Normally, when selecting a polymer for a particular application the main consideration is the performance required from the part. It is then a case of matching the material properties to those requirements. For medical applications things become a lot more complicated. Not only does biocompatibility need to be considered but so does the sterilisation method that is to be used. This makes material selection particularly difficult and often only a limited choice is available.
Design becomes increasingly important. It may not be possible to select a polymer that fully meets the performance properties required, so parts may need to be designed to compensate for this.
It must also be remembered that gaining approval for medical applications takes longer and is more costly than for non-medical products. Understandably, there is a considerable amount of form-filling needed, even at the beginning when trying to obtain data on suitable materials.
Providing as much information as possible on the application of the device (see Medical Standards Classifications) will help to speed the process.