A Novel Pulsed Stimulation Pattern in Spinal Cord Stimulation: Clinical Results and Postulated Mechanisms of Action in the Treatment of Chronic Low Back and Leg Pain.

OBJECTIVES: The aim of this article is to discuss the possible mechanisms of action (MOAs) and results of a pilot study of a novel, anatomically placed, and paresthesia-independent, neurostimulation waveform for the management of chronic intractable pain. MATERIALS AND METHODS: A novel, multilayered pulsed stimulation pattern (PSP) that comprises three temporal layers, a Pulse Pattern layer, Train layer, and Dosage layer, was developed for the treatment of chronic intractable pain. During preliminary development, the utility was evaluated of anatomical PSP (aPSP) in human subjects with chronic intractable pain of the leg(s) and/or low back, compared with that of traditional spinal cord stimulation (T-SCS) and physiological PSP. The scientific theory and testing presented in this article provide the preliminary justification for the potential MOAs by which PSP may operate. RESULTS: During the pilot study, aPSP (n = 31) yielded a greater decrease in both back and leg pain than did T-SCS (back: -60% vs -46%; legs: -63% vs -43%). In addition, aPSP yielded higher responder rates for both back and leg pain than did T-SCS (61% vs 48% and 78% vs 50%, respectively). DISCUSSION: The novel, multilayered approach of PSP may provide multimechanistic therapeutic relief through preferential fiber activation in the dorsal column, optimization of the neural onset response, and use of both the medial and lateral pathway through the thalamic nuclei. The results of the pilot study presented here suggest a robust responder rate, with several subjects (five subjects with back pain and three subjects with leg pain) achieving complete relief from PSP during the acute follow-up period. These clinical findings suggest PSP may provide a multimechanistic, anatomical, and clinically effective management for intractable chronic pain. Because of the limited sample size of clinical data, further testing and long-term clinical assessments are warranted to confirm these preliminary findings.

Post-symptomatic detection of COVID-2019 grade based mediative fuzzy projection.

The concept of fuzzy set, intuitionistic set, and mediative fuzzy set as a generalization of a crisp set have been introduced in many real-life applications. The concept of crisp relation between elements of sets can be extended to fuzzy relations. Extended relations will be considered as relations on fuzzy sets. In this work, we developed the concept of mediative fuzzy relation and meditative fuzzy projection in the context of fuzzy relation and fuzzy projection. We extended the basic operations of fuzzy projection into intuitionistic fuzzy projection and then in the mediative fuzzy projection. We have shown the credibility and impact of mediative index factor involves in the mediative fuzzy projection in context of prediction work in relation to the proposed model. Further, we applied the mediative fuzzy projection in the medical diagnosis in post-COVID-19 patients. The obtained results have also been discussed with their geometrical representation.

A novel current steering method for targeted spinal cord stimulation.

Spinal Cord Stimulation (SCS) with leads embedded in the epidural space has become a recognized and effective clinical therapy for chronic pain relief. Leads with multiple electrodes placed close to the spinal cord allow targeted stimulation. This paper presents a novel current steering method to achieve targeted spinal cord stimulation by determining the optimal current sourced through a set of electrodes to maximize current density in a specified region of the spinal cord. The method provides a flexibility for personalized pain relief therapy, while minimizing stimulation in unwanted regions. The paper proposes a new optimization problem to achieve current steering. The optimization problem uses a solution of the Poisson equation evaluated using Finite Element Analysis (FEA) over a geometric model of the spinal cord and the embedded leads. The solution to the optimization problem determines the optimal current sourced through a set of electrodes to achieve a targeted stimulation.

Modeling the Impact of the Variation in Peripheral Nerve Anatomy on Stimulation.

Introduction: The peripheral nervous system has a complex anatomical structure. Stimulation of nerve fibers in the peripheral nervous system depends on the fiber diameter and myelination as well as its location within the nerve, packing fraction and fascicle distribution within the nerve bundle. This paper analyzes the impact of the variation in peripheral nervous system anatomy and the distance of the stimulating electrodes on the probability of generating an action potential. Methods: A mathematical model for effective fascicle conductivity has been developed to capture the variation in the packing fraction and fiber diameter. A linear activating function is utilized to analyze the impact of this effective conductivity and fascicle distribution as an indicator of generating an action potential. Results: Finite element simulations are performed for the nerve-electrode configuration to evaluate the electric field. The simulation results are used to analyze the activating function for different packing fractions and type of nerve fibers. The effect of electrode distance on activating function and the total current through a nerve bundle has also been studied. Discussion: The simulation results indicate that the peripheral nerve anatomy and electrode distance have a significant effect on the action potential generation.