Precise control of stimulation parameters in low impedance conditions

1965 ◽  
Vol 20 (2) ◽  
pp. 334-338 ◽  
Author(s):  
L. W. Mills ◽  
J. E. Swett
Keyword(s):  
Operational Amplifier ◽  
Pulse Generator ◽  
Impedance Matching ◽  
Stimulus Pulse ◽  
Precise Control ◽  
Dual Channel ◽  
Stimulation Parameters ◽  
Impedance Conditions ◽  
Isolation Transformer ◽  
Deep Brain

A system is described for accurate control of stimulation parameters in conditions where impedances between 100 and 30,000 ohms are encountered across the secondary of a stimulus isolation transformer. The dual-channel stimulator is constructed mainly from Tektronix 160 series pulse and waveform generators. The stimulator was designed primarily for evoked potential studies in the nervous system with peripheral nerve stimulation but will operate equally well with concentric or needle electrodes in deep brain structure, providing that total electrode-tissue impedances are kept within the stipulated limits. The unique feature of the stimulator is embodied in the operational amplifier interposed between the Tektronix stimulus pulse generator and the primary of the isolation transformer. This system is designed to read directly in stimulus intensities relative to any stipulated physiological threshold. Absolute stimulus voltages may be continuously monitored to ± 3% accuracy. The impedance matching characteristics of the described system will permit effective stimulation of excitable tissues while maintaining stimulus control by the operational amplifier settings within ± 1%. The large range of pulse durations, stimulus intensities, and the use of more than one type of stimulus waveform, have been sacrificed in favor of maintaining rigid control over pulse waveforms and amplitudes with passage of large stimulating currents at low intensities. This system comes close to achieving those qualities embodied in the ideal constant voltage stimulator. physiological stimulation; biological stimulator; low impedance stimulation; Tektronix-adapted units for biological stimulation; isolated stimulator; nerve stimulator; physiological threshold stimulator Submitted on July 10, 1964

scholarly journals Neurological Worsening After Implantable Pulse Generator Replacement

2019 ◽  
Vol 46 (5) ◽  
pp. 527-532
Author(s):  
Niraj Kumar ◽  
Aditya Murgai ◽  
Mandar Jog
Keyword(s):  
Pulse Generator ◽  
Retrospective Chart Review ◽  
Electrical Energy ◽  
Therapeutic Interventions ◽  
Pulse Generators ◽  
Dual Channel ◽  
Stimulation Parameters ◽  
A Minor ◽  
Electrophysiological Correlate ◽  
Deep Brain

ABSTRACT:Background:Most of the implantable pulse generators (IPGs) in deep brain stimulation (DBS) used to date are non-rechargeable requiring regular replacements. IPG replacement is a minor surgical procedure, but adverse events including neurological worsening have been reported. In this study, we determine the possibility of neurological worsening after IPG replacement in Parkinson’s disease (PD) cases on chronic DBS therapy (CDT) and its electrophysiological basis along with the therapeutic interventions used to alleviate them.Methods:This study is a retrospective chart review of PD cases on CDT followed at London Movement Disorders Centre from January 2010 to December 2016. Included cases were those who underwent one or more IPG replacement.Results:A total of 45 PD cases on CDT underwent 62 IPG replacements involving 121 channels. Neurological worsening was observed in 16 (35.5%) cases following 17 (27.4%) IPG replacements, all following dual-channel IPG replacements. Tremor (41.2%), speech (35.3%), and gait (23.5%) worsened most commonly. Deviation from the pre-replacement parameters including voltage and impedance resulting in change in total electrical energy delivered (TEED) was the most common electrophysiological correlate, observed in 82.4% (14/17) IPGs having neurological worsening. This included switched laterality in a dual-channel IPG. Neurological worsening in the remaining 17.6% cases was hardware-related.Conclusion:Neurological worsening followed 27.4% of IPG replacements in PD cases on CDT with approximately 82.4% of these being avoidable by carefully monitoring stimulation parameters to match pre-replacement TEED values.

Deep brain stimulation lead-contact heating during 3T MRI: single- versus dual-channel pulse generator configurations

2013 ◽  
Vol 124 (3) ◽  
pp. 166-174 ◽  
Author(s):  
Jules M. Nazzaro ◽  
Joshua A. Klemp ◽  
William M. Brooks ◽  
Galen Cook-Wiens ◽  
Matthew S. Mayo ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Pulse Generator ◽  
3T Mri ◽  
Dual Channel ◽  
Contact Heating ◽  
Single Versus ◽  
Deep Brain

Diplopia associated with loop routing in deep brain stimulation: illustrative case

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Yasushi Miyagi ◽  
Eiichirou Urasaki
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Electromagnetic Interference ◽  
Illustrative Case ◽  
Pulse Generators ◽  
Replacement Surgery ◽  
Dual Channel ◽  
Stimulation Parameters ◽  
External Sources ◽  
Deep Brain

