United States Court of Appeals 

for the Federal Circuit ______________________ 

TRIREME MEDICAL, LLC,

Plaintiff-Appellant

v.

ANGIOSCORE, INC.,

Defendant-Appellee

______________________ 

2015-1504

______________________ 

Appeal from the United States District Court for the 

Northern District of California in No. 3:14-cv-02946-LB, 

Magistrate Judge Laurel Beeler.

______________________ 

Decided: February 5, 2016 

______________________ 

DAVID A. CAINE, Arnold & Porter, LLP, Palo Alto, CA, 

argued for plaintiff-appellant. Also represented by 

THOMAS T. CARMACK, MICHAEL DUY KHIEM NGUYEN,

JAMES C. OTTESON. 

PETER J. ARMENIO, Quinn Emanuel Urquhart & Sullivan, LLP, New York, NY, argued for defendant-appellee. 

Also represented by WILLIAM ADAMS, MATTHEW ROBSON,

CLELAND B. WELTON, II; AARON BERGSTROM, San Francisco, CA. 
2 TRIREME MEDICAL, LLC v. ANGIOSCORE, INC. 

______________________ 

Before PROST, Chief Judge, DYK, and CHEN, Circuit 

Judges.

DYK, Circuit Judge. 

 AngioScore, Inc. (“AngioScore”) claims exclusive 

ownership of U.S. Patent Nos. 8,080,026 (“the ’026 patent”), 8,454,636 (“the ’636 patent”), and 8,721,667 (“the 

’667 patent”) (collectively, “the AngioScore patents”). 

TriReme Medical, LLC (“TriReme”), claiming to have 

received an assignment of an interest in the AngioScore 

patents from Dr. Chaim Lotan, brought suit for correction 

of inventorship. It sought to have Dr. Lotan named as an

inventor on the patents pursuant to 35 U.S.C. § 256. The 

district court dismissed for lack of subject matter jurisdiction, holding that any interest Dr. Lotan may have had in 

the AngioScore patents had been assigned earlier to 

AngioScore under a consulting agreement, and that 

TriReme as a consequence lacked standing. TriReme

appeals. We reverse and remand for further proceedings. 

BACKGROUND

AngioScore sells a line of angioplasty balloon catheters called AngioSculpt, which are designed to open 

arterial blockages. To accomplish this, an AngioSculpt 

device is inserted into a blood vessel and inflated when it

reaches the targeted occlusion area. The balloon contains 

a metal spiral on its surface, which expands as the balloon inflates and scores the plaque lining the occluded

blood vessel. The balloon is then deflated and the device 

removed from the vessel. All three AngioScore patents

relate to this concept. Each lists three inventors: Dr. 

Eitan Konstantino, Tanhum Feld, and Nimrod Tzori. 

None lists Dr. Chaim Lotan as an inventor. 
TRIREME MEDICAL, LLC v. ANGIOSCORE, INC. 3

TriReme is a competitor of AngioScore. Apparently 

concerned that AngioScore might charge TriReme with 

infringement of the ’026, ’636, and ’667 patents, TriReme 

sought to acquire an interest in the AngioScore patents 

from Dr. Lotan, who performed consulting services for 

AngioScore. In June 2014, Dr. Lotan granted TriReme an 

exclusive license to “any and all legal and equitable 

rights” he held in the AngioScore patents. J.A. 317. Dr. 

Lotan testified that he retained no financial interest in 

the patents. If Dr. Lotan was an inventor of the patents

and TriReme acquired his interest, TriReme could practice the patents and would have a defense to infringement. See 35 U.S.C. § 262; Shum v. Intel Corp., 629 F.3d 

1360, 1369 (Fed. Cir. 2010). 

Dr. Lotan claims that his inventive contribution arose 

from his work in connection with the development of the 

AngioSculpt catheters in 2003, which is reflected in the

AngioScore patents. AngioScore’s defense to this claim is 

based on a contract entitled “AngioScore, Inc. Consulting 

Agreement” (“Consulting Agreement”) between AngioScore and Dr. Lotan, with an effective date of May 1, 

2003. J.A. 309. AngioScore asserts that it had acquired 

rights to all inventive work completed by Dr. Lotan under 

both § 9(a) and § 9(b) of the Consulting Agreement. 

