Production of a Device to Obtain Continuous Ambulatory Vestibular Assessment (CAVA) - Healthy Volunteer Trial

• Sponsor: Julie Dawson (Other)
• Overall Status: Completed
• CT.gov ID: NCT03661762
• Collaborator: University of East Anglia (Other), Medical Research Council (Other)
• Enrollment: 18
• Location: 1
• Actual Duration (Months): 7.4
• Patients Per Site Per Month: 2.4

Study Details

Study Description

Brief Summary

Clinical investigation of a medical device (CAVA) for recording eye movements. Healthy volunteers will wear the device for 23 hours a day, for 30 days. On 8 separate days of the trial they will induce optokinetic nystagmus (a normal reflex in response to full-field motion) by watching a short video of less than 1 minute in duration. The data will be analysed offline by a scientist, who will attempt to identify the dates that the nystagmus was induced.

Condition or Disease	Intervention/Treatment	Phase
Optokinetic Nystagmus	Device: CAVA

Detailed Description

Dizziness is a common condition that is responsible for a significant degree of material morbidity and burden on the National Health Service. There are multiple causes of dizziness, and these originate from pathologies affecting a large variety of different organ systems. Dizziness is usually episodic and short-lived, so when a patient presents to their health care provider, examination is often normal. As such, diagnosis is challenging and patients often experience significant delay in receiving a diagnosis. The investigators have developed a prototype device for monitoring dizziness and have tested it in a small group of volunteers. The results showed that their device is capable of accurately, precisely and reliably identifying periods of dizziness over a short period of time. Independent market research has confirmed that their device could meet the required clinical need, would be desired by clinicians, and that there is no equivalent solution currently available. The investigators have received an award from the Medical Research Council to trial their device in a large cohort of healthy volunteers. Once completed, they will be positioned well to test their device in a cohort of patients with a defined dizziness syndrome, before further testing their device in a more diverse patient population. Once validated, developed and brought to market, the device would provide early diagnosis and accurate treatment for a significant proportion of the patient population. This would save the National Health Service money by reducing multiple visits to General Practitioner clinics, reducing referrals to multiple specialist clinics, and reducing treatment required from falls and other conditions associated with dizziness.

The overall aim of this trial is to test a fully evolved device for the continuous recording of eye movements over a prolonged period of time. For the purpose of this study, the monitoring period is 23 hours a day, for 30 days. The device is composed of two components: a bespoke single-use sensor array that adheres to the participant's face, and a small reusable module that contains a battery, microcomputer, data storage facility, battery and connection port.

The investigators intend to confirm that the device will be able to capture any occurrence, of a minimum period of thirty seconds, of artificially induced nystagmus, within a 24-hour period of time. Each participant will be provided with the device and enough single-use electrode arrays to allow the array to be changed every 24 hours, for thirty days. Participants will be allowed to remove the sensor array for up to 60 minutes each day to allow them to wash and/or shower. On eight of the thirty days for which they wear the array, each participant will be required to induce physiological nystagmus by viewing optokinetic video footage. The footage will be viewed on a portable screen (of a deactivated mobile phone) inside a Virtual Reality headset. These will be issued to the participants at the beginning of the trial. Participants will undertake the procedure whilst stationary for the first four days, and whilst walking gently on the spot for the remaining four days. The identity of these days will not be revealed to the blinded investigator who will later analyse the data. At the end of the thirty-day trial, the sensitivity and specificity of the device will be determined by assessing whether the data can be used to correctly identify the dates that participants induced nystagmus.

