Amster Rothstein and Ebenstein, LLP - Intellectual Property Law

Same Word, Different Meanings

- Journal of Intellectual Property Law and Practice, August 19, 2010
Author(s): Charles R. Macedo

HaemoneticsCorp. v Baxter Healthcare Corp., No. 2009-1557, 2010 US App. LEXIS 11122, US Court of Appeals for the Federal Circuit, 2 June 2010 (‘Haemonetics II’)


The term ‘centrifugal unit’ is held to have different meanings in different claims of the same patent, based on the context of each claim.

Legal context

It is axiomatic that, under US patent law, the claims define the invention. Typically, the same words used in different claims of the same patent are often interpreted to have the same construction. However, this is not an absolute rule. Rather, based on the context of a particular claim, the same claim term in different claims—even in the same patent with the same specification—may nonetheless be construed to have different meanings.


Haemonetics is the owner of US patent no. 6,705,983, ‘Compact centrifuge device and use of same’ (‘983 Patent’). The patent includes twenty-two claims, of which claims 1, 16 and 20 are in independent form. All independent claims use the term ‘centrifugal unit’.

Haemonetics brought a patent infringement suit against Fenwal Inc.’s corporate predecessor (Baxter) in the US District Court for the District of Massachusetts, alleging infringement. After claim construction and summary judgment motions, Haemonetics limited its allegation of patent infringement to claim 16. Fenwal counterclaimed that claim 16 was invalid as indefinite, anticipated by prior invention and obvious.

Claim 16 provides as follows:

A centrifugal unit comprising a centrifugal component and a plurality of tubes, said unit to turn around an axis to separate the components of a liquid, blood in particular, with such plurality of tubes displaying a single tubular component wherein said unit includes:

a base in the form of a disk;

an external cylindrical wall extending from the base; an internal cylindrical wall extending from the base and separated by the external wall so as to define a ringshaped separation chamber among each other;

a tubular housing almost extending coaxially to said rotating axis from the base to receive an end of a tubular unit; and

a plurality of channels extending radially in the base of the centrifugal unit, with each channel providing communication between a respective tube of the tubular unit and the separation chamber, with the centrifugal unit having a radius between 25 and 50 mm and a height between 75 and 125% of the radius.

In an August 2007 claim construction order, the US District Court construed the term ‘centrifugal unit’ as used in claim 16 in Haemonetics Corp. v Baxter Healthcare Corp., 517 F. Supp. 2d 514, 518–20 (D. Mass. 2007) (‘Haemonetics I’). In particular, the US District Court construed (and the parties agreed) the term ‘centrifugal unit’ as used in the preamble to mean ‘the combination of both the vessel and the tubing.’ (Id at 518.) The US District Court, however, further went on to construe the term ‘centrifugal unit’ as used a second and third time in the body of claim 16 to mean only the vessel (id. at 519–20). At trial, the jury found that Fenwal infringed claim 16 under these constructions, and awarded Haemonetics over $11.3 million in lost profits and over $4.3 million in reasonable royalty damages. Fenwal appealed to the US Court of Appeals for the Federal Circuit, challenging the District Court’s claim construction, as well as other issues not pertinent to the present discussion.


While Haemonetics II addresses various issues, the present discussion focuses on the claim construction issue. At issue was whether the term ‘centrifugal unit’ was misconstrued by the US District Court when it was construed in claim 16 as being merely the vessel and not the vessel and the tubing as provided in the preamble of the claim. The Federal Circuit agreed with Fenwal that the US District Court misconstrued the claim.

In its claim construction analysis, the Federal Circuit found that in the context of claim 16, the claim language itself defined the ‘centrifugal unit’ in the preamble as explicitly including both ‘a centrifugal component and a plurality of tubes’ (Haemonetics II, 2010 US App. LEXIS 11122 at *78). The Federal Circuit went further to explain:

The claim then further recites, not the centrifugal component and not a centrifugal unit, but “the centrifugal unit” as “having a radius between 25 and 50 mm and a height between 75 and 125% of the radius.” Reading “the centrifugal unit” in the context of the dimensional limitations to refer exclusively to the vessel, as the district court did, ignores the antecedent basis for “the centrifugal unit,” and fails to give effect to the claim language “comprising a centrifugal component.” (Id. at *10.)

The Federal Circuit reached this construction even though the parties agreed that, in claim 1, the same term ‘centrifugal unit’ would be properly construed to cover only the vessel:

Furthermore, the specification defines “centrifugal unit” in the context of the height and radius limitations in two different embodiments, one that tracks the language of claim 1, in which the parties agree that “centrifugal unit” refers to the vessel alone, and one that tracks the language of claim 16. (Id.)

Based on these different embodiments in the specification, and different uses in the claim, the Federal Circuit found different constructions of the same term in different claims of the same patent to be the correct construction:

The patentee’s inconsistent use of identical height and radius limitations for two different embodiments thus indicates that “the centrifugal unit” in the context of the dimensional limitations must have different meanings in the context of different claims. In other words, the description of two embodiments with each tracking the language of different independent claims most reasonably supports a construction in which “centrifugal unit” has one meaning in claim 1 and another in claim 16. (Id. at *11–12, citations omitted.)

Thus, while the Federal Circuit rejected a construction of the same term in the same claim as having two different meanings, it nonetheless adopted a different construction for the same term in two different claims of the same patent.

Practical Significance

In Haemonetics II, the Federal Circuit reinforces the principle that the scope of a claim term must be considered in the context of the claim at issue. While use of a claim term in other claims, the specification and prosecution history are certainly important factors to consider in the claim construction process, in the end, the context in which the claim term is used in the claim at issue is a paramount consideration.


Charles R. Macedo
Amster, Rothstein & Ebenstein LLP, New York, NY

Charles R. Macedo is a Partner, at Amster, Rothstein & Ebenstein LLP, and the author of The Corporate Insider’s Guide to U.S. Patent Practice, published by Oxford University Press in 2009. His practice specializes in intellectual property issues including litigating patent, trademark and other intellectual property disputes, prosecuting patents before the U.S. Patent and Trademark Office and other patent offices throughout the world, registering trademarks and service marks with U.S. Patent and Trademark Office and other trademark offices throughout the world, and negotiating and drafting intellectual property agreements. He may be reached at [email protected].

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