How to assess patent infringement risks: a semantic patent claim analysis using dependency relationships

Abstract

We propose a semantic patent claim analysis that can examine patents for possible infringements and identify which needs to be manually perused. So far, numerous approaches have been devised to systemise this burden, but have not been useful in practice because of a lack of consideration of semi-structure of patent claim data and claim element-based procedure of adjudicating patent infringement. At the heart of our method is a hierarchical keyword vector for representing the dependency relationships among claim elements (as well as unstructured textual information) and a tree matching algorithm for comparing claim elements of patents. A case study of the patents about DNA chip technology shows our method has considerable advantages in terms of accuracy and significance. We believe the suggested method could be employed in various research areas and serve as a starting point for developing more general models.

Keywords:

• technology intelligence
• patent infringement
• semantic patent claim analysis
• hierarchical keyword vector
• tree matching algorithm

Notes

In the year 2008, the total number of patent infringement cases filed in the US courts was 2,896, which had increased at a compound annual growth rate of 5.6% since 1991. The average cost of litigating a patent case today is US$2.5 million, which is also increasing annually, by some 10–15%.

The first step in the litigation process is to examine the literal infringement by comparing features of the accused product (or elements of its patent claim(s)) with those of the plaintiff's patent. It has been noted that a US claim is more like a checklist of components (or method steps) that all need to be present in an accused device (or method) for the claim to be literally infringed by the accused device.