adaptive medical devices

 

In 2013, I designed a printable medical device to treat patient with severe gastroesophageal reflux disease (GERD). GERD remains the most common gastrointestinal-related diagnosis by physicians. Acid reflux, the most prevalent of the many symptoms this disease causes, affects an estimated 23 million people two or more times a week in the United States alone. 

 

Most treatments of GERD and its symptoms today understandably target the acid buildup. For one, drugs that reduce acid are—for the most part—more reliable and specific than mechanical substitutions for a deficient sphincter. Proton pump inhibitors, as these drugs are called, form the third largest drug market in the world. These treatments, however, don't work. Over 40% of patients who are on daily regiments of PPIs reported partial or complete lack of response. 

 

I set out to design a device that would effectively replace the esophageal sphincter. This device combined the benefits of chemical responsiveness and mechanical design. 

 

One of the requirements for this device was the ability to constrict in acidic environments and expand in non-acidic conditions, in fact augmenting the functionality of current natural sphincters, which simply act as a non-responsive one-way valve. The capability of a tight seal in acidic environments prevents large acid buildup in the stomach from flowing into the esophagus, but also allow food to enter the stomach freely. 

 
 
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Using a polyacrylamide gel composition for the backbone of my sphincter, I designed the device such that swelling would occur under low pH environment and the opposite would occur under high pH conditions. The ability to 3D print this gel allows for customizability for each patient's physiological profile. For more details of the design, click here.

 

The design demonstrated that the intersection between biomaterials engineering and 3D printing provides a platform that has the potential to address the increasingly individual demands of medical treatment.