Biomedical Engineering Reference
In-Depth Information
8.5.2
Feasibility
Design ideas for new or improved joint replacement implants will come from
orthopedic surgeons, sales people, or engineers. In the initial stages of the project
the feasibility will be assessed. This will include outlining the clinical indications,
assessing the market potential of a new joint replacement implant, and reviewing
the intellectual property to assess if there is scope to protect the design through
patents.
Beforeajointreplacementimplantcanbedesigned,itisessentialthatthe
design requirements for the implant are produced. The design requirements
capture everything that is required of the implant to ensure that it fulfills the
required performance once implanted into a patient. Various standards exist to
help determine the design requirements for implants ranging from a general
standard BS EN ISO 14630 [55] to standards that are specific to certain joint
replacement implants, such as the hip BS EN 12563 [56] and knee BS EN 12564
[57]. Besides considering the requirements of the joint replacement implant, it
is vital to consider the requirements of the packaging and labeling. In addition,
the requirements of any surgical instruments must be considered early in the
design process. It is not always the design of an implant on its own that dictates
good clinical success; high-quality instruments that are easy to use and enable
accurate placement of the implants are vital. The design requirements for a joint
replacement implant will include details on
•
intended performance
•
design attributes
•
materials
•
design evaluation
•
manufacture
•
testing
•
instruments required
•
sterilization
•
packaging
•
information to be supplied by the manufacturer.
8.5.3
Design
At the concept design stage, design solutions that meet the design requirements
are generated. It is important that design concepts are not dismissed in the initial
stages. An open mind is important to try and consider all possible solutions. The
concept design stage may involve
•
sketches of design solutions;
•
computer-aided design models; and
