The role of patent citations as a footprint of technology
本文提出从专利引用中提取“技术足迹”数据结构，用于追踪技术演化，并以计算机鼠标和计算机断层扫描为例展示可视化效果。
The fact that patents are documents highly constrained by law and structured by international treaties make them a unique body of publications for tracing the history and evolution of technology. The distinctiveness of prior art patent citations compared to bibliographic references in the nonpatent literature is discussed. Starting from these observations and using the patent classification scheme as a framework of reference, we have identified a data structure, the “technology footprint,” derived from the patents cited as prior art for a selected set of patents. This data structure will provide us with dynamic information about the technological components of the selected set of patents, which represents a technology, company, or inventor. Two case studies are presented in order to illustrate the visualization of the technology footprint: one concerning an inventor—Mr. Engelbart, the inventor of the “computer mouse”—and another concerning the early years of a technology—computerized tomography.