Cardiac Implantable Electronic Miniaturized and Micro Devices

Abstract

Advancement in the miniaturization of high-density power sources, electronic circuits, and communication technologies enabled the construction of miniaturized electronic devices, implanted directly in the heart. These include pacing devices to prevent low heart rates or terminate heart rhythm abnormalities (‘arrhythmias’), long-term rhythm monitoring devices for arrhythmia detection in unexplained syncope cases, and heart failure (HF) hemodynamic monitoring devices, enabling the real-time monitoring of cardiac pressures to detect and alert for early fluid overload. These devices were shown to prevent HF hospitalizations and improve HF patients’ life quality. Pacing devices include permanent pacemakers (PPM) that maintain normal heart rates, defibrillators that are capable of fast detection and the termination of life-threatening arrhythmias, and cardiac re-synchronization devices that improve cardiac function and the survival of HF patients. Traditionally, these devices are implanted via the venous system (‘endovascular’) using conductors (‘endovascular leads/electrodes’) that connect the subcutaneous device battery to the appropriate cardiac chamber. These leads are a potential source of multiple problems, including lead-failure and systemic infection resulting from the lifelong exposure of these leads to bacteria within the venous system. One of the important cardiac innovations in the last decade was the development of a leadless PPM functioning without venous leads, thus circumventing most endovascular PPM-related problems. Leadless PPM’s consist of a single device, including a miniaturized power source, electronic chips, and fixating mechanism, directly implanted into the cardiac muscle. Only rare device-related problems and almost no systemic infections occur with these devices. Current leadless PPM’s sense and pace only the ventricle. However, a novel leadless device that is capable of sensing both atrium and ventricle was recently FDA approved and miniaturized devices that are designed to synchronize right and left ventricles, using novel intra-body inner-device communication technologies, are under final experiments. This review will cover these novel implantable miniaturized cardiac devices and the basic algorithms and technologies that underlie their development. Advancement in the miniaturization of high-density power sources, electronic circuits, and communication technologies enabled the construction of miniaturized electronic devices, implanted directly in the heart. These include pacing devices to prevent low heart rates or terminate heart rhythm abnormalities (‘arrhythmias’), long-term rhythm monitoring devices for arrhythmia detection in unexplained syncope cases, and heart failure (HF) hemodynamic monitoring devices, enabling the real-time monitoring of cardiac pressures to detect and alert early fluid overload. These devices were shown to prevent HF hospitalizations and improve HF patients’ life quality. Pacing devices include permanent pacemakers (PPM) that maintain normal heart rates, defibrillators that are capable of fast detection and termination of life-threatening arrhythmias, and cardiac re-synchronization devices that improve cardiac function and survival of HF patients. Traditionally, these devices are implanted via the venous system (‘endovascular’) using conductors (‘endovascular leads/electrodes’) that connect the subcutaneous device battery to the appropriate cardiac chamber. These leads are a potential source of multiple problems, including lead-failure and systemic infection that result from the lifelong exposure of these leads to bacteria within the venous system. The development of a leadless PPM functioning without venous leads was one of the important cardiac innovations in the last decade, thus circumventing most endovascular PPM-related problems. Leadless PPM’s consist of a single device, including a miniaturized power source, electronic chips, and fixating mechanism, implanted directly into the cardiac muscle. Only rare device-related problems and almost no systemic infections occur with these devices. Current leadless PPM’s sense and pace only the ventricle. However, a novel leadless device that is capable of sensing both atrium and ventricle was recently FDA approved and miniaturized devices designed to synchronize right and left ventricles, using novel intra-body inner-device communication technologies, are under final experiments. This review will cover these novel implantable miniaturized cardiac devices and the basic algorithms and technologies that underlie their development.

Rapid safety assessment and mitigation of radiofrequency induced implant heating using small root mean square sensors and the sensor matrix Qs

“…The necessity to get the signal from the tip to the communications chip, typically in the generator housing, would persist, however. This could be achieved by a thin extra lead but more intelligent solutions are conceivable 93 …”

Soft Implantable Bioelectronics

“…Soft cardiac interfacing devices enable both electrophysiological recording and electromechanical treatment in vivo . − Although significant advances have been achieved, their application to actual clinical trials requires further investigation. In particular, unlike brain–machine interfaces, cardiac–machine interfaces require different designs and material selections to meet the requirements of high stretchability and reliable electrical/mechanical performances under large deformations due to the volumetric expansion and shrinkage of the heart .…”

Implant-Associated Infections: A Review of the Safety of Cardiac Implants

“…Such an approach was previously confirmed as an important strategy to prevent cardiac IAIs as evidenced by the results of the Worldwide Randomized Antibiotic Envelope Infection Prevention Trial (WRAP-IT). This trial recommends the use of TYRX, an antibiotic eluting mechanism that releases the antimicrobial agent into the surgical pocket for a minimum of seven days and thereby prevents IAIs among high-risk patients including cancer patients [40] Miniaturized and micro implantable devices used to treat cardiac conditions were noted to substantially minimize the risk of complications and infection-related hospitalizations among patients [5].…”

“…Conversely, an implant may be an electronic device used for the proper functioning of muscles, brain, and heart. Cardiac implants that are frequently used to treat heart patients including cardiac implantable electronic devices (CIED), such as a pacemaker, implantable cardioverter-defibrillator (ICD), implantable cardiac loop recorder, and cardiac resynchronization therapy devices [ 4 , 5 ].…”

“…Miniaturized and micro implantable devices used to treat cardiac conditions were noted to substantially minimize the risk of complications and infection-related hospitalizations among patients [ 5 ].…”