Medical Use Exception v. Divided Infringement (Part 1 of 3): Value Added to Medical Method and Diagnostic Patents through Induced Divided Infringement
January 15, 2013

The Federal Circuit recently handed down a game-changing decision concerning what constitutes induced infringement in Akamai Tech. v. Limelight Networks. Limelight may allow patentees to capture new value from medical procedure and diagnostic method claims when infringement results from multiple independent actors.

To show inducement of infringement under the new Limelight test, the patentee must show that the inducer (1) knew of the method patent, (2) induced the performance of steps of the method, and (3) that the claimed method steps were performed. It is not necessary to prove that all the steps were committed by a single actor; all that is required is that all the claimed steps are performed. It is enough that the inducer “cause[s], urge[s], encourage[s], or aid[s]” the infringing conduct and that the induced conduct is carried out.

Consider the following representative diagnostic method claim:

1. A method of probing a target in a sample comprising:

(a) drawing a sample from a patient;

(b) exposing the sample to a probe comprising a binder coupled to an enzyme under conditions suitable for the binding of the probe to the target;

(c) reacting the probe in step (b) with an enzyme substrate coupled to a fluorescent signal generator; and

(d) observing a signal from the fluorescent signal generator of step (c).

Suppose a diagnostic test developer learned of this method claim and created a test kit that performs steps (b) and (c) when a biological sample is applied to the test kit. The developer wants to perform the test as a service to hospitals around the country, so the developer encourages hospitals to use its services by sending patient samples to its labs. Prior to the Limelight case, the diagnostic test developer could avoid induced infringement liability if the method steps were performed by multiple actors, which is a highly likely scenario; i.e., a medical practitioner will perform step (a) and then the sample will be sent to the lab, where steps (b-d) will be performed.

Not any longer. Under Limelight, the patentee may seek damages from the diagnostic test developer for inducing divided infringement because the diagnostic test developer knew of the method patent, encouraged the infringing conduct to occur, and all steps of the method were performed. This change in the law may give medical and diagnostic method claim drafters alternative approaches to provide valuable claims for their clients.

Stay tuned for Part 2 of this post, which explores the medical procedure exception.

By: Douglas J. Bucklin, PhD

Note:  Special thanks to Amber Stiles, Law Clerk at Volpe and Koenig, for her contributions to this post.