VALSE: Integration of Neuromodulation and Exoskeleton Systems for Mobility in Individuals With Chronic Spinal Cord Injury (VALSE)

The purpose of this clinical study is to evaluate the preliminary safety and feasibility of using the VALSE system, which combines spinal cord stimulation with the TWIICE robotic exoskeleton, to support motor recovery and reduce reliance on laboratory-based equipment during rehabilitation in participants with traumatic spinal cord injury. The TWIICE exoskeleton is integrated through the NR system, a platform developed by EPFL. The goal is to assess the clinical safety and practical application of this combined neuroprosthetic approach in a small number of participants, in order to guide future refinements of the device and protocol, support the development of scalable interventions integrating spinal stimulation with robotic assistance, and inform strategies for delivering rehabilitation in more accessible, real-world environments.

Study Overview

• Status: Not yet recruiting
• Conditions: Spinal Cord Injury
• Intervention / Treatment: Combination product: TWIICE Rise 1.0 robotic exoskeleton combined with epidural electrical stimulation (EES)

Detailed Description

Spinal cord injury (SCI) disrupts communication between the brain and spinal cord below the lesion, often resulting in severe and permanent motor impairments. Despite advances in rehabilitation, recovery of walking remains limited and restoring mobility is consistently identified as a top priority by individuals living with SCI.

Epidural electrical stimulation (EES) of the spinal cord has emerged as a promising approach to restore movement after paralysis. By activating spinal motor circuits below the lesion, EES can enable standing, stepping, and walking in individuals with chronic SCI. ONWARD Medical has developed the ARC-IM spinal stimulation platform, which is currently being evaluated in several clinical studies, including BoxSwitch (NCT05942339), Think2Go (NCT06243952), and STIMO-BSI (NCT04632290).

In the BoxSwitch trial, optimized spatiotemporal EES protocols enabled participants with chronic SCI to perform standing, stepping, and walking movements. Building on these findings, the Think2Go and STIMO-BSI studies integrated the WIMAGINE implantable electrocorticography (ECoG) system developed by Clinatec (CEA, Grenoble, France) with spinal stimulation, creating a brain-spine interface capable of decoding motor intentions and translating them into spinal stimulation. These studies demonstrated that implantable brain-spine interfaces can restore voluntary control of lower-limb movements and support functional walking after severe paralysis.

Although these technologies have shown encouraging results, their use remains largely restricted to specialized rehabilitation settings. In parallel, robotic exoskeletons have been developed to support overground walking in individuals with SCI. The TWIICE exoskeleton is a lightweight and modular system specifically designed for use beyond rehabilitation centers and may complement spinal stimulation by providing functional support during walking.

In this study, the investigators will evaluate the preliminary safety and feasibility of the VALSE system, which combines the ARC-IM spinal cord stimulation platform with the TWIICE robotic exoskeleton in individuals with chronic traumatic SCI. Participants will be recruited from ongoing clinical studies at Lausanne University Hospital (CHUV), including BoxSwitch (NCT05942339), Think2Go (NCT06243952), and STIMO-BSI (NCT04632290), after completion of the relevant study phases.

As an early feasibility investigation, the study aims to generate preliminary safety and usability data on the combined use of spinal neuromodulation and robotic assistance during mobility tasks. The results will support the development of future neuroprosthetic solutions designed to improve walking ability, independence, and quality of life for people living with SCI.

• Study Type: Interventional
• Enrollment (Estimated): 12
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Henri Lorach, PhD; Phone Number: +41 77 495 50 48; Email: henri.lorach@epfl.ch
• Study Contact Backup: Name: Jocelyne Bloch, Prof.; Phone Number: +41 79 556 29 51; Email: jocelyne.bloch@chuv.ch

Study Locations

• Switzerland
  • Canton of Vaud
    • Lausanne, Canton of Vaud, Switzerland, 1005
      • Centre Hospitalier Universitaire Vaudois (CHUV)
      • Contact: Jocelyne Bloch; Phone Number: 0795568979; Email: Jocelyne.bloch@chuv.ch

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Currently enrolled participants who have completed the relevant phase of their parent study at CHUV: BoxSwitch (NCT05942339, after the optimisation phase), Think2Go (NCT06243952, after the rehabilitation phase, or STIMO-BSI (NCT04632290, after the calibration and training phase of the optional extension with system upgrade),
• Must have a functional neuromodulation system,
• Must be at least 18 years old,
• Must be suffering from non-progressive traumatic spinal cord injury, sustained at least 12 months before signing the consent form,
• Must weigh less than 100 kg,
• Must have a standing height between 160 and 190 cm,
• Must be able to grasp and lift bilateral crutches in a seated position,
• Must have stable medical, physical and psychological condition as considered by the investigator,
• Must be able to understand and interact with the study team in French or English,
• Must agree to comply in good faith with all conditions of the study and to attend all scheduled appointments,
• Must provide Informed Consent as documented by signature prior to any study-related procedures.

