Amputees
Conditions
Brief summary
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
DEVICEPressure 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 task and daily live activity performance wearing the PULSE device.
DEVICEPressure 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.
DEVICEVibrotactile 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.
Sponsors
University of Pisa
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
DEVICE_FEASIBILITY
Masking
NONE
Intervention model description
All the subjects test all the conditions after a waashout period between the different trial.
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Embodiment | 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". | A 7-point Likert scale-basede questionnaire will be use to determine the sense of embodiment. Scores range from "-3" to "+3", where "-3" indicates "completely disagree" and "+3" indicates "completely agree" |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Discrimination capability | 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". | Number of object recognized and errors during the discrimination task will be recorded |
| Activity test | 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". | The subject will perform a list of daily living activity. The researcher will time every activity and asses the percentual of integration of the prostetic limb in the activity. The activity performed will be: Unscrew and screw the cap of a water bottle Cut a piece of modeling clay using a knife and fork Unscrew and screw the lid of a jar Tear a sheet of paper into four pieces Draw a straight line on a sheet of paper using a ruler and pencil Cut a sheet of paper in half using scissors Fold a sheet of paper and place it into an envelope pen a sealed envelope Staple sheets of paper Close a shoe box with a ribbon Tie a scarf Open and close the zipper of a pencil case Squeeze toothpaste onto a toothbrush Spread a tablecloth on a table Roll up a poster and secure it with a rubber band Unscrew and screw the cap of a child-resistant medication bottle Open a glasses case and take out the pair of glasses Open a packet of paper tissues and take out one tissue Move a shoe box |
Countries
Italy
Contacts
CONTACTValentina Azzollini, MD
Outcome results
None listed