Study Design

• Study Type: Observational
• Actual Enrollment: 18 participants
• Observational Model: Cohort
• Time Perspective: Other
• Official Title: Production of a Device to Obtain Continuous Ambulatory Vestibular Assessment (CAVA) - Healthy Volunteer Trial
• Actual Study Start Date: Aug 23, 2018
• Actual Primary Completion Date: Dec 12, 2018
• Actual Study Completion Date: Apr 5, 2019

Arms and Interventions

Arm	Intervention/Treatment
Healthy Volunteers All trial participants are within this group. All trial participants will wear the CAVA device for up to 23 hours a day, for 30 days.	Device: CAVA; prototype device for monitoring dizziness

Outcome Measures

Primary Outcome Measures

1. Sensitivity and Specificity of a Computer Algorithm to Detect Artificially Induced Nystagmus [30 days]

   Dates containing nystagmus. Of the ~450 days' worth of data captured during the study, 120 will contain artificially induced nystagmus. A computer algorithm has been developed at the University of East Anglia for detecting nystagmus. The key measurements are the sensitivity and specificity of the algorithm's results when applied to data captured during the trial. This measurement will be assessed post-trial.

Secondary Outcome Measures

1. Post-trial Participant Questionnaire. [30 days]

   A 2-page questionnaire producing qualitative and quantitative data. Participants rate different aspects of their experiences with the device using a sliding scale and have the opportunity to write more detailed descriptions.

2. Compliance With the Device. [30 days]

   1 - There is a minimum of 80% compliance with wearing the device for each single day of the trial for a minimum of 80% of participants. 2 There is a minimum of 80% compliance with wearing the device for the entirety of the 30-day trial for a minimum of 80% of participants.

3. Data Usefulness [30 days]

   The device provides less than 5% non-useful data for each participant. We will report the percentage of non-useful data (corrupted or flat-line data) that is captured for each participant.

4. Data Usefulness [30 days]

   The device provides less than 5% non-useful data for the entirety of the 30-day trial across all participants. We will report the percentage of non-useful data (corrupted or flat-line data) that is captured over the entire trial, across all participants.

5. Event Marker Functioning [30 days]

   During a return visit, the event marker on each device will be pressed and the time noted. Post-trial, the data on the device will be examined to confirm that an event was recorded on the correct date. This will produce either a positive or negative outcome, depending on whether the event marker button press is present in the data or not. The percentage of identifiable button presses across all devices will be reported.

6. Time Stamp Accuracy [30 days]

   The difference will be calculated between the time noted by the research team and the time logged by the device when the event marker was activated. The time difference (in hh:mm:ss) will be calculated across all devices and we will report the average and standard deviation of the clock drift.

7. Accelerometer Functioning [30 days]

   Participants will perform a number of head movements and the device data will be examined visually to confirm that they can be identified. This will produce either a positive or negative outcome for each head movement, depending on whether the movement is visible in the data or not. The proportion of successfully identified head movements will be reported.

8. Accuracy of Nystagmus Beat Direction [1 hour]

   Participants will undergo caloric testing at the end of the trial, during which they will wear conventional Videonystagmography (VNG) goggles as well as the CAVA device. The beat direction (whether the fast phase of the nystagmus is towards the left or right ear) will be determined from both sources of data during the period of nystagmus captured. This will produce either a positive or negative outcome, depending on whether the beat direction matches in both data sources. The proportion of matches will be reported.

9. Accuracy of Nystagmus Onset Time [1 hour]

   Also from the data captured during caloric testing, the start time of nystagmus will be identified from both the VNG data and data captured by the CAVA device. The time difference (in mm:ss) will be calculated between the two data sources and the mean time difference will be reported.

10. Accuracy of Nystagmus Finishing Time [1 hour]

    Also from the data captured during caloric testing, the finishing time of nystagmus will be identified from both the VNG data and data captured by the CAVA device. The time difference (in mm:ss) will be calculated between the two data sources and the mean time difference will be reported.

11. Accuracy of Nystagmus Peak Time [1 hour]

    Also from the data captured during caloric testing, the time at which the nystagmus reaches its maximum slow phase velocity will be calculated from the VNG data and the data captured by the CAVA device. The time difference (in mm:ss) will be calculated between the two data sources and the mean time difference will be reported.

12. Accuracy of Nystagmus Frequency [1 hour]

    Also from the data captured during caloric testing, the number of beats will be counted during the period identified as the nystagmus peak time. This will be calculated for both the VNG data and the data captured by the CAVA device. From the number of beats and time duration examined, the frequency of the nystagmus will be determined. The difference between the two systems will be calculated and the mean difference will be reported. The Unit of Measure will be Hz (number of beats per second).