TriReme brought suit for correction of inventorship

pursuant to 35 U.S.C. § 256, seeking to have Dr. Lotan 

named as an inventor of the AngioScore patents. AngioScore moved to dismiss for lack of subject matter jurisdiction, arguing that TriReme lacked standing because 

Dr. Lotan had assigned any rights he may have had in his 

inventive contribution to the patents to AngioScore under 

the Consulting Agreement, and that, accordingly, Dr. 

Lotan had nothing to later license to TriReme. The 

district court granted AngioScore’s motion and dismissed 

the complaint. See TriReme Med., LLC v. AngioScore, 

Inc., No. 14-cv-02946-LB, 2015 WL 1246532 (N.D. Cal. 
4 TRIREME MEDICAL, LLC v. ANGIOSCORE, INC. 

Mar. 17, 2015). It held that the “question of when Dr. 

Lotan completed work is ultimately immaterial,” interpreting the Consulting Agreement to provide for assignment of Dr. Lotan’s interest to AngioScore regardless of 

the date of his work. J.A. 8. TriReme appealed. We have 

jurisdiction pursuant to 28 U.S.C. § 1295(a)(1). Standing

in an inventorship dispute is a question of law that we 

review de novo. Chou v. Univ. of Chicago, 254 F.3d 1347, 

1355 (Fed. Cir. 2001). We also review the interpretation 

of a contract de novo. Intel Corp. v. ULSI Sys. Tech., Inc., 

995 F.2d 1566, 1569 (Fed. Cir. 1993).

DISCUSSION

When the owner of a patent assigns away all rights to 

the patent, neither he nor his later assignee has a “concrete financial interest in the patent” that would support 

standing in a correction of inventorship action. Chou, 254 

F.3d at 1359; see also Larson v. Correct Craft, Inc., 569 

F.3d 1319, 1326–27 (Fed. Cir. 2009). The question is 

whether such an assignment to AngioScore occurred here. 

Necessary to understanding this dispute is a description of the Consulting Agreement. The Consulting 

Agreement contains two provisions material to this appeal: § 9(a), which relates to Dr. Lotan’s work before the

May 1, 2003, effective date; and § 9(b), which relates to 

Dr. Lotan’s work after the effective date. The Consulting 

Agreement provides: 

9. Inventions

(a) Inventions Retained and Licensed. Consultant has attached hereto, as part of Exhibit C, a 

list describing all inventions, original works of authorship, developments, improvements, and trade 

secrets which were made by Consultant prior to 

the date of this Agreement (collectively referred to 

as “Prior Inventions”), that belong solely to Con-
TRIREME MEDICAL, LLC v. ANGIOSCORE, INC. 5

sultant or belong to Consultant jointly with another and that relate to any of the Company’s current or proposed businesses, products or research 

and development; or if no such list is attached, 

Consultant represents that there are no such Prior Inventions. If, in the course of providing the 

Services, Consultant incorporates into a Company 

product, process or machine or into any Invention 

(as defined below), a Prior Invention owned by 

Consultant or in which Consultant has an interest, the Company is hereby granted and shall 

have a non-exclusive license (with the right to 

sublicense) to make, have made, copy, modify, 

make derivative works of, use, sell and otherwise 

distribute such Prior Inventions as part of or in 

connection with such product, process, machine or 

Invention.

(b) Assignment of Inventions. Consultant agrees 

to promptly disclose to the Company and hereby 

assigns to the Company, or its designee, all right, 

title and interest in and to all inventions, original 

works of authorship, developments, concepts, 

know-how, improvements or trade secrets, whether or not patentable, that Consultant may solely 

or jointly conceive or develop or reduce to practice 

during the term of this Agreement that relate to 

the Services (collectively referred to as “Inventions”). 

J.A. 310 (underlining in § 9(b) other than final “Inventions” added). 

AngioScore’s theory under § 9(a) is that § 9(a) required Dr. Lotan to attach a list of any “Prior Inventions” 

made before May 1, 2003, in Exhibit C of the Consulting 

Agreement. Id. He did not list any such inventions in 

Exhibit C. The Consulting Agreement provides that 
6 TRIREME MEDICAL, LLC v. ANGIOSCORE, INC. 

failure to attach a list amounts to a representation that 

there are “no such Prior Inventions.” Id. The result, 

AngioScore contends, is that such unlisted inventions 

belong to AngioScore. 

AngioScore’s theory under § 9(b) is that § 9(b) governs 

all inventions, developments, concepts, and improvements 

relating to Dr. Lotan’s work for AngioScore that Dr. Lotan 

conceived, developed, or reduced to practice after the 

effective date, and provides that AngioScore shall be 

assigned all such inventions. AngioScore contends that it 

was assigned all of Dr. Lotan’s rights to his inventive 

contribution because his work relating to that contribution continued after May 1, 2003.

