Collision Warning Device for Blind and Visually Impaired

• ClinicalTrials.gov Identifier: NCT03057496
• Recruitment Status: Completed
• First Posted: February 20, 2017
• Results First Posted: December 21, 2020
• Last Update Posted: February 10, 2021
• Sponsor: Massachusetts Eye and Ear Infirmary
• Information provided by (Responsible Party): Alexandra Bowers, Massachusetts Eye and Ear Infirmary

Tracking Information

• First Submitted Date: February 14, 2017
• First Posted Date: February 20, 2017
• Results First Submitted Date: October 30, 2020
• Results First Posted Date: December 21, 2020
• Last Update Posted Date: February 10, 2021
• Actual Study Start Date: January 22, 2018
• Actual Primary Completion Date: November 8, 2019 (Final data collection date for primary outcome measure)

Current Primary Outcome Measures (submitted: October 30, 2020)

Number of Collision Incidents (All Contacts) [ Time Frame: During the one-month period of device use ]

Collision incidents recorded by the device in everyday use, including long cane contacts and body contacts with surrounding objects in the environment.

Original Primary Outcome Measures (submitted: February 15, 2017)

Number of collision incidents in everyday device use [ Time Frame: Number of collision incidents during the two-month period of device use ]

The primary outcome measure will be the difference in the number of collision incidents in the active and silent modes during everyday device use.

Current Secondary Outcome Measures (submitted: October 30, 2020)

• Number of Body Contacts [ Time Frame: During the one-month period of device use ]
  Collision incidents with body contacts recorded by the device
• Device Questionnaire [ Time Frame: During the one-month period of device use ]
  Questionnaire addressing participants' experiences of using the device. Scores were on a 5-point rating scale (1 to 5) with higher scores representing a better score. Questions were grouped into four main categories: i) overall satisfaction, ii) comfort, iii) mobility benefit, and iv) ease of operation. An average score was computed for questions within each category.

Original Secondary Outcome Measures (submitted: February 15, 2017)

• Indoor obstacle course - number of contacts [ Time Frame: Assessed at the final study visit (week 8) ]
  The number of obstacle contacts will be recorded on a high-density, indoor obstacle course. The difference in the number of contacts when using the device and when not using the device will be compared.
• Indoor obstacle course - preferred walking speed [ Time Frame: Assessed at the final study visit (week 8) ]
  Walking speed on the obstacle course will be quantified in terms of the percentage of preferred walking speed (PPWS) relative to walking on an obstacle-free path. The PPWS when using the device and when not using the device will be compared
• Independent mobility questionnaire [ Time Frame: Administered once at baseline without the device and once at the final study visit (week 8) ]
  Perceived level of mobility difficulties quantified using the Independent Mobility Questionnaire (rates level of difficulty with mobility in various situations on a 5-point scale)

• Current Other Pre-specified Outcome Measures: Not Provided
• Original Other Pre-specified Outcome Measures: Not Provided

Descriptive Information

• Brief Title: Collision Warning Device for Blind and Visually Impaired
• Official Title: Wearable Collision Warning Device for Blind and Visually Impaired: Clinical Trial (As Part of: 'Development of a Vision Assistive Device for Veterans With Traumatic Brain Injury-Associated Visual Dysfunctions')
• Brief Summary: This study evaluates a novel collision warning device to help people with severe vision impairment or blindness avoid collisions with obstacles. The main hypothesis to be tested is that the device reduces the number of collisions with obstacles in everyday activities.
• Detailed Description: Participants with blindness or severe visual field loss (hemianopia or tunnel vision) will be trained to use a collision warning device that alerts them to impending collisions. Participants will use the device at home during everyday mobility for about 1 month. The device is designed to supplement existing mobility devices, such as a long cane or dog guide. The device will provide warnings about potential collisions with mid- or high-level obstacles (which are typically not detected by a long cane).
• Study Type: Interventional
• Study Phase: Not Applicable

Study Design

Allocation: N/A
Intervention Model: Single Group Assignment
Intervention Model Description:

The device will operate in two modes: active mode (intervention condition), when it gives warnings and, silent mode (control condition), when it does not give warnings. The device will be programmed to generate a different randomized active/silent schedule for each subject. Participants will not know whether it is in the active or silent mode.

