About Polyvinylidene Film (PVDF)

How do Dymedix airflow sensors compare to thermocouples and thermistors?

Dymedix patented sensors are made of polyvinylidene fluoride (PVDF) film. PVDF film is a specially treated plastic film that is flexible, lightweight, and tough. PVDF film generates a voltage when exposed to temperature changes, pressure changes, force changes, vibration, and sound.

Dymedix airflow sensors:

  • Detect apneas, hypopneas, and UARS
  • Have faster signal response time
  • Have a linear signal response and increased signal strength
  • Improve signal-to-noise ratio

How do Dymedix sensors compare to air pressure transducers (APT)?

Dymedix sensors utilize PVDF film technology, which accurately detects apneas, hypopneas, and UARS. The unique PVDF technology detects oral and nasal flow equally well and is comparable in both sensitivity and response time to air pressure transducers.

Dymedix airflow sensors:

  • Do not result in nasal resistance
  • Are resistant to mucus
  • Provide the highest degree of patient tolerance
  • Do not lose data due to dislodging or patient movement
  • Are highly linear

About Disposable Airflow Sensors

My patient has a moustache. Can I still use a Dymedix airflow sensor?

The Dymedix airflow sensor does not need to be in direct contact with the skin. For patients with facial hair, follow the disposable airflow sensor instructions, except do not peel the tab off the back of the sensor. This will prevent any patient hair from sticking to the adhesive back. To secure sensor, tape the wires onto the patient’s cheeks.

Will the self-adhesive airflow sensor stay on patients throughout the sleep study? Especially on patients who perspire excessively?

The Dymedix airflow sensor works well even on those patients who perspire excessively or have oily skin. Clean the skin before applying the airflow sensor. Light porous medical tape (such as 3M™ Micropore™) may be used over the sensor, but is usually unnecessary.

Can I use a cannula in conjunction with the Dymedix airflow sensor?

Yes. Simply place the airflow sensor on the patient first and then place the cannula on top of it. However it should be noted that this combination can limit the sensitivity of the airflow sensor in some cases, especially when snore data is also being derived from the airflow sensor. Pediatric sleep specialists prefer to use the Dymedix infant and pediatric airflow sensors with an ETCO2 cannula placed on top. This combination increases patient tolerance, comfort, and accuracy of flow detection.

Can I trim the airflow sensor?

No. The PVDF film is positioned within the sensor to for optimal data collection. Cutting the sensor could damage the film and destroy its sensing capabilities.

Can I use the Dymedix airflow sensor during CPAP or BIPAP titration?

Yes. The Dymedix airflow sensor works great under a CPAP mask. The thin sensor wires do not break the seal of the mask.

What are the advantages of disposable sensors?

Dymedix recognizes the benefit to patients and healthcare workers of adhering to safe practices that help prevent infection. The Dymedix disposable airflow sensors offer several benefits:

  • Infection control and prevention
  • Ensures test uniformity
  • Saves time by eliminating the need to sterilize between patients
  • More convenient setup

About Perfect Fit™ II Effort Belts

Is the Dymedix PVDF Perfect Fit™ II Effort Belt included in the Respiratory Rules Section of the AASM Scoring Manual?

Yes. On December 19, 2011 the AASM made changes to the Scoring Manual, effective immediately, to include polyvinylidene fluoride (PVDF) effort sensors using thoracoabdominal belts.

Do I tighten the Dymedix Perfect Fit™ II Effort Belt as I would with a piezo crystal belt?

No. Once the belt is placed on patient, one’s hand should be able to slide comfortably underneath the effort belt.

Does the Perfect Fit™ II PVDF Effort Belt lose elasticity after several uses?

No. The durable Perfect Fit™ Effort Belt maintains elasticity and provides superior signals throughout the two-year warranty period.

Is there a Dymedix PVDF Perfect Fit™ II Effort Belt with SUM capabilities?

Yes. Dymedix currently offers a PVDF Perfect Fit SUM Effort Belt system. It is available in adult and pediatric sizes.

Why are there several sizes of belt straps for the Dymedix PVDF Perfect Fit™ II Effort Belt?

In order to cover nearly every body size, including bariatric patients, Dymedix offers various sizes of straps. 

  • For adults, the 45” strap is used the majority of the time. 
  • For pediatrics, it is especially important to order to avoid bunched-up belts and overlapping. We offer 15”, 25”, and 35” straps for pediatric patients, while the 25” strap is used most often.

Can the Perfect Fit™ effort belt straps be machine washed?

Yes. Straps can be machine laundered on gentle cycle with hospital-approved fabric laundry detergent.

How do I set up the SUM channel on my PSG System?

The SUM channel EFM (electronic filtration module) includes three sets of output connectors: chest, abdomen, and SUM. The SUM connectors are plugged into any open AC channel and labeled on the montage as SUM. Settings are identical to chest and abdomen.

Which portable monitoring devices can I use the PVDF Perfect Fit™ effort belts on?

Please contact Dymedix for more information on compatibility.

Does it matter if I use an AC channel or DC channel for the PVDF Perfect Fit™ effort belt?

Yes, Dymedix PVDF technology requires an AC channel.