Using the Global Health Innovation Compass framework described in Lecture 1, map out two healthcare interventions to show how medical technology can play an important role in treatment.

Your two options are:

1. Asthma
2. Cardiovascular Disease (using Rheumatic Heart Disease as an example)

The exercise will be evaluated on:

• How well you were able to show the relationships between solutions
• The use of adequate Device Design Parameters in showing a solution (you have show at least 5 parameters)

Asthma

The National Library of Medicine offers this description of asthma:

"Asthma is a chronic disease that affects your airways. Your airways are tubes that carry air in and out of your lungs. If you have asthma, the inside walls of your airways become sore and swollen. That makes them very sensitive, and they may react strongly to things that you are allergic to or find irritating. When your airways react, they get narrower and your lungs get less air. This can cause wheezing, coughing, chest tightness and trouble breathing, especially early in the morning or at night.

When your asthma symptoms become worse than usual, it's called an asthma attack. In a severe asthma attack, the airways can close so much that your vital organs do not get enough oxygen. People can die from severe asthma attacks.

Asthma is treated with two kinds of medicines: quick-relief medicines to stop asthma symptoms and long-term control medicines to prevent symptoms."

In resource-poor settings, the wonder drugs that have made asthma a chronic manageable disease in industrialized countries are not affordable to the majority of the population. Glaxo makes a drug called Advair which is a combination of Fluticasone and Salmeterol. Fluticasone, a corticosteroid, is the anti-inflammatory component of the combination, while salmeterol treats constriction of the airways. Together, they relieve the symptoms of coughing, wheezing and shortness of breath better than either fluticasone or salmeterol taken on its own. The unit price of typical Advair inhaler: $150.

An asthma attack, if left untreated, can be fatal. 250,000 people die from an asthma attack each year. It is estimated that about a third of those are children.

A particularly tragic emergency scenario that often occurs in the developing world is an attack in a remote part of the country just beyond the perimeter of a clinic with the appropriate medication and treatment devices for an asthma attack. Asthma attacks can be treated with a variety of medicines. One of the most popular ones is albuterol. Albuterol is a fast acting bronchodialitor that can stop an attack within minutes. The drug is available as a metered dose inhaler as well as via a nebulizer.

An albuterol metered dose inhaler contains as many as 200 doses is available at that dose count for around $30. These fast acting inhalers are rare in developing country clinics because of the high price and the less than optimal synchronized breathing required for pediatric patients. View this video of a metered dose inhaler:

An alternative to the albuterol metered dose inhaler is the nebulizer. Nebulizer act by inducing a low pressure vortex into a liquid solution that results in a very soft mist that can also be inhaled. Nebulizers have certain advantages over MDIs in that the medication can be used one dose at a time (instead of 200 for instance) and the rate of inhalation can be over an extended period of time (5 to 10 minutes). This extra time is preferred for infants since they cannot be trained to breath the medication in under a 2 seconds like the person in the above video is demonstrating. The downside is that the nebulizer devices are powered by electricity to drive an air compressor.

For an anatomical look at what as asthma attack looks like see:

Healthcare providers along this chain will include:

• Nurses
• General Practitioners
• Pulmonologists
• Respiratory Therapists

Equipment includes:

• Albuterol Inhalers
• Nebulizers
• Stethoscopes and their accessories
• Systemic corticosteroid injections
• Anything else that you can think that will add to the Device Design Parameters used in class.

For this exercise, consider all the opportunities for emergency when administering medicine to stop an asthma attack.

For a full case example of asthma treatment, see Cooper, P. J., et al. Asthma in Latin America: A Public Health Challenge and Research Opportunity." Allergy 64, no. 1 (January 2009): 5-17. DOI: 10.1111/j.1398-9995.2008.01902.x.

Rheumatic Heart Disease

In many developing countries, Rheumatic Heart Disease is responsible for the most common form of valvular heart disease in developing countries.

The condition begins with Rheumatic fever brought on by a strep throat from streptococcal infection. The resulting fever produces connective tissue inflammation, including the heart, joints, brain or skin. Damage to the heart often goes unnoticed during the initial stage of the disease. Unfortunately the results are long lasting: damage heartfelt is unable to fully closed or open. In the worst scenario, the patient develops can get congestive heart failure. This is a condition in which the heart enlarges and is unable to pump out all its blood.

Prevention and Treatment

The best defense against RHD is to prevent rheumatic the fever from occurring in the first place. This requires detection of strep A infection and treatment with penicillin or an antibiotic. Rapid Strep A tests can be purchased for about $1.25 per test and may take about 20 minutes to show results.

If Rheumatic Fever has already occurred, then the next step is to screen them for valvular damage. valve disorders can usually be diagnosed by listening to the heart with a stethoscope. when the blood passes through a normal valve, no sound is heard. If the valve is damaged, the diseased valve creates a whooshing noise, also called a murmur.

Listen to a murmur: (WAV)

Compare it with a normal heart: (WAV)

and with a different type of damage called Mitral Regurgitation: (WAV)

The following chart shows the progression of the disease and opportunities for care.

Figure by MIT OpenCourseWare. After Carapetis, NEJM 2007.

Healthcare providers along this chain will include:

• Nurses
• General Practitioners
• Cardiologists
• Nurses who have been trained in listening to heart sounds
• Community Health Care workers
• Cardiac Surgeons

Equipment & Technology includes:

• Thermometers, Digital and Analog
• Diagnostics for Strep A
• Antibiotics
• Stethoscopes and their accessories
• Echocardiograms for advanced heart diagnostics
• Anything else that you can think that will add to the Device Design Parameters used in class.

For a full case example of rheumatic heart disease in the developing world see: Carapetis J. R. "Rheumatic Heart Disease in Developing Countries." NEJM 357 (2007): 439-441.

For this exercise, consider all the opportunities for care along the progression of the disease. As with all diseases, prevention is the best case. We want to explore what happens when you've crossed that threshold along the different routes.