13. Data Drop-outs [30 days]

    The device provides less 5 drop-outs for each single day of the trial for each participant. We will report the maximum number of drop-outs (periods when the device stopped logging) per participant, per day.

14. Data Drop-outs [30 days]

    The device provides less 60 drop-outs for the entirety of the 30-day trial across all participants. We will report the total number of drop-outs that occurred over the entire trial, across all participants.

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years and Older
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

Inclusion Criteria:

• Adults aged 18 and over

• Able to commit to 30 days of continuous wear of the trial device as per the study plan

• Own a telephone

Exclusion Criteria:

• Potential participants who have a history of dermatological disease or damage around the forehead

• Potential participants who have an allergy to plasters and/or medical adhesives

• History of dizziness, vertigo, balance disorders, or syncope

• History of hypertension or cardiac problems (uncontrolled, acute or de-compensated phase)

• History of ear disease, or previous ear surgery

• History of psychotic/neurotic disorders or epilepsy

• History of eye disease, or previous eye surgery

• Unable to follow the testing protocol

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Norfolk and Norwich University Hospitals NHS Foundation Trust	Norwich	Norfolk	United Kingdom	NR4 7UY

Sponsors and Collaborators

• Julie Dawson
• University of East Anglia
• Medical Research Council

Investigators

• Principal Investigator: John Phillips, Consultant, Clinical Research and Trials Unit (Norfolk & Norwich University Hospital, UK)

Study Documents (Full-Text)

• Study Protocol and Statistical Analysis Plan - Sep 20, 2018

More Information

Publications

None provided.

• Responsible Party: Julie Dawson, Manager Research Services, Norfolk and Norwich University Hospitals NHS Foundation Trust
• ClinicalTrials.gov Identifier: NCT03661762
• Other Study ID Numbers: 240847 (28-02-18)
• First Posted: Sep 7, 2018
• Last Update Posted: Dec 10, 2020
• Last Verified: Nov 1, 2020

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: No
• Keywords provided by Julie Dawson, Manager Research Services, Norfolk and Norwich University Hospitals NHS Foundation Trust: eye movements; electronystagmography; nystagmus; electrooculogram; vestibular assessment
• Additional relevant MeSH terms: Nystagmus, Pathologic

Study Results

Participant Flow

Arm/Group Title	Healthy Volunteers
Arm/Group Description	All trial participants are within this group. All trial participants will wear the CAVA device for up to 23 hours a day, for 30 days.
Period Title: Overall Study
STARTED	18
COMPLETED	10
NOT COMPLETED	8

Baseline Characteristics

Arm/Group Title	Healthy Volunteers
Arm/Group Description	All trial participants are within this group. All trial participants will wear the CAVA device for up to 23 hours a day, for 30 days. CAVA: prototype device for monitoring dizziness
Overall Participants	18
Age (Count of Participants)
<=18 years	0 0%
Between 18 and 65 years	18 100%
>=65 years	0 0%
Sex: Female, Male (Count of Participants)
Female	12 66.7%
Male	6 33.3%
Race and Ethnicity Not Collected (Count of Participants)
Healthy Volunteers (Count of Participants)
Count of Participants [Participants]	18 100%

Outcome Measures

1. Primary Outcome

Title	Sensitivity and Specificity of a Computer Algorithm to Detect Artificially Induced Nystagmus
Description	Dates containing nystagmus. Of the ~450 days' worth of data captured during the study, 120 will contain artificially induced nystagmus. A computer algorithm has been developed at the University of East Anglia for detecting nystagmus. The key measurements are the sensitivity and specificity of the algorithm's results when applied to data captured during the trial. This measurement will be assessed post-trial.
Time Frame	30 days

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Healthy Volunteers
Arm/Group Description	All trial participants are within this group. All trial participants will wear the CAVA device for up to 23 hours a day, for 30 days.
Measure Participants	17
Sensitivity	99.1
Specificity	98.6

