Pulse generator

AccessScience ◽  
2015 ◽  
Keyword(s):  
Pulse Generator

Implanted vagus nerve stimulation in 126 patients: surgical technique and complications

2020 ◽  
Vol 99 (7) ◽  
Keyword(s):  
Vagus Nerve ◽  
Vocal Cord ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Pulse Generator ◽  
Operative Procedure ◽  
Intractable Epilepsy ◽  
Vagal Nerve ◽  
University Hospital ◽  
Nerve Stimulator

Introduction: Vagus nerve stimulation is a palliative treatment for patients with refractory epilepsy to reduce the frequency and intensity of seizures. A bipolar helical electrode is placed around the left vagus nerve at the cervical level and is connected to the pulse generator placed in a subcutaneous pocket, most commonly in the subclavian region. Methods: Between March 1998 and October 2019, we performed 196 procedures related to the vagal nerve stimulation at the Neurosurgery Department in Motol University Hospital. Of these, 126 patients were vagal nerve stimulator implantation surgeries for intractable epilepsy. The cases included 69 female and 57 male patients with mean age at the time of the implantation surgery 22±12.4 years (range 2.1−58.4 years). Results: Nine patients (7.1%) were afflicted by complications related to implantation. Surgical complications included postoperative infection in 1.6%, VNS-associated arrhythmias in 1.6%, jugular vein bleeding in 0.8% and vocal cord paresis in 2.4%. One patient with vocal cord palsy also suffered from severe dysphagia. One patient (0.8%) did not tolerate extra stimulation with magnet due to a prolonged spasm in his throat. The extra added benefit of vagus stimulation in one patient was a significant reduction of previously regular severe headaches. Conclusion: Vagus nerve stimulation is an appropriate treatment for patients with drug-resistant epilepsy who are not candidates for focal resective surgery. Implantation of the vagus nerve stimulator is a relatively safe operative procedure.

Androgenic and oestrogenic steroid participation in feedback control of luteinizing hormone secretion in male sheep

1983 ◽  
Vol 102 (4) ◽  
pp. 499-504 ◽  
Author(s):  
M. J. D'Occhio ◽  
B. D. Schanbacher ◽  
J. E. Kinder
Keyword(s):  
Luteinizing Hormone ◽  
Pulse Generator ◽  
Hormone Secretion ◽  
Pulse Interval ◽  
Serum Concentrations ◽  
Luteinizing Hormone Secretion ◽  
Lh Release ◽  
Lh Secretion ◽  
Additional Feedback ◽  
Male Sheep

Abstract. The acute castrate ram (wether) was used as an experimental model to investigate the site(s) of feedback on luteinizing hormone (LH) by testosterone, dihydrotestosterone and oestradiol. At the time of castration, wethers were implanted subdermally with Silastic capsules containing either crystalline testosterone (three 30 cm capsules), dihydrotestosterone (five 30 cm capsules) or oestradiol (one 6.5 cm capsule). Blood samples were taken at 10 min intervals for 6 h 2 weeks after implantation to determine serum steroid concentrations and to characterize the patterns of LH secretion. Pituitary LH response to exogenous LRH (5 ng/kg body weight) were also determined at the same time. The steroid implants produced serum concentrations of the respective hormones which were either one-third (testosterone) or two-to-four times (dihydrotestosterone, oestradiol) the levels measured in rams at the time of castration. Non-implanted wethers showed rhythmic pulses of LH (pulse interval 40–60 min) and had elevated LH levels (16.1 ± 1.6 ng/ml; mean ± se) 2 weeks after castration. All three steroids suppressed pulsatile LH release and reduced mean LH levels (to below 3 ng/ml) and pituitary LH responses to LRH. Inhibition of pulsatile LH secretion by all three steroids indicated that testosterone as well as its androgenic and oestrogenic metabolites can inhibit the LRH pulse generator in the hypothalamus. Additional feedback on the pituitary was indicated by the dampened LH responses to exogenous LRH.

DESIGN OF HIGH PERFORMANCE PULSE GENERATOR TO PERFORM AUTOMATIC TEST IN VLSI CIRCUITS

2019 ◽  
Vol 9 (3) ◽  
pp. 26
Author(s):  
P. LOKESH ◽  
V. THRIMURTHULU ◽  
PRIYA L. MIHIRA ◽  
◽  
◽  
...  
Keyword(s):  
High Performance ◽  
Pulse Generator ◽  
Vlsi Circuits ◽  
Automatic Test

SELECTION OF THE DRIVE OF THE PULSE GENERATOR FOR WAVE DEFORMATION HARDENING

2020 ◽  
Author(s):  
Andrey Kirichek ◽  
Dmitriy Solovyev
Keyword(s):  
Strain Hardening ◽  
Pulse Generator ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Impact Frequency ◽  
Metal Consumption ◽  
Pulse Generators ◽  
Energy Impact ◽  
Deformation Hardening ◽  
Selection Of

The article is devoted to the analysis of known structures of impact devices used in industry in order to obtain recommendations for their adaptation or when creating new structures for wave strain hardening by surface plastic deformation. The analysis was carried out on the used drive and on the main parameters of impact devices: impact energy, impact frequency, relative metal consumption and efficiency. The options are the best combinations of parameters for electric, pneumatic and hydraulic drives. Recommendations are given on the use of such devices, with appropriate adaptation, as pulse generators for wave strain hardening.

