SCH: Context-aware Freezing of Gait Mitigation in Real-world Setting
Conditions: Parkinson Disease
Sponsor: Virginia Commonwealth University

Protocol Title:  SCH: Context-aware Freezing of Gait mitigation in real-world setting 
 
Identification: NCT NumberNCT04746846 
Unique Protocol IdHM20020085 
 
PI: Ingrid Pretzer-Aboff 
 
Version Date: 6/13/2023 
 
IRB approval date: 7/31/2023 

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Full Study Title: SCH: Context-aware Freezing of Gait mitigation in real-world setting 
PROTOCOL DOCUMENT  
4.2. Study Design:  
 
4.2.a.    Narrative Study Description 
Design. This is a single site clinical trial involving 3 tasks with the purpose of development and testing 
feasibility of a device.  In total, 32 participants with Parkinson’s disease (PD) who experience freezing of gait 
(FoG) will complete this 3-year study. We will enroll up to 50 participants to account for screen fails and 
withdrawals. 
 
Procedures. All procedures are performed exclusively for research purposes. After obtaining consent from the 
PD patient, a member of the research team will administer the Montreal Cognitive Assessment (MoCA) test to 
determine cognitive eligibility (must score at 21 or higher to be eligible). If the participant is eligible, they will be 
assigned a code number, then asked to complete a demographic form, a physical performance test (10-Meter 
Walk test) and the remaining scales in Table 1, to capture relevant physical and neuropsychological 
covariates. 
 
Table 1. Physical and Neuropsychological Scales (total participant time for all the below measures is 30 minutes). 
 
Factor 
Validated Scale 
Cognition 
Montreal Cognitive Assessment [1] 
Fatigue 
Parkinson’s Disease Fatigue Scale [2] 
Balance Confidence 
Activities-specific Balance Confidence (ABC) scale [3] 
Fear of Falling 
Falls Efficacy Scale-International [4] 
Quality of Life 
Parkinson’s Disease Questionnaire-8 [5] 
Freezing of Gait 
New Freezing of Gait questionnaire [6] 
Nonmotor Symptoms 
MDS-UPDRS part 1 questionnaire [7] 
Walking Speed and Step Length 
10 Meter Walk Test [8] 
 
All 32 participants will be screened with the same inclusion and exclusion criteria described in section 2.2 
above. All will undergo the same consenting procedure described above. Each study participant will wear a 
safety belt and have trained spotters to deter falls. The specific procedures for each of the 3 tasks are as 
follows: 
 
In Task 1, a convenience sample of five participants will be recruited for CNN model training. For each patient, 
we plan to collect data for 2.8 hours, among which at least 17 minutes will be FoG data. Each participant will 
be asked to wear one UG motion sensor (watch like device with a soft band) around each ankle to collect raw 
data that will be used to detect FoG and develop models. They will be video-taped (for the purpose of 
validating the FoG detection models) as they walk each of the five 5-meter FoG triggering courses illustrated in 
Figure 1. All assessments in Task 1 will be performed on PD participants who are OFF their PD medications 
(overnight washout) to maximize the amount of time spent in FoG, thereby minimizing the length of evaluation 
time [19]. It is common in both clinical practice and research studies to bring PD patients in for assessments off 
their PD medications; thus, this is not anticipated to be a barrier to recruitment. The 6 participants in Task 1 will 
not participate in Task 2 & 3.  
 
Task #1: Each subject is expected to spend up to 4 hours in the clinical lab, one visit. This can be divided into 
two sessions if the subject prefers.  
 
 
 
 
 

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Figure 1: Five FoG Triggering Scenarios shall include a 5-meter walking path with one of 5 triggers inserted into the path: (A) walking  
through a narrow passage, (B) turning 540 degrees, (C) approaching a destination (e.g., chair), (D) walking while dual tasking (e.g., 
performing a verbal fluency challenge while walking), and (E) a time sensitive task such as walking through an elevator door 
before it closes. 
 
 
Table 2. Task 2 Neuropsychological Scales (total participant time for all the below measures is 88 to 118 minutes). 
 