We first consider AngioScore’s claim under § 9(a) of 

the Consulting Agreement. Before the May 1, 2003,

effective date, Dr. Lotan performed a single-day study 

testing AngioSculpt prototypes in pig arteries. During the 

study, Dr. Lotan discovered a “clear retention problem” in 

which the metal spiral on the surface of the balloon 

dislodged from the device upon retraction from the pigs’ 

arteries. J.A. 418. Dr. Lotan suspected that the problem 

arose because the spiral was only affixed to the balloon at 

one end—the other end was “free-floating” to enable the 

spiral to move in response to the balloon’s expansion and 

contraction. J.A. 512. After observing this problem, Dr. 

Lotan contributed to a memorandum summarizing the 

study, which highlighted the retraction issue and recommended that the unattached end be better secured. 

According to Dr. Lotan, during two follow-up meetings 

with AngioScore he further recommended that the unattached end be affixed to the balloon with a polymer tube, 

which he believed would more securely bond the spiral to 

the balloon while still allowing the spiral to expand and 

contract synchronously with the balloon. The later issued

AngioScore patents claim a balloon catheter with an 

attachment structure similar to that allegedly recom-
TRIREME MEDICAL, LLC v. ANGIOSCORE, INC. 7

mended by Dr. Lotan. According to Dr. Lotan, it was not 

until 2013 that he learned that the AngioScore patents

had incorporated his alleged recommendation. Dr. Lotan 

testified that he did not list his work on the pig study 

under Exhibit C of the Consulting Agreement because he 

did not consider it an invention at the time. 

AngioScore argued before the district court that it had

acquired all of Dr. Lotan’s interest in the pre-May 1, 2003, 

work under § 9(a) of the Consulting Agreement. AngioScore contended that Dr. Lotan’s work on the pig study 

qualified under the terms of the Consulting Agreement as 

an “invention,” “development,” or “improvement” that 

related to AngioScore’s business and was made by Dr. 

Lotan “prior to the date of [the] Agreement.” J.A. 310. 

Thus, AngioScore argued, Dr. Lotan was required to list 

the pig study under Exhibit C of the Consulting Agreement pursuant to § 9(a), and his failure to do so resulted

in an assignment—not simply a license—of his rights to 

AngioScore. The district court agreed, reasoning based on 

the “purpose” of the Consulting Agreement that § 9(a) 

“together” with § 9(b) operated to assign Dr. Lotan’s

rights in his inventive contribution to AngioScore as a 

consequence of his failure to list the pig study. J.A. 13. 

Contrary to the district court’s conclusion, § 9(a) does 

not provide for assignment of Dr. Lotan’s rights. California law, which governs the interpretation of this contract, 

requires that we construe the Consulting Agreement 

according to the plain meaning of the language employed

if possible. See Cal. Civ. Code § 1639; Cedars-Sinai Med. 

Ctr. v. Shewry, 137 Cal. App. 4th 964, 979–80 (2006). 

Section 9(a) is entitled “Inventions Retained and Licensed,” but nothing in its terms suggests that anything 

not listed as a “Prior Invention” would not be “retained.” 

J.A. 310. And it certainly does not provide that inventions that are not listed are assigned, rather than licensed. Indeed, granting an assignment for any “Prior 
8 TRIREME MEDICAL, LLC v. ANGIOSCORE, INC. 

Invention” would make little sense, because listed inventions under § 9(a) could theoretically encompass independent inventions dating back many years before the 

start of the Consulting Agreement. 

What § 9(a) does, at most, is grant AngioScore a nonexclusive license in the event that the consultant incorporates a Prior Invention into an AngioScore product during 

the term of the Consulting Agreement. But such license 

is not exclusive and would not prevent Dr. Lotan from 

subsequently assigning his rights in those contributions

to TriReme. In short, the district court erred to the extent 

it relied on § 9(a) to find that Dr. Lotan assigned his 

rights to AngioScore. 

AngioScore argues, however, that estoppel by contract—codified by § 622 of the California Evidence Code—

binds TriReme, as Dr. Lotan’s successor in interest, to Dr. 

Lotan’s representation under § 9(a) that he had no “Prior 

Inventions” relevant to AngioSculpt and therefore “owned 

no rights in any purported ‘development’ or ‘improvement’ 

of AngioScore’s prototype.” Appellee’s Br. 28. This representation, AngioScore argues, precludes TriReme from 

now alleging that Dr. Lotan made an inventive contribution on which TriReme could base an inventorship claim.

