Neuromusculoskeletal Modeling-Based Prostheses for Recovery After Spinal Cord Injury

Abstract

Concurrent stimulation and reinforcement of motor and sensory pathways has been proposed as an effective approach to restoring function after developmental or acquired neurotrauma. This can be achieved by applying multimodal rehabilitation regimens, such as thought-controlled exoskeletons or epidural electrical stimulation to recover motor pattern generation in individuals with spinal cord injury (SCI). However, the human neuromusculoskeletal (NMS) system has often been oversimplified in designing rehabilitative and assistive devices. As a result, the neuromechanics of the muscles is seldom considered when modeling the relationship between electrical stimulation, mechanical assistance from exoskeletons, and final joint movement. A powerful way to enhance current neurorehabilitation is to develop the next generation prostheses incorporating personalized NMS models of patients. This strategy will enable an individual voluntary interfacing with multiple electromechanical rehabilitation devices targeting key afferent and efferent systems for functional improvement. This narrative review discusses how real-time NMS models can be integrated with finite element (FE) of musculoskeletal tissues and interface multiple assistive and robotic devices with individuals with SCI to promote neural restoration. In particular, the utility of NMS models for optimizing muscle stimulation patterns, tracking functional improvement, monitoring safety, and providing augmented feedback during exercise-based rehabilitation are discussed.

Digital Twins for Multiple Sclerosis

“…The use of DTs in medical care is still in its infancy. So far, only in a few areas of medicine, DTs were applied, such as oncology (97-99), geriatrics (100, 101), cardiology (45,(102)(103)(104)(105)(106), epidemic outbreaks (107), genomic medicine (48, 108), internal medicine (109,110), orthopedics (111) and vascular medicine (112,113). For example, Corral-Acero et al present early steps of a DT in the field of cardiovascular medicine by describing the synergies between mechanistic and statistical models, the pillars of the DT (45).…”

“…The use of DTs in medical care is still in its infancy. So far, only in a few areas of medicine, DTs were applied, such as oncology ( 97 – 99 ), geriatrics ( 100 , 101 ), cardiology ( 45 , 102 – 106 ), epidemic outbreaks ( 107 ), genomic medicine ( 48 , 108 ), internal medicine ( 109 , 110 ), orthopedics ( 111 ) and vascular medicine ( 112 , 113 ). For example, Corral-Acero et al.…”

Non-invasive approaches to functional recovery after spinal cord injury: Therapeutic targets and multimodal device interventions

“…Unlike the corticospinal tract, the segmental spinal neural circuits do not mediate volitional movement. They, however, can elicit spinal locomotion pattern generation, serving as a target for developing pharmacological neuromodulation, computer interfacing, functional stimulation, and comprehensively integrated rehabilitation systems (e.g., the human digital twin; see below; Krucoff et al, 2016;McPherson et al, 2015;Pizzolato et al, 2019;Sasada et al, 2014).…”

“…Neuromechanical prostheses encompass assistive and rehabilitative devices that interface with the individual's sensorimotor system (Pizzolato et al, 2019). Biological signals acquired via neuromechanical prosthesis include a range of electrical biopotentials (e.g., electroencephalograms [EEG], EMG, electrocardiogram [ECG]), biomechanical variables (e.g., limb movement and forces, hand gestures), and respiratory parameters (e.g., tidal volume, rate, and minute ventilation).…”

“…However, there is presently no consensus regarding the optimal delivery modality and amount of biofeedback, which type of afferent signals to augment, and how to best convert mechanoreceptor signals into interpretable feedback data. We and others postulated that providing biofeedback that is consistent and time-synchronized with native and intact proprioceptive signals might more effectively promote functional recovery in chronic stage of SCI (Jackson and Zimmermann, 2012;Pizzolato et al, 2019).…”