Exclusion Criteria:

• Must not be diagnosed with severe osteoporosis/penia:

Dual Energy X-ray Absorptiometry (DEXA) results indicating a t-score below -3.5 at either the femoral neck or the total proximal femur.

Dual Energy X-ray Absorptiometry (DEXA) results indicating a bone mineral density (BMD) < 0.60 gm/cm2 at any knee region (distal femur, proximal tibia)

• Must not have deep vein thrombosis in lower extremities within the past 6 months.
• Must not have experienced lower extremity fractures within the last two years.
• Must not have current pressure ulcer of the arms, trunk, pelvic area, or lower extremities
• Must not present with a flexion contracture >15° at the hip or knee
• Must not have severe concurrent medical conditions that contraindicate moderate to intense exercise (e.g., uncontrolled hypertension, coronary artery disease, congestive heart failure).
• Must not have heterotopic ossification that impairs joint mobility
• Must not be implanted with a life-supporting medical device (devices implanted in the parent study are not considered life-supporting),
• Must not be pregnant,
• Must not be the investigator himself, his/her family members, employees, or other dependent persons.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: All participant; All participants receive the same intervention. Each participant will complete 3 predefined study periods within 1 year of enrolment. Each study period lasts 3 weeks, and study periods are separated by a minimum interval of 1 month.

Combination product: TWIICE Rise 1.0 robotic exoskeleton combined with epidural electrical stimulation (EES); Participants will use the VALSE system, which combines the TWIICE Rise 1.0 robotic exoskeleton with epidural electrical stimulation (EES) delivered through previously implanted neuromodulation systems. The system is intended to support upright mobility and overground walking in individuals with chronic spinal cord injury (SCI) who are currently enrolled in, or have completed key phases of, neuromodulation clinical trials at CHUV, including Think2Go (NCT06243952), STIMO-BSI (NCT04632290), and BoxSwitch (NCT05942339). The TWIICE exoskeleton provides robotic gait assistance, while EES facilitates activation of spinal motor circuits below the level of injury. Exoskeleton movements are initiated and controlled through participant-generated inputs, including finger-click commands and, where applicable, brain-derived control signals from previously implanted brain-spine interface systems. The VALSE system is used in supervised clinical and controlled real-world.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Preliminary safety	Occurrence of Serious Adverse Events (SAE) and Adverse Events (AE) that are deemed related or possibly related to the procedure or to the TWIICE exoskeleton in combination with the neuromodulation therapies (VALSE system)	From enrollment until the end of study timepoint, up to 1 year after enrollment.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessment of the experimental session conditions	Location and type of ground walked on.	At each in-clinic training session during the three study periods, up to 1 year after enrollment.
Number of steps	Total number of steps recorded by the exoskeleton during each experimental (EX) session.	At each experimental (EX) session during the three study periods, up to 1 year after enrollment.
Step frequency	Average step frequency (cadence) recorded by the exoskeleton during each experimental (EX) session.	At each experimental (EX) session during the three study periods, up to 1 year after enrollment.
Mid-stride pauses	Number of mid-stride pauses recorded by the exoskeleton during each experimental (EX) session.	At each experimental (EX) session during the three study periods, up to 1 year after enrollment.
Distance walked	Total distance walked recorded by the exoskeleton during each experimental (EX) session.	At each experimental (EX) session during the three study periods, up to 1 year after enrollment.
Walking time	Total walking time recorded by the exoskeleton during each experimental (EX) session.	At each experimental (EX) session during the three study periods, up to 1 year after enrollment.
Standing time	Total standing time recorded by the exoskeleton during each experimental (EX) session.	At each experimental (EX) session during the three study periods, up to 1 year after enrollment.
Kinematic gait parameters	Kinematic gait parameters recorded during overground walking and functional locomotor tasks (change of walking speed, stepping over and turn around obstacles, climb stairs, walk with cognitive load (e.g., counting backward by threes)) using the VALSE system.	At each experimental (EX) session during the three study periods, up to 1 year after enrollment.
Electromyographic (EMG) activity	Muscle activation patterns recorded by surface electromyography during overground walking and functional locomotor tasks while using the VALSE system.	At each experimental (EX) session during the three study periods, up to 1 year after enrollment.
Brain-computer interface (BCI) performance	Brain-computer interface performance metrics recorded during overground walking and functional locomotor tasks while using the VALSE system.	At each experimental (EX) session during the three study periods, up to 1 year after enrollment.
Donning and Doffing Time	Assessment of the time it takes to put on and take off the system. Donning time is recorded from the start of preparation until the participant is fully ready for ambulation. Doffing time is recorded from the start of removal until the participant is fully disengaged from the system.	At the last experimental (EX) session of each of the three study periods, up to 1 year after enrollment.
Level of Assistance (LOA)	Assessment to evaluates the amount of physical support required by the participant during walking and mobility activities with the device.	At the last experimental (EX) session of each of the three study periods, up to 1 year after enrollment.
System Usability Scale (SUS)	A validated 10-item questionnaire measuring usability across multiple domains. Scores range from 0-100, with higher values indicating greater usability. Will be filled in by participants and physiotherapists.	At the last experimental (EX) session of each of the three study periods, up to 1 year after enrollment.
ASA Task Load Index (NASA-TLX)	A 6-dimension tool assessing perceived workload (mental demand, physical demand, temporal demand, performance, effort, frustration). Will be filled in by participants and physiotherapists.	At the last experimental (EX) session of each of the three study periods, up to 1 year after enrollment.