BACKGROUNDDeep brain stimulation (DBS) is a powerful surgical option for drug-resistant movement disorders; however, electromagnetic interference (EMI) from external sources poses a potential risk for implanted electronics.OBSERVATIONSA 61-year-old woman with Parkinson’s disease originally had two implantable pulse generators (IPGs) for bilateral subthalamic DBS, which were then replaced with one dual-channel IPG routed in a loop. After the replacement surgery, with the same DBS programming as before the IPG replacement (bipolar setting for right, unipolar setting for left), the patient began to complain of transient paroxysmal diplopia. After multiple attempts to adjust the stimulation parameters, the diplopia was resolved by changing the left unipolar setting to a bipolar setting. At the authors’ institution, before the present case, four other patients had undergone IPG replacement with loop routing. None of these previous patients complained of diplopia; however, two of the four presented with diplopia in an experimental unipolar setting.LESSONSClinicians should be aware that loop-routed circuits may generate distortion of the stimulus field in DBS, even in the absence of external EMI sources.

Stability of symptom control after replacement of impulse generators for deep brain stimulation

2009 ◽  
Vol 110 (6) ◽  
pp. 1274-1277 ◽  
Author(s):  
Niels Allert ◽  
Holger Kirsch ◽  
Waldemar Weirich ◽  
Hans Karbe
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Single Channel ◽  
Short Circuit ◽  
Symptom Control ◽  
Technical Problems ◽  
Dual Channel ◽  
Stimulation Parameters ◽  
The Stability ◽  
Deep Brain

Object Impulse generators (IPGs) for deep brain stimulation (DBS) need to be replaced when their internal batteries fail or when technical problems occur. New IPGs are routinely programmed with the previous stimulation parameters. In this study, the authors evaluate the stability of symptom control after such IPG replacements. Methods The authors retrospectively analyzed the outcome of 56 IPG replacements in 42 patients with various movement disorders treated using DBS. Results Stable symptom control was found in 65% of single-channel IPG replacements and 53% of dual-channel IPG replacements. Worsening of symptoms resulted primarily from changes in stimulation effects requiring reprogramming of stimulation parameters (17% of dual-channel IPG and 25% of single-channel IPG). In 14% of dualchannel IPG replacements, instability resulted from erroneous extension adjustment with change in laterality. A new short circuit of active with previously inactive contacts of the quadripolar stimulation lead resulted in a worsening of symptoms in 4% of replacements. Conclusions Replacement of the IPG requires careful follow-up of patients with DBS to ensure stable symptom control.

Bowstringing as a Complication of Deep Brain Stimulation

Neurosurgery ◽  
2010 ◽  
Vol 66 (6) ◽  
pp. E1205-E2010 ◽  
Author(s):  
Christopher Janson ◽  
Robert Maxwell ◽  
Akshay A. Gupte ◽  
Aviva Abosch
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Pulse Generator ◽  
Single Channel ◽  
Case Series ◽  
Deep Brain Stimulator ◽  
Pulse Generators ◽  
Dual Channel ◽  
Operative Revision ◽  
Deep Brain

Abstract OBJECTIVE This retrospective case series describes bowstringing as a complication of deep brain stimulator implantation for Parkinson's disease, defined as abnormal tethering of leads between the pulse generator and stimulating electrode, associated with contracture of the patient's neck over the extension cable. There are no previous reports of this specific complication, which presumably has been more broadly classified under hardware-related complications. CLINICAL PRESENTATION Bowstringing may result in discomfort, restriction of movements, and/or equipment malfunction. Patients were identified by postoperative surveillance in clinic and by review of our database of Parkinson's disease patients who had undergone subthalamic nucleus deep brain stimulator placement. The incidence of this complication was 2.6% (6/228) in our overall clinic population, composed of 0% (0/181) of patients who received a Soletra pulse generator and 12.7% (6/47) of patients who received a Kinetra pulse generator. INTERVENTION The proportion of patients with bowstringing requiring operative revision was 83% (5/6), with 60% (3/5) patients undergoing conversion to single-channel pulse generators and 40% (2/5) undergoing revision of the original dual-channel pulse generator. CONCLUSION Factors associated with bowstringing include the use of dual-channel pulse generators and scar lysis complicated by seroma or infection. The mean time from implantation to bowstringing was 8.6 months with a range of 0.5 to 22 months. Bowstringing is a rare but potentially serious complication, and further study is needed to accurately predict and avoid this problem.

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.

