Mentor: Dr. William Phillip
Location of Research: 121 B Cushing Hall, Notre Dame University
Category of Research: Engineering
Working Title: Visualizing and Improving the Operation of an Inhaled Medication Disposition Chamber Tube

9/25/12: Met with Dr. Phillip and discussed possible projects (polymer membranes and aero chamber tubes)
10/2/12: Talked with Dr. Phillip about engineering a better chamber tube and began paperwork and grant application. Also talked about goals and a tentative procedure. Split the project into two major parts; analyzing and learning about the current commercial chamber tubes and then making improvements to create a better and more effective chamber tube.

Blast each chamber tube with mixtures of ethanol or other liquids. Using 3D camera and video camera technology the flow field of the liquid through the chamber will be visualized and interpreted using several vacuums and pressures (normal breath and attack rate). Doing this with several commercial chamber tubes will allow for me to design a tube that has a flow field slow enough to travel through the human throat to effectively reach the lungs (when the medicine travels to fast it coheres to the back of the throat and also travels into the stomach and other organs). Designing a new chamber tube with have many benefits such as saving medication, avoiding irritation, and better utilization of the medicine.
11/8/12-11/29/12: Collecting materials around campus and testing different types of tubing, soap solutions, and vacuum rates to build a volumetric flow rate apparatus. After testing several concentrations of soap and water, I proposed the idea of using an actual bubble solution that you but at the drug store. This idea was a success and will be used for the apparatus. Using a plastic tubing, burette, ringstand, clamps, and rubber tubing i was able to make my apparatus.

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12/7/12: Today I began my actual test for flow rate. I attached the commercial chamber tube to the end of the burette and set the vacuum at a very low temperature (1/16 of a revolution of the knob) and slowing began squeezing the bubble mixture. The bubbles then form a ring around the inside of the tube and will travel up the tube. By timing the amount of seconds it takes to travel a given distance I can find the flow rate. You can do so by dividing the volume (mL) by the time (s) to get a flow rate in mL/s. However, I was only able to calculate two flow rates. 1/16 and 1/8. This is because as the vacuum got any faster than 1/8 the bubble was inverted sideways up the tube and then popped at around 7mL, which is too fast to time. In order to get more data points, i will have to find a more accurate way of measuring the rate of the vacuum so I can then use lower rates.

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January 2013
Met with Dr. Patel at Sneeze & Snooze clinic in Niles. He provided me with placebo inhalers to run adherence tests.
Researched best commercial tubes. Ordered 5 tubes and peak flow meter.
Designed the human inhalation simulator apparatus:
Vacuum system set up with a 10-100 LPM flow meter, tubing, and a ball valve attached to the chamber and inhaler.
Febuary 2013
Ran 45 adherence tests using 5 commercial tubes.
Opti Haler



Ventilab Chamber




Vacuum
Initial Mass
Final Mass
Change In mass
Vacuum
Initial Mass
Final Mass
Change In mass

15 LPM
41.2467
41.2489
0.0022
15 LPM
38.6938
38.7054
0.0116

15 LPM
41.2468
41.2487
0.0019
15 LPM
38.6933
38.7036
0.0103

15 LPM
41.2467
41.2488
0.0021
15 LPM
38.6939
38.7045
0.0106

30 LPM
41.2463
41.2476
0.0013
30 LPM
38.6942
38.6973
0.0031

30 LPM
41.2464
41.2477
0.0013
30 LPM
38.6941
38.6977
0.0036

30 LPM
41.2464
41.2474
0.0010
30 LPM
38.6946
38.6981
0.0035

45 LPM
41.2463
41.2469
0.0006
45 LPM
38.6946
38.6959
0.0013

45 LPM
41.2466
41.2472
0.0006
45 LPM
38.6948
38.6958
0.0010

45 LPM
41.2465
41.2472
0.0007
45 LPM
38.6946
38.6959
0.0013










Optichamber Advantage



Optichamber Diamond




Vacuum
Initial Mass
Final Mass
Change In mass
Vacuum
Initial Mass
Final Mass
Change In mass

