Effectiveness of high dose spinal cord stimulation for non-surgical intractable lumbar radiculopathy

OBJECTIVES: Spinal cord stimulation (SCS) is being increasingly used in non-surgical intractable low back pain. This study was designed to evaluate the efficacy of high-dose (HD) SCS utilizing sub-perception stimulation with higher frequency and pulse width in non-surgical predominant low-back pain population at 12 months. MATERIALS AND METHODS: A total of 20 patients were recruited (280 screened between March 2017 and July 2018) to undergo percutaneous fluoroscopic-guided SCS (Medtronic 8 contact standard leads and RestoreR IPG), with T8 and T9 midline anatomical parallel placement. Sixteen patients completed 12 months follow-up (500 Hz frequency, 500 μs pulse width, and 25% pulse density). Differences in patients’ clinical outcome (NRS back, NRS leg, ODI, PGIC, and PSQ) and medication usage (MQS) at 1, 3, and 12 months from the baseline were assessed using non-parametric Wilcoxon paired test. RESULTS: The mean NRS scores for back pain (baseline 7.53) improved significantly at 1, 3, and 12 months; 2.78 (p < 0.001), 4.45 (p = 0.002), and 3.85 (p = 0.002), respectively. The mean NRS score for leg pain (baseline 6.09) improved significantly at 1 and 3 months; 1.86 (p < 0.001) and 3.13 (p = 0.010), respectively. Mean NRS for leg pain at 12 months was 3.85 (p = 0.057). ODI and sleep demonstrated significant improvement as there was consistent improvement in medication particularly opioid usage (MQS) at 12 months. CONCLUSIONS: This study demonstrates that anatomical placement of leads with sub-perception HD stimulation could provide effective pain relief in patients who are not candidates for spinal surgery

Heat Transfer in a MHD Nanofluid Over a Stretching Sheet

The intention behind carrying out this research work is to analyze the heat transfer characteristics in a Magnetohydrodynamic (MHD) boundary layer nanofluid flow over a stretching sheet. Two phase representation of nanofluid studied the consequence of Brownian motion along with thermophoresis. The major purpose of study is to investigate the significant role of prominent fluid parameters thermophoresis, Brownian motion, Eckert number, Schmidt number and magnetic parameter on profile of velocity, temperature distribution and concentration. Runge–Kutta Fehlberg (RKF) method was adopted to numerically solve the non-linear governing equations and the linked boundary conditions by use of shooting technique. Over all the consequence of prominent fluid parameters are explained via graphs, whereas distinction of several valuable engineering quantities like skin friction coefficient, local Nusselt number and local Sherwood number are also tabulated. The finding of present study helps to control the rate of heat transportation as well as fluid velocity in any manufacturing processes and industrial applications to make desired quality of final product

A Study of Temperature-dependent Fluid Properties on MHD Free Stream Flow and Heat Transfer over a Non-Linearly Stretching Sheet

AbstractAn analysis has been done for non-linearly stretching sheet with temperature-dependent fluid properties with free stream mag- netohydrodynamic (MHD) flow. The transverse magnetic field and the stretching velocity are assumed to vary as a power of the distance. The thermal conductivity shows linear variation whereas the fluid viscosity varies inversely with temperature. We have incorporated similarity transformations in our study to mould partial differential equations into non-linear equations. These equations are solved using Runge-Kutta Fehlberg method with the shooting techniques. In the present study, we discuss effects of various fluid parameters on the profiles of velocity and temperature in the presence of free stream. The effect with variations of these parameters has been investigated. We found that the free stream velocity reduces the boundary layer thickness

Stability analysis of MHD outer velocity flow on a stretching cylinder

A study has been done on axisymmetric magnetohydrodynamic (MHD) flow of a viscous incompressible outer velocity fluid along a stretching cylinder. The momentum and heat partial differential equations are mold using similarity transformations into a set of nonlinear ordinary differential equations. These equations have been solved with the help of Runge-Kutta Fehlberg scheme numerically with shooting technique. It is found that the solution is not unique for stretching cylindrical surface. The dual solution exists for a certain range of fluid parameters on stretching surface. The stability analysis shown that the upper branch is a stable solution and the lower branch is a unstable solution. The critical point λc=-0.03211 of outer velocity parameter and the range of the unstable solution -0.03211=λc⩽λ⩽λr=0.1411 have been obtained for certain magnetic parameter. Also, the effects of MHD and outer velocity parameter with various other fluid parameters on heat transfer and flow characteristics have been analyzed and shown by figures and tables. The outcomes show that the outer velocity parameter has a substantial effect on MHD fluid flow in stretching cylindrical surface. Keywords: Stability analysis, MHD, Stretching cylinder, Heat transfer, Outer velocity, Dual solutio

