Friday, May 4, 2012
Final Project: Strengths and Weaknesses
The
InhaleSur device described herein offers a unique opportunity to improve
compliance in a market that is untapped; proactive inhaler protocol training
occurs in physicians offices and pharmacies, but a thorough literature search
uncovered no core technology that continually monitors inhaler usage throughout
the entire course of treatment. InhaleSur will improve compliance with inhaler
protocols first by ensuring that each canister is sufficiently shaken before
inhalation of the medications within. Proof-of-concept for this device has been
successfully demonstrated with a simple Arduino microcontroller that uses an
accelerometer and a push button to detect the magnitude and frequency of device
shaking; it also records when the canister has been compressed to alert the
user when a refill is required. The accelerometer used for this proof-of-concept
device can only measure tilt relative to gravitational forces rather than
actual linear acceleration when transmitting data in real-time, and this is
currently a device design weakness. Future work will incorporate a more
sophisticated accelerometer into the design. Miniaturization of the device is
also critical to ensure portability. The core strengths of InhaleSur are that
it provides real-time feedback for the entire course of treatment for a patient
suffering from asthma and removes the ambiguity associated with guessing
whether or not the medication is sufficiently mixed. Additionally, knowing when
to replace the medication canister reduces wasted drugs and ensures that
patients are getting as effective a treatment as possible. Future design
iterations will include the ability monitor the user’s force of inhalation as well
as the ability to alert the user to the proper compression time of the canister.
Commercialization designs of InhaleSur will also incorporate auditory alerts to
these factors to make the
device accessible to blind persons.
InhaleSur will improve compliance with inhaler procedures and has the
potential to dramatically impact the quality of life for asthma sufferers.
Final Project: Feature-Benefit Table
Feature
|
Benefit
|
Button
|
Each button press adds one “use” to a counter
that tells the user how many uses are remaining and when a refill is
required.
|
LCD Screen
|
The LCD screen is used to deliver messages to
the user such as the number of uses remaining or an inhaler refill is
required. In the future, the LCD screen could be replaced with an LED or a
auditory alert to notify the user.
|
Accelerometer
|
Used to quantify shaking. Provides us with the
tools to measure both the magnitude and frequency of shaking.
|
Portability
|
Competitive products (i.e. T-Haler) are
intended for use in physicians’ offices or pharmacies. InhaleSur allows users
to keep the device with them at all times.
|
Usage Tracking
|
This feature offers the user with a simple way
to recognize when a refill is required instead of having to keep track with a
calendar and simply guessing when the canister is empty. Avoids waste and
ensures optimal dosage delivery.
|
Real-time Monitoring
|
This coincides with portability, but there is
no guesswork or delay involved with using the InhaleSur product. Patients
know exactly when their inhaler is sufficiently shaken.
|
Final Project: Proof-of-Concept Device
Device Description
The goal
of InhaleSur is to deliver a reliable dose of bronchodilator by ensuring that
the medication is sufficiently shaken prior to delivery. In order to do this,
the device senses when the user has shaken the inhaler with enough acceleration
and force over a period of six seconds. Once the shaking threshold is met, the
device outputs a message on the liquid crystal display (LCD) telling the user
that the inhaler is “ready to use.” With each compression of the inhaler, a
button is triggered on the inside of the InhaleSur case. This button allows the
device to keep track of the number of inhaler uses remaining before a
medication refill is needed. The number of “uses remaining” is printed on the
LCD screen. If the inhaler has zero uses remaining, an additional message is
printed on the LCD screen saying “refill required.” InhaleSur is easy to use, provides key
feedback to the user, and guarantees an adequately mixed dosage of medication.
Representative InhaleSure Device
Picture of circuit used on Arduino board
Device being shaken
Inhaler is sufficiently shaken
Device notifying the user how many uses remaining
Device notifying the user that refill is required
Final Project: Block Diagram
Block Diagram
The
following diagram illustrates the hardware and software components of
InhaleSur. The inputs for the device are the amount of shaking performed by the
user and the button, which is used to determine when the canister has been
compressed. The outputs for the device are the three displays on the LCD
screen: “ready to use,” “uses remaining,” and “refill required.” When the
inhaler is shaken with some quantifiable acceleration, the accelerometer
measures this value in terms of x, y, and z components. The Arduino algorithm
then determines whether any one of the x, y, or z acceleration values are
greater than 800. The threshold of acceleration was set to 800 based on
experimental testing which indicated that resting acceleration was around 400,
while forceful shaking was around 800. The accelerometer outputs a value
between 0 and 1023 corresponding to a voltage between 0 volts and 5 volts.
