General Considerations for the Development of Biomedical Devices - Advanced Design and Manufacturing Technologies for Biomedical Devices - page 22

• The development of new bioabsorbable materials that are body compatible which
degrade a certain time after being implanted while only producing non-toxic
matter that can be eliminated or metabolised by the body. Outstanding progress
has been made in the synthesis of bioabsorbable and biodegradable polymers
that can be applied to a large number of devices designed for the controlled deliv-
ery of drugs (Lendlein and Langer 2002 ), as well as for support tasks for tissue
engineering (Freed et al. 1994 ; Kawanishi et al. 2004 ).
• The discovery of new active materials that enable functionalities to be inbuilt
and so open up new horizons for the development of active implantable medical
devices thanks to their potential use as sensors and actuators (Davis 2003 ; Lendlein
and Kelch 2005 ; Wong and Bronzino 2007 ; Peterson and Bronzino 2008 ).

These advances mutually favour one another and used in combination can pro-
vide multiple novel responses to conditions for which, up to a decade ago, there was
no adequate treatment. All this has boosted the development of prototypes for a
large number of medical devices, many of which benefi t from the use of active
materials.
The following section provides an introduction to the systematic process of prod-
uct development and goes on to examine the further considerations that must be
borne in mind should the device under development respond to a medical need. It
will then go on to examine the infl uence of these considerations on the different
stages of the proposed systematic process.

2.2 Special Issues for the Development of Biodevices

2.2.1 Special Diffi culties

The design process of medical devices has a series of added diffi culties that involve
considerable changes and additional issues regarding the systematic methodology
for designing the products previously mentioned.
These additional challenges, diffi culties or issues can be classifi ed into the three
different groups set out below:

• Technical issues - These are related to the geometries, materials and the princi-
ples of functionality that can be utilised in a specifi c device as they are bounded
by the implications involved by their contact with human body tissue. They are
also bounded by the infl uence of the corporeal environment on the in-service
performance of the materials used and their progressive deterioration due to this
environment.
• Legal issues - The direct action on the body of the developed devices and their
associated risks increase the responsibility of those involved in the design and
give rise to certain changes to the prescribed methodology. The design process of
medical devices is therefore subject to strict rules, and care must be taken to