Experience based localization in wide open indoor environments

This paper solves the problem of localization for indoor environments using visual place recognition, visual odometry and experience based localization using a camera. Our main motivation is just like a human is able to recall from its past experience, a robot should be able to use its recorded visual memory in order to determine its location. Currently experience based localization has been used in constrained environments like outdoor roads, where the robot is constrained to the same set of locations during every visit. This paper adapts the same technology to wide open maps like halls wherein the robot is not constrained to specific locations. When a robot is turned on in a room, it first uses visual place recognition using histogram of oriented gradients and support vector machine in order to predict which room it is in. It then scans its surroundings and uses a nearest neighbor search of the robot’s experience coupled with visual odometry for localization. We present the results of our approach test on a dynamic environment comprising of three rooms. The dataset consists of approximately 5000 monocular and 5000 depth images

Predictive text analysis using eye blinks

The current work aims to facilitate interaction with others to those with the inability to perform activities requiring motor skills or those who cannot speak. It proposes a modus operandi or a system based on Histogram of Oriented Gradients (HOG) and Support Vector Machine (SVM), which automatically identifies eye blinks in real-time to predict a lexicon. The system implements an auxiliary input that enables individuals to interact with others with the help of a device, where voluntary long blinks help in transition from a counter to a predictive table, while the short blinks are used to make the counter stop and select the lexicon. The system does not require prior manual initialization, special lighting, or previous face detection as it can calibrate it if the user is in the camera region and close. The proposed user interface makes the process of words detection by blinking easier with 74% accuracy

Dynamic Brain Imaging Response to Spinal Cord Stimulation Differential Frequencies DiFY SCS-PET clinical trial

OBJECTIVES: This study with sequential 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)-computed tomography (CT) scanning was designed to investigate any objective measurable effect of differential frequency stimulation (40 Hz, 4000 Hz, and 10,000 Hz) on specific pain matrix areas in patients who underwent spinal cord stimulation (SCS) for intractable lumbar neuropathic pain. MATERIALS AND METHODS: In this single-center, randomized, blinded study, four brain 18F-FDG PET scans were performed for each patient-at baseline before SCS implant and after 40-Hz, 4000-Hz, and 10,000-Hz stimulation. After 40-Hz stimulation for four weeks, patients were randomized 1:1 (4000 Hz/10,000 Hz), crossing over at another four weeks. 18F-FDG PET-CT brain scans acquired on the GE-Discovery 710 PET system (GE Healthcare, Chicago, IL) with 128-slice CT (250-MBq dose) were analyzed using the PMOD software (PMOD Technologies Ltd, Zurich, Switzerland). A total of 18 pain regions, the right and left prefrontal cortex (PFC), insula, anterior cingulate cortex (ACC), hippocampus, amygdala, primary somatosensory cortices, secondary somatosensory cortices (SSCII), thalami, parabrachial, and periaqueductal gray (PAG), were analyzed. RESULTS: A total of 14 patients received 40 Hz for four weeks before crossing over to 10,000 Hz/4000 Hz. A total of 57 PET-CT scans (15 for baseline and 14 each for 40 Hz, 4000 Hz, and 10,000 Hz) were analyzed for maximum standardized uptake value (SUVmax), with a statistically significant difference in SUVmax between 40 Hz and baseline (p = 0.002) and 4000 Hz and baseline (p = 0.001) when pooled across 18 pain matrices. There was no statistical difference in SUVmax between 10,000 Hz and baseline. The pooled analysis showed a proportionately higher thalamic region reduction (59.5%) in metabolic activity than other pain matrices, PFC (52%), insula (50%), ACC (52%), SSCII (49%), and PAG (52%). CONCLUSION: This large cohort of brain PET scans (n = 57) shows statistically significant differences in brain metabolic activity at 40 Hz and 4000 Hz from baseline, with effect on both nociceptive and affect-cognitive pathways (proportionately higher reduction in the thalamus), highlighting the possible mechanism of SCS. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT03716557