15 LPM
67.2377
67.2501
0.0124
15 LPM
57.8668
57.8700
0.0032

15 LPM
67.2404
67.2515
0.0111
15 LPM
57.8666
57.8699
0.0033

15 LPM
67.2375
67.2524
0.0149
15 LPM
57.8665
57.8708
0.0043

30 LPM
67.2400
67.2430
0.0030
30 LPM
57.8663
57.8677
0.0014

30 LPM
67.2396
67.2438
0.0042
30 LPM
57.8666
57.8677
0.0011

30 LPM
67.2423
67.2498
0.0075
30 LPM
57.8661
57.8672
0.0011

45 LPM
67.2400
67.2407
0.0007
45 LPM
57.8662
57.8667
0.0005

45 LPM
67.2422
67.2433
0.0011
45 LPM
57.8658
57.8667
0.0009

45 LPM
67.2435
67.2447
0.0012
45 LPM
57.8661
57.8670
0.0009













Able Spacer








Vacuum
Initial Mass
Final Mass
Change In mass





15 LPM
52.0070
52.0213
0.0143





15 LPM
52.0059
52.0210
0.0151





15 LPM
52.0063
52.0217
0.0154





30 LPM
52.0059
52.0112
0.0053





30 LPM
52.0062
52.0119
0.0057





30 LPM
52.0063
52.0112
0.0049





45 LPM
52.0064
52.0070
0.0006





45 LPM
52.0066
52.0079
0.0013





45 LPM
52.0067
52.0081
0.0014





















Percent of Medication Adhering to walls

15LPM

Optihaler
7.09%

Optichamber Advantage
43.24%

Ventilab
36.49%

Optichamber Diamond
12.16%

Ablespacer
50.34%




30 LPM

Optihaler
4.05%

Optichamber Advantage
16.55%

Ventilab
11.49%

Optichamber Diamond
3.72%

Ablespacer
17.91%




45 LPM

Optihaler
2.03%

Optichamber Advantage
3.38%

Ventilab
4.05%

Optichamber Diamond
2.70%

Ablespacer
3.72%





Found Optihaler to perform the best, ablespacer the worst. Possibly a smaller volume works better? Also the length from the mouthpiece to the blasting area?
From performing several literature searches and reading reviews on current leading chamber tubes, a list of ideal and most effective characteristics of chamber tubes was made. Some of these characteristics include; a shape that can withhold a conically expanding plume (T. Purewal), this means that the shape of the chamber tube must be able to support the natural shape of the blast traveling through the tube. Typically these ideal shapes are a type of slightly conically shaped tube. Large volume and small volume spacers have been used. The large volume spacers are very beneficial in the inhalation of drugs but the size is not appealing to customers. Therefor another ideal characteristic would be to be both compact and easily cleanable. Chamber tubes need to be cleaned as over time the medication adheres to the walls and takes away from the electrostatic charges on the chamber walls. Also, slots in the tube should be avoided as they can cause a leakage of medication from the spacer. These and the above observations would all make for an ideal spacer tube .From the data collected pertaining the amount of medication adhering to the walls of chamber tubes, faults and successes in designs can be inferred. The best performing tube, OptiHaler, had an adherence percentage of as little as 2.03% at 45 LPM. The notable characteristics of this tube are; its small size, easily cleanable, and the unique canister only inhaler application area. The next best performing tube was the OptiChamber Diamond. A close second to the Optihaler, it had only 2.70% medication adhering at 45 LPM. It adhered slightly less than the leading Optihaler at 30 LPM. Its notable features include; a very complex design including several valves and slit applications, not easily cleanable, and portable. Third, the VentiLab branded tube did significantly worse. With as much as 36% of the medication adhering to the walls, more than the necessary amount of the medication was lost. The features of this spacer include; a very simple design, slight conical shape, very hard to clean, and bigger in size. The decreased performance in this tube is likely due to its lack of adequate valves and larger volume. A close competitor, the Optichamber Advantage had 43% adherence at its worse. This is likely due to its large size. Notable characteristics of this design include; very large volume, not compactable, easy to clean, and tubular shape. Lastly, the worst performing spacer, the Able Spacer chamber tube, adhered 50.34% of the medication at 15LPM. That means less than 50% of the medication even made it into the mouth of the patient, let alone the lungs. Features of this spacer include; a nearly closed mouth valve, prism like shape, and not easy to clean. The lack of medication leaving the tube is due to its valves that are nearly closed. From this experiment, faults and success of the highest ranked branded spacers can be compiled and used to develop a newer model
Method:

