Regulatory Challenges in Biomaterials: Focus on Medical Devices - Biomaterials Science: An Integrated Clinical and Engineering Approach - page 254

FIGuRE 10.3
(right) Frontal view of the chest showing a quarter stuck in the distal portion of the esophagus
in a young child. (Courtesy of Hunter, T.)
(e.g., a surgical sponge) can cause problems later when its intended purpose
goes awry (e.g., a sponge left in the abdomen after surgery, a chest tube col-
lapsing the lung instead of removing the air collection in a pneumothorax)
(Figures 10.4 and 10.5).
Despite the extensive regulatory procedures for introducing new medi-
cal devices for medical applications and for reporting death or injury
caused by such devices, there seems to be no specific national standards
or laws that define or ever require an expected radiologic appearance for
a given medical device. This can be very problematic for physicians and
healthcare workers using diagnostic radiologic studies to care for patients.
For example, it is often difficult to discern the difference between a naso-
gastric tube and an endotracheal tube on a chest radiograph. They usually
lie on top of each other in an anterior-posterior direction on a portable
chest radiograph and can have similar appearances (Figure 10.6). It would
be ideal for the endotracheal tube tip to be outlined with a prominent
radiographic density, allowing for the tube's presence and tip position to
be easily noted.
The days of totally radiolucent central catheters seem to be behind us, but
many of today's catheters and tubes still remain poorly marked and difficult
to appreciate. A particularly bad offender is the intra-aortic balloon pump
(IABP) (Figure 10.2), which is typically totally radiolucent, except for a tiny
metallic marker on its tip. Even though proper positioning of an IABP is criti-
cal for patients with severe cardiac problems, it is nearly impossible to discern