Validity searches establish the enforceability of an issued patent for an infringement defense or to thoroughly inspect a patent before assignment or license.
The claims of the subject patent are compared to prior art patents published before the filing date of the subject patent. This can be a challenging exercise when the doctrine of equivalents is accounted for. The focus is on discovering prior art references that correspond to the independent claims set forth in the subject patent.
A thorough invalidity exercise would involve study of the file wrapper (examination history) for a given patent in order to review the prior art exchanges between the patent examiner and patent agent over the claims as revised.
In the USA, the Festo court decision greatly affects the breadth of amended claims in terms of the Doctrine of Equivalents. If you need this level of legal analysis, engaging the services of a registered patent agent with experience litigating the art in question might be advisable.
Cost: $85/hour x 18-22 hours. $1530 to $1870 plus computer database charges.