Ventral Intermediate Thalamic Stimulation for Monoclonal Gammopathy-Associated Tremor: Case Report

Neurosurgery ◽  
2011 ◽  
Vol 68 (5) ◽  
pp. E1464-E1467 ◽  
Author(s):  
Donald C. Shields ◽  
Alice W. Flaherty ◽  
Emad N. Eskandar ◽  
Ziv M. Williams
Keyword(s):  
Daily Living ◽  
Monoclonal Gammopathy ◽  
Clinical Presentation ◽  
Sensory Loss ◽  
Intention Tremor ◽  
Deep Brain Stimulator ◽  
Thalamic Stimulation ◽  
Central Nervous System Dysfunction ◽  
Stimulation Parameters ◽  
Deep Brain

Abstract BACKGROUND AND IMPORTANCE: Peripheral and central sensory loss are often associated with significant tremor or sensory ataxia, which can be highly refractory to medical therapy. CLINICAL PRESENTATION: We present the case of a 67-year-old man with progressive and debilitating intention tremor from monoclonal gammopathy-associated peripheral neuropathy. The patient was implanted with bilateral thalamic deep brain stimulator electrodes under microelectrode guidance. Following optimization of stimulation parameters, the patient's appendicular tremor and gait improved, as did his general activities of daily living. CONCLUSION: These initial findings suggest that deep brain stimulation may benefit not only tremor presumed to originate from central nervous system dysfunction, but also tremor originating peripherally from neuropathy-related sensory loss.

scholarly journals iHandU: A Novel Quantitative Wrist Rigidity Evaluation Device for Deep Brain Stimulation Surgery

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 331 ◽  
Author(s):  
Elodie Múrias Lopes ◽  
Maria do Carmo Vilas-Boas ◽  
Duarte Dias ◽  
Maria José Rosas ◽  
Rui Vaz ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Lessons Learned ◽  
Wrist Flexion ◽  
Stimulation Parameters ◽  
Average Accuracy ◽  
Gyroscope Sensor ◽  
Work Done ◽  
Deep Brain Stimulation Surgery ◽  
Deep Brain

Deep brain stimulation (DBS) surgery is the gold standard therapeutic intervention in Parkinson’s disease (PD) with motor complications, notwithstanding drug therapy. In the intraoperative evaluation of DBS’s efficacy, neurologists impose a passive wrist flexion movement and qualitatively describe the perceived decrease in rigidity under different stimulation parameters and electrode positions. To tackle this subjectivity, we designed a wearable device to quantitatively evaluate the wrist rigidity changes during the neurosurgery procedure, supporting physicians in decision-making when setting the stimulation parameters and reducing surgery time. This system comprises a gyroscope sensor embedded in a textile band for patient’s hand, communicating to a smartphone via Bluetooth and has been evaluated on three datasets, showing an average accuracy of 80%. In this work, we present a system that has seen four iterations since 2015, improving on accuracy, usability and reliability. We aim to review the work done so far, outlining the iHandU system evolution, as well as the main challenges, lessons learned, and future steps to improve it. We also introduce the last version (iHandU 4.0), currently used in DBS surgeries at São João Hospital in Portugal.

scholarly journals Differential Dynamic of Action on Cortical and Subcortical Structures of Anesthetic Agents during Induction of Anesthesia

2007 ◽  
Vol 107 (2) ◽  
pp. 202-212 ◽  
Author(s):  
Lionel J. Velly ◽  
Marc F. Rey ◽  
Nicolas J. Bruder ◽  
François A. Gouvitsos ◽  
Tatiana Witjas ◽  
...  
Keyword(s):  
Pulse Generator ◽  
Subcortical Structures ◽  
Quantitative Parameters ◽  
Anesthetic Agents ◽  
Deep Brain Stimulation Electrode ◽  
Power Frequency ◽  
Median Power Frequency ◽  
Noxious Stimuli ◽  
Stimulation Electrode ◽  
Deep Brain

Background Dynamic action of anesthetic agents was compared at cortical and subcortical levels during induction of anesthesia. Unconsciousness involved the cortical brain but suppression of movement in response to noxious stimuli was mediated through subcortical structures. Methods Twenty-five patients with Parkinson disease, previously implanted with a deep-brain stimulation electrode, were enrolled during the implantation of the definitive pulse generator. During induction of anesthesia with propofol (n = 13) or sevoflurane (n = 12) alone, cortical (EEG) and subcortical (ESCoG) electrogenesis were obtained, respectively, from a frontal montage (F3-C3) and through the deep-brain electrode (p0-p3). In EEG and ESCoG spectral analysis, spectral edge (90%) frequency, median power frequency, and nonlinear analysis dimensional activation calculations were determined. Results Sevoflurane and propofol decreased EEG and ESCoG activity in a dose-related fashion. EEG values decreased dramatically at loss of consciousness, whereas there was little change in ESCoG values. Quantitative parameters derived from EEG but not from ESCoG were able to predict consciousness versus unconsciousness. Conversely, quantitative parameters derived from ESCoG but not from EEG were able to predict movement in response to laryngoscopy. Conclusion These data suggest that in humans, unconsciousness mainly involves the cortical brain, but that suppression of movement in response to noxious stimuli is mediated through the effect of anesthetic agents on subcortical structures.

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