Bacterial/Viral Filter for Pulmonary Function Testing


The AstraGuard Bacterial/Viral Filter provides virtually perfect infection protection for expiratory and inspiratory spirometry testing. Its single-patient use greatly reduces costly and time-consuming disinfection procedures.

This easy-to-use disposable mouthpiece incorporates a highly efficient woven filter that virtually eliminates cross-contamination from patient to patient and from patient to health care professional.

AstraGuard Features

  • 99.9% Bacterial and viral efficiency*
  • Low resistance to air flow
  • Small, non-threatening size
  • Comfortable oval mouthpiece
  • Reduces risk of cross-contamination
  • Less time spent disinfecting equipment

Download AstraGuard Brochure.


filter cut-awayCross-section of filter

Shows placement of interior media. Edge of media is bonded to exterior housing to form tight seal.
Woven filterInterior filter media

Woven material is tailored to fit inside mouthpiece.

     Part No.  Description  Qty.  Packaging
AstraGuard     29-7990-050  AstraGuard™ Filter 50  Box 
   29-7990-100  AstraGuard™ Filter 100   Box
   29-7990-200  AstraGuard™ Filter 200  4 Boxes/50ct 
   29-7990-300  AstraGuard™ Filter 300   Box


AstraGuard™ Kits

     Part No.  Description  Qty.  Packaging
AstraGuard w/The Klip     29-7996-050  AstraGuard™ Filter + The Kushion Klip 50  Box 
   29-7996-100  AstraGuard™ Filter + The Kushion Klip 100   Box
   29-7996-200  AstraGuard™ Filter + The Kushion Klip 200  4 Boxes/50ct 
   29-7996-300  AstraGuard™ Filter + The Kushion Klip 300   Box



The AstraGuard™ PFT Filter is designed to fit all Astra™ Spirometers. 

Astra 300™


Astra BT™











Contact Information


SDI Diagnostics
Ten Hampden Drive
Easton, Massachusetts 02375
Phone: (800) 678-5782
Fax: (508) 230-2752 

SDI Diagnostics