Peripheral Nerve Stimulation: The Evolution in Pain Medicine

Peripheral nerve stimulation (PNS) involves the application of electrical stimulation near the proximity of peripheral nerves. Although the mechanism of action remains unknown, PNS likely modulates both the central and peripheral nervous systems to provide analgesia for a wide variety of pain disorders involving the head, extremities, and trunk. Historically, PNS was not utilized widely due to underwhelming results from earlier studies. However, significant innovations in device technologies, including improved implantation techniques, hardware miniaturization, and externalized pulse generators, have led to the resurgence of PNS in the field of pain medicine. This editorial briefly reviews the evolution of PNS in the field of pain medicine and highlights areas for future investigation.

Four Channel 6.5 kV, 65 A, 100 ns-100 µs Generator with Advanced Control of Pulse and Burst Protocols for Biomedical and Biotechnological Applications

Pulsed electric fields in the sub-microsecond range are being increasingly used in biomedical and biotechnology applications, where the demand for high-voltage and high-frequency pulse generators with enhanced performance and pulse flexibility is pushing the limits of pulse power solid state technology. In the scope of this article, a new pulsed generator, which includes four independent MOSFET based Marx modulators, operating individually or combined, controlled from a computer user interface, is described. The generator is capable of applying different pulse shapes, from unipolar to bipolar pulses into biological loads, in symmetric and asymmetric modes, with voltages up to 6.5 kV and currents up to 65 A, in pulse widths from 100 ns to 100 µs, including short-circuit protection, current and voltage monitoring. This new scientific tool can open new research possibility due to the flexibility it provides in pulse generation, particularly in adjusting pulse width, polarity, and amplitude from pulse-to-pulse. It also permits operating in burst mode up to 5 MHz in four independent channels, for example in the application of synchronized asymmetric bipolar pulses, which is shown together with other characteristics of the generator.

Nonlinear pulse reshaping in a typically designed silicon on insulator waveguide and its application to generate high repetition rate pulse train

A Silicon on Insulator (SOI) planar waveguide is designed here possessing a small group velocity dispersion (β2) ∼ 2.212 (ps2/m) with quite high nonlinear coefficient (γ) of ∼ 360.57 (W.m)-1. The so designed waveguide is capable of reshaping a Super-Gaussian input optical pulse into parabolic pulse (PP), without any use of external gain. The same waveguide with relatively longer length is also able to generate triangular pulse (TP) by using positive chirp at the input. In both cases PP and TP are created at much shorter optimum length (Lopt) of few mm, when compared to previously reported works on normal dispersion optical fibers. The interaction of a pulse pair inside such a SOI waveguide is investigated also for the first time as per our knowledge to generate of a high frequency (~ 4.8 THz) pulse train, while lower repetition rate (~180 GHz) pulses are used at the input. This study as a whole enables one to have potential device applications in the domain of tunable high frequency (THz) pulse generators, optical signal processing and many more.

High Frequency of Low-Virulent Microorganisms Detected by Sonication of Implanted Pulse Generators: So What?

<b><i>Introduction:</i></b> Deep brain stimulation (DBS) has become a well-established treatment modality for a variety of conditions over the last decades. Multiple surgeries are an essential part in the postoperative course of DBS patients if nonrechargeable implanted pulse generators (IPGs) are applied. So far, the rate of subclinical infections in this field is unknown. In this prospective cohort study, we used sonication to evaluate possible microbial colonization of IPGs from replacement surgery. <b><i>Methods:</i></b> All consecutive patients undergoing IPG replacement between May 1, 2019 and November 15, 2020 were evaluated. The removed hardware was investigated using sonication to detect biofilm-associated bacteria. Demographic and clinical data were analyzed. <b><i>Results:</i></b> A total of 71 patients with a mean (±SD) of 64.5 ± 15.3 years were evaluated. In 23 of these (i.e., 32.4%) patients, a positive sonication culture was found. In total, 25 microorganisms were detected. The most common isolated microorganisms were <i>Cutibacterium acnes</i> (formerly known as <i>Propionibacterium acnes</i>) (68%) and coagulase-negative <i>Staphylococci</i> (28%). Within the follow-up period (5.2 ± 4.3 months), none of the patients developed a clinical manifest infection. <b><i>Discussions/Conclusions:</i></b> Bacterial colonization of IPGs without clinical signs of infection is common but does not lead to manifest infection. Further larger studies are warranted to clarify the impact of low-virulent pathogens in clinically asymptomatic patients.

Implantable Pulse Generators for Deep Brain Stimulation: Challenges, Complications, and Strategies for Practicality and Longevity

Deep brain stimulation (DBS) represents an important treatment modality for movement disorders and other circuitopathies. Despite their miniaturization and increasing sophistication, DBS systems share a common set of components of which the implantable pulse generator (IPG) is the core power supply and programmable element. Here we provide an overview of key hardware and software specifications of commercially available IPG systems such as rechargeability, MRI compatibility, electrode configuration, pulse delivery, IPG case architecture, and local field potential sensing. We present evidence-based approaches to mitigate hardware complications, of which infection represents the most important factor. Strategies correlating positively with decreased complications include antibiotic impregnation and co-administration and other surgical considerations during IPG implantation such as the use of tack-up sutures and smaller profile devices.Strategies aimed at maximizing battery longevity include patient-related elements such as reliability of IPG recharging or consistency of nightly device shutoff, and device-specific such as parameter delivery, choice of lead configuration, implantation location, and careful selection of electrode materials to minimize impedance mismatch. Finally, experimental DBS systems such as ultrasound, magnetoelectric nanoparticles, and near-infrared that use extracorporeal powered neuromodulation strategies are described as potential future directions for minimally invasive treatment.