Therefore, a threshold of acceleration of 800 corresponds to a voltage of 3.9
volts. Once the user has reached an x, y, or z acceleration greater than or
equal to 800, the user than has 500 milliseconds to surpass the acceleration
threshold again. The user must repeat this pattern 12 times, which correlates
to a shaking time of 6 seconds. If the user does this in less than 500
milliseconds, the timer immediately restarts for the next 500 milliseconds
interval. If the user does not meet the threshold 12 times consecutively, the
algorithm restarts.
Once the threshold has been reached 12 times,
the Arduino prints “ready to use” on the LCD screen. The user then compresses
the inhaler canister once to deliver the medication. When compressed, the canister
also compresses a button on the inside of the InhaleSur case. When the button
is compressed, one “use” is subtracted from an internal counter, and then the
remaining uses are printed on the LCD screen. If the number of uses remaining
is equal to zero, the Arduino prints “refill required” on the LCD screen. The
block diagram in Figure 1 also demonstrates the Arduino’s connection to a power
source and to a computer via a USB connection.
Final Project: Specifications
Specification
|
Value, Value Range, or
Quality Relating to Spec
|
Comments about rationale
for specification
|
Battery
life
|
4
months
|
Device
needs to last the duration of use for the inhaler. Inhalers typically contain
200 dosages (Bailey, 2012). At
minimum, 2 sprays per day is equivalent to a minimum battery life of 100 days.
We added an additional safety margin to this value.
|
Button Sensitivity
|
Button must register
only one “use” per canister compression
|
Button needs to count
to relay reliable data about remaining medication to user
|
Shaking Voltage
|
Minimum thresholds to qualify
as a sufficient shake in the x, y, and z directions is 800 units
|
The threshold of
shaking was defined via experimental testing. Shaking with a voltage greater
than 800 was classified as one successful shake. The accelerometer generates
a number between 0 and 1023 corresponding to a voltage value between 0V and
5V, so the threshold of 800 corresponds to a voltage of 3.9V measured by the
accelerometer.
|
Number of times
shaking
|
Reach the voltage
threshold 12 (each within 500 msec) times to qualify as sufficiently shaken
|
This is equivalent to
six seconds of shaking; the minimum on official Instructions for Use for
inhalers often states at least five seconds (PDR Network, 2011).
|
Final Project: Competitive Technologies and Reverse Engineering
T-Haler: A competitive technology and its design
Within
the asthma market, it is expected that doctors and pharmacies offer patients a
training session upon prescribing or distributing an inhaler for treatment (Kamps,
2000). This type of training must be viewed as the current market incumbent
that would compete with InhaleSur in the market. Cambridge Consultants, a
technology design and development firm, has created an asthma inhaler training
device called the “T-Haler.” Cambridge Consultants "develops breakthrough products, creates and licenses intellectual property, and provides business consultancy in technology critical issues for clients worldwide (Cambridge Consultants, 2012). The product
is an interactive training “game” that wirelessly monitors whether the patient
has shaken the inhaler, the force with which they breathed in, and when the
canister is pressed down to release the drug (Cambridge Consultants, 2012). The T-haler uses a unique combination of
sensors and wireless transmitting technology to function. This technology was just released in March 2012;
it is not yet officially on the market for sale. As such, no public list price
is available. The website for the product promotes that the T-Haler doubles the
compliance rates for inhaler protocol use.
REVERSE ENGINEERING ADVANTAGES AND DISADVANTAGES
REVERSE ENGINEERING ADVANTAGES AND DISADVANTAGES
When
entering a market, one must consider the advantages and disadvantages competitor
products offer. The T-Haler offers an advantage compared to doctors and
pharmacies that provide inhaler training through staff personnel because the
T-Haler minimizes the time and resources required by employees to individually
train each patient. However, this tool is only a training device and is
intended for use as a tool in doctors’ offices, pharmacies, and clinics. The
T-Haler is at a disadvantage compared to InhaleSur because InhaleSur is
designed to stay with the patient over the entire course of treatment, not just
an initial training period. InhaleSur is available for at home use. Additionally,
while the T-Haler currently provides feedback on other factors of inhaler protocol,
there is no reason why future iterations of InhaleSur could not alert the user
in real-time to other factors like inhalation force (with a simple gas pressure
sensor) or the time the canister is compressed. Proof-of-concept of the shaking
feature demonstrates that these elements can be monitored on a simple
microcontroller device, so InhaleSur will be able to successfully compete in
the asthma inhaler market space. The blog posts will provide a detailed
explanation of InhaleSur’s functionality.