Anxiety 
State Trait Anxiety Inventory (STAI- State & Trait) [9] 
Positive and Negative Affect Schedule (PANAS-State) [10] 
Semi-structured qualitative interview 
Salivary Alpha-Amylase [11-13] 
Sleep 
RegUlarity, Satisfaction, Alertness, Timing, Efficiency, and Duration (RU SATED) [14] 
Insomnia Severity Index (ISI) [15] 
Pittsburgh Sleep Quality index (PSQI) [16] 
Actigraph 
Consensus Sleep Diary [17] 
Self-Efficacy 
General Self-Efficacy Scale (GSE) [18] 
Illness Self-Concept 
Illness Self-Concept Scale (ISCS) [19-20] 
 
The goals of Task 2 are to (1) determine the optimal frequency and vibration settings to mitigate freezing of 
gait (FoG) and (2) explore the role of neuropsychological factors such as sleep and anxiety in FoG outcomes 
(see Table 1 & 2). Thus, response surface methodology is proposed. Specifically, a central composite design 
(CCD) [38] will be used to determine the best dose of vibration (frequency and amplitude) for each of five 
common triggers for FoG (Figure 1). Estimating the response surface requires only a small sample of human 
participants, e.g., one participant for each design point with five repeats at the center point. For the current 
project, a convenience sample of only 13 participants with PD who experience FoG in at least two of the 
scenarios, confirmed by a neurologist will be needed. The 13 participants will be asked to walk through each of 
five, 5-meter walking courses that will each include one of the triggering scenarios. Each of the 13 PD 
participants with FoG will be randomly assigned to one of 9 different ff and va settings as prescribed by the 
CCD. In the current case, the goal is to estimate the ff and va settings that will maximize the difference 
between the baseline (no vibration) and post-treatment time spent in a FoG state for each of the 5 triggering 
scenarios individually and in total. Measurements will be taken once at baseline and again in triplicate as they 
walk the paths wearing the FoG detection/vibration device. 
 
Additional activities for Task 2 participants: 
Visit #1: After the consenting process is completed, a sample of saliva will be collected (see procedure below) 
to measure salivary alpha amylase levels at baseline. The UG device and PDVibe3 will be placed on the 
participants who will then perform a 10-meter walk test on site and a baseline walk of the five triggering 

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scenarios. They will complete the questionnaires/scales listed in tables 1 and 2. Participants will then be 
instructed on how to wear the actigraph device on their dominant wrist (Actigraph GT9X Link) to collect 
objective sleep data for up to 14 days prior to their Visit #2. They will also be instructed on how to complete the 
sleep diary during the same time period during which the actigraph is collecting sleep data. Visit #1 will last 
approximately 90 minutes. 
Participants will wear the ActiGraph GT9X Link for up to 14 consecutive, 24-hour days beginning at baseline, 
pre-intervention. Actigraphs are devices that are worn on the dominant wrist and contain a built-in 
accelerometer that records movements in order to estimate sleep parameters, including total sleep time, sleep-
onset latency, wake after sleep onset, and sleep efficiency. Sleep data will be analyzed using the ActiLife 6.0 
data analysis software platform and bedtime and waketime will be verified via sleep diary-reported data. Prior 
to receiving the actigraph, participants will receive verbal instructions regarding the purpose of the actigraph 
(i.e., that the actigraph records movement to estimate sleep parameters) as well as appropriate use (i.e. should 
be worn on the dominant wrist at all times for up to fourteen consecutive days unless bathing, swimming, etc.). 
Participants will be provided with moleskin as necessary to minimize risk of skin abrasion. Participants will be 
encouraged to reach out to study personnel with any questions or concerns related to wearing the actigraph 
device while at home. 
 
Participant saliva will be collected with the aim to assess salivary alpha amylase, a biomarker shown to be a 
reliable indicator of anxiety and stress in individuals with PD. Saliva sample collection will occur three times 
over the course of Task 2- at baseline (Visit #1), pre walking tasks and post walking tasks (Visit #2). Saliva will 
be collected using a passive drool method, a method of saliva collection that requires participants to lean 
forward and allow saliva to naturally pool into the collection vessel rather than actively spitting. This method of 
saliva collection allows for whole saliva to be collected, avoiding localized salivary secretions and providing for 
a more consistent biospecimen. Saliva samples will be collected utilizing Salimetrics Saliva Collection Aid, a 
mechanism which fits securely into a collection vial designed to reduce sample foaming and facilitates direct 
sample collection and storage. Samples will be refrigerated within 30 minutes of initial collection and frozen at 
or below -20 degrees Celsius within 4 hours of collection. Samples can be stored for up to 6 months and will be 
stored until all participant samples are collected, at which point an alpha amylase assay will be run. Prior to 
participating in saliva collection, participants will receive verbal instructions on how to correctly provide a saliva 
sample. Participants will be advised to avoid eating a major meal for at least one hour and will be asked to 
rinse their mouths thoroughly with water 10 minutes prior to collection.  
 
