Design and In Vivo Test of a Batteryless and Fully Wireless Implantable Asynchronous Pacing System.

Goal: The aim of this study is to develop a novel fully wireless and batteryless technology for cardiac pacing. METHODS: This technology uses radio frequency (RF) energy to power the implanted electrode in the heart. An implantable electrode antenna was designed for 1.2 GHz; then, it was tested in vitro and, subsequently, integrated with the rectifier and pacing circuit to make a complete electrode. The prototype implanted electrode was tested in vivo in an ovine subject, implanting it on the epicardial surface of the left ventricle. The RF energy, however, was transmitted to the implanted electrode using a horn antenna positioned 25 cm above the thorax of the sheep. RESULTS: It was demonstrated that a small implanted electrode can capture and harvest enough safe recommended RF energy to achieve pacing. Electrocardiogram signals were recorded during the experiments, which demonstrated asynchronous pacing achieved at three different rates. CONCLUSION: These results show that the proposed method has a great potential to be used for stimulating the heart and provides pacing, without requiring any leads or batteries. It hence has the advantage of potentially lasting indefinitely and may never require replacement during the life of the patient. SIGNIFICANCE: The proposed method brings forward transformational possibilities in wireless cardiac pacing, and also in powering up the implantable devices.

A comparison of barbed and smooth sutures for ovine cesarean delivery.

OBJECTIVE: To determine the adequacy of barbed and smooth sutures for closing the uterus and fascia in pregnant ewes. METHODS: Nine ewes that underwent cesarean delivery were randomized to each receive 2 different suture materials for both the uterus and the fascia. The sutures used were: barbed poliglecaprone 25, smooth poliglecaprone 25, braided polyglactin 910, and smooth chromic sutures on the uterus; and barbed polydioxanone (PDO), barbed poliglecaprone 25, braided polyglactin 910, and smooth chromic sutures on the fascia. RESULTS: In 4 of the ewes, the fascia suture line failed prematurely, leading to dehiscence prior to planned euthanasia and necropsy. The remaining 5 ewes were euthanized on days 2, 7, or 28. All suture materials (smooth and barbed) were adequate for uterine closures. Barbed PDO, smooth poliglecaprone 25, and braided polyglactin 910 were adequate for fascia closures, whereas both barbed poliglecaprone 25 and smooth chromic resulted in premature suture line ruptures and fascia dehiscence. CONCLUSION: In a small pilot study, absorbable knotless barbed suture was adequate and equivalent to absorbable knotted smooth suture for closing the uterus following ovine cesarean delivery. On the rectus fascia, however, sutures-whether barbed or smooth-with lower tensile strength resulted in fascial dehiscence.

Behavioral management: it's everyone's job.

In this day and age of regulatory demands and with the ever-increasing flow of environmental enhancement data and opinions, it can become very confusing for animal programs to create and maintain a successful behavioral management program. Behavioral management as a concept provides a common ground from which animal facilities may start to build a successful facility behavioral program. In addition, the implementation of a behavioral management program can help to break down barriers between members of the various disciplines within the biomedical community. It is everyone's responsibility and duty to work together with this common goal: to provide the best care and environment we can for the animals in our charge. Working together to improve animal behavior can help us to achieve this goal.