Collaborators and Investigators

• Sponsor: Ecole Polytechnique Fédérale de Lausanne
• Investigators: Principal Investigator: Jocelyne Bloch, Prof., Centre Hospitalier Universitaire Vaudois (CHUV)

Publications and helpful links

General Publications

• Rowald A, Komi S, Demesmaeker R, Baaklini E, Hernandez-Charpak SD, Paoles E, Montanaro H, Cassara A, Becce F, Lloyd B, Newton T, Ravier J, Kinany N, D'Ercole M, Paley A, Hankov N, Varescon C, McCracken L, Vat M, Caban M, Watrin A, Jacquet C, Bole-Feysot L, Harte C, Lorach H, Galvez A, Tschopp M, Herrmann N, Wacker M, Geernaert L, Fodor I, Radevich V, Van Den Keybus K, Eberle G, Pralong E, Roulet M, Ledoux JB, Fornari E, Mandija S, Mattera L, Martuzzi R, Nazarian B, Benkler S, Callegari S, Greiner N, Fuhrer B, Froeling M, Buse N, Denison T, Buschman R, Wende C, Ganty D, Bakker J, Delattre V, Lambert H, Minassian K, van den Berg CAT, Kavounoudias A, Micera S, Van De Ville D, Barraud Q, Kurt E, Kuster N, Neufeld E, Capogrosso M, Asboth L, Wagner FB, Bloch J, Courtine G. Activity-dependent spinal cord neuromodulation rapidly restores trunk and leg motor functions after complete paralysis. Nat Med. 2022 Feb;28(2):260-271. doi: 10.1038/s41591-021-01663-5. Epub 2022 Feb 7.
• Gorgey AS, Gill S, Holman ME, Davis JC, Atri R, Bai O, Goetz L, Lester DL, Trainer R, Lavis TD. The feasibility of using exoskeletal-assisted walking with epidural stimulation: a case report study. Ann Clin Transl Neurol. 2020 Feb;7(2):259-265. doi: 10.1002/acn3.50983. Epub 2020 Feb 5.
• Hong E, Gorman PH, Forrest GF, Asselin PK, Knezevic S, Scott W, Wojciehowski SB, Kornfeld S, Spungen AM. Mobility Skills With Exoskeletal-Assisted Walking in Persons With SCI: Results From a Three Center Randomized Clinical Trial. Front Robot AI. 2020 Aug 4;7:93. doi: 10.3389/frobt.2020.00093. eCollection 2020.
• Vouga T, Fasola J, Baud R, Manzoori AR, Pache J, Bouri M. TWIICE One powered exoskeleton: effect of design improvements on usability in daily life as measured by the performance in the CYBATHLON race. J Neuroeng Rehabil. 2022 Jun 27;19(1):63. doi: 10.1186/s12984-022-01028-0.
• Zhang T, Jia Y, Wang N, Chai X, He Q, Cao T, Mu Q, Lan Q, Zhao J, Yang Y. Recent advances in potential mechanisms of epidural spinal cord stimulation for movement disorders. Exp Neurol. 2025 Oct;392:115330. doi: 10.1016/j.expneurol.2025.115330. Epub 2025 Jun 4.

Study record dates

Study Major Dates

• Study Start (Estimated): September 15, 2026
• Primary Completion (Estimated): May 1, 2028
• Study Completion (Estimated): September 1, 2028

Study Registration Dates

• First Submitted: June 25, 2026
• First Submitted That Met QC Criteria: August 3, 2026
• First Posted (Actual): August 4, 2026

Study Record Updates

• Last Update Posted (Actual): August 4, 2026
• Last Update Submitted That Met QC Criteria: August 3, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: exoskeleton; Spinal cord stimulation; Brain spine interface
• Additional Relevant MeSH Terms: Central Nervous System Diseases; Nervous System Diseases; Wounds and Injuries; Trauma, Nervous System; Spinal Cord Diseases; Spinal Cord Injuries
• Other Study ID Numbers: VALSE

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No