This new argument is unavailing. Estoppel by contract 

does not apply here, because neither Dr. Lotan nor his 

successor in interest (TriReme) seeks to enforce any rights 

under the contract. See Gas Appliance Sales Co. v. W.B. 

Bastian Mfg. Co., 262 P. 452, 455 (Cal. Dist. Ct. App. 

1927); see also Bank of Am. v. Banks, 101 U.S. 240, 247 

(1879); Popplewell v. Stevenson, 176 F.2d 362, 364 (10th 

Cir. 1949). AngioScore has cited no case that applies 

estoppel by contract where the cause of action is not 

founded upon the written instrument itself. Accordingly, 

estoppel by contract does not bind TriReme in its correction of inventorship action here. 
TRIREME MEDICAL, LLC v. ANGIOSCORE, INC. 9

We next consider AngioScore’s alternative argument

that Dr. Lotan assigned it all rights in his inventive 

contribution pursuant to § 9(b). The parties dispute the 

significance of Dr. Lotan’s role in the development of 

AngioSculpt after the May 1, 2003, effective date. It is 

not disputed, however, that all of Dr. Lotan’s work during 

the term of the Consulting Agreement related to designing, implementing, and analyzing clinical trials, including 

collecting regulatory data. Section § 9(b) explicitly provides for assignment of all “inventions, original works of 

authorship, developments, concepts, know-how, improvements or trade secrets” that Dr. Lotan “conceive[d] or 

develop[ed] or reduce[d] to practice during the term” of 

the Consulting Agreement that relate to his work for 

AngioScore. J.A. 310. AngioScore’s theory under § 9(b) is 

that Dr. Lotan’s work relating to his inventive contribution continued after May 1, 2003, and amounted to both 

“development” and “reduction to practice” within the 

meaning of § 9(b). Id. Thus, AngioScore contends, all of 

Dr. Lotan’s rights in his inventive contribution were 

assigned to AngioScore even if some of his work was 

performed before May 1, 2003. Whether Dr. Lotan assigned his rights under § 9(b) thus depends on whether 

Dr. Lotan’s continued work on AngioSculpt after the 

effective date in fact amounted to “developing,” or “reducing to practice” an “invention,” “development,” or “improvement” pursuant to § 9(b). Id. Only if Dr. Lotan’s 

continued work after May 1, 2003, constituted “developing,” or “reducing to practice” would his inventive contribution have been assigned to AngioScore under § 9(b) of 

the Consulting Agreement. Id. 

It is undisputed that while Dr. Lotan no longer 

worked on the physical design of the catheter after the 

effective date, he continued “talking” with AngioScore,

performing work relating to designing, implementing, and 

analyzing clinical trials. J.A. 14. The parties dispute the 
10 TRIREME MEDICAL, LLC v. ANGIOSCORE, INC. 

significance of this clinical trial work, however, disagreeing as to whether it amounted to “conceiving,” “developing,” or “reducing to practice” an “invention,” 

“development,” or “improvement” pursuant to § 9(b). 

Discovery before the district court was limited regarding

Dr. Lotan’s work after May 1, 2003, and there was no 

trial. Nor did the district court make any findings about 

this work. The district court merely found that Dr. Lotan’s post-effective date work on AngioSculpt “might have 

amounted to” “developing” or “reducing to practice” his 

recommendations.1 J.A. 15. Whether this work falls 

under § 9(b) remains a question of fact that cannot be 

resolved on a motion to dismiss. We remand for the 

district court to consider whether Dr. Lotan’s continued 

work on AngioSculpt after the effective date came within 

the language of § 9(b).2

REVERSED AND REMANDED

COSTS

Costs to Appellee.

 

1 AngioScore inaccurately asserts that “the district 

court ruled that Lotan’s work on the catheter after May 1, 

2003 constituted such ‘development’ and ‘reduction to 

practice.’” Appellee’s Br. 14–15 (emphasis added). In 

fact, the district court merely found that such work 

“might have amounted to” “developing” or “reducing to 

practice” his recommendations. J.A. 15. 2 Our opinion should not be read as resolving the 

question of whether (if Dr. Lotan performed work after 

May 1, 2003, covered by § 9(b)) Dr. Lotan’s pre-May 1, 

2003, work was assigned to AngioScore under § 9(b).