Federal Circuit reverses claim construction and noninfringement finding

June 27, 2007
Post by Blog Staff

In a claim construction appeal, the Federal Circuit found that the doctrine of claim differentiation, combined with statements made in a petition to make special, led to a broader claim construction than that offered by the district court. Also, there was no unequivocal disclaimer of the broader claim scope during prosecution of either the patent-in-suit or its parent application, as found by the district court. As a result, the district court's claim construction and associated summary judgment of noninfringement were reversed.

The Saunders Group holds patents relating to spinal traction devices. The patent at issue in this case relates to cervical traction devices, and a related parent application matured into a patent relating to lumbar traction devices. Claim 1 of the patent-in-suit is representative:

A cervical traction device comprising:
[1] a support structure having a track;
[2] a carriage having a slide bracket slidable along a portion of the track;
[3] a restraining mechanism adapted to releasably restrain a portion of a patient's body to the carriage;
[4] a pneumatic cylinder having a first end and a moveable piston rod at a second end, one of the pneumatic cylinder or the piston rod attached to the support structure and the other attached to the carriage, the pneumatic cylinder adapted to move the carriage along the track relative to the support structure when in a pressurized state, the pneumatic cylinder maintaining a generally static traction force for a period in excess of 10 minutes when in the pressurized state without additional pressurized air being supplied; and
[5] a hand pump fluidly connected to the pneumatic cylinder and adapted to inject pressurized air into the pneumatic cylinder, the hand pump having a handle moveable relative to a body portion to injecting at least 138 kPa (20 psi) of pressure into the pneumatic cylinder.

The district court construed the term "pneumatic cylinder" to require that the cylinder at issue also have at least one pressure activated seal. This finding was based largely on two facts: the only example provided in the specification described such a seal, and an unequivocal disclaimer of other types of seals. Based on this construction, the district court entered summary judgment of noninfringement for the defendants, Comfortrac and Care Rehab and Orthopaedic Products.

The Federal Circuit reversed. The court noted that the fact that only a single example is disclosed in the specification of a patent is insufficient reason to limit the scope of the patent's claims to such an embodiment. Further, here, the doctrine of claim differentiation supported a broader construction, as claims 6 and 7, which depend from claim 1, require a pressure activated seal. In addition, during prosecution, Saunders filed a petition to make special to expedite prosecution on the basis that there were incidents of infringement occurring in the marketplace. The only claims in the application that Saunders alleged were infringed in that petition were the ones that did not require a pressure activated seal. As a result, the Federal Circuit found the district court's narrower construction to be in error.

The court also found no "unequivocal disclaimer" of other types of seals in the prosecution history. As an initial matter, the court noted that because the claim language of the parent application (which led to the lumbar patent) and the application that led to the patent-in-suit was different, disclaimers made in the parent would not affect the patent-in-suit. Specifically, the court stated:

When the purported disclaimers are directed to specific claim terms that have been omitted or materially altered in subsequent applications (rather than to the invention itself), those disclaimers do not apply.

The defendants argued that some of the disclaimers related to language used in both applications. Examining the statements made during prosecution, the court found no such disclaimer: "the prosecution history contains no argument that the prior art devices failed to maintain the requisite traction force because of the absence of activated seals."

Interestingly, after finding the district court's claim construction too narrow, the court then spends about a page of the opinion describing the inherent tension between claim construction and validity. The court references a prior case, Liebel-Flarsheim Co. v. Medrad, Inc., where the district court initially construed the claims too narrowly, and the Federal Circuit reversed. However, on remand, the defendant successfully argued that the broader claims were invalid, a finding affirmed on appeal. This illustrates the difficult balancing act patent prosecutors and litigators must perform: claims need to be broad enough to cover products offered or methods performed by competitors, but not at the cost of the patent's validity.

To read the full decision in Saunders Group, Inc. v. Comfortrac, Inc., click here.

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