Masking: None (Open Label)
Masking Description:

Although this is a single-arm study, participants will be masked in the sense that they will not know whether the device is operating in the active mode (intervention condition), when it gives warnings, or the silent mode (control condition), when it does not give warnings. The device will be programmed to generate a different randomized active/silent schedule for each subject. The investigator conducting the statistical analyses will also be masked as to whether the device was in the active or silent mode

Primary Purpose: Other

Condition

• Hemianopia
• Hemianopsia
• Peripheral Visual Field Defect
• Blindness
• Retinitis Pigmentosa
• Glaucoma

Intervention

Device: Collision warning device

The collision warning device is a pocket-sized, electronic system that includes a micro-computer, a clip-on miniature camera, a gyro-sensor, an accelerometer, and a rechargeable battery, all contained within a shoulder bag. It is about the size of a smart phone. When a potential collision is detected by the device it emits a warning to the user, either in the form of an audible beep or a tactile warning through bracelets worn on the wrist. The time to collision will be coded in both the auditory and tactile domains. The device is designed to only give warnings about high risk collisions, so the users will not be continually bombarded by warnings for every potential collision object in the environment.

Study Arms

Experimental: Intervention

Participants will use the collision warning device as much as possible for about one month during everyday activities, when walking indoors and outdoors.

Intervention: Device: Collision warning device

• Publications *: Pundlik S, Baliutaviciute V, Moharrer M, Bowers AR, Luo G. Data Acquisition, Processing, and Reduction for Home-Use Trial of a Wearable Video Camera-Based Mobility Aid. Transl Vis Sci Technol. 2020 Jun 11;9(7):14. doi: 10.1167/tvst.9.7.14. eCollection 2020 Jun.

Recruitment Information

• Recruitment Status: Completed
• Actual Enrollment (submitted: November 24, 2020): 49
• Original Estimated Enrollment (submitted: February 15, 2017): 90
• Actual Study Completion Date: December 5, 2019
• Actual Primary Completion Date: November 8, 2019 (Final data collection date for primary outcome measure)

Eligibility Criteria

Inclusion Criteria:

• Blindness (or very limited vision with visual acuity no better than "counting fingers"),
• Or severe peripheral field loss / tunnel vision (≤ 40° remaining visual field) with visual acuity of at least 20/200,
• Or homonymous hemianopia with visual acuity of at least 20/200;
• Able to walk independently either with or without mobility aids such as a long cane or guide dog (but without the aid of a sighted guide);
• Reports at least minor bumps or collisions within the last 3 months;

Exclusion Criteria:

• Currently participating in a mobility training program
• Diagnosed dementia
• Significant cognitive decline
• Participants with hemianopia will be excluded if they have hemianopia for less than 3 months and/or have spatial neglect

Sex/Gender

• Sexes Eligible for Study: All

• Ages: 18 Years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Contacts: Contact information is only displayed when the study is recruiting subjects
• Listed Location Countries: United States

Administrative Information

• NCT Number: NCT03057496
• Other Study ID Numbers: 1007377
• Has Data Monitoring Committee: No

U.S. FDA-regulated Product

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: Yes
• Product Manufactured in and Exported from the U.S.: No

IPD Sharing Statement

• Plan to Share IPD: No

• Responsible Party: Alexandra Bowers, Massachusetts Eye and Ear Infirmary
• Study Sponsor: Massachusetts Eye and Ear Infirmary
• Collaborators: Not Provided

Investigators

• Principal Investigator: Alex Bowers, PhD; Schepens Eye Research Institute, Mass Eye and Ear
• Principal Investigator: Gang Luo, PhD; Schepens Eye Research Institute, Mass Eye and Ear

• PRS Account: Massachusetts Eye and Ear Infirmary
• Verification Date: January 2021