Problem:
Disposable eye shields are used by healthcare workers to create a physical barrier in front of the healthcare worker’s eyes, which is clear (see-through) and doesn’t distort their vision or field of view. Disposable eye shields prevent droplets coming into contact with the healthcare worker’s eyes, which can be a route for infection in COVID-19. If a patient is Covid positive or in droplet isolation the healthcare worker will wear a full face shield, for every other setting the healthcare worker may wear eye shield frames and visors. A disposable eye shield is donned when going to see a patient, and will be doffed immediately after the patient has been seen. Disposable eye shields are of two parts: a visor (which the HCW sees through) and the frame (which holds the visor in front of their eyes. In certain circumstances, the visor alone may be disposed of, and the frame reused. One disposable eye shield (or visor, if the frame is being reused) is consumed with each patient visit. There are specific guidelines both donning and doffing this PPE (therefore, a consideration in design is that these guidelines can be followed).

Statement of need:

HSPC “Interim Guidance for use of PPE COVID 19 v1.0 17_03_20.pdf” describes eye protection as required PPE in the following situations:

Eye protection/Face visor: should be worn when there is a risk of contamination to the eyes from splashing of blood, body fluids, excretions or secretions (including respiratory secretions):
-Surgical mask with integrated visor
-Full face shield or visor
-Goggles / safety spectacles

Eye protection is considered required PPE by the HSPC “Interim Guidance for use of PPE COVID 19 v1.0 17_03_20.pdf” in the following clinical situations (summarised here, refer to link for full details):
-Patients with respiratory symptoms/suspected/confirmed COVID-19 who require an aerosol generating procedure
-Patients with respiratory symptoms/suspected/confirmed COVID-19 who do not require an aerosol generating procedure but do require high contact patient care activities that provide increased risk for transfer of virus and other pathogens to the hands and clothing of healthcare workers (this includes a wide range of activities including examinations, device monitoring/ care and transferring patients. Full list available in PDF - but the range of situations is broad)
-Patients with respiratory symptoms/suspected/confirmed COVID-19 where the tasks being performed are unlikely to provide opportunities for the transfer of virus/other pathogens to the hands and clothing

The document further states:
“Decontamination of eye/face protection for example goggles where there is a shortage of equipment
In situations where there is a shortage of disposable eye protection AND the activity being undertaken involves a high risk of splash or spray to
the eyes, HCWs may reuse goggles/safety spectacles.
Where reuse of eye protection is being considered
-Ensure there is no obvious signs of damage – Discard if signs of damage
-Ensure there are no cloth elements - items with cloth elements cannot be effectively decontaminated
-Check they are visibly clean before attempting to decontaminate – Discard if visibly soiled with blood/body fluids including respiratory secretions as heavily soiled items cannot be effectively decontaminated.
-The item should then be carefully decontaminated using a disinfectant wipe.

The risk of reusing Eye protection should be balanced against the risk to the user of a risk of splash or spray to the eyes.
Where practical to do so, decontamination of goggles should be centralized in a facility which normally reprocesses items may add additional margin of safety”
Arguably, this demonstrates a concern regarding stocks of eye/ face protection.

Some considerations regarding design and materials (based on current discussion, research, and consideration of users):
-Disposable & single use
-Latex free
-Provides good visibility to wearer and patient
-Minimises glare
-Minimal optical distortion
-Fog resistant
-Shatterproof




 

The two commercial standards appear to be described as:

-TidiShield 9211-100-CM by TIDI Products

-Safeview SV100F by Kimberly-Clark (Click for Visor (“Lenses”) and Frames)

Details:
These are devices of two parts: the visor provides a physical barrier in front of the eyes and the frame holds the visor in place in front of the eyes. The frame is threaded through two holes punched into either side of the visor. It may be possible to allow frame reuse with several visors, while the visor itself is disposed of after single use. 

Who produced this design and where?
-Kimberly-Clark and TIDI products (there appear to be many generic producers also) are commercial providers that could be referenced
-OSVX Project 14 Disposable Eye Shields has discussed the design and manufacture of such eye shields, between April 08, 2020 and early May 2020. 

What are the features?
Eye protection is provided by a single sheet of thin clear plastic film, supported and held in place by a lightweight flexible frame with arms that are threaded through holes punched in the clear film, and held onto the sides of the wearer’s head with light compression.

How many iterations has it gone through and why? What has been modified?
-A trial model was made for review from heat formed acrylic.
-A number of digital models were created from 2d digital drawings.
-A number of samples were trialed with different fabrication techniques (3D printing and laser cutting).
-Other fabrication methods were also discussed
-Another method of manufacturing a frame with short arms has been suggested, attaching cardboard drinking straws to extend the frame arms   (video here)

Has it been used yet? What was the response?
Has not been used yet.

Has it been validated yet? How/where? OR which stage of the process is it at?
Trying to establish demand more precisely and the scale of demand. This will dictate the optimal method of manufacture.

PRO’s of this design
-Simple
-Minimal materials
-Familiar to healthcare workers
-Likely to be inexpensive, and compact: a benefit for fabrication, distribution, storage, dispensing, and disposal.
-Less intimidating to patients unfamiliar with receiving care from health care workers wearing PPE that obscures their identity

CON’s of this design
-Not as much protection provided compared with enclosed goggles, full face shield, or more rigid safety glasses

A store of disposable eye shields will be available outside a ward or room, from which the eye shield will be taken. Healthcare workers will don the disposable eye shields as they go to see a patient, according to PPE guidelines issued by the HSE (including the order in which PPE is donned, and the method for donning each PPE item). Once they have finished with the patient, they will immediately doff the disposable eye shields (again, according to HSE guidelines, intended to ensure any potential infectious droplets that do land on the shield do not travel further). The eye shield (and maybe the visor, depending on ultimate design) will be disposed of in a bin outside the room, as the healthcare worker is leaving. Consequently, many of these disposable eye shields will be used per day.

Manufacture is of two components: the Frame and the Visor, each of which have several available techniques.
Frame
1. Potential techniques discussed so far:
2. Injection moulding
3. 3D printing
4. Manual jig heatforming
5. Laser cutting
6. CNC bending
7. Hollow extrusion
8. Recycled filament compression

Visor
1. Potential techniques discussed so far:
2. Laser cutting
3. Die-cutting
4. CNC knife cutting
5. Manual cutting
6. Water jet cutting

A spreadsheet (click to access) has been developed to assist with decision making for fabrication. The purpose is to suit local material availability and requirements. There are 3 tabs (each reflecting volume requirements). For each demand level, the fabrication methods can be ranked in terms of several criteria:
1. Unit cost
2. Entry cost (i.e. setup, initial investment, requirements, etc)
3. Environmental sustainability
4. Time per unit
5. Comfort
6. Cleanability
7. Tried and tested
8. Quality

These can be ranked according to preference (or indeed availability of materials and methods), from easiest to most difficult. Using several dimensions allows for complexity in decision making, and further complexity could be added, if required.
Please note: The current data is a best-guess, informed estimate for Ireland, but may require further input for validation. The ranking (1 - 7) can be changed as required by local needs. Once values are included, the spreadsheet would look like this:

OSVX Project Managers:

Mark M, Connor Cahill

OSVX Tech Writer:
Brendan Strong

Team Members: 
Sean Walsh, Ivan Kelly, Roisin Lyons, Chris Harper, Eoin ,Scott MacEachainn ,Tim Kennedy ,Dermot Brabazon ,Alison Gapert ,David Kyle ,Emmanuel Stone, Peter Knief, Rex Fox O’Loughlin