1. Analyzing Current Commercial Products:
A. Obtain several different types of the leading commercial chamber tubes
B. Obtain a type of inhaler device that emits a substance very similar to albuterol rescue inhalers
C. Set up two vacuums on mouthpiece end of the chamber tube that simulate two scenarios: a normal human inhalation and an inhalation of a human who is under an asthma attack
D. Blast each inhaler device into tube with vacuum attached and, using 3D camera technology, analyze the flow of the mist blasted through the chamber tube.
E. Trial and error with different vacuum suctions and tube designs
F. Repeat with each commercial tube
2. Improving the Chamber Tube
A. Using the observations from the experiments of the commercial products, brainstorm possible improvements that can be made
B. Using several brainstormed designs repeat steps 1A-1E using the designed chamber tubes


Abstract:

When Metered Dose Inhalers (MDIs) are used, typically a type of chamber tube is used alongside. When a MDI is used alone, a significant amount of medication is lost. The medicine adheres to the mouth and pharynx of the patient, and not all of the intended medication reaches the patient’s lungs. Chamber tubes are attached to MDIs and designed to slow down the flow rate of the blast so more medicine can reach the lungs. However, the current commercial chamber tubes do not work as effectively as intended. Although the flow is slowed down, the difference between using a tube and not is found to be insignificant. More medication is lost on the inner walls of the tube. In this project, first experiments and observations of current chamber tubes are being conducted to help build a list of ideal designs. These experiments include adherence tests and the use of high speed cameras to analyze the flow of MDIs through different tubes. Eventually, several designs will be formulated from the observations made and will be tested accordingly. From this, a new model can be made that both delivers maximum medication to lungs and is also portable and easily cleanable.



Introduction:
Metered-dosed inhalers are very common in today’s society. They provide several hundred doses of medication in a compact unobtrusive casing; this practical and portable device serves well. Often when metered does inhalers are used, extension or chamber tubes are used alongside. These tubes are effective but far from perfect. This experiment will serve as means to eventually create an alternate chamber tube. This will be done by visualizing faults in the current leading tube and then using these observations to make improvements.
Chamber tubes are used to help administer aerosol medication especially in children. They are used to help the medication flow efficiently to the lungs without adhering to the back of the patient’s throat. Altering the flow rate of the medication through the tube allows for this to be done. When the flow rate is too high the medication shoots into the back of the throat through the tube and adheres to it. This means the medication is not getting to the intended organs, the lungs. If the improper amount of medication is administered to the lungs, it will not have the maximum effect. When the flow rate is just right, the aerosol will smoothly go down the patient’s throat with minimal loss of the medication. The patient will be able to more effectively coordinate their breathe with the flow of the medication. Studies have been done to show that these chamber
tubes are more successful then a simple inhaler in providing maximum amount of medicine to the lungs (1). However, the current commercial chamber tubes are far form perfect. There are many insufficiencies in the leading brands. These include; impractical shape of tube, medication adherence to tube, insufficient flow rate, and many more. By observing these inefficiencies, improvements will be made to reach the goal of a more precise inhaler chamber tube. I am very driven to be successful in this project as I have a person connection with asthma and inhalers. Ever since I was 5 years old, I have struggling with asthma. I have been
using metered does inhalers and extension tubes throughout my life and have never noticed a significant difference between using an inhaler with and without the chamber tube. Ideally, through visualizing complications with current commercial chamber tubes, a new and improved model can be engineered.


Significance:

The resulting product to this project could be very beneficial. If successful, a new model for inhaler chamber tubes will be made. This model will help provide a more effective tube that delivers maximum amount of medication to the lungs. This will be more cost effective, as it will not use up unnecessary medication, and also more productive, as it allows for the entire dosage to reach the lungs. On a more personal side, this project will provide me with research experience as one day I hope to make a career in science and research. Everything from writing this grant to working on my project provides experience. Also, having a personal connection with this project enables me to be even more interested in the project and more driven towards my goal.




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