BioE 1160/1161 Senior Design 2004-2005
Initial Hazard Analysis –
Active Mobile Asthma Inhaler
Design Team:
Annemarie K. Alderson
Annie Saha
Stephanie T. Shaulis
Robert J. Toth
Advisor: Timothy E. Corcoran, PhD
Revision Date – November 17, 2004
This document presents a preliminary treatment of the predominant hazards associated
with the proposed inhaler device being developed. The causes and effects of the
described hazardous conditions, a qualitative assignment of general risk associated with
the potential hazardous conditions, and the intended response of the system to the
hazardous conditions are presented.
The most serious hazard associated with the inhaler device is the potential for a
propellant mechanism malfunction. A malfunction of this particular mechanism can
result in two major outcomes regarding the discharge of the medication; a complete
misfire/inadequate ejection of the proper dosage or an exceedingly forceful ejection.
This type of failure would be attributable to causes ranging from poor propellant
mechanism design to manufacturing error to nonstandard use of the device. It should be
noted that the design specifications for this device incorporate inherent safety regarding
proper use of the device, i.e. if it is utilized according to the instructions in a manner
consistent with its indications then propellant mechanism failure cannot be caused by
patient use. However, if the device is utilized in a manner inconsistent with its intended
use, malfunction of the propellant mechanism can be induced. The consequences of a
propellant failure could be inadequate administering of the proper dosage of drug and the
subsequent physiological effects of an untreated asthmatic episode. In addition, a
chemical propelled ejection with a force in excess of specifications can potentially cause
damage to the mouth, throat, and other components of the upper to mid respiratory tract.
In general, the risk associated with this hazard is intermediate. The potential adverse
consequences can be serious, however to probability of such a failure given adequate
design and manufacturing controls is minimal. The system – consisting of the inhaler
device – should respond to a propellant mechanism failure by simply becoming
nonfunctional, which minimized the hazardous condition and whereby it can be mediated
by replacement of the defective device with a new inhaler. This is not a serious problem
considering that the device is intended to be single-use-only and disposable.
An additional hazard associated with the device is improper dosage loading.
Since the device is designed to be single-use-only, the potential for inadequate or
excessive dosage exists as an inherent limitation. The hazard is associated with the
physiological effects of under- or over-medicating the asthmatic condition. In general,
the risk associated with this hazard is minimal because, the device could be produced
with varying dosages and the proper dosage device selected for the specific
circumstances.
Since the device is designed to be completely sealed and hence water-proof,
weather-proof, and reliable; the possibility exists for hazards associated with material
compromise and subsequent premature drug dispensing. Again, the implied hazards
involve lack of treatment of the condition. However, in addition, a compromise of the
outer casing material (the development of a crack/tear, puncture, rupture, etc.) could
create sharp plastic edges which pose a laceration hazard, or an unexpected ejection of
the chemical propellant while; for example, the device was close to the face and eyes,
which poses a reaction hazard. Such a hazard could be caused by a deficiency in the
plastic casing material, an improper design choice of material, or an external device
compromise such as inadvertent puncture. As indicated in prior examples, proper design
and manufacturing controls and care with indicated usage would make the risk associated
with this hazard minimal.
Finally, in terms of predominant hazards associated with the inhaler device being
developed, a number of potential ergonomic/human factors hazards exist within the scope
of proper utilization of the device. Since the device is designed to be able to be utilized
in an active setting such as during physical activity like running or swimming, there are
hazards involving complications to use during such activities. For example, the
possibility exists for an impact between the device and the user during both active use
and during the storage of the device at its peripheral location during activity. While
properly administering medication from the device while running, the user’s attention
may be diverted and an impact between the user and an unsuspecting third party may
occur. This impact may subsequently cause a secondary collision of the device to the
oral area of the user’s face, which could cause resulting damage. Also, for example,
while being worn in a necklace fashion during running activity, the device may become
caught on an article of clothing of the user and result in an injury to the user’s neck.
These types of hazards are associated with proper use of the device and are attributable to
the awareness of the user. Consequently, the risk associated with the device is low, and
can be avoided by common awareness of the user’s environment.
This document was intended to serve as an initial treatment of the potential hazards
associated with the proposed inhaler device being developed. It should be noted that
additional hazards do exist, however a complete treatment of all potential hazards would
be an encumbering exercise and that the predominant hazards discussed here represent
the most serious and therefore those of most importance.