theCylinder.net - Appropriate Medical Technologies

Just Say No to (Free) Drugs!

2008-09-01T07:00:00.000-07:00

I recently signed a pledge at NoFreeLunch.org that I will no longer dispense sample drugs. It wasn't an easy decision as I have many uninsured patients that would benefit from free medicine. But I often see patients come in who are no longer taking a much needed medicine because they cannot afford it. They were first prescribed the medicine as a sample. Sample drugs are almost exclusively new drugs that are still on patent and therefore expensive. Patients may not know that there are often cheaper and/or generic options to these medicines.

One example of this that I see frequently is Advair, a medication used to control asthma symptoms. Asthma care is broken down into a series of steps. The first step is to treat mild intermittent symptoms with albuterol only. If you have moderate persistent symptoms, you advance to Step Two and are prescribed an inhaled steroid. Patients who still need more control of symptoms go to Step Three where a third drug, a long acting beta agonist (LABA), is added.

Advair is a combination of the inhaled steroid fluticasone and the LABA salmeterol so it is a Step 3 medicine. However, it is also a new medicine that is on patent so samples are given to providers. Patients with and without insurance are given this medicine as a sample and later, when they run out of medicine, lose their insurance, and/or change providers, they find that it can cost around $180 per month. So folks now have to decide between spending money they may not have or deciding not to treat their or their child's asthma.

My experience has been that many of these people are probably at Step Two in the asthma treatment guideline and only need an inhaled steroid. These are also somewhat expensive, but at $75 per month, significantly cheaper than Advair.

There are times when the newer drug is the better drug but often these drugs are "me too" drugs.

Most of my patients understand why I am doing this. For patients that do need expensive medications, there are patient assistance programs where the pharmaceutical companies will provide with free medications.

A bike pump nebulizer adapter (and how about a bike powered nebulizer?)

2008-08-31T05:49:00.000-07:00

Problem: Providing nebulized asthma medications when there is no electricity available. MDI or HFA inhalers are definitely an option but some people need more medicine than these can provide.

Summary: John D. Klich has a patent on nebulizer bike pump adapter which filters the air through a device that fits between the pump and the nebulizer.

Two posted discussions both suggest and discourage the use of a bike pump to operate a nebulizer.

But the bike technology best suited for nebulizer function may be the bike itself, which could be used to power the nebulizer's own compressor. This would help circumvent the problem of oil and other foreign matter from the bike pump entering the nebulizer. I hope to work on this idea at some point. I'm sure it's been done already, but I haven't found any documentation on it yet.

Safety Net Antibiotic Prescriptions (SNAP)

2008-08-15T06:44:00.000-07:00

This is a simple way to offer patients and parents the option of either treating an infection or waiting to see if the infection will resolve on its own.

A patient may be seen with an infection when it is too early to determine if it is a viral infection that will resolve on its own or develop into a bacterial infection that requires antibiotic treatment. A prescription for an antibiotic is written with the instructions to not fill it unless the infection persists or worsens.

This process often creates an opportunity discuss appropriate antibiotic use. Parents and patients like the option of treating without having to come in (and pay for) another visit.

References
Treatment of Otitis Media With Observation and a
Safety-Net Antibiotic Prescription. Pediatrics 2003; Siegel et al. 112 (3): 527.

An evidence based approach to reducing antibiotic use in children with acute otitis media: controlled before and after study. BMJ 1999;318:715-716 (13 March)

Asthma Bottle Spacers: Overview

2008-05-28T21:38:00.000-07:00

Problem
Asthma is one of the fastest growing urban health problems throughout the world. It affects children in low income areas more than others and can contribute to early mortality and delayed development. Inhaled medications are the mainstay of asthma therapy. Plastic tubes, called “spacers” are used to make delivery of the medication more efficient by allowing more of the medication to go where it is needed. This also makes the inhaler to be more cost effective.
Inhalers can cost as much as $60 each and an individual using multiple inhalers can spend as much as $150 per month on inhalers.

Spacers are also expensive, costing the patient between $10 and $30 each. Spacers are often not covered by insurance plans. Providers may not prescribe spacers and parents often forego the purchase of a spacer because of the expense already incurred for expensive inhalers.

Summary
An asthma spacer is used with an asthma inhaler to make the medicine more effective by slowing down the spray and allowing the patient to coordinate their breath with the medication delivery. It can improve the efficiency of an inhaler by 70%.

