Wireless Pacing Using an Asynchronous Three-Tiered Inductive Power Transfer System

Yousefi

IEEE Trans. Biomed. Eng.

et al. 2020

Self Cite

The elimination of integrated batteries in biomedical implants holds great promise for improving health outcomes in patients with implantable devices. However, despite extensive research in wireless power transfer, achieving efficient power transfer and effective operational range have remained a hindering challenge within anatomical constraints. Objective: We hereby demonstrate an intravascular wireless and batteryless microscale stimulator, designed for (1) low power dissipation via intermittent transmission and (2) reduced fixation mechanical burden via deployment to the anterior cardiac vein (ACV, ~3.8 mm in diameter). Methods: We introduced a unique coil design circumferentially confined to a 3 mm diameter hollow-cylinder that was driven by a novel transmitter-based control architecture with improved power efficiency. Results: We examined wireless capacity using heterogenous bovine tissue, demonstrating >5 V stimulation threshold with up to 20 mm transmitter-receiver displacement and 20 o of misalignment. Feasibility for human use was validated using Finite Element Method (FEM) simulation of the cardiac cycle, guided by pacer phantom-integrated Magnetic Resonance Images (MRI). Conclusion: This system design thus enabled sufficient wireless power transfer in the face of extensive stimulator miniaturization. Significance: Our successful feasibility studies demonstrated the capacity for minimally invasive deployment and low-risk fixation. Index Terms-wireless medical devices, wireless pacemaker, inductive power transfer, implantable medical devices, implantable cardiovascular devices I. INTRODUCTION MPLANTABLE stimulators, including cardiac pacemakers and neuromodulation devices used for spinal cord, deep brain, and peripheral nerve stimulation, demand the use of device leads for the transmission of power from the pulse generator to the stimulation electrodes. Despite their extensive use, implanted leads can result in a variety of medical complications.

Section: Discussionmentioning

confidence: 99%

A Multi-Dimensional Analysis of a Novel Approach for Wireless Stimulation

Yousefi

IEEE Trans. Biomed. Eng.

et al. 2020

Self Cite

“…Because of the suboptimal operational stability and output power, self-powered pacing devices have remained at the investigational stage. Alternatively, wireless power transmission, including magnetic induction, radio frequency (RF), and ultrasound, represents a viable strategy to charge the pacemakers in vivo (16)(17)(18)(19)(20)(21). While the optimal coil design for sufficient power transfer efficiency can be developed for the implantable electronics, open-chest surgery (thoracotomy) is required to implant the bioelectronic patches onto the epicardium (surface of the heart) (22)(23)(24)(25).…”

Section: Introductionmentioning

confidence: 99%

A self-assembled implantable microtubular pacemaker for wireless cardiac electrotherapy

Wang,

Cui,

Abiri

et al. 2023

Sci. Adv.

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The current cardiac pacemakers are battery dependent, and the pacing leads are prone to introduce valve damage and infection, plus a complete pacemaker retrieval is needed for battery replacement. Despite the reported wireless bioelectronics to pace the epicardium, open-chest surgery (thoracotomy) is required to implant the device, and the procedure is invasive, requiring prolonged wound healing and health care burden. We hereby demonstrate a fully biocompatible wireless microelectronics with a self-assembled design that can be rolled into a lightweight microtubular pacemaker for intravascular implantation and pacing. The radio frequency was used to transfer energy to the microtubular pacemaker for electrical stimulation. We show that this pacemaker provides effective pacing to restore cardiac contraction from a nonbeating heart and have the capacity to perform overdrive pacing to augment blood circulation in an anesthetized pig model. Thus, this microtubular pacemaker paves the way for the minimally invasive implantation of leadless and battery-free microelectronics.

ACS Appl. Electron. Mater.

“…According to product specifications and recent studies, leadless pacemakers are expected to have a battery life of 5–12 years, depending on patient needs. − Currently, depleted leadless pacemakers are not extracted and are left implanted in the heart; however, studies have begun to investigate the potential for extraction. − Patients who outlive their first pacemaker require additional implantation surgery, which increases the risks of infections and costs to patients. Numerous solutions have been proposed including wireless recharging, − but the ideal choice is autonomous, self-sustainable powering because it eliminates the need for external power sources and promotes greater patient convenience and mobility. Energy harvesting, which is the capture of ambient energy, has the potential to allow for self-sustainable powering.…”

Section: Introductionmentioning

confidence: 99%

All-Electrospun Piezoelectric Energy Harvesting for Leadless Pacemakers

Closson,

Xu,

Kubiak

et al. 2023

Leadless pacemakers are an emerging implantable medical device technology that improves patient outcomes through miniaturization; however, these devices still need to be replaced due to battery depletion, creating additional risk due to surgery. With energy harvesting, the lifetime of a battery may be extended. Latest research has investigated the use of harvesting devices that replace the bulk of the pacemaker’s inner electronics and battery. Integrating the energy harvesting element with the current leadless pacemaker becomes more challenging due to this factor. Positioning the energy harvesting element on the outer shell of the leadless pacemaker would mitigate interference with the inner electronics and potentially enable a more seamless integration of the device. We hypothesize that a piezoelectric outer layer on an implanted leadless pacemaker can harvest energy from the heart’s motion due to heart tissue contracting around the device during systole. We fabricated an all-electron energy harvesting device with piezoelectric and conductive nanofibers as a coating for a leadless pacemaker. A drop treatment step is investigated for improving material properties and its effect on the energy harvesting output. The final device was characterized in vitro with a custom-built simulated heart contraction test and in vivo with animal studies. This resulted in a highly scalable method to fabricate an energy harvesting device on a leadless pacemaker, as well as a system for evaluating energy harvesting performance from simulated squeezing of heart tissue. We observed a voltage output of up to 60 mVpp (peak-to-peak) in a swine’s heart, and device performance was shown experimentally to be mainly affected by relative motion, such as an increased heart rate and movement within the ventricle. The strategy demonstrated the seamless coupling of a leadless pacemaker with a scalable piezoelectric energy harvesting device and presented a potential solution for powering various implantable medical devices.