production of a device to obtain continuous ambulatory vestibular assessment (cava) - healthy volunteer trial

Conditions: Optokinetic Nystagmus

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.

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.

Eligibility criteria:
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

Keywords: eye movements electronystagmography nystagmus electrooculogram vestibular assessment