Biohazard Mask Filter

Abstract

An exhalate filter medium for a biohazard mask is made of polytetrafluoroethylene (PTFE) and surrounding layers of a wicking material and an antimicrobial material. The exhalate filter may be contained in a removable and replaceable cartridge snap-fit into the surface of a biohazard mask.

Description

RELATED APPLICATIONS[0001]This application is a continuation-in-part, claiming priority to application Ser. No. 10 / 459,417, filed Jun. 11, 2003, “BIOHAZARD MASK SUITABLE FOR CIVILIANS.” The disclosure of the '417 application is incorporated herein by reference.FIELD OF THE INVENTION[0002]This invention relates to filter media for masks which protect against biological hazards.BACKGROUND OF THE INVENTION[0003]Recent developments in antimicrobial respirators have taken the approach of filtering exhaled breath as well as inhaled breath (U.S. Pat. No. 6,584,976 B2, issued to Japuntich et al.; '417 application, filed by Freriks et al.; both incorporated herein by reference). By filtering exhalation, the wearer is prevented from exhaling both biologic entities such as bacteria and viruses into the environment where they can contaminate their surroundings and infect other people. Also, they are prevented from exhaling particles which would disturb or contaminate environments that are inten...

AI Technical Summary

Benefits of technology

[0010]The present invention also contemplates, in another embodiment, a pair of horseshoe shaped filter cartridges, just below the nose portion of the mask. These cartridges rest inset into the surface of the mask, but external to the valve assembly (which is integral to the mask). One horseshoe-shaped filter cartridge is for inhalation, and one for exhalation. The cartridges are snap-fit (in any manner known in the art), and can be ejected (popped out) by pushing a button, or any other suitable mechanical actuator.

Problems solved by technology

Unfortunately, there would be problems to overcome with this approach to filtering.

In particular, the filtering of exhalation would likely result in moisture build up in the filter media making the pressure drop (resistance) to exhalation extremely high and making respiration difficult.

This would result in frequent changes of respirators or filters and exposing wearer's and others to unwanted contamination.

Modern membrane technologies have resulted in HEPA level filtration characteristics with very low resistance, but none has been designed specifically for the filtering of human exhalation or use in respirators which accomplish this purpose.