2. Secondary Outcome

Title	Post-trial Participant Questionnaire.
Description	A 2-page questionnaire producing qualitative and quantitative data. Participants rate different aspects of their experiences with the device using a sliding scale and have the opportunity to write more detailed descriptions.
Time Frame	30 days

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

3. Secondary Outcome

Title	Compliance With the Device.
Description	1 - There is a minimum of 80% compliance with wearing the device for each single day of the trial for a minimum of 80% of participants. 2 There is a minimum of 80% compliance with wearing the device for the entirety of the 30-day trial for a minimum of 80% of participants.
Time Frame	30 days

Outcome Measure Data

Analysis Population Description

For the 30-day trial compliance, the number of participants differs as not all participants completed the trial in full.

Arm/Group Title	Healthy Volunteers
Arm/Group Description	All trial participants are within this group. All trial participants will wear the CAVA device for up to 23 hours a day, for 30 days.
Measure Participants	17
Daily compliance	82 455.6%
30-day compliance	100 555.6%

4. Secondary Outcome

Title	Data Usefulness
Description	The device provides less than 5% non-useful data for each participant. We will report the percentage of non-useful data (corrupted or flat-line data) that is captured for each participant.
Time Frame	30 days

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Healthy Volunteers
Arm/Group Description	All trial participants are within this group. All trial participants will wear the CAVA device for up to 23 hours a day, for 30 days.
Measure Participants	17
Mean (Standard Deviation) [Percentage of non-useful data]	0 (0)

5. Secondary Outcome

Title	Data Usefulness
Description	The device provides less than 5% non-useful data for the entirety of the 30-day trial across all participants. We will report the percentage of non-useful data (corrupted or flat-line data) that is captured over the entire trial, across all participants.
Time Frame	30 days

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Healthy Volunteers
Arm/Group Description	All trial participants are within this group. All trial participants will wear the CAVA device for up to 23 hours a day, for 30 days.
Measure Participants	17
Number [percentage of non-useful data]	0

6. Secondary Outcome

Title	Event Marker Functioning
Description	During a return visit, the event marker on each device will be pressed and the time noted. Post-trial, the data on the device will be examined to confirm that an event was recorded on the correct date. This will produce either a positive or negative outcome, depending on whether the event marker button press is present in the data or not. The percentage of identifiable button presses across all devices will be reported.
Time Frame	30 days

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Healthy Volunteers
Arm/Group Description	All trial participants are within this group. All trial participants will wear the CAVA device for up to 23 hours a day, for 30 days.
Measure Participants	17
Number [percentage of button presses identified]	100

7. Secondary Outcome

Title	Time Stamp Accuracy
Description	The difference will be calculated between the time noted by the research team and the time logged by the device when the event marker was activated. The time difference (in hh:mm:ss) will be calculated across all devices and we will report the average and standard deviation of the clock drift.
Time Frame	30 days

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Healthy Volunteers
Arm/Group Description	All trial participants are within this group. All trial participants will wear the CAVA device for up to 23 hours a day, for 30 days.
Measure Participants	17
Mean (Standard Deviation) [minutes per day]	-17.49 (1.47)

8. Secondary Outcome

Title	Accelerometer Functioning
Description	Participants will perform a number of head movements and the device data will be examined visually to confirm that they can be identified. This will produce either a positive or negative outcome for each head movement, depending on whether the movement is visible in the data or not. The proportion of successfully identified head movements will be reported.
Time Frame	30 days

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Healthy Volunteers
Arm/Group Description	All trial participants are within this group. All trial participants will wear the CAVA device for up to 23 hours a day, for 30 days.
Measure Participants	17
Slow head turning	97
Slow head nodding	100
Slow head tilting	100
Fast head turning	93
Fast head nodding	100
Fast head tilting	97

9. Secondary Outcome

Title	Accuracy of Nystagmus Beat Direction
Description	Participants will undergo caloric testing at the end of the trial, during which they will wear conventional Videonystagmography (VNG) goggles as well as the CAVA device. The beat direction (whether the fast phase of the nystagmus is towards the left or right ear) will be determined from both sources of data during the period of nystagmus captured. This will produce either a positive or negative outcome, depending on whether the beat direction matches in both data sources. The proportion of matches will be reported.
Time Frame	1 hour

