Trends in Cardiac Pacemaker Batteries

Batteries used in Implantable cardiac pacemakers-present unique challenges to their developers and manufacturers in terms of high levels of safety and reliability. In addition, the batteries must have longevity to avoid frequent replacements. Technological advances in leads/electrodes have reduced energy requirements by two orders of magnitude. Micro-electronics advances sharply reduce internal current drain concurrently decreasing size and increasing functionality, reliability, and longevity. It is reported that about 600,000 pacemakers are implanted each year worldwide and the total number of people with various types of implanted pacemaker has already crossed 3 million. A cardiac pacemaker uses half of its battery power for cardiac stimulation and the other half for housekeeping tasks such as monitoring and data logging. The first implanted cardiac pacemaker used nickel-cadmium rechargeable battery, later on zinc-mercury battery was developed and used which lasted for over 2 years. Lithium iodine battery invented and used by Wilson Greatbatch and his team in 1972 made the real impact to implantable cardiac pacemakers. This battery lasts for about 10 years and even today is the power source for many manufacturers of cardiac pacemakers. This paper briefly reviews various developments of battery technologies since the inception of cardiac pacemaker and presents the alternative to lithium iodine battery for the near future

Magnetic Resonance Imaging in patients with ICDs and Pacemakers

Magnetic resonance (MR) imaging has unparalleled soft-tissue imaging capabilities. The presence of devices such as pacemakers and implantable cardioverter/defibrillators (ICDs), however, is historically considered a contraindication to MR imaging. These devices are now smaller, with less magnetic material and improved electromagnetic interference protection. This review summarizes the potential hazards of the device-MR environment interaction, and presents updated information regarding in-vivo and in-vitro experiments. Recent reports on patients with implantable pacemakers and ICDs who underwent MR scan shows that under certain conditions patients with these implanted systems may benefit from this imaging modality. The data presented suggests that certain modern pacemaker and ICD systems may indeed be MR safe. This may have major clinical implications on current imaging practice

Epithermal Neutron Beam Interference with Cardiac Pacemakers

Peer reviewe

Refurbishing Pacemakers: A Viable Approach

Cardiologists implant permanent pacemakers widely for indications like sick sinus syndrome and complete heart block. The guidelines for such implantations are well established1. However, in developing countries like India, all patients who need pacemakers do not receive them because of financial constraints. Even when such patients get a pacemaker, it is often a more affordable VVI pacemaker rather than the costly DDD pacemaker. The lack of a health insurance scheme and improper social support programs prevent the more widespread implantation of appropriate pacemakers. However, in the developed countries and in affluent pockets of developing countries like India, the pacemaker implantation rates are quite high. Often permanent pacemakers are implanted in the very old and people with predicted brief longevities, due to medico-legal and other social reasons. There are quite a few instances when pacemakers are explanted within a year or even within a few months. This is often due to the unfortunate death of the patient due to unrelated causes. Such pacemakers have battery lives, which are near normal. These can be explanted from the dead patient after taking consent from the relatives and “refurbished” for use in another needy patient. Refurbishing involves proper re-sterilization, checking of battery life, pacing mode and other parameters and re-labelling with the current parameters including predicted battery life. These refurbished pacemakers are a suitable alternative for the financially ‘no option’ group of patients who otherwise would not afford a pacemaker. These can last nearly as long as the original pacemakers. Even pulse generators whose shelf lives have expired can also be resterilised and used gainfully for the economically deprived

Irradiation treatment of laryngeal cancer in a patient with an implantable cardioverter-defibrillator (ICD)

Background: Due to an aging population the incidence of both cardiac and tumor-related illnesses is increasing. A problem may arise if radiotherapy is necessary in close anatomic proximity to an implantable cardioverter-defibrillator (ICD). These highly precise devices may respond to ionizing radiation with a loss of function or uncontrolled stimulation, with both effects being potentially life threatening. Available guidelines recommend the dose maximum to a pacemaker to be cumulative below 2 Gy. For most patients undergoing radiation therapy of the neck or of the chest this limit is exceeded, thus making a removal of the device and an implantation of an external ICD necessary. Case Report: A patient with severe cardiac problems underwent an implantation of an ICD. However, a recurrence of a laryngeal cancer was diagnosed. The irradiation dose after resection was 60 Gy to the tumor region and 50 Gy to the lymph nodes. Irradiation peakload to the ICD was calculated to be 2.5 Gy. This dose was verified with thermoluminescence measurements. The ICD was externally deactivated during the sessions of irradiation. Device checks demonstrated no malfunction. Conclusion: Even though the dose limits of the ICD of 2 Gy were exceeded, the device demonstrated a regular function during and after radiotherapy

Effects of hearing aid programming equipment and assistive listening devices on implantable cardiac devices

This study examines the potential for electromagnetic interference from the use of neck-worn hearing aid programming equipment and assistive listening devices to affect cardiac pacemakers and defibrillators

Is 35 U.S.C. § 271(F) Keeping Pace With The Times?: The Law After the Federal Circuit’s Cardiac Pacemakers Decision

In a common business arrangement, an American software company designs software in the United States, then sends the software code abroad where copies are mass-produced and distributed. Prior to the Federal Circuit’s ruling in Cardiac Pacemakers, Inc. v. St. Jude Medical, Inc., the American company could have been found liable for patent infringement under Section 271(f) of the Patent Act if the software mass-produced abroad infringed a United States patent.Cardiac Pacemakers, however, leaves United States patent owners defenseless when the allegedly infringed patent claims are method claims. The background of Cardiac Pacemakers, the Court’s rationales, and the implications of the decision are the subject of this Note

Discussion of Difference Equation Model of Ventricular Parasystole as an Interaction Between Cardiac Pacemakers Based on the Phase Response Curve

24 pages, 1 article*Discussion of Difference Equation Model of Ventricular Parasystole as an Interaction Between Cardiac Pacemakers Based on the Phase Response Curve* (Leslie, Nandi Olive; Villegas, Miriam Araceli Nuno; Del Castillo, Alicia Yvonne Simms) 24 page