Originally Published MD&DI June 2009
Gallery of Devices/Then and Now
How Far They’ve Come
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These days, medical devices incorporate innovative technology that helps clinicians vastly improve patient quality of life.
Device manufacturers continually strive to design products that are easier for healthcare providers to use and offer patients the fastest recovery possible. During the past 30 years, devices incorporated biocompatible materials to promote better healing and began providing a wealth of information about the body within seconds. Although it’s impossible to condense the accomplishments of medical device designers in a few pages, here are some examples of how far these amazing devices have evolved since MD&DI first hit the newsstands.
Computed Tomography (CT)
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THEN: The original Siretom scanner from 1974 was used for head scanning before the systems evolved into full body use. |
NOW: The Somatom Flash Definition scans at speeds of 430 mm/sec, which means it can scan the entire body in less than 5 seconds. |
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THEN: Images generated by the original Siretom show soft brain tissue. |
NOW: With the Somatom Flash Definition, body parts such as the heart can be scanned in half a heartbeat (250 ms). Images courtesy of SIEMENS HEALTHCARE |
CT scanners landed on the map in the 1970s. By integrating x-ray and computer technology, the devices generated cross-sectional images and became a revolutionary way for clinicians to look inside the body. Instead of initial surgery, a doctor can use a CT scan to evaluate a patient’s condition. Although the first scanners could take hours to process images, a complete scan of an area such as the chest now takes less than one second, produces higher-resolution images, and exposes patients to less radiation. Not only does the faster scanning make patients more comfortable, but it also eliminates artifacts caused by a patient breathing or moving.
Orthopedic Knee Implants
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THEN: Released in 1983, the ACG total knee implant offered complete component interchangeability. Image courtesy of BIOMET INC. |
NOW: The iDuo bicompartmental knee resurfacing implant is personalized to fit the patient. Image courtesy of CONFORMIS |
NOW: The iFit mapping plane from ConforMIS converts imaging data into precise implant sizes. Image courtesy of CONFORMIS |
In 1979, one of the newest developments for knee implants was computer modeling, which often required weeks to complete a design. Computer engineering software enabled the development of finite-element analysis and rapid prototyping for implants. Now, modeling an implant can be completed within hours. In this competitive market, companies continue to strive for stronger implants that improve motion and fit individuals better. Companies are recognizing the differences in patient anatomy, which has led to implants with a more accurate fit. Some are offered in a system of interchangeable sizes, while Zimmer’s Gender Solutions implant specifically addresses the female anatomy. ConforMIS has taken matters a step further by using imaging technology to create patient-specific implants and instruments.
The materials of choice for knee implants remain cobalt chrome and ultrahigh-molecular-weight polyethylene (UHMWPE). Ceramics (alumina and zirconia) have gained recognition for their strength, with some ceramic implants showing improved the wear rate up to 85%.
Heart Valves
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THEN: The Bjork-Shiley mechanical heart valve (1978) featured a tilting disk and convexo-concave design to reduce clot formation. Image courtesy of TEXAS HEART INSTITUTE |
NOW: The Carpentier-Edwards Perimount Magna bioprosthesis is the most widely implanted tissue valve in the world. Image courtesy of EDWARDS LIFESCIENCES |
NOW: Currently an investigational device, the Edwards Sapien valve uses a minimally-invasive technique to deliver it through a catheter. Image courtesy of EDWARDS LIFESCIENCES |
Heart valves were around long before 1979, but they’ve come a long way in the past 30 years. The devices have evolved from mechanical valves to devices that incorporate tissue from animals or human cadavers to promote better blood flow. Now, the next big innovation in heart valve replacement could be transcatheter valves, which are placed into the body via a catheter. Edwards Lifesciences and CoreValve Inc. (both Irvine, CA) are at the forefront of this revolution, as both companies have transcatheter valves on the market in Europe. Edwards Lifesciences is conducting a clinical trial of the Edwards Sapien valve in the United States, where it is currently limited to investigational use. The study involves two delivery systems that are available in Europe for valve replacement—one that is inserted via the leg and one via between the ribs.
Insulin Pumps
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THEN: Medtronic’s first insulin pump hit the market in 1983. Its 507C pump (pictured) was released in 1996. Image courtesy of MEDTRONIC INC. |
NOW: This personal diabetes manager from Insulet Corp. officially launches in June 2009. Image courtesy of INSULET CORP. |
As insulin pumps became portable in the 1970s, they quickly began shrinking in size. Today, these pumps are lighter and smaller than ever, and some even come in exciting colors. In fact, Insulet Corp.’s insulin delivery system refers to its device as a “pod” to reflect how it makes diabetes a smaller part of life for patients. Newer pumps also feature real-time, continuous glucose monitoring, which alerts patients to dangerously low or high glucose levels and helps them maintain an awareness of their condition. Some insulin pumps come in models specially designed for children as well.
Prosthetic Limbs
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THEN: This early single-axis modular knee joint is made of stainless steel. Image courtesy of OTTOBOCK HEALTHCARE |
NOW: The C-Leg is a fully microprocessor-controlled knee. By anticipating movement in real time, the technology allows the user to speed up or slow down, walk hills, and recover from stumbles. Image courtesy of OTTOBOCK HEALTHCARE |
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THEN: Early myoelectric hand technology provided movement and an alternative to the conventional hook. Photos courtesy of OTTOBOCK HEALTHCARE |
NOW: The i-Limb hand from Touch Bionics is the first prosthetic device with five individually powered digits. Image courtesy of TOUCH BIONICS |
Prosthetic limbs have come a long way in providing a more natural fit for users. The prosthetic hands of the 1970s were beginning to incorporate myoelectric control for better grip and flexibility, especially compared with traditional hooks. A myoelectric hand prosthesis consists of surface electrodes that are embedded into a socket. An electric motor, generated by an electric signal, enables the hand to perform a function. Today’s devices are becoming more advanced, and the future could be even more exciting. The Touch Bionics i-Limb Hand uses myoelectronics as part of an intuitive control system and has been hailed as the world’s first commercially available bionic hand. In addition, the i-Limb is equipped with a realistic flexible skin (called cosmesis) that covers the prosthesis.
Implantable Cardioverter-Defibrillators (ICDs)
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THEN ---> NOW The earliest automatic implantable defibrillator, the AID-B (1985), and today’s Teligen ICD (2008), the smallest and thinnest high-energy ICD at 31.5 cm3 and 9.9 mm thick. mage courtesy of BOSTON SCIENTIFIC |
Since the first defibrillator implantation in 1980, ICDs have significantly changed technologically. It took nearly 10 years for the ICD to prove itself against drug therapy. Now the life-saving devices are implanted in more than 100,000 patients each year. They now boast longer battery life than the original designs, result in fewer complications, and provide more therapy options than ever in arrhythmia management.
Copyright ©2009 Medical Device & Diagnostic Industry
