Before Lourie, Clevenger, and Gajarsa, Circuit Judges.
The opinion of the court was delivered by: Clevenger, Circuit Judge.
Appealed from: United States District Court for the Northern District of Illinois Judge Harry D. Leinenweber
Opinion for the court filed by Circuit Judge CLEVENGER. Dissenting opinion filed by Circuit Judge LOURIE.
Smiths Industries Medical Systems, Inc. ("Smiths") appeals from the judgment of the United States District Court for the Northern District of Illinois that claim 4 of Smiths's patent for a manual resuscitator is invalid and is not infringed by two accused products manufactured by appellee Vital Signs, Inc. ("Vital Signs"). See Smiths Indus. Med. Sys., Inc. v. Vital Signs, Inc., 4 F. Supp. 2d 746, 748-52 (N.D. Ill. 1997). For the reasons set forth below, we conclude that the district court misinterpreted claim 4 of Smiths's patent. We therefore reverse the district court's judgment of invalidity under 35 U.S.C. § 103 and vacate its judgment of noninfringement. The case is remanded to the district court for further proceedings.
This appeal involves United States Patent No. 4,774,941, issued on October 4, 1988, to Wallace F. Cook (the "'941 patent" or the "Cook patent"). The '941 patent is assigned to Intertech Resources, Inc., which has been succeeded by plaintiff-appellant Smiths, and is directed to a manual resuscitator device. Both Smiths and Vital Signs manufacture and sell disposable manual resuscitator devices, which are used by medical personnel in emergency or trauma situations to supply air or oxygen to patients who have difficulty breathing on their own or who have stopped breathing.
Manual resuscitators are typically composed of three main elements: a face-mask that seals around the patient's nose and mouth, a directional valve assembly that directs gas to and from the patient, and a squeezable bag ("squeezebag") that supplies pressure for forcing gas to the patient. Some resuscitators employ a squeezebag with a single opening, which are known in the art as "single-entry bags." In a single-entry bag resuscitator, gas to be delivered to the patient first enters the squeezebag from a supply source and collects in the squeezebag; when the squeezebag is compressed, the collected gas exits the squeezebag through the same opening and is directed to the patient by the valve assembly. In contrast, "double-entry bags" have two openings at opposite ends; gas enters through one opening and is stored in the squeezebag, and is then delivered to the patient through the other opening. A further variation of the manual resuscitator, known in the art as a "mouth-to-mask" resuscitator, omits the squeezebag altogether. The mouth-to-mask resuscitator has a hollow tube in place of a squeezebag; a rescue worker supplies the pressure needed to force air into a patient's lungs by blowing through the hollow tube.
The key feature in manual resuscitators is the directional valve assembly. The valve assembly allows a resuscitator to operate in three different modes. First, during forced inhalation, a worker compresses the squeezebag, and the valve assembly allows gas to be forced into the patient's lungs. Second, during exhalation, the patient breathes out and the valve assembly directs the exhaled gases away from the patient and to the exterior of the resuscitation system. Third, during spontaneous breathing, the valve assembly allows a patient who is breathing on her own to draw air and/or oxygen though the squeezebag and to exhale into the outside environment. Thus, during inhalation, the valve assembly simultaneously opens a passageway from the squeezebag to the patient and closes off the air passage between the patient and the external environment; conversely, during exhalation, the valve assembly simultaneously closes off the passageway from the patient to the squeezebag and opens the air path from the patient to the external environment, so that exhaled gases are discharged to the exterior of the resuscitation system.
Figures 2 and 3 of the Cook patent, reproduced here, depict the operation of the '941 invention's valve assembly and the flow of air through the resuscitator during two of the three operating modes described above. Figure 2 shows the state of the valve assembly during forced inhalation. In this mode, a "duck-billed" diaphragm (30) seals against the end (36a) of a tube (36) to close off the exit port (38). The arrows show that the gas inside the squeezebag (12) passes through the duck-billed valve (30a) to the patient. Figure 3, in contrast, shows the operation of the valve during patient exhalation. The duck-billed diaphragm (30) disengages from the end of the tube (36), the duck-billed valve (30a) closes, and exhaled gases pass from the patient through the exit port (38) to the external environment.
Vital Signs, the defendant, sells three lines of products that are accused of infringing the '941 patent: a double-entry squeezebag resuscitator (the "Vital Blue"), a single-entry squeezebag resuscitator (the "Code Blue"), and a mouth-to-mask resuscitator (the "MM 7100"). Smiths brought suit in district court alleging that all three products infringe claim 4 of the '941 patent.
Claim 4 is one of two independent claims in the '941 patent and reads in relevant part:
"1. A resuscitator comprising:
"(a) means for supplying gas having a hollow interior and first and second openings at opposite ends thereof;
"(b) a directional control valve assembly fastened to said gas supplying means at said first opening; . . .
"(d) said assembly further comprising a tubular patient port joined to said first end of said valve housing and adapted to be coupled in gas flow communication to a patient . . . ;
"(e) . . . an annular exit passage being formed between said valve housing and said extension and an interior flow passage being formed within said extension, said interior flow passage being in flow communication with said first opening;
"(f) an unobstructed exit port formed in said valve housing in flow communication with said ...