Biomedical Engineering Reference
In-Depth Information
sell the product - right? In reality, the science is only part, and likely
a small part, of why practitioners choose a specific medical device.
Some biomaterial implants are made from a single material, but many
are a component of a composite such as bone putty or some of the
other composites discussed in this topic. In many cases, the ''science'' is
covered up with a pliable resin or a polymer for forming the material
to the desired shape during surgery. Ultimately, a surgeon is going to
decide whether or not they use your device based on cost, the form of
the device, ease of use, and the expected outcome.
A specific biological response (i.e. bone bonding) is the reason that a
specific biomaterial or bioactive glass is chosen initially. However, ease
of use is likely what a doctor cares about most. No one wants a great
material that is impossible to use. A moderately effective material with
excellent handling characteristics will sell much better and be used more
often in surgery. Understanding the clinical need and addressing how
doctors would ideally apply the material most effectively is the first thing
to find out when developing a new biomaterial product. The second step
is to get the material of interest into that form. When the product is
what the clinician desires, the product has a greater chance of success.
Something about biomaterial design and product development that is
often ignored in university is cost. For instance, say we were developing
an electrical wire. Assuming that conductivity was most important, a
material like gold or silver might be the best choice, because of their
high electrical conductivity. Realistically, we also know that we will
need relatively low cost. Therefore, a much cheaper material with lower,
but still acceptable, conductivity - like copper - becomes the material of
choice. The same is true for making biomaterials.
Cost-effective materials and methods are imperative to scale the prod-
uct to a level that is sufficient for demand. What can be done on a bench
top is not necessarily how something will be scaled for production. For
example, we may have a two million dollar machine that can produce
8 g of viable material a day. This is not a scalable process, because the
cost of the material would not be competitive, regardless of the biolog-
ical outcome, and the only way to increase output is by buying more
machines. In the described model, equipment overhead costs would be
the major hurdle to overcome. Ideally, the idea could be closely mim-
icked by a much less expensive method of production, yielding a similar
product with similar biological outcomes at a mere fraction of the cost.
Ease of manufacture is another issue often not covered in typical
biomaterial courses. Manufacturing yield is a hidden cost in material
processing that can have a significant impact on product success. For