Peak Flow Meter

2008-05-28T10:22:00.000-07:00

This page contains the work of University of Michigan - Dearborn students Tom Silka, Chris Marquette, Anthony Darkangelo, and Ryan Kiblawi. Their final design project for the Spring 2007 session of ME 379 Thermal-Fluids Lab is based on an experimental low-cost peak flow meter originally designed by Steve McCrosky.

Abstract:
A Peak Flow Meter (PFM) was designed to achieve consistent exhalation results for the diagnosis and management of asthma. A calibration procedure was used to modify the flow meter to achieve consistency. To accomplish this, the behavioral characteristics of air, the working fluid, had to be understood. The air proved to be incompressible, with a steady laminar flow at constant properties in the fully developed region of a straight circular pipe. The Peak Flow Meter was fabricated using common materials, including PVC pipe, a mechanical pencil spring, a small piece of aluminum and a reciprocating saw blade. Calibration was conducted by the time in which it took to fully compress a raft pump with respect to pressure flow. The raft pump simulated the diaphragm in the human respiratory system and the flow chamber simulated lung capacity. Before the trials were started for the calibration process, the commercial PFM was attached to the raft pump first, to serve as a standard of comparison. The raft pump was compressed at a time recorded by a stop watch. A variety of trials were run in order to assign specific flow rates with respect to the time the stop-watch indicated. This procedure was performed again for our PFM. To calibrate our PFM, holes were drilled at the base and lower shaft of the PFM to alleviate pressure and simulate the performance of the commercial PFM. Trials were conducted until consistent resulted were achieved. Flow rates were then indicated on the saw blade by a color coded system.

Introduction:
A Peak Flow Meter (PFM) is a portable, hand-held device that helps the user check how effectively their asthma is controlled by measuring the volumetric flow rate of the air that is exhaled. A variety of commercial Peak Flow Meter’s can be seen below.
Figure 1: Commercial Peak Flow Meters A healthy person in their twenties can expect a peak flow rate of around 600 L/min. Patients with asthma will typically have a flow rate less than this, but will vary with their own health conditions. By using a peak flow meter every day and keeping track of the results, doctors will be able to see how a patients asthma is doing on a daily basis and will help determine what type of medical treatment is needed.

Objectives:
Peak Flow Meters are useful at home and in clinics. This is especially true when a patient is able to see a change in the results before and after an in-office treatment. They would be able to notice any decline in the condition of their asthma and then relay the information to their doctor at their next appointment. Often a reduction of a person’s maximum exhalation flow rate is a sign of a worsening health condition. The problem is that peak flow meters are not easily attainable everywhere people may need them. In many developing or remote areas, medical instruments like the peak flow meter are not easily found. This design project will concentrate on a simple Peak Flow Meter design which could be used by clinicians in developing or rural areas. The challenge is to design a device that can be built with supplies available in any small city in the world. This way, anyone who gets hold of the design could access all of the materials needed. The materials being used for the peak flow meter consist of PVC tubing for the body and a piece of aluminum used to measure the volumetric flow rate of the person’s exhalation. The design should be standardized so that whoever builds it will get an accurate reading. The main challenge will not be the construction of the device itself, but rather its calibration. It must be assured that the low-cost peak flow meter is capable of repeatable results akin to production peak flow meters. Research has shown that there are no other similar efforts to design a low cost peak flow meter.

Experimental Apparatus:
A peak flow meter consists of a hollow tube with a plunger inside that can travel freely. The part of the PFM that is blown into by a person should be perpendicular to the hollow tube that encases the plunger. The plunger is the device that is being displaced in proportion to the volumetric flow rate. Attached to the plunger is a mechanism that keeps the plunger at its maximum elevation in the hollow tube. In this design, a reciprocating saw blade on a spring loaded pivot point enables PFM measurement to take place.

Figure 1: Peak Flow Meter Cross Sectional View

A hand operated air pump is connected to a flow chamber that is used to disperse an even flow into the PFM. When the pump handle is depressed, the standing air in the flow chamber is displaced, and moves into the peak flow meter. This process is designed to mimic that of a human blowing into the PFM, where the raft pump represents the diaphragm and the flow chamber simulates lung capacity.

