Evaluation of a Multimodal Tactile Feedback System for Upper Limb-loss Users: Embodiment and Performance

Official title

ENG: Evaluation of the Effectiveness of a Feedback Device Fully Integrated Within a Prosthesis for Users With Upper Limb Amputation. IT: Valutazione Dell'Efficacia di un Dispositivo di Feedback Completamente Integrato All'Interno di Una Protesi, Per Utenti Che Presentano Amputazione Dell'Arto Superiore.

Overview

The aim of this study is to evaluate the effect of integrating tactile feedback systems into a robotic upper-limb prosthesis. These systems deliver pressure stimuli (through small silicone chambers that inflate), vibration stimuli (through small circular actuators), or a combination of both to the arm, in order to improve the feeling of owning and controlling the artificial hand. In this way, when the robotic hand touches, grasps, and holds an object, the user receives sensory feedback that may make prosthesis use more natural, intuitive, and functional in everyday life. This is expected to improve the sense of bodily integration of the prosthesis, particularly by enhancing the perception of owning the bionic limb and the feeling of control over it, thereby improving the ability to perform daily activities with the prosthesis. In addition, the study aims to investigate whether the simultaneous delivery of multiple stimuli may confuse or discomfort the user or they are well integrated by the sensitive system improving the experience of tactile sensation. This is a pilot, open-label study, meaning that both the researchers and the participants will be aware of the different phases of the study. The study population will include individuals with unilateral transradial upper-limb loss, either acquired or congenital. The planned sample size is 9 participants who meet the inclusion and exclusion criteria and who provide written informed consent to take part in the study. The study consists of two phases. Phase 1: Rubber Hand Illusion experiment During this phase, the feedback devices called WISH (pressure sensation provided by the inflation of silicone chambers), VIBES (vibration sensation), and PUSE (both devices applied and activated together to provide both sensations, either synchronously or with minimal delay) will be placed on the residual limb and secured with elastic Velcro straps. A robotic hand, controlled by the participant through electromyographic sensors, will be positioned on a table in front of the participant. The participant will see the robotic hand move while receiving sensory feedback synchronized with its movements. Different stimulation conditions (pressure only, vibration only, and combined feedback) will be tested. At the end of each condition, a questionnaire will be administered to assess the perception of ownership and agency. Phase 2: Upper-limb prosthesis use In the second phase, the actuators will be integrated into the socket of a SoftHand robotic prosthesis, a myoelectric upper-limb prosthesis. Participants will be asked to wear the prosthesis and perform tasks under each of the feedback conditions tested in Phase 1. After a free-use familiarization period of approximately 10 minutes, participants will be asked to perform tasks involving object and surface recognition, as well as activities of daily living, which will be timed. The results of the different conditions will be compared to identify the feedback configuration associated with the best performance, defined as fewer errors and shorter execution time. At the end of each condition, a questionnaire will be administered to assess ease of use and tolerability of the prosthesis.

Interventions

• Device Pressure and vibrotactile feedbak
  In this arm we will test the combination of a pressure and a vibrotactile feedback. The Prosthetic Upper Limb Sensory Enhancement (PULSE) device is a dual-feedback system, combining both the VIBES and WISH devices. It includes two silicone chambers (WISH) to transmit pressure stimuli related to grip force and two vibrotactile motors (VIBES) to provide high-frequency stimuli capable of conveying surface contact and texture signals. The subject will undergo a rubber hand illusion task, recognition
• Device Pressure feedback
  The feedback configuration tested in this arm will give a pressure resembling the grip force of the robotic hand. The Wearable Integrated Soft Haptic (WISH) is a pneumatic device acting as a force feedback system, capable of transmitting pressure information related to the grip force of a robotic hand during grasping actions.
• Device Vibrotactile feedback
  We will evaluate the Vibro-Inertial Bionic Enhancement System (VIBES). This device can convert acceleration information from Inertial Measurement Units (IMUs) into vibratory stimuli that can be associated with texture and first contact with an object. The subject will undergo a rubber hand illusion task, recognition task and daily live activity performance wearing the VIBES device.

Primary outcome measures

• Embodiment [Time frame: Day 1: Timepoint(T) - 0 "Baseline, pre-procedure"; T - 1 "immediately after the first aptic feedback tested"; T - 2 "immediately after the second aptic feedback tested"; T - 3 "immediately after the third aptic feddback tested".]

