Final Project: InhaleSur Video

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

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.