Trial Outcomes & Findings for Analysis and Suppression of Tremor During Grasp Using Ultrasound Imaging and Electrical Stimulation (NCT NCT05308368)

Last Updated: 2025-10-27

Results Overview

The investigators will use ultrasound features collected on participants to develop novel models for tremor that can accurately predict the joint position. The joint position measured by the IMU will used as a benchmark and the root mean squared error (RMSE \[Deg.\]) between the model's predicted joint angle and the true angle will be used as a metric. A higher RMSE (in the scale of 0-100%) implies lower model accuracy.

Recruitment status

COMPLETED

Study phase

Target enrollment

12 participants

Primary outcome timeframe

Through Completion of Study, an average of 3 years

Results posted on

2025-10-27

Participant Flow

2021-recruitment of 1 participant 2022- recruitment of 8 participants 2023- recruitment of 3 participants

Participant milestones

Participant milestones
Measure	Tremor Group Individuals with either parkinson's disease or essential tremor will be recruited in this group
Overall Study STARTED	12
Overall Study COMPLETED	12
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

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

Baseline characteristics by cohort

PRIMARY outcome

Timeframe: Through Completion of Study, an average of 3 years

Population: Only participants who completed assessment are included.

Outcome measures

Outcome measures
Measure	Tremor Group n=6 Participants Individuals with either parkinson's disease or essential tremor will be recruited in this group
Tremor Model Accuracy Tremor Model Prediction Accuracy without stimulation	24 Normalized RMSE (%) Standard Deviation 4.49
Tremor Model Accuracy Tremor Model Prediction Accuracy with stimulation	21 Normalized RMSE (%) Standard Deviation 2.66

PRIMARY outcome

Timeframe: Through Completion of Study, an average of 3 years

Population: Only participants who completed assessment are included in the analysis

The investigators will benchmark the performance of the ultrasound features (fascicle length \[mm\], muscle thickness \[mm\]) in detecting the actual tremor frequency (Hz) measured by an inertial measurement unit (IMU) sensor and electromyography (EMG). Here error between the tremor frequency measured with IMU and the ultrasound feature-derived tremor frequency is reported. A lower mean error (0-100%) implies higher concurrence with the IMU-derived or EMG-derived tremor frequency.

Outcome measures

Outcome measures
Measure	Tremor Group n=6 Participants Individuals with either parkinson's disease or essential tremor will be recruited in this group
Ultrasound Imaging Based Frequency Detection Frequency Comparison with EMG	6.4 Error percentage (%) Standard Deviation 0.39
Ultrasound Imaging Based Frequency Detection Frequency Comparison with IMU	8.9 Error percentage (%) Standard Deviation 0.57

PRIMARY outcome

Timeframe: Through Completion of Study, an average of 3 years

Population: Only participants who completed these experiments are included in the analysis

The investigators will use the developed tremor models to develop closed loop control methods using FES which enable tremor suppression. The goal of the controller will be to maintain a desired wrist angle position while performing a grasping motion. A tremor suppression ratio metric, formulated as 1-(W\_t/W\_b), where W\_t is the angular velocity of the wrist around the vertical during periods in which stimulation was turned on and W\_b is the angular velocity during baseline periods without any stimulation, is used as an evaluation metric. A higher tremor suppression ratio (0-100%) means higher effectiveness in suppressing the tremor.

Outcome measures

Outcome measures
Measure	Tremor Group n=8 Participants Individuals with either parkinson's disease or essential tremor will be recruited in this group
Tremor Suppression (Percentage)	62.4 Percentage Suppression Standard Deviation 18.93

Adverse Events

Tremor Group

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Nitin Sharma

NC State University

Phone: 9195130787

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place

Measure	Tremor Group n=12 Participants Individuals with either parkinson's disease or essential tremor will be recruited in this group Ultrasound Imaging: We will collect ultrasound images during the grasping motion for both groups Electromyography: 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): 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): 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 Ultrasound Imaging: We will collect ultrasound images during the grasping motion for both groups Electromyography: 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): 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): 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	Total n=12 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	—	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	4 Participants n=5 Participants	—	4 Participants n=5 Participants
Age, Categorical >=65 years	8 Participants n=5 Participants	—	8 Participants n=5 Participants
Sex: Female, Male Female	4 Participants n=5 Participants	—	4 Participants n=5 Participants
Sex: Female, Male Male	8 Participants n=5 Participants	—	8 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants n=5 Participants	—	0 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	12 Participants n=5 Participants	—	12 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	—	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants	—	0 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants	—	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	1 Participants n=5 Participants	—	1 Participants n=5 Participants
Race (NIH/OMB) Black or African American	0 Participants n=5 Participants	—	0 Participants n=5 Participants
Race (NIH/OMB) White	11 Participants n=5 Participants	—	11 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants	—	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	—	0 Participants n=5 Participants
Region of Enrollment United States	12 participants n=5 Participants	—	12 participants n=5 Participants