The New Silicone N99 Half-Piece Respirator

Summary

Filter facepiece respirator (FFR) is a critical equipment to prevent the transmission of respiratory tract infection disease especially the dreadful corona virus 2(SARs-CoV-2).The N95 mask is the prototype of high efficiency protective device and can effectively protect airborne pathogens of less than 0.3 μm by more than 95%. It is tightly fit and had high filtration capacity. The widespread pandemic of COVID-19 leads to greater requirement of FFR. A rising in demand would greatly exceed current productive capabilities and stockpiles and would almost certainly result in a robust shortage.

In order to solve these problems, our team had invented a new type of half-piece respirator made from silicone and assembled with hepa or elastostatic filter . A variety of methods have been used to evaluate this new device, including qualitative fit test with Bitrex® test kit and filtration test.

Conditions

• COVID
• Personal Protective Equipment

Interventions

DEVICE

Fit test

Bitrex Fit Test The Bitrex test uses a person's ability to test a bitter solution to determine whether a respirator fits properly\[11\]. Each subject was given a taste-threshold screening test prior to each fit test to ensure that he or she could taste. This process was done without subject wearing a respirator. After passing the sensitivity test, the subject will process to 7 steps of fit test as following * Breathe normally * Breathe deeply * Head side to side * Head up and down * Bent over wrist, jogging * Talking * Breath normally Each step took 60 seconds and the Bitrex solution was refilled into the hood every 30 seconds with half dosage of the amount of the previously test. We asked the participant if he / she could taste the solution during each steps of the test . The test was considered a failure, otherwise, a pass.

DEVICE

Filtration Test

Respirator Performance The real time respirator performance test method was developed using MT-05U machine (SIBATA model, Saitama, Japan), which measure particle concentrations of diameter 0.03 - 0.06 µm using and particle generator laser beam scattering particle counter that measure particles outside and inside the mask. The ratio between these two values reflected % leak as following: * leak=((Paticle inside the filter))/((Paticle inside the filter)) x 100 And calculate % filter performance = 100 - % leak We tested at the airflow rate of 40L/min which is 3-4 times higher than normal physiology, assuming that there should be no leakage through the filter. We tested 2 types of filter is CareStar and SafeStar that was incorporated with the silicone mask. CareStar is limited for 24 hour usage and SafeStar is for 72 hour duration. Study protocol

Sponsors & Collaborators

• Bangkok Metropolitan Administration Medical College and Vajira Hospital

  lead OTHER_GOV

Principal Investigators

• Thananda Trakarnvanich, M.D. · Bangkok Metropolitan Administration and Vajira Hospital

Study Design

Allocation

NA

Purpose

PREVENTION

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2020-05-01

Primary Completion

2020-05-15

Completion

2020-05-31

Countries

• Thailand

Study Locations