Visit #2:  In addition to what is described in Task #1 above, saliva samples will be collected from participants 
before and after their participation in the walking tasks. They will also complete 2 surveys, the STAI-State and 
PANAS-State after they finish walking. The sleep diary that was filled out at home will be collected from 
participant and actigraphy will be retrieved. Following completion of walking tasks, participants will be invited to 
schedule a time to engage in a semi-structured qualitative interview virtually or by phone. Visit #2 will last 
approximately 120 to 180 minutes). 
Visit #3: Participants will engage in a semi-structured interview via telephone or virtually according to 
participant preference. The interview will ask participants to reflect on and engage in discussion related to 
experiences of FoG; perceptions of the association between sleep, anxiety, and FoG; illness self-concept; 
mobility self-efficacy; general feedback about the interview and participation in the study overall (see submitted 
interview protocol document). Visit #3 will last approximately 30 to 60 minutes. 
 
Participants will be ON their PD medications during this phase of testing. The study staff, except for the PC, 
will be blinded to the treatment allocation. The PC will be setting the VibeForward vibration parameters (ff and 
va) for each participant according to a randomized list generated by the co-I and biostatistician, Dr. R.K. 
Elswick Jr. All participants will wear safety belts and have trained spotters to deter falls. Participants will be 
asked to also participate in Task 3.  
 
Task #2: Each subject is expected to spend up to 5 hours in the clinical setting, across three visits. 

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In Task 3 we will test the device at the optimal vibration setting in a “real world” setting. Due to the innovative 
nature of studying this device in a real-world environment, no pilot data exists from which to run a traditional 
power analysis. However, Van Belle proposed that a minimum of 12 observations should be used to calculate 
confidence intervals based on the t-statistic with n – 1 degrees of freedom. This rule is based on the fact that 
the half-width confidence interval for the mean decreases rapidly up to n = 12, at which point the decrease is 
less dramatic and the half-width curve begins to asymptotically decrease. Thus, in order to ensure the good 
estimates of the means and variances (pre- and post-) [39] a convenience sample of thirteen volunteers who 
have been diagnosed with PD by a neurologist and who exhibit FoG will be asked to participate in the testing 
of the device.  
 
Participants will walk the pathway once without vibration (pre-treatment), and then three times with vibration 
(post treatment). They will be ON their medications. We will compare the differences in the duration and 
number of FoG episodes, time walking through the path, average stride length, and speed of walking. It is 
anticipated that “pre” versus “post” trials for each of these five variables will be compared using a paired t-test.  
 
All participants in Task 3 will be described in terms of demographics, disease, and psychological 
characteristics as in Task 2. Detailed field notes will be made of observations from study staff and comments 
from subjects to record the extent and type of unpredictable challenges faced by each participant. Qualitative 
questions will be asked after each participant finishes the walking portion of the study. If a participant from 
Task 2 does not participate in Task 3, they will be replaced. The replacement will then complete the baseline 
walking portion and scales (Table 1) from Task 2 at a separate visit prior to completing Task 3. Patients from 
Task 2 will be reconsented for Task 3. 
 
When the PC contacts participants who have already completed Task 2 to participate in Task 3, the PC will ask 
if they want to participate in a follow-up phone call with the interviewer they spoke with earlier. If yes, the 
interviewer will contact the participants and will share the main overall themes that surfaced from qualitative 
analysis of completed interviews. Participants will be asked (via phone, zoom, or in-person) to provide their 
feedback on these overall themes. Their feedback will then be incorporated into final analysis and 
interpretation of qualitative interviews. It is anticipated that this will take from 15 – 30 minutes. Participants can 
decline this portion of the study. 
 
Participants in Task 3 will walk the 5 triggering scenarios (Figure 1) in a community setting (at the Short Pump 
Town Center) while wearing the UG device and the PDVibe3. Prior to walking in the community setting, 
participants will be consented and complete the questionnaires in Table 3 in a private VCU space (at the Short 
Pump Pavilion clinic).   
 
Table 3. Physical and Neuropsychological Scales (total participant time for all the below measures is 30 minutes). 
 
Factor 
Validated Scale 
Cognition 
Montreal Cognitive Assessment [1] 
Freezing of Gait 
New Freezing of Gait questionnaire [6] 
Motor Symptoms 
MDS-UPDRS part 3 [7] 
Walking Speed and Step Length 
10 Meter Walk Test [8] 
Fatigue 
Rating of Fatigue Scale [21] 
 
Task #3: Each subject that completed Task 2 is expected to spend up to 5 hours in the community setting 
(outside setting), and clinical setting, across two visits. Each subject that did not complete Task 2 is expected 
to spend up to 8 hours in the VCU clinical setting and an outside community setting, across two visits.