Load Modulation For Leadless Pacemaker Synchronization In A Dual Chamber Pacemaker System

Abstract

Leadless Pacemakers are a new generation of pacemakers, providing therapy for patients with bradyarrhythmias. Studies are performed to extend the existing single chamber pacing to dual chamber pacing system. For such a system, the implanted leadless pacemakers should be synchronized to provide atrium and ventricular co-ordination. Given size constraints from the first commercial products, the signal transmission efficiency has been investigated for varying distances between the two devices. The two devices are coupled thanks to electromagnetic inductive resonance. The energy consumed for providing synchronization is evaluated and is compared to available device battery capacity (220mAh), in order to test feasibility and estimate longevity. Device longevity plots for both simulation and experimental studies, for varying distances are analyzed, it is found that predicted longevity is less than 20 days (experimental study) for distances greater than 3mm.In this paper, electromagnetic resonance coupled load modulation technique is considered for providing synchronization and is tested for feasibility in simulation and experimental studies. In general, the results indicate that the load modulation technique is feasible to provide synchronization in between leadless pacemakers for small distances (< 15mm) with a decrease in system longevity. Keywords -Leadless pacemaker synchronization, inductive communication, load modulation in the leadless pacemaker, bio-circuits and systemI.

Potentiality of magnetoelectric composites for Wireless Power Transmission in medical implants

“…In this paper, two systems are considered and compared. The first one (Fig 1.A) is based on a near field transmission technique, which can be used for energy delivery [7] and for communications [10]. It consists on the wireless interaction between two coils connected to resonant circuits, the receiver (Rx) and the transmitter (Tx) units.…”

“…The maximum of the efficiency is shown when the two coils are coaxial and at close distance (few cm of distance) [11]; so it could be problematic employing this technology to charge/communicate with movable implants, i.e. leadless pacemaker [10].…”

Patient Specific Strategies to Enhance Leadless Pacemaker Lifetime in Synchronized Dual Chamber System

“…The feasibility analysis of using an RF technology for providing synchronization has been verified in our previous work [10]. Load modulation and Human Body Communication (HBC) are the other possible technologies that could be used for providing synchronization [9], [13]. In this paper, a low power off-shelf RF transceiver circuit, which satisfies leadless pacemaker space constraint, operating in the ISM band 915MHz range is considered [14].…”

“…The steady state or stationary state occupancy vector is given by Eq. (13). The average pacing error is given by the product of steady-state occupancy and average pacing error associated with the state, as shown in Eq.…”

“…In the case of patients with bradyarrhythmia's, atrium and the ventricular chambers experience change in rhythm and are missing to contract at coordinated time instants. The dual-chamber leadless pacemaker systems are being utilized to regulate the rhythm, and it is available in different pacing configurations [4], [9], [13]. The pacing configuration has several pacing modes, but DDD mode is considered to mimic the heart best than other modes [21].…”