Vincent Gemar

Vincent Gemar

Master's Thesis

Design Of Lumbosacral Spinal Cord Stimulation Implants For Selective Afferent Recruitment By Model-Based Optimization


Dr. Andreas Rowald, Abdallah Alashqar (M. Sc.), Prof. Dr. Björn Eskofier, Prof. Dr. med. Thomas M. Kinfe, Dr. Esra Neufeld


01 / 2023 – 07 / 2023


Spinal cord stimulation (SCS) refers to a host of technologies and stimulation modalities, including Dorsal Root Ganglion (DRG) stimulation, high-frequency technologies, burst stimulation, and others, that generate electric fields between metal contacts residing in the epidural space. Although SCS is an effective and clinically approved neurostimulation strategy for the treatment of neuropathic pain, SCS is simultaneously actively being investigated for the treatment of a host of other neurological disorders, most notably the support of motor function. While promising, rapid advances made by clinical studies investigating safety and efficacy have often preceded the scientific understanding of the mechanisms underlying the interactions between stimulation and the nervous system during SCS. Even with titanic efforts and budgets, it is infeasible to comprehensively explore and optimize the multi-dimensional possibilities of SCS through clinical research alone. Instead, we believe that the future of SCS strongly depends on novel modeling tools that can rapidly explore the multi-dimensional parameter space of SCS to deconstruct mechanisms of action and guide stratification and therapy.

In silico modeling of SCS exposure and the resulting physico-electrophysiological impact is crucial for treatment safety and efficacy assessment and optimization purposes – be it for device design, in silico trial, or treatment planning purposes. Personalized modeling is required to account for the important inter-individual variability in anatomy. Thus, we will generate a digital twin catalogue of the human spinal cord in large and diversified patient-cohorts by consolidating and standardizing existing spinal cord models. The digital twin catalogue will contain at least 15 models of the lumbar spinal cord. Each model will contain Gray Matter (GM), White Matter (WM), dorsal and ventral rootlets (Roots), CerebroSpinal Fluid (CSF), Epidural Fat (Fat), Vertebral Bone (Bone), intervertebral Discs (Discs), and will be placed in a Saline conductor (Saline) to approximate the surrounding human body. The digital twin catalogue will be based on the existing models presented in Rowald et al. 2022[1].


[1] A. Rowald, S. Komi, R. Demesmaeker, et al., “Activity-dependent spinal cord neuromodulation rapidly restores trunk and leg motor functions after complete paralysis,” Nature Medicine, vol. 28, no. 2, pp. 260–271, 2022.
[2] F. Rattay, “The basic mechanism for the electrical stimulation of the nervous system,” Neuroscience, vol. 89, no. 2, pp. 335–346, 1999.