Secondary outcome measures (2)

• Discrimination capability [Time frame: Day 2: Timepoint(T') - 0 "Baseline, pre-procedure"; T' - 1 "immediately after the first aptic feedback tested"; T' - 2 "immediately after the second aptic feedback tested"; T' - 3 "immediately after the third aptic feddback tested".]
• Activity test [Time frame: Day 2: Timepoint(T') - 0 "Baseline, pre-procedure"; T' - 1 "immediately after the first aptic feedback tested"; T' - 2 "immediately after the second aptic feedback tested"; T' - 3 "immediately after the third aptic feddback tested".]

Eligibility criteria

Inclusion criteria

• Presence of a stump at the transradial level
• Active lifestyle (i.e., K-level K4, according to Medicare functional level classification)
• Ability to understand and provide Informed Consent to participate in the study - Ability to participate in experimental acquisitions

Exclusion criteria

• Bilateral transradial amputation
• Learning disabilities
• Inability to understand the informed consent form
• History or evidence of any medical, neurological or psychiatric conditions, which may affect brain function, metabolism, balance or motion, perception, representing, thus, a contraindication to the study (also stump pain or tenderness), other than the medical conditions or pathologies that have caused the upper-limb amputation
• Hypertension, cardiovascular disease, and other endocrine diseases, neuromuscular diseases, malignancies
• Vision and/or hearing problems severe enough to interfere with experimental procedures
• Carrier of infectious diseases
• Alcoholism or other substance abuse

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Crossover

Masking

Open label

Primary purpose

Device feasibility

Study locations

Italy · 1 center

• Department of Neurorehabilitation, Univeristy Hospital of Pisa — Pisa

Publications

• Ivani AS, Barontini F, Catalano MG, Grioli G, Bianchi M, Bicchi A. VIBES: Vibro-Inertial Bionic Enhancement System in a Prosthetic Socket. IEEE Int Conf Rehabil Robot. 2023 Sep;2023:1-6. doi: 10.1109/ICORR58425.2023.10304768. PMID 37941194
• Ivani AS, Barontini F, Catalano MG, Grioli G, Bianchi M, Bicchi A. Characterization, Experimental Validation and Pilot User Study of the Vibro-Inertial Bionic Enhancement System (VIBES). IEEE Trans Haptics. 2025 Jan-Mar;18(1):32-44. doi: 10.1109/TOH.2024.3435588. Epub 2025 Mar 21. PMID 39078769
• Ivani AS, Catalano MG, Grioli G, Bianchi M, Visell Y, Bicchi A. Tactile Perception in Upper Limb Prostheses: Mechanical Characterization, Human Experiments, and Computational Findings. IEEE Trans Haptics. 2024 Oct-Dec;17(4):817-829. doi: 10.1109/TOH.2024.3436827. Epub 2024 Dec 19. PMID 39093675
• Sensinger JW, Dosen S. A Review of Sensory Feedback in Upper-Limb Prostheses From the Perspective of Human Motor Control. Front Neurosci. 2020 Jun 23;14:345. doi: 10.3389/fnins.2020.00345. eCollection 2020. PMID 32655344
• Kaczmarek KA, Webster JG, Bach-y-Rita P, Tompkins WJ. Electrotactile and vibrotactile displays for sensory substitution systems. IEEE Trans Biomed Eng. 1991 Jan;38(1):1-16. doi: 10.1109/10.68204. PMID 2026426
• Tognetti A, Lorussi F, Bartalesi R, Quaglini S, Tesconi M, Zupone G, De Rossi D. Wearable kinesthetic system for capturing and classifying upper limb gesture in post-stroke rehabilitation. J Neuroeng Rehabil. 2005 Mar 2;2(1):8. doi: 10.1186/1743-0003-2-8. PMID 15743530
• Rossi M, Bianchi M, Battaglia E, Catalano MG, Bicchi A. HapPro: A Wearable Haptic Device for Proprioceptive Feedback. IEEE Trans Biomed Eng. 2019 Jan;66(1):138-149. doi: 10.1109/TBME.2018.2836672. Epub 2018 May 15. PMID 29993527
• Svensson P, Wijk U, Bjorkman A, Antfolk C. A review of invasive and non-invasive sensory feedback in upper limb prostheses. Expert Rev Med Devices. 2017 Jun;14(6):439-447. doi: 10.1080/17434440.2017.1332989. PMID 28532184

Identifiers

NCT: NCT07418645 · THE_FBHAND

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