Propeller Sensor (Propeller Health, Wisconsin, USA)
The Propeller sensor is compatible for use with a wide range of devices,
including pMDIs, Diskus®, Ellipta®, Turbohaler®, Easyhaler®, Breezhaler®
and Respimat®(29). As such, the Propeller sensors can be used for both
preventer and reliever inhalers recording the date, time and location of
actuation(30). The sensors record when the inhalers are opened and
closed as a surrogate for drug delivery, but inhaler technique is not
recorded. As well as monitoring use, electronic notifications can be
enabled to alert patients and providers of omitted doses.
The sensor transmits information via Bluetooth to a paired smartphone
application and securely uploads the data to remote servers. Email
notifications or text message alerts notify individuals and physicians
about a change in asthma control based on reliever use. By providing
personalised feedback, individuals are enabled to action changes and
reduce the risk of an
exacerbation(30, 31). Global
Positioning System (GPS) transmitted through a smartphone provides
geospatial information with the potential to help patients and HCPs
identify asthma triggers. For example, increased SABA use may occur in a
certain location associated with high exposure to a particular
aeroallergen. When exposed to the same set of triggers in the future,
patients are warned of the risk of a possible exacerbation(32).
Propeller sensors have been used in several
studies to monitor ICS adherence,
including change in ICS use for patients with asthma and COPD during the
first few months of the COVID-19 pandemic(33-35). In an adult population
with uncontrolled asthma, an increase in the percentage of SABA-free
days was demonstrated in the group that received reminders and feedback
on ICS and SABA use compared to a control group without feedback.
Adherence changed minimally in the intervention group, whereas a
significant decrease was seen in the control group(36). This study also
identified a positive response in younger participants and those with
worse asthma control at baseline, a subset of patients who are likely to
particularly benefit from EMDs(36). Finally, as well as improvements in
adherence to ICS and SABA use, a recent study has additionally reported
a reduction in asthma-related emergency department visits and
hospitalisations with the Propeller sensor highlighting the benefits of
EMDs to both the patient and healthcare systems(33).