Final Project: Need for Device and Desired Outcome
Both asthma
controller medication and quick relief medication treatments mentioned above commonly
deliver therapeutic agents through an inhaler device. Inhalers are simple
medical devices that release a mist of medication into the airways and lungs
when a pressurized canister is compressed. Inhalers have a very specific set of
instructions that must be followed in order for the medication to be most
effective. However, a study published in the Journal of Pediatric Pulmonology showed
that only 29% of children who had been trained using an inhaler performed all
essential steps correctly, compared to 79% who had received comprehensive
inhalation instructions in addition to follow-up technique checks at a pharmacy
or in a clinical trial (Kamps, 2000). Other reports show that up to 90% of
adults use incorrect techniques with their inhalers (National Asthma Council
Australia, 2008). Proper inhalation techniques could avoid up to 75% of
hospital admissions resulting from asthma attacks (Cambridge Consultants, 2012).
One of the key steps for proper inhaler technique is shaking the inhaler for a
minimum of five seconds prior to use. Dr. Howard Panitch, a Pediatric
Pulmonologist at the University of Pennsylvania Hospital System, stated that one
minute of device shaking would be ideal (Panitch, personal communication, April
3, 2012). While the literature suggests that inhaler training is not fully
effective at ensuring procedure compliance to ensure that users get the most
optimal dosage, current technologies on the market focus on better training
tools to teach patients how to use their inhalers. A novel medical device that
tells the user when the medication is sufficiently shaken is desired in order
to deliver the most reliable dose. InhaleSur monitors the magnitude and
frequency of shaking in order to tell the patient when the asthma inhaler is
sufficiently shaken before inhalation.
Final Project: Target Population
Asthma
is a chronic respiratory disease that affects an estimated 18.7 million adults
and 7.0 million children in the United States alone (CDC, 2012). Asthma is caused
by airway inflammation and a narrowing of the airways that leads to shortness
of breath, coughing, wheezing, and chest pain. While asthma cannot be
prevented, its symptoms can be controlled. There are two key types of asthma treatment
medication; one is referred to as “controller medication” and the other is
referred to as “quick relief medication” (WedMD, 2012). Controller medication
uses corticosteroids as an anti-inflammatory agent to reduce swelling and mucus
production in the airways. Quick relief medication, also known as rescue
medication, uses short-acting beta-agonists (bronchodilators) to relax the
muscles that tighten around the airways during an acute attack. Even with
available treatments, the prevalence of asthma continues to increase in the
population. The Centers for Disease Control reports that in 2009, 4.2% of the
population had at least one asthma attack; this is equivalent to 8.7 million adults
and 4.0 million children (Akinbami, 2011). Of those people already diagnosed
with asthma, 52% had a severe attack in 2009 (Akinbami, 2011). The market to
improve and design novel asthma interventional products is huge. Innovation for
the asthma population will improve the quality of care and quality of life for
patients, and there is an enormous business opportunity within this target
population.
Here are the references for the Final Project Blog posts:
Here are the references for the Final Project Blog posts:
References
Akinbami,
L. J., Moorman, J. E., & Liu, X. (2011, January). Asthma prevalence,
health care use, and mortality: United States, 2005-2009 (Rep. No. 32).
Hyattsville, MD: U.S. Department of Health and Human Services.
Bailey,
W. (2012). Asthma
inhaler overview. http://www.uptodate.com/contents/patient-information-asthma-inhaler-techniques-in-adults-beyond-the-basics
Cambridge
Consultants. (2012). New asthma training device more than doubles proper use
rates. Retrieved April 14, 2012, from http://www.cambridgeconsultants.com/news_pr319.html
CDC.
(2012). Asthma: Data for the U.S. Retrieved from http://www.cdc.gov/nchs/fastats/asthma.htm
Granata,
A. (Interviewer) & Panitch, Howard (M.D). (Interviewee). Attending
pulmonolgist;Director, Pulmonary Medicine Fellowship Program. April 11, 2012.
Kamps,
A. W., van Ewijk, B., Roorda, R. J., & Brand, P. (2000). Poor inhalation
technique, even after inhalation instructions, in children with asthma. Journal
of Pediatric Pulmonology, 29, 39-42.
National
Asthma Council Australia. (2008). Inhaler technique in adults with asthma or
COPD [Pamphlet]. South Melburne, VC, Australia: National Asthma Council
Australia Ltd.
PDR
Network. (2011). Advair HFA. Retrieved from http://www.pdrhealth.com/drugs/advair-hfa
WebMD.
(2012). Asthma medications. Retrieved from http://www.webmd.com/asthma/guide/asthma-medications
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