Chapter §6.04 "Inventor in Possession" Test

• Jurisdiction: United States

§6.04 "Inventor in Possession" Test

To satisfy the disclosure requirement for an adequate written description of a claimed invention, a patent application as originally filed must convey with reasonable clarity to persons of ordinary skill in the art that, as of the application's filing date, the inventor was "in possession" of the subject matter subsequently claimed as her invention.³¹ "Possession" in this context is understood as conceptual or "constructive" possession; an inventor need not have actually reduced her invention to practice, e.g., by building a prototype, to "possess" it.³²

[A] How the Specification Conveys Possession

The precise manner in which a claimed invention is described in a patent's specification is not critical, so long as that description is capable of conveying to ordinarily skilled artisans reading the patent that the inventor had actually invented the claimed subject matter as of the application filing date. Compliance with the written description of the invention requirement should not be so burdensome as to prohibit an applicant from claiming "undisclosed, but obviously art-recognized equivalent[s]"³³ of expressly disclosed aspects of the invention; these "equivalents" are considered within the inventor's possession.³⁴

For example, as one of the Federal Circuit's predecessor courts, the Court of Customs and Patent Appeals (CCPA), posited in In re Smythe,³⁵ if the original written description of a patent application directed to the "scales of justice" disclosed only a one-pound lead weight as a counterbalance to determine the weight of a pound of flesh, the applicant should not be prevented by the written description of the invention requirement from later more broadly claiming the counterbalance as a "metal weight" or even generically as a one-pound "weight." The broader claims should be permitted because the applicant's disclosure of the use and function of the lead weight as a counterbalance would immediately convey to others that the applicant had invented a scale with a one-pound counterbalance weight, regardless of what material the weight was made of.³⁶

A satisfactory written description of a claimed invention need not even be in writing or otherwise reduced to words. For example, the medical device patent at issue in Vas-Cath Inc. v. Mahurkar³⁷ claimed a catheter having double lumens (tubes) of diameters within a specified range of ratios. The Federal Circuit had to decide whether the drawings of Dr. Mahurkar's earlier-filed design patent application³⁸ could provide adequate written description support for the diameter range limitations later claimed in Mahurkar's utility patent.³⁹ Even though the design patent application drawings depicted only one particular ratio of diameters falling within the broader range recited in the utility patent claims, the Federal Circuit concluded that the drawings provided an adequate written description of the invention: "Under proper circumstances, drawings alone may provide a 'written description' of an invention as required by [section] 112."⁴⁰ The fact that the drawings did not (and by their nature could not) show every possible embodiment of the claimed catheter within the recited diameter range was not dispositive. Expert testimony confirmed that persons of skill in the art viewing the drawings would be aware that only certain diameter relationships would produce a physiologically acceptable change in pressure at the transition between catheters.⁴¹

The level of disclosure required to satisfy the written description of the invention requirement will vary with the maturity, complexity, and predictability of the involved technology. For example, a 2019 Federal Circuit decisions illustrated that it may be relatively easier to show that an inventor had possession of what she later claims when those claims involve technologies such as communications and electronics rather than chemical, pharmaceutical, or genetic technologies. In Centrak, Inc. v. Sonitor Techs., Inc.,⁴² a patentee obtained reversal of a district court's summary judgment of invalidity for failure to satisfy the written description of the invention requirement, even though its patent specification's disclosure of implementation details concerning the claimed alternative communications embodiment was relatively minimal. Based largely on the understanding of the communications technology involved, as well as the district court's error in failing to sufficiently credit testimony of the patentee's expert witness, the Centrak Circuit concluded that a material dispute of fact existed

as to whether the named inventors actually possessed an ultrasonic RTL [real-time location] system at the time they filed their patent application or whether they were "leaving it to the . . . industry to complete an unfinished invention." Novozymes A/S v. DuPont Nutrition Biosciences APS, 723 F.3d 1336, 1350 (Fed. Cir. 2013) (quoting Ariad, 598 F.3d at 1353). ⁴³

