Analysis and Suppression of Tremor During Grasp Using Ultrasound Imaging and Electrical Stimulation

NCT ID: NCT05308368

Last Updated: 2025-10-27

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 12 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-04-11
• Study Completion Date: 2025-07-31

Brief Summary

Individuals experiencing tremors face difficulty performing activities of daily living caused by involuntary oscillation of the muscles in the hands and arms. Current solutions to help suppress tremors include medication, surgery, assistive devices and lifestyle change. However, each of these has a drawback of its own including cost and unwanted side effects. Aside from the solutions listed, it has been shown that functional electrical stimulation (FES) is a possible solution to help suppress tremor. Additionally, FES can be combined with different technologies including accelerometers, gyroscopes and motion capture to develop a closed loop system for tremor suppression. However, this has drawbacks including signal interference and the need for multiple sensor to fully classify the tremor. Ultrasound imaging solves some of these issues because it can provide a direct visualization of hand muscles that contribute to tremor. This study will focus on detecting characterizing and differentiating tremors from voluntary hand motion using ultrasound imaging. The results obtained from this study will help design FES-based tremor-suppression techniques in the future. This study will target both subjects with different tremor disorders and able bodied subjects.

Conditions

Parkinson Disease; Essential Tremor

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: OTHER
• Blinding Strategy: NONE

Study Groups

Tremor Group

Individuals with either parkinson's disease or essential tremor will be recruited in this group

Group Type: EXPERIMENTAL

Ultrasound Imaging

Intervention Type: DEVICE

We will collect ultrasound images during the grasping motion for both groups

Electromyography

Intervention Type: DEVICE

We will collect electromyography (EMG) signals of both the flexor and extensor muscles of the wrist during the grasping motion for both groups

Inertial Measurement Units (IMU)

Intervention Type: DEVICE

We will use data from the ultrasound images and EMG to develop a tremor model. The model will be validated in comparison to joint angle measurements from an Inertial Measurement Unit (IMU) collected during the grasping motion

Functional Electrical Stimulation (FES)

Intervention Type: DEVICE

We will use the develop closed-loop control methods for tremor suppression using information from the ultrasound-image based tremor models. FES will be used to provide stimulation that will help with tremor suppression

Able Body Group

Individuals with no disorders will be recruited in this group

Group Type: EXPERIMENTAL

Ultrasound Imaging

Intervention Type: DEVICE

We will collect ultrasound images during the grasping motion for both groups

Electromyography

Intervention Type: DEVICE

We will collect electromyography (EMG) signals of both the flexor and extensor muscles of the wrist during the grasping motion for both groups

Inertial Measurement Units (IMU)

Intervention Type: DEVICE

We will use data from the ultrasound images and EMG to develop a tremor model. The model will be validated in comparison to joint angle measurements from an Inertial Measurement Unit (IMU) collected during the grasping motion

Functional Electrical Stimulation (FES)

Intervention Type: DEVICE

We will use the develop closed-loop control methods for tremor suppression using information from the ultrasound-image based tremor models. FES will be used to provide stimulation that will help with tremor suppression

Interventions

Ultrasound Imaging

We will collect ultrasound images during the grasping motion for both groups

Intervention Type: DEVICE

Electromyography

We will collect electromyography (EMG) signals of both the flexor and extensor muscles of the wrist during the grasping motion for both groups

Intervention Type: DEVICE

Inertial Measurement Units (IMU)

We will use data from the ultrasound images and EMG to develop a tremor model. The model will be validated in comparison to joint angle measurements from an Inertial Measurement Unit (IMU) collected during the grasping motion

Intervention Type: DEVICE

Functional Electrical Stimulation (FES)

We will use the develop closed-loop control methods for tremor suppression using information from the ultrasound-image based tremor models. FES will be used to provide stimulation that will help with tremor suppression

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

1. At least 40 years of age, and no more than 90 years of age.

2. Meet UK Parkinson's disease brain bank diagnostic criteria

3. Have clinical evidence of rest tremor of one or both upper extremities defined as involuntary, rhythmic oscillations about any joint within the upper extremities

4. Tremor amplitude must be at minimum 1 cm as determined by expert opinion by a movement disorders specialist.

5. Due to the nature of measurements occurring during a grasp maneuver, the tremor must be deemed to become re-emergent with a fixed posture. This shall be defined by development of postural tremor that does not begin immediately upon grasping the vertical object, but instead with a delay in development of oscillatory movement of at least half a second as timed by a stopwatch, and that may grow in amplitude over seconds to maximum amplitude without changing the force of the grasp at first. Note that within-individual intermittency and variability of tremor can be influenced by anxiety, stress, cold temperature, and fatigue. In an effort to reduce this variability, we will have subjects perform tasks in a comfortable area, providing up to 20 minutes to allow them to relax in a temperature-neutral location, and reduce anxiety

Subjects will fall under the able body category if they exhibit no movement disorders and can perform grasping motion with no inhibition.

Exclusion Criteria

1. Muscle weakness as determined by Medical Research Council grade less than 5/5 on direct testing in the upper limb afflicted with rest tremor

2. Infection at the upper limb at time of assessment

3. Pre-existing, concomitant neuromuscular or cerebellar disorders

4. Use of medications that can alter the function of the neuromuscular junction.

5. Those with concomitant essential tremor as determined by history or confirmed by movement disorders specialist prior to assessments.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 90 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of North Carolina, Chapel Hill

OTHER

Sponsor Role: collaborator

North Carolina State University

OTHER

Sponsor Role: lead

Responsible Party

Nitin Sharma

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Engineering Building III

Raleigh, North Carolina, United States

Countries

United States

Provided Documents

Document Type: Study Protocol

View Document

Document Type: Statistical Analysis Plan

View Document

Other Identifiers

5R21EB032059

Identifier Type: NIH

Identifier Source: secondary_id

View Link

19247

Identifier Type: -

Identifier Source: org_study_id