Neurostimulation System (neurostimulation + system)

Distribution by Scientific Domains


Selected Abstracts


Neurostimulation systems for deep brain stimulation: In vitro evaluation of magnetic resonance imaging,related heating at 1.5 tesla

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2002
Ali R. Rezai MD
Abstract Purpose To assess magnetic resonance imaging (MRI)-related heating for a neurostimulation system (Activaź Tremor Control System, Medtronic, Minneapolis, MN) used for chronic deep brain stimulation (DBS). Materials and Methods Different configurations were evaluated for bilateral neurostimulators (Soletraź Model 7426), extensions, and leads to assess worst-case and clinically relevant positioning scenarios. In vitro testing was performed using a 1.5-T/64-MHz MR system and a gel-filled phantom designed to approximate the head and upper torso of a human subject. MRI was conducted using the transmit/receive body and transmit/receive head radio frequency (RF) coils. Various levels of RF energy were applied with the transmit/receive body (whole-body averaged specific absorption rate (SAR); range, 0.98,3.90 W/kg) and transmit/receive head (whole-body averaged SAR; range, 0.07,0.24 W/kg) coils. A fluoroptic thermometry system was used to record temperatures at multiple locations before (1 minute) and during (15 minutes) MRI. Results Using the body RF coil, the highest temperature changes ranged from 2.5°,25.3° C. Using the head RF coil, the highest temperature changes ranged from 2.3°,7.1° C.Thus, these findings indicated that substantial heating occurs under certain conditions, while others produce relatively minor, physiologically inconsequential temperature increases. Conclusion The temperature increases were dependent on the type of RF coil, level of SAR used, and how the lead wires were positioned. Notably, the use of clinically relevant positioning techniques for the neurostimulation system and low SARs commonly used for imaging the brain generated little heating. Based on this information, MR safety guidelines are provided. These observations are restricted to the tested neurostimulation system. J. Magn. Reson. Imaging 2002;15:241,250. © 2002 Wiley-Liss, Inc. [source]


Intraoperative Assessment of an Implantable Electrode Array for Cavernous Nerve Stimulation

THE JOURNAL OF SEXUAL MEDICINE, Issue 8 2008
Arthur L. Burnett
ABSTRACT Introduction., Erectile dysfunction remains a major functional complication of radical prostatectomy in the modern era despite surgical techniques to preserve the penile autonomic nerve supply. Aim., To develop and evaluate a neurostimulation system for cavernous nerve electrical stimulation for future use as a chronic implantation device that neurotrophically promotes erectile function recovery following radical prostatectomy. Method., After radical retropubic prostatectomy, the neurovascular bundle was stimulated using a temporarily placed electrode array of an implantable neurostimulation system (20 Hz frequency, 260 ” seconds pulse width, 5 mA,60 mA amplitude up to 10 minutes), and penile circumference increases were measured. Main Outcome Measure., Increase in penile circumference. Results., Among 12 men (mean age 60.3 years) enrolled in this study, 6 (50%) demonstrated measurable increases in penile circumference in response to cavernous nerve stimulation. Among these six men, the mean increase was 5.0 mm (range 1.6 mm to 7.0 mm). Temporary surgical placement of the device was done with relative ease, and there was no evidence of injury to the neurovascular bundle. Conclusions., A chronic implantable nerve stimulation system for cavernous nerve stimulation having possible neuromodulatory effects on the recovery of penile erections after radical prostatectomy is feasible. Burnett AL, Teloken PE, Briganti A, Whitehurst T, and Montorsi F. Intraoperative assessment of an implantable electrode array for cavernous nerve stimulation. J Sex Med 2008;5:1949,1954. [source]