systems constantly monitor interstitial fluid glucose levels and alert users to highs and lows through a transmitter and receiver device. Integrated insulin pump-CGM systems deliver automatic corrections via insulin pumps based on real-time glucose trends. These closed loop “artificial pancreas” devices significantly improve diabetes management.
Other applications
Many other medical conditions are also treated with AIMDs. Middle ear implants help restore hearing for conductive and mixed hearing losses. Bone conduction devices transmit sound through vibrations picked up by cheekbones for patients with outer and middle ear disorders.
Cochlear nucleus implants bypass damaged inner ear areas and directly stimulate the cochlear nucleus region of the brainstem to provide hearing. Auditory brainstem implants are used for neurofibromatosis type 2 patients who cannot benefit from cochlear implants.
Sensors and stimulators are being developed to treat obesity by electrical stimulation of gastrointestinal tract nerves. Pacemakers are also used in treatment of gastroparesis by electrical pacing of stomach muscles. Cardiac resynchronization devices treat heart failure by resynchronizing lower chambers of heart through biventricular pacing.
Advancements
Advancements in electronics, biocompatible materials, battery technologies, and sensing/telemetry capabilities continue to drive innovation in AIMDs. Future pacemakers may automatically regulate heart rate based on physical activity and metabolic demand. DBS devices may help treat neurological conditions beyond movement disorders like epilepsy, obsessive compulsive disorder and depression.
Implantable biosensors may provide real-time physiological monitoring of multiple biomarkers to diagnose and manage chronic diseases better. Wireless power transfer and rechargeable batteries may replace conventional primary batteries in many AIMDs. Targeted drug delivery using implantable micropumps activated by AIMDs holds promise in novel therapies. Application of AIMDs will surely widen as technology evolution opens up more possibilities to alleviate human suffering.
Conclusion
AIMDs have revolutionized management of many previously debilitating or fatal medical conditions. Despite the high costs involved, they provide significant clinical benefits, improve quality of life and reduce healthcare costs in the long run. However, long-term safety, biocompatibility and reliability are key challenges faced by these devices. Continued advances coupled with stringent safety standards will help unlock the full potential of implantable medical technology in addressing unmet healthcare needs globally.
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- Source: Coherent Market Insights, Public sources, Desk research
- We have leveraged AI tools to mine information and compile it
