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IN RE MAHURKAR DOUBLE LUMEN HEMODIALYSIS CATHETER

December 5, 1991

IN THE MATTER OF: MAHURKAR DOUBLE LUMEN HEMODIALYSIS CATHETER PATENT LITIGATION

EASTERBROOK, Circuit Judge. *


The opinion of the court was delivered by: FRANK H. EASTERBROOK

EASTERBROOK, Circuit Judge.* All defendants have moved for summary judgment, maintaining that the hemodialysis catheters they make or used to make do not infringe Dr. Mahurkar's patent No. 4,134,402 (the '402 patent). This, the oldest of the Mahurkar patents in issue (five other U.S. utility patents, one U.S. design patent, and one Canadian design patent play large roles), is the basis of infringement claims against all of the remaining defendants' products.

 Mahurkar replied to the motions with an affidavit under Fed. R. Civ. P. 56(f) and a motion to compel additional discovery. His adversaries lodged motions for protective orders. All parties have filed voluminous documents in support of their positions. It is all but impossible to decide the motions to compel (and for protective orders) without deciding the motions for summary judgment. I therefore describe the grounds of the motions and of Mahurkar's opposition, which appears not only in his motion to compel but also in his statement of the respects in which he believes the accused devices infringe the '402 patent.

 I limit discussion to Vas-Cath's products, as Mahurkar concedes that the "Kendall and IMPRA catheters are substantially identical to [Vas-Cath's] VACCESS catheter" for purposes of this motion. This similarity is the basis of Mahurkar's motion to compel common treatment of the '402 infringement issues. If the VACCESS catheter does not infringe Mahurkar's '402 patent, neither do Kendall's or IMPRA's catheters.

 Claim 1 of the '402 patent is the only independent claim asserted against these defendants' catheters. Claim 1 reads:

 A double lumen hemodialysis catheter, comprising a unitary straight tube the periphery of which in transverse cross section defines a single closed plane curve at any point along the entire straight tube, an internal divider extending along a longitudinal portion of said tube and forming said tube into a blood intake lumen and a blood return lumen, one end of said blood return lumen extending beyond the associated end of said blood inlet lumen a distance sufficient to prevent mixing of the returned blood with the blood taken in, the one end of said blood return lumen being beveled with the extending [sic] from the lumen periphery opposite said divider and rearward of the distal end toward the distal end and said divider, the associated end of said blood inlet lumen being beveled with the bevel extending from the lumen periphery opposite said divider and rearward of the associated distal end toward the associated distal end and said divider, the distal end of said blood inlet lumen terminating rearward of the juncture of the blood return lumen bevel and the associated lumen periphery each of said lumens defining blood flow paths parallel one to the other along the entire length thereof and at the ends thereof such that blood entering said intake lumen and blood leaving said return lumen enter and exit the associated blood vessel in a direction substantially parallel to the vessel wall.

 Figure 1 from the patent shows a side view of the catheter, and figure 2 shows the catheter inserted in a blood vessel.

 [SEE EXHIBIT IN ORIGINAL]

 Figure 1

 Figure 2

 Blood enters the catheter upstream (at 4 in figure 1) and exits downstream (at 5). The tip is beveled. As the tube is circular at the tip, the bevel produces a point. A catheter with a rigid point may be inserted percutaneously (that is, the same way a needle is inserted, without the need for additional apparatus). The parallel flow of blood throughout the catheter reduces sudden changes in direction of the blood that cause turbulence and in turn may rupture the cells or diminish the rate of flow.

 Vas-Cath contends that its catheters do not infringe Claim 1 for three reasons: (i) they have perpendicular rather than parallel blood flow at the intake; (ii) they have a tapered nozzle at the return end rather than a beveled tip; and (iii) they lack a bevel at the inlet. Figure 3 shows Vas-Cath's VACCESS catheter:

 [SEE EXHIBIT IN ORIGINAL]

 Figure 3

 Blood enters the catheter at 54, a hole cut through the tubing. The intake lumen ends there; the shaded portion is solid. The return lumen ends in a tip cut perpendicular to the tapering tube, and the blood exits through 40. The FLEXXICON catheter, Vas-Cath's current product, terminates this way:

 [SEE EXHIBIT IN ORIGINAL]

 Figure 4

 Again the blood enters through holes cut in the side of the shorter lumen and is returned downstream at a tapered tip cut perpendicular to the tube. The intakes in the FLEXXICON catheter are not so clearly flush with the surface of the tubing, however, and one of the two holes is cut in a portion of the tube that is itself angled with respect to the main body of the catheter.

 These diagrams make it simple to see what Vas-Cath is driving at. The tip of the catheter described in Claim 1 of the '402 patent is cut at an angle to form a point; the tips of Vas-Cath's catheters are tapered to a point rather than being cut on a bevel. The intake of the catheter described in the '402 patent is formed by cutting away the end of the intake lumen, producing parallel blood ...


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