SCIENCE & TECHNOLOGY
FOCUSED Srinivasan working with the excimer laser.
INVENTORSHIP WOES Chemist Rangaswamy Srinivasan's battle for proper credit reveals pitfalls of collaboration WILLIAM G. SCHULZ, C&EN WASHIN
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W h e n their collaboration effectively ended more than a decade later, Srinivasan says, Trokel patented their discoveries, list ing himself as sole inventor. Srinivasan says Trokel never informed him of the contents of the patent, which was issued to Trokel in 1992 by the U.S. Patent & Trademark Office (PTO). Indeed, Trokel is named as the sole inventor on the U.S. patents that relate to corneal refractive surgery with the excimer laser. Along with the original patent, the P T O has issued two continuations, again naming Trokel as sole inventor. And Trokel is a stakeholder in Visx, Santa Clara, Calif, a publicly held company that owns the patents and markets laser equip ment and the surgical procedure under the trade name LASIK. The U.S. market for laser eye surgery was estimated at $2.8 billion in 2 0 0 0 and growing by 2 0 % per
F ALL THE STORIES OF SCIEN-
tific collaboration gone wrong, physical chemist Rangaswamy Srinivasan's cautionary tale stands apart. The retired IBM research scientist with expertise in pho tochemistry claims that his naivete about such partnerships allowed him to be "swin dled" out of co-inventorship on a lucrative medical patent. Srinivasan, who is a member of the National Academy of Engineering, is blunt in telling his story He says that Columbia