Centrak obtained U.S. Patent No. 8,604,909 ('909 patent), which concerned an RTL system useful for locating and identifying items of equipment and persons in a facility such as a hospital. The claimed system required the use of ultrasonic technology for, inter alia, communications between base stations mounted in fixed locations such as hospital rooms and portable devices that detected the ultrasonic location codes from ultrasonic base stations located nearby.⁴⁴

Notably, the '909 patent issued from a divisional application. Centrak had previously obtained U.S. Patent No. 8,139,945 ('945 patent) from the parent application of the divisional. Centrak's earlier '945 patent contained claims similar to those of its '909 patent now in suit, but the earlier '945 patent claims recited infrared (IR) technology instead of ultrasound technology for use in communicating between base stations and nearby portable devices.

Thus, Centrak illustrates one permutation of what this author considers the "classic" variety of written description inquiry; i.e., whether an earlier-filed application provided adequate written description support for later-presented claims (in this case, the specification of the parent and divisional patents being the same except for the divisional adding claims to the alternative ultrasound embodiment).

The Federal Circuit in Centrak candidly acknowledged that while all claims of the '909 patent in suit recited "ultrasonic components," the "vast majority" of the '909 patent's specification focused on IR or radio frequency (RF) components.⁴⁵ In fact, the specification of the '909 patent in suit included only the following two sentences concerning the ultrasound alternative embodiment now claimed:

Although IR base stations 106 are described, it is contemplated that the base stations 106 may also be configured to transmit a corresponding BS-ID by an ultrasonic signal, such that base stations 106 may represent ultrasonic base stations. Accordingly, portable devices 108 may be configured to include an ultrasonic receiver to receive the BS-ID from an ultrasonic base station. ⁴⁶

Despite the relative paucity of detail on the ultrasonic embodiment, the Federal Circuit in Centrak vacated the district court's summary judgment of invalidity for failure to satisfy the written description of the invention requirement. The district court had erred in determining that the claimed alternative (i.e., ultrasound) embodiment was not adequately described in the patent application. The specification's express, albeit brief, description of the alternative embodiment was sufficient to survive summary judgment and to distinguish the precedent relied on by the validity challenger:

In this case, genuine issues of material fact remain as to whether disclosure of the implementation details that the district court identified is necessary to satisfy the written description requirement. The considerations relied on by the district court and Sonitor do not compel summary judgment for lack of written description. As an initial matter, the district court leaned heavily on the fact that the specification devoted relatively less attention to the ultrasonic embodiment compared to the infrared embodiment. But in ScriptPro LLC v. Innovation Associates, Inc., 833 F.3d 1336, 1341 (Fed. Cir. 2016), we explained that "a specification's focus on one particular embodiment or purpose cannot limit the described invention where that specification expressly contemplates other embodiments or purposes."

Here, as in ScriptPro, the fact that the bulk of the specification discusses a system with infrared components does not necessarily mean that the inventors did not also constructively reduce to practice a system with ultrasonic components. Sonitor attempts to distinguish ScriptPro on the basis that the specification at issue disclosed multiple problems and multiple, exemplary solutions, but "the written description requirement does not demand either examples or an actual reduction to practice; a constructive reduction to practice" may be sufficient if it "identifies the claimed invention" and does so "in a definite way." Ariad, 598 F.3d at 1352.

Further, the Circuit distinguished additional precedent relied on by validity challenger Sonitor. For example, in Rivera v. International Trade Commission,⁴⁷ the appellate court had affirmed an invalidity finding because the specification at issue did not make any mention of the later-claimed container with an integrated filter and thus did not provide written description for such a container. In contrast, the Centrak '909 patent specification expressly disclosed the ultrasonic embodiment, even though briefly. In Lockwood v. American Airlines, Inc.,⁴⁸ the Circuit had affirmed a summary judgment ruling that a patent was not entitled to an earlier priority date because its parent applications did not make any reference to an "individual merchandising apparatus that contained video disk players or other equivalent storage means," a claimed...