Figure 2: Experimental Apparatus

As can be seen in Figure 4, to overcome the calibration challenge, our peak flow
meter will be connected to the regulated air supply. This will simulate human
lung power providing steady bursts of flow to calibrate the peak flow meter.
Holes are drilled in a controlled pattern along the shaft to evenly release air
pressure build-up underneath the plunging object inside the PVC pipe.

To create the Peak Flow Meter a 10 in section of a 1.25 in ID PVC tubing and a T-joint that has a 0.75 in female slip fitting on the perpendicular side will be used. A 1.25 in male plug is inserted on the bottom of the T-joint. The 0.75 in female slip fitting simulates the mouthpiece size on a commercial PFM. A 0.75 in female end cap smoothly fits inside the 1.25 in PVC this is how the plunger was formulated. The plunger consists of two 0.75 in caps attached with a 1 in section of 0.75 in pipe. At the top of the PFM there is a 1.25 in female cap with a slot cut in it. The slot serves as an access way for the reciprocating saw blade to slide through. A piece of aluminum is bent to match the angle of the teeth on the reciprocating saw blade. A 0.125 in hole is drilled through on one of the caps just before the convex dome. A pin is inserted through this hole to hold the reciprocating saw blade. A slot is cut in the cap of the plug, allowing the end of the spring loaded reciprocating saw blade to pivot about the pin inside the cap. The compression spring was taken from a retractable pen. This spring was super-glued perpendicular to the blade edge. The spring supplies enough resistance to press the blade against the aluminum catch device at the top of the PFM. A 0.125 in hole is drilled 1 in from the bottom of the 10 in section of PVC pipe and a pin is inserted. The purpose of this pin is to allow the plunger to start at a consistent level every time the plunger is reset. The first hole that needs to be drilled in the 10 in section of pipe has a 5/16 in diameter and is located 1.16 in from the bottom of the pipe. The second hole has a 7/32 in diameter and is located 0.84 in from the bottom of the pipe. A 3/8 in diameter hole is drilled in the middle of the T-joint directly across from the 0.75 in female opening. The last hole also has a 3/8 in diameter that is located on the center of the bottom 1.25 in male plug. The figure below shows a cross sectional view of the location where the holes should be drilled.

Figure 3: Cross-sectional View Showing Hole Location

A commercial raft pump was modified and fitted with a stop watch to allow for precise timing of air flow. The setup is as follows: A standard stopwatch was disassembled, and shielded wires were soldered to the start/stop button’s metal activation surfaces. The wires lead to two simple buttons. One of the buttons is attached to the handle of the pump, and another was inserted into the bottom surface of the inside of the pump. When the user begins to push down on the handle, the handle button is pressed. Upon reaching the bottom of the plunger’s travel, it depresses the button in the bottom of the pump and automatically stops the stopwatch. The reset button of the stopwatch was retained so that the time can be reset and multiple trials can be run.
A raft pump was connected via 0.75” tubing to a device known as a flow chamber. The flow chamber consists of two 1” by 1.25” adapters connected with an 8” section of 2” PVC pipe. On each end of the flow chamber, 1” male hose adapters were threaded into the flow chamber making certain to use Teflon tape to prevent any sort of air leakage.

Experimental Procedure:
Before the trials were started for the calibration process it was verified that the raft pump tubing and all PVC joints were securely connected, and the stop-watch is zeroed out. To serve as a standard of comparison, the commercial PFM was attached to the raft pump first. The setup was placed on a table making certain that none of the holes were obstructed. Prior to compressing the pump it was assured the plunging device on the PFM was reset to the zero position. The raft pump was compressed at a time recorded by the stop watch. To activate the stop-watch the red handle button was pressed simultaneously as the handle to the raft pump was being compressed. The handle was completely pressed to stop the time on the stop-watch. The compressed air then travels into the flow chamber to create a constant volumetric flow rate to the PFM. A variety of trials were run in order to assign specific flow rates with respect to the time the timer indicated. This procedure was performed again for the designed PFM. To calibrate the deisgned PFM, specific size holes were drilled at the base and lower shaft of the PFM to alleviate pressure and simulate the performance of the commercial PFM. Trials were conducted until consistent results were achieved. The midpoint was then noted on the reciprocating saw blade. Referencing the standard data that was achieved in the trials, a correlation was achieved for flow rate. Flow rates were then indicated on the saw blade by means of a color coded system.