TRIGGERING PULSE GENERATORS DEVELOPED FOR THE HIGH-VOLTAGE DISCHARGERS OF MAGNETIC SYSTEMS AND FOR THE GENERATOR OF PULSE VOLTAGES USED BY THE RELATIVISTIC ELECTRON BEAM ACCELERATOR “TEMP-B”

The pulse generators were developed to trigger the high-voltage dischargers of magnetic systems and the dischargers of the generators of pulsed voltages used by the relativistic electron beam (REB) accelerator “TEMP-B”. The description of the triggering pulse generators designed by the NSC KIPT to actuate the dischargers of the pulsed voltage generators (PVG) and the dischargers of magnetic systems has been given. These are used by the commutation systems of capacitor banks with the stored energy margin in the range of 60 to 150 kJ. The generators provide the generation of voltage pulses with the amplitude of up to 20 kV.

Wireless endovascular nerve stimulation with a millimeter-sized magnetoelectric implant

Implanted bioelectronic devices have the potential to treat disorders that are resistant to traditional pharmacological therapies; however, reaching many therapeutic nerve targets requires invasive surgeries and implantation of centimeter-sized devices. Here we show that it is possible to stimulate peripheral nerves from within blood vessels using a millimeter-sized wireless implant. By directing the stimulating leads through the blood vessels we can target specific nerves that are difficult to reach with traditional surgeries. Furthermore, we demonstrate this endovascular nerve stimulation (EVNS) with a millimeter sized wireless stimulator that can be delivered minimally invasively through a percutaneous catheter which would significantly lower the barrier to entry for neuromodulatory treatment approaches because of the reduced risk. This miniaturization is achieved by using magnetoelectric materials to efficiently deliver data and power through tissue to a digitally-programmable 0.8 mm2 CMOS system-on-a-chip. As a proof-of-principle we show wireless stimulation of peripheral nerve targets both directly and from within the blood vessels in rodent and porcine models. The wireless EVNS concept described here provides a path toward minimally invasive bioelectronics where mm-sized implants combined with endovascular stimulation enable access to a number of nerve targets without open surgery or implantation of battery-powered pulse generators.

Fixed-Life or Rechargeable Battery for Deep Brain Stimulation: Preference and Satisfaction in Chinese Patients With Parkinson's Disease

Introduction: DBS is a widely used therapy for PD. There is now a choice between fixed-life implantable pulse generators (IPGs) and rechargeable IPGs, each having advantages and disadvantages. This study aimed to evaluate the preference and satisfaction of Chinese patients with Parkinson's disease (PD) who were treated with deep brain stimulation (DBS).Materials and Methods: Two hundred and twenty PD patients were treated with DBS and completed a self-reported questionnaire to assess their long-term satisfaction and experience with the type of battery they had chosen and the key factors affecting these choices. The survey was performed online and double-checked for completeness and accuracy.Results: The median value of the postoperative duration was 18 months. The most popular way for patients to learn about DBS surgery was through media (79/220, 35.9%) including the Internet and television programs. In total, 87.3% of the DBS used rechargeable IPGs (r-IPG). The choice between rechargeable and non-rechargeable IPGs was significantly associated with affordability (χ(1)2 = 19.13, p &lt; 0.001). Interestingly, the feature of remote programming significantly affected patients' choices between domestic and imported brands (χ(1)2 = 16.81, p &lt; 0.001). 87.7% of the patients were satisfied with the stimulating effects as well as the implanted device itself. 40.6% of the patients with r-IPGs felt confident handling devices within 1 week after discharge. More than half of the patients checked their batteries every week. The mean interval for battery recharge was 4.3 days. 57.8% of the patients spent around 1 h recharging, and 71.4% of them recharged the battery independently.Conclusions: Most patients were satisfied with their choice of IPGs. The patients' economic status and the remote programming function of the device were the two most critical factors in their decision. The skill of recharging the IPG was easy to master for most patients.

Fixed-Life or Rechargeable Batteries for Deep Brain Stimulation: Preference and Satisfaction Among Patients With Hyperkinetic Movement Disorders

Background: Deep brain stimulation (DBS) is an established treatment for hyperkinetic movement disorders. Patients undergoing DBS can choose between the use of a rechargeable or non-rechargeable battery for implanted pulse generators (IPG).Objectives: In this study, we aimed to evaluate patient preferences and satisfaction with rechargeable and non-rechargeable batteries for IPGs after undergoing DBS.Methods: Overall, 100 patients with hyperkinetic movement disorders (dystonia: 79, Tourette syndrome: 21) who had undergone DBS took a self-designed questionnaire to assess their satisfaction and experience with the type of battery they had chosen and the factors influencing their choice.Results: Of the participants, 87% were satisfied with the stimulating effects of the treatment as well as the implanted device; 76% had chosen rechargeable devices (r-IPGs), 71.4% of whom recharged the battery themselves. Economic factors were the main reason for choosing both r-IPG and non-rechargeable IPG (nr-IPG). The questionnaire revealed that 66% of the patients checked their r-IPG battery every week. The mean interval for battery recharge was 4.3 days.Conclusions: The majority of the patients were satisfied with their in-service-IPG, regardless of whether it was a r-IPG or nr-IPG. Affordability was the main factor influencing the choice of IPG. The majority of the patients were confident in recharging the battery of their r-IPG themselves; only 11% of patients experienced difficulties. Understanding the recharge process remains difficult for some patients and increasing the number of training sessions for the device may be helpful.