Reoperation for device infection and erosion following deep brain stimulation implantable pulse generator placement

2020 ◽  
Vol 133 (2) ◽  
pp. 403-410 ◽  
Author(s):  
Travis J. Atchley ◽  
Nicholas M. B. Laskay ◽  
Brandon A. Sherrod ◽  
A. K. M. Fazlur Rahman ◽  
Harrison C. Walker ◽  
...  
Keyword(s):  
Risk Factors ◽  
Logistic Regression ◽  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Movement Disorders ◽  
Pulse Generator ◽  
Rank Test ◽  
Implantable Pulse Generator ◽  
Device Infection ◽  
Deep Brain

OBJECTIVEInfection and erosion following implantable pulse generator (IPG) placement are associated with morbidity and cost for patients with deep brain stimulation (DBS) systems. Here, the authors provide a detailed characterization of infection and erosion events in a large cohort that underwent DBS surgery for movement disorders.METHODSThe authors retrospectively reviewed consecutive IPG placements and replacements in patients who had undergone DBS surgery for movement disorders at the University of Alabama at Birmingham between 2013 and 2016. IPG procedures occurring before 2013 in these patients were also captured. Descriptive statistics, survival analyses, and logistic regression were performed using generalized linear mixed effects models to examine risk factors for the primary outcomes of interest: infection within 1 year or erosion within 2 years of IPG placement.RESULTSIn the study period, 384 patients underwent a total of 995 IPG procedures (46.4% were initial placements) and had a median follow-up of 2.9 years. Reoperation for infection occurred after 27 procedures (2.7%) in 21 patients (5.5%). No difference in the infection rate was observed for initial placement versus replacement (p = 0.838). Reoperation for erosion occurred after 16 procedures (1.6%) in 15 patients (3.9%). Median time to reoperation for infection and erosion was 51 days (IQR 24–129 days) and 149 days (IQR 112–285 days), respectively. Four patients with infection (19.0%) developed a second infection requiring a same-side reoperation, two of whom developed a third infection. Intraoperative vancomycin powder was used in 158 cases (15.9%) and did not decrease the infection risk (infected: 3.2% with vancomycin vs 2.6% without, p = 0.922, log-rank test). On logistic regression, a previous infection increased the risk for infection (OR 35.0, 95% CI 7.9–156.2, p < 0.0001) and a lower patient BMI was a risk factor for erosion (BMI ≤ 24 kg/m2: OR 3.1, 95% CI 1.1–8.6, p = 0.03).CONCLUSIONSIPG-related infection and erosion following DBS surgery are uncommon but clinically significant events. Their respective timelines and risk factors suggest different etiologies and thus different potential corrective procedures.

scholarly journals Effect of defibrillation on the performance of an implantable vagus nerve stimulation system

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Imad Libbus ◽  
Scott R. Stubbs ◽  
Scott T. Mazar ◽  
Scott Mindrebo ◽  
Bruce H. KenKnight ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Function ◽  
Vagus Nerve ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Pulse Generator ◽  
High Energy ◽  
Implantable Pulse Generator ◽  
Defibrillation Pulse ◽  
Stimulation System

Abstract Background Vagus Nerve Stimulation (VNS) delivers Autonomic Regulation Therapy (ART) for heart failure (HF), and has been associated with improvement in cardiac function and heart failure symptoms. VNS is delivered using an implantable pulse generator (IPG) and lead with electrodes placed around the cervical vagus nerve. Because HF patients may receive concomitant cardiac defibrillation therapy, testing was conducted to determine the effect of defibrillation (DF) on the VNS system. Methods DF testing was conducted on three ART IPGs (LivaNova USA, Inc.) according to international standard ISO14708-1, which evaluated whether DF had any permanent effects on the system. Each IPG was connected to a defibrillation pulse generator and subjected to a series of high-energy pulses. Results The specified series of pulses were successfully delivered to each of the three devices. All three IPGs passed factory electrical tests, and interrogation confirmed that software and data were unchanged from the pre-programmed values. No shifts in parameters or failures were observed. Conclusions Implantable VNS systems were tested for immunity to defibrillation, and were found to be unaffected by a series of high-energy defibrillation pulses. These results suggest that this VNS system can be used safely and continue to function after patients have been defibrillated.

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