Conclusions

It can confidently be concluded that this design project was a success. From the inception of the project until the end, we found ourselves utilizing multiple skills acquired over the years spent here at The University of Michigan – Dearborn. A Peak Flow meter was designed with very basic materials, and was able to be calibrated to replicate the flow results of a commercial flow meter. A large obstacle was being mindful of the budget in the creation of the Peak Flow Meter. As can be inferred from our Budget, seen in the Appendix, our PFM with out calibration instruments, totaled to be $7.65, which is less than half the price of the cheapest PFM out on the market.
Although we did achieve accurate results that were consistent with that of the commercial peak flow meter, our design did present us with some unexpected inaccuracies. Fortunately, these turned out to be present at the very high and very low range of peak flow readings. Our major flow measurement inaccuracies stemmed from the design of the flow indicator. The flow indicator (reciprocating saw blade) is lightly pressed against the aluminum stopper by a small spring. At most flow values, the spring does not have an appreciable effect on the operation of the device. However, at higher flow values, the spring is stretched further and more force is put on the indicator. This load was not initially accounted for, and thus presents an inaccuracy. Fortunately, someone capable of achieving an upper flow value (> 700 L/min) is not expected to have problems which would entail the regular usage of a peak flow meter. Also presenting a source of inaccuracy was the weight of the plunger itself. At lower flow values, the force of the air pushing against the plunger is not sufficient for the generation of accurate, repeatable results. However, it is likely that a person achieving a peak flow of less than 350 L/min will require medical attention beyond the scope of home peak flow meters.

Fig 4 Flow Rates

Fig. 5 Plug travel distance.

Retrieved from "http://www.appropedia.org/Peak_flow_meter"

Asthma Bottle Spacers: How to Use

2008-05-28T10:16:00.001-07:00

[edit] Instructions
[edit] Using a bottle spacer with your asthma medication
These instructions are also available by download.
What is a spacer? A spacer is an empty chamber that can be attached to some asthma inhalers. Spacers make the medicine more effective while reducing side effects.
How does the spacer work? When a dose of medicine is sprayed from an inhaler, it is moving very fast. When a spacer is not used, much of the medicine sticks to the inside of the mouth and throat instead of the lungs. A spacer slows the medicine down so the user can inhale the medicine slowly and get more medicine to the lungs where it is needed.
Why should I use a spacer? Spacers make inhalers up to 70% more effective. This saves money and reduces the need for medicine. Spacers also reduce side effects like thrush, nervousness, bad taste, and sore throat that can be caused by inhaled medicine. [1]
Why is this spacer made out of a bottle? Commercial spacers can cost $20-$40 each and are not always paid for by health insurance. Several studies have shown that bottle spacers are as effective as commercial spacers. By providing this simple, low-cost spacer to our patients, we can improve your asthma treatment while saving you money. [2][3]
What should I do the first time I use the bottle spacer?
Remove the cap. Because each spacer is made from an unused water bottle, removing the cap for the first time should break the seal between the cap and the bottle.
Rinse the bottle and look inside the bottle, making sure that there is nothing inside.
Fill a pot (or other container large enough to hold the entire spacer) with cool water. Stir in a few drops of household dish detergent and soak the bottle for at least 5 minutes. The detergent helps reduce a static charge that makes the spacer less efficient.[4] Allow the spacer to drip-dry for at least 12 hours.
Clean your spacer this way at least once a month.
How do I use the bottle spacer?
Shake your inhaler and insert it into hole in base of bottle.
Put mouthpiece of spacer in your mouth.
Close your lips around the mouthpiece and make a tight seal.
Press down on the inhaler, spraying a dose into the spacer.
Take a slow, deep breath.
Hold your breath for 10 seconds.

[edit] References
↑ Journal of Aerosol Medicine, September 1995
↑ Archives of Disease in Childhood, February 2007
↑ Lancet, September 1999
↑ European Respiratory Journal, March 1999

Asthma Bottle Spacers: Production

2008-05-28T10:11:00.000-07:00

Production
Equipment and Supplies
Tools Needed
Drill press
Laser printer
15/16" flat drill bit
Utility Knife
Supplies Needed
4" PVC tubing and 2 pair hinges
wood and hardware needed for mounting brace to your type of drillpress

8 1/2" x 11" all weather laser print labels for stick er

8 1/2" x 11" paper for instructions
500 cc plastic water bottles. This size was used in the published trials. Several characteristics make the Metromint 500 cc mint water bottle a good choice. It is clear which makes it easier to see medicine in chamber. It has a smooth surface so that the sticker can be applied and is thicker and more durable than other brands. Metromint has recently agreed to doante clean empty bottles to this project. (Please contact Steve McCrosky if you wish to build spacers with these bottles.)
3/8" OD clear vinyl tubing
Panel fasteners (ITW Fastex Christmas Tree Clip, part number 354-125300-00.)

