We are asked in this appeal to reexamine the issue of the validity of the patent held valid by this court five years ago in
Mercantile National Bank of Chicago v. Quest, Inc.,
The patent, which covers a portable device for providing continuous-suction evacuation of a closed surgical wound through a needle and tube connected to a spring-loaded plastic chamber, is adequately described in our earlier opinion. With the exception noted below, the same may be said of the prior art agаinst which its obviousness must be judged.
A litigant who attacks the validity of a patent before a court that has held the patent valid in a prior case has the burden of persuading the court that there is a “materiаl distinction” between that case and the case at bar. See
American Photocopy Equipment Co. v. Rovico, Inc.,
In the case at bar, defendants argue that the material distinction between the facts relating to validity in this and the earlier Quest decision, supra, is that a relevant portion of the prior art, namely, the Barron bottle, was not before the court in that case. The Barron bottle was disclosed in an article by Dr. J. N. Barron in the July 1959 issue of the British Journal of Plastic Surgery and was therefore a part of the prior аrt, if, as we assume for present purposes, the determinative date of the invention of the patent was the date of the application, July 14, 1960. The device described by Barron used a cylindrical plastic bottle as the chamber in which the negative pressure is created and maintained. After being squeezed, or compressed, the bottle slowly returned to its original shape and, as it did so, develoрed a negative pressure which caused fluid in the wound to be drawn through a connecting tube into the bottle. Defendants argue that this device renders obvious the device disclosed in the patent, which uses a chamber resem *1033 bling a concertina, with spring-loaded end pieces and bellows-type sidewalls, to develop the negative pressure and receive the fluid from the wound.
While the Barron bottle wаs not a part of the prior art shown in the earlier case, that art did include a device known as the Dakin syringe. Though somewhat different in shape, the Dakin syringe is nonetheless very similar to the Barron bottle in operation and principle. Defendants’ counsel, in fact, conceded this at oral argument but argued that the prior art references before the court in the earlier case did not disclоse the use of the Dakin syringe for continuous wound evacuation, while the Barron article showed the use of the Barron bottle for this purpose.
The issue is thus narrowed to whether the record in Quest discloses that the Dakin syringe could be used for continuous wound evacuation. 1 Clearly it does. As this court there observed, after describing the surgical technique of postoperative wound evacuation by negative pressure,
“This surgical technique is now commоnly used by surgeons; however, the method of providing the suction or negative pressure has varied. Compressed bulb syringes may in some cases be satisfactory but are not generally used.”431 F.2d at 264 .
The court also referred to an article contained in the prior art exhibits:
“Defendant further relies on the Maloney article, defendants’ exhibit as prior art. The article describes ‘Apposition and Drainage of Largе Skin Flaps by Suction,’ and is a further development of this technique. However, the suction pressure recommended by Maloney is ‘either a bottle with a negative underwater seal or an electric or wаter pump’ or ‘the use of a syringe of the Dakin variety * * *Id. at 265.
The article itself, which appeared in The Australian and New Zealand Journal of Surgery, describes the technique of continuous wound evacuation by suction and various devices that can be used for that purpose and states as follows:
“Another method of obtaining a negative pressure is by the use of a syringe of the Dakin variety which is attached to the drainage tube after the rubber bulb has been compressed. It gives a means of suction which is readily portable for ambulant patients.”
Defendants argue that the Dakin syringe appeared
from the
record in the Quest case to be less satisfactory than the Barron bottle appears from this record to have been, and that the belief that the syringe was not satisfactory was the basis for the court’s finding of invention in the Quest case. It is true that the court found the results of the methods of obtaining negative pressure shown in the prior art not to be “as advantageous as the results obtained from the patent in issue.”
*1034 Since the only prior art claimed to be significant which was not before the court in the earlier case is the Barron bottle, and yet the use of the very similar Dakin syringe for continuous wound evacuation was a part of the prior art before the court in that case, defendants have failed to make the necessary showing of a material distinction between the facts relating to obviousness in the two cases. We therefore adhere to the holding of Quest that the subject of the patent was not obvious. In view of this, it is unnecessary tо consider whether the agreed date of conception, which antedated the Barron article, is controlling, and the issue whether after conception the inventors used reasonable diligence in reducing their invention to practice thus becomes academic.
Defendants also argue that the District Court neglected to make the step-by-step prior art analysis prescribed by
Graham v. John Deere Co.,
We turn now to the other defense that merits discussion here,
viz.,
that the patent is unenforceable because one of the joint inventors breached an equitable duty to assign his interest in the patent to a third party. Unfortunately considerable time and expense appear to have been devoted to discovery and trial on the fаct questions relating to this defense. All this was unnecessary in our view, because the defense was insufficient in law. It has long been settled that a third party’s equitable rights in a patent may not be asserted as a defense in an action for infringement brought by the owner of title to the patent.
McMichael & Wildman Mfg. Co. v. Ruth,
The remaining questions raised on appeal, infringement and inventorship, 3 are *1035 not of sufficient general interest or importance to justify treating them in a published opinion, under the standards stated in Circuit Rule 28. They are adequately disрosed of by the findings and conclusions relating to them contained in the memorandum opinion of the District Court, which we adopt.
Plaintiffs have not cross-appealed from the District Court’s denial of damagеs or attorneys’ fees. Their motion in this court for an allowance of attorneys’ fees on appeal is denied, but they will recover their costs.
Judgment of the District Court is affirmed.
Affirmed.
Notes
. Whether it was actually so used is, as defendants conсede, immaterial, since mere publication of information rendering the subject matter of the patent obvious would cause the patent to be invalid. See 1 Walker, Patents, § 60 (2d ed. 1964).
. An analogous rule is stated in
United States v. Oregon,
“A bill to quiet title may not be defeаted by showing that the plaintiff’s interest, otherwise sufficient to support the bill, is subject to possibly superior rights in third persons not parties to the suit.”
The rule is the same with respect to trespass to land. See,
e.g., Duck Island Hunting & Fishing Club v. Whitnah,
. On the issue of inventorship, defendants ask us to undertake an independent analysis of the facts, since the findings below were based largely upon documentary evidence rather *1035 than oral testimony. While the “clearly erroneous” standard of review of Fed.R.Civ.P. 52(a) is less inhibiting when documеntary rather than demeanor evidence is the basis for the District Court’s findings (see Wright & Miller, Federal Practice and Procedure, § 2587 (1971)), those findings are nevertheless entitled to deference, and we are unable to say that we have come to a definite and firm conviction that an error has been committed in the findings on inventorship.