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

10. Secondary Outcome

Title	Accuracy of Nystagmus Onset Time
Description	Also from the data captured during caloric testing, the start time of nystagmus will be identified from both the VNG data and data captured by the CAVA device. The time difference (in mm:ss) will be calculated between the two data sources and the mean time difference will be reported.
Time Frame	1 hour

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

11. Secondary Outcome

Title	Accuracy of Nystagmus Finishing Time
Description	Also from the data captured during caloric testing, the finishing time of nystagmus will be identified from both the VNG data and data captured by the CAVA device. The time difference (in mm:ss) will be calculated between the two data sources and the mean time difference will be reported.
Time Frame	1 hour

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

12. Secondary Outcome

Title	Accuracy of Nystagmus Peak Time
Description	Also from the data captured during caloric testing, the time at which the nystagmus reaches its maximum slow phase velocity will be calculated from the VNG data and the data captured by the CAVA device. The time difference (in mm:ss) will be calculated between the two data sources and the mean time difference will be reported.
Time Frame	1 hour

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

13. Secondary Outcome

Title	Accuracy of Nystagmus Frequency
Description	Also from the data captured during caloric testing, the number of beats will be counted during the period identified as the nystagmus peak time. This will be calculated for both the VNG data and the data captured by the CAVA device. From the number of beats and time duration examined, the frequency of the nystagmus will be determined. The difference between the two systems will be calculated and the mean difference will be reported. The Unit of Measure will be Hz (number of beats per second).
Time Frame	1 hour

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

14. Secondary Outcome

Title	Data Drop-outs
Description	The device provides less 5 drop-outs for each single day of the trial for each participant. We will report the maximum number of drop-outs (periods when the device stopped logging) per participant, per day.
Time Frame	30 days

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Healthy Volunteers
Arm/Group Description	All trial participants are within this group. All trial participants will wear the CAVA device for up to 23 hours a day, for 30 days. CAVA: prototype device for monitoring dizziness
Measure Participants	17
Mean (Standard Deviation) [Number of drop outs]	0.2353 (0.4372)

15. Secondary Outcome

Title	Data Drop-outs
Description	The device provides less 60 drop-outs for the entirety of the 30-day trial across all participants. We will report the total number of drop-outs that occurred over the entire trial, across all participants.
Time Frame	30 days

Outcome Measure Data

Analysis Population Description

Healthy volunteers

Arm/Group Title	Healthy Volunteers
Arm/Group Description	All trial participants are within this group. All trial participants will wear the CAVA device for up to 23 hours a day, for 30 days.
Measure Participants	17
Number [Total number of drop outs]	4

Adverse Events

Time Frame	30 days
Arm/Group Title	Healthy Volunteers
Arm/Group Description	All trial participants are within this group. All trial participants will wear the CAVA device for up to 23 hours a day, for 30 days.
All Cause Mortality
	Healthy Volunteers
	Affected / at Risk (%)	# Events
Total	0/18 (0%)
Serious Adverse Events
	Healthy Volunteers
	Affected / at Risk (%)	# Events
Total	0/18 (0%)
Other (Not Including Serious) Adverse Events
	Healthy Volunteers
	Affected / at Risk (%)	# Events
Total	10/18 (55.6%)
Product Issues
Disturbed sleep	1/18 (5.6%)	1
Respiratory, thoracic and mediastinal disorders
Sore throat	1/18 (5.6%)	1
Swollen lymph nodes	1/18 (5.6%)	1
Skin and subcutaneous tissue disorders
Over rubbed under left eye	1/18 (5.6%)	1
Erosion under all electrode sites	1/18 (5.6%)	1
Redness under electrodes	8/18 (44.4%)	8
Allergic reaction	1/18 (5.6%)	1

Limitations/Caveats

[Not Specified]

More Information

Certain Agreements

All Principal Investigators ARE employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.