Medical Industry
Having a heart for polymers Polymeric materials, with their broad range of properties, are ushering in advancements for cardiovascular devices, says Angelica Buan in this article.
ETH researchers have developed a silicone heart that beats almost like a human heart
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AUGUST 2017
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ike a thief in the night”, that is how cardiovascular diseases (CVDs) are epitomised, bringing havoc to patients unexpectedly and silently. CVDs are the number one cause of death globally, says the World Health Organisation (WHO) that accounts more deaths linked to CVDs than from any other causes. CVDs, defined as conditions involving the heart and circulation, are preventable with lifestyle changes and managing risk factors; and if interventions are prescribed, there is an array of cardiovascular treatment modalities available today. The global cardiovascular device market is expected to achieve close to US$70 billion by 2022, growing at a CAGR of 4.3% from 2017, according to the report period covered by US market research firm Lucintel. It also noted the rising demand for portable heart monitoring devices, transcatheter aortic valve replacement (TAVR) procedures, and bioresorbable stents – devices which we would not have thought of having 40 years ago when the first angioplasty was performed, and which thereafter have become a common medical intervention. Also in demand is cardiovascular equipment such as catheters, balloons, stents, and others. Moreover, new materials, specifically polymers, are being engineered for more efficient, more biocompatible, and more cost-effective cardiovascular devices applications. The surgical devices segment is further categorised as pacemakers, stents, catheters and accessories, guide wires, cannulae, electrosurgical procedures, valves, and occlusion devices. The stent segment, among other surgical devices, accounted for the largest market share in 2015. Preference for stents over bypass surgeries is primarily driving their dominance. Furthermore, rising demand for minimally invasive surgeries is increasing the application of stents in the treatment of coronary artery disease. Potential for a cloned silicone heart We only have one heart, but with today’s technology, who says we cannot duplicate it? The Functional Materials Laboratory at ETH Zurich in Switzerland has created a prototype heart made of silicone using a 3D printing lost-wax casting technique. It weighs 390 g and has a volume of 679 cu cm. Resembling a real, human heart, which “beats, with right and left ventricles; and a central chamber”, the silicone heart still falls short to substituting a real heart. For one, the material of this model heart – a silicone monoblock, degrades after 3,000 beats (corresponding to 45 minutes), after which, the material can no longer withstand the strain. Development of the synthetic heart was undertaken by Nicholas Cohrs, a doctoral student in the group led by Professor Wendelin Stark at ETH Zurich. The team remarked: “The reasoning why nature should be used as a model is clear. Currently used blood pumps have many disadvantages - their mechanical parts are susceptible to complications while the patient lacks a