[edit] Step by step production

Fig. 1. Metromint bottles have several properties that make them great spacers.

Fig 2. The brace attached to the drill press.

Fig 3. Placing the bottle in the brace.

Fig 4. Drilling the hole in the base of bottle.

About "theCylinder.net"

2008-04-17T14:42:00.000-07:00

The name of the index is derived from le Cylindre, Rene Laennec's 1816 invention for listening to the lungs of his patients. Created at the bedside with only the materials at hand, it provides an excellent example of appropriate medical technology. Le Cylindre later became known as the stethoscope.

I started the Cylinder in 2004. I had been trying to organize my often disparate interests. After an exercise of self exploration, I found that there were three common themes to my interests: health, development and technology. I decided that a web site that would index different AMT's would allow me to explore all three of these areas and would be a tool for exploring what was already out there.

In 2007, I discovered Appropedia and have been transferring most of the AMT's that were indexed in the Cylidner to the health and safety category of Appropedia. The ones that remain here are projects on which I am working or in which I have a special interest. It was also around this time that the cylinder was converted to a blog.

Glossary of Terms

2007-05-23T14:11:00.000-07:00

appropriate technology (AT) - "technology that can be made at an affordable price by ordinary people using local materials to do useful work in ways that do the least possible harm to both human society and the environment." [1]Some good examples of appropriate technology are a hand powered water pump or an efficient clay oven.

appropriate medical technology (AMT) - appropriate technologies used in primary care, public health, rehabilitation or any other health care setting. They can be as simple as making your own saline solution or as complex as an intraocular lens. They can be as abstract as a teaching method or as real as a plastic bottle used for asthma or water distillation.

appropriate information technology - designing information resources and computer technology in order to include as many users as possible. Viewers in developing countries may have slower internet connections. To reduce bandwidth, the files on this site are small and images are kept on separate pages so that viewers can choose when to download those larger files. .

South-South technology transfer - sharing knowledge and information between two different areas in the southern hemisphere.

South-to-North technology transfer - sharing knowledge gained in the southern hemisphere with those in the northern hemisphere.

evidence-based practice - Practice supported by research findings and/or demonstrated as being effective through a critical examination of current and past practices. [2]

[1] McGraw Hill Online Learning Center, Environmental Science: A Global Concern
William P. Cunningham, University of Minnesota;
Mary Ann Cunningham, Vassar College;
Barbara Woodworth Saigo, St. Cloud State University.

[2] http://www.cona-nurse.org/standards/glossary.htm

Adobe Natural Medicine Pharmacy

2007-05-23T13:00:00.000-07:00

Problem
Poor access to medicine in rural El Salvador. Decreasing knowledge of indigenous natural medicine among Cacaopera community. Deforestation worsened by wood-fired kilns used to fire bricks.

Summary
This building was built to be a natural medicine pharmacy; it's current funtion is unknown. Adobe was chosen to reduce costs and the use of wood for firing bricks.

Developers
Comunidad Indigena de Cacaopera

"the Cylinder": the first stethoscope

2007-05-20T21:31:00.000-07:00

Problem
"In 1816, I was consulted by a young woman labouring under general symptoms of diseased heart, and in whose case percussion and the application of the hand were of little avail on the account of the great degree of fatness..."

Summary
"...I rolled a quire of paper (24 sheets) into a kind of cylinder and applied one end of it to the region of the heart and the other to my ear..." -Rene Laennec, 1816

Developers
Rene Laennec

Website
www.antiquemed.com

References
Agnew R. The prelude to stethoscopy: some French, British and Irish contributions in the early nineteenth century. J Med Biogr. 2003 Aug;11(3):135-41.

Merino JG. [Laennec and the creation of auscultation signs] Gac Med Mex. 2003 Mar-Apr;139(2):165-8.

For kids: Hear Your Heart by Paul Showers