Studies Into Touch in Healthy Humans to Provide Sensory Feedback in Prostheses

NCT05548322 | Recruiting

• 2 other identifiers: C21-192021-A01604-37
• Study Type: interventional
• Target: 210
• Locations: 1 country
• Sites: 2

Brief Summary

Our sense of touch is essential to explore our environment and experience life and is based on signals from receptors in the body that are sensitive to different types of stimulation. The TACTHUM projects aims to investigate the fundamental firing of mechanoreceptors in the body to various external stimuli, with an end-aim to better understand the human somatosensory system and to apply this knowledge to provide comprehensive sensory feedback in prosthetics. We have a vast system of peripheral receptors in the skin and muscles that provide us with exquisitely detailed information about our everyday interactions. When there is injury to a body part, such as in amputation, there is a significant loss of somatosensory input. Prosthetic devices have greatly developmed in the past few years, especially with the introduction of useful sensory feedback. However, there is a lot to discover both about the workings of the somatosensory system and how to recreate this to give feedback in a prosthetic device. The main objective of the TACTHUM project is to understand how to recover and apply useful somatosensory feedback in prostheses for amputees. There are a number of other sub-objectives, to:

1. 1.Determine how tactile mechanoreceptors encode the texture of natural surfaces during passive and active exploration.
2. 2.Investigate how our sense of touch varies with emotional state.
3. 3.Explore what happens to our sense of touch when we explore surfaces at different temperatures.
4. 4.Understand the origin of our perception of humidity.
5. 5.Investigate differences in the encoding of tactile information with age.
6. 6.Determine the perceptions generated by the stimulation of single tactile afferents.
7. 7.Study changes in spontaneous activity and responses to tactile stimulation on the residual limb of amputees.

Conditions

Somatosensory Disorders; Amputation; Tactile Disorders; Aging; Prosthesis User

Keywords

Touch; Temperature; Somarosensation; Prosthetics; Microneurography; Tactile; Mechanoreceptor

Outcome Measures

Primary Outcomes (1)

• Microneurography recording

  The discharge of a peripheral nerve fiber will be recorded during the stimulation conditions. From this recording, measures of the total number of impulses evoked, the instantaneous and average frequencies, firing variability, and frequency composition will be extracted.

  Measured during the experiment (single event, max. 6 hours), during stimulation intervention

Secondary Outcomes (7)

• Electrodermal response

  Measured during the experiment (single event, max. 6 hours), during stimulation intervention

• Heart rate

  Measured during the experiment (single event, max. 6 hours), during stimulation intervention

• Electromyography

  Measured during the experiment (single event, max. 6 hours), during stimulation intervention

• Electroencephalography

  Measured during the experiment (single event, max. 6 hours), during stimulation intervention

• Perceptual ratings of pleasantness

  Measured during the experiment (single event, max. 6 hours), directly after the stimulation intervention

Study Arms (7)

Study of tactile afferent responses to natural surfaces

EXPERIMENTAL

Device: Different surfaces to be touched

Modulation of touch according to the emotional state

EXPERIMENTAL

Device: Different surfaces to be touched; Behavioral: Emotional state change

Effect of temperature on tactile sensitivity

EXPERIMENTAL

Device: Different surfaces to be touched

Origin of wetness perception

EXPERIMENTAL

Device: Different surfaces to be touched

Aging and tactile sensitivity

EXPERIMENTAL

Device: Different surfaces to be touched; Behavioral: Emotional state change; Device: Electrical stimulation

Tactile perceptions induced by the stimulation of single sensory fibers

EXPERIMENTAL

Device: Electrical stimulation

Study of tactile feedback after amputation

EXPERIMENTAL

Device: Different surfaces to be touched; Device: Electrical stimulation

Interventions

Different surfaces to be touched DEVICE

The participant will touch various different surfaces and textures, including ones of different temperature and including solids and liquids.

Aging and tactile sensitivity; Effect of temperature on tactile sensitivity; Modulation of touch according to the emotional state; Origin of wetness perception; Study of tactile afferent responses to natural surfaces; Study of tactile feedback after amputation

Emotional state change BEHAVIORAL

The emotional state of the participant will be modulated by listening to music.

Aging and tactile sensitivity; Modulation of touch according to the emotional state

Electrical stimulation DEVICE

The participant will receive electrical stimulation of single nerve fibers (a few microamps) to artificially excite an individual afferent.

Aging and tactile sensitivity; Study of tactile feedback after amputation; Tactile perceptions induced by the stimulation of single sensory fibers

Eligibility Criteria

• Age: 20 Years - 70 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Men and women aged between 20 and 70.
• Be a member of a social security scheme, or a beneficiary of such a scheme
• Be calm enough to sit still for four hours.
• Specific for people participating in Arm 7 on amputees: People with an upper or lower limb amputation (unilateral) of more than 2 years.

You may not qualify if:

• Have peripheral neuropathy (diabetes, Raynaud's disease) or chronic muscle and/or sensory pain.
• Have a neurological or psychiatric history.
• Be subject to epilepsy.
• Be pregnant (declared) or breastfeeding, having given birth within the last year.
• Be afraid of injections.
• Being under dermatological treatment.
• Have a pacemaker.
• Not being able to understand the information leaflet and the consent form or sign it.
• Be subject to a legal protection measure (declarative)
• Be a protected adult (curatorship or guardianship)

Sponsors & Collaborators

• Institut National de la Santé Et de la Recherche Médicale, France: lead

Study Sites (2)

CNRS - Aix-Marseille University UMR7291

Marseille, 13003, France

RECRUITING

Hôpital HIA Lavéran

Marseille, 13013, France

NOT YET RECRUITING

MeSH Terms

Conditions

Somatosensory Disorders

Interventions

Electric Stimulation

Condition Hierarchy (Ancestors)

Sensation Disorders; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Physical Stimulation; Investigative Techniques

Study Officials

• Maya Elzeiere, MD

  CNRS - Aix-Marseille University

  PRINCIPAL INVESTIGATOR

• Rochelle Ackerley, PhD

  CNRS - Aix-Marseille University

  STUDY DIRECTOR

Central Study Contacts

Rochelle Ackerley, PhD

CONTACT

0033413550888; rochelle.ackerley@univ-amu.fr

Jean-Marc Aimonetti, PhD

CONTACT

0033413550833; jean-marc.aimonetti@univ-amu.fr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: SPONSOR

Model Details: Participants will take part in experiments that investigate the seven arms of the study. Participants with an amputation will only take part in arm 7. Healthy participants may take part in one to six arms (arms 1-6). However, this is dependent upon the recordings found in the experiment.

Study Record Dates

• First Submitted: September 2, 2022
• First Posted: September 21, 2022
• Study Start: April 15, 2024
• Primary Completion (Estimated): October 2, 2034
• Study Completion (Estimated): November 2, 2034
• Last Updated: March 4, 2026

Record last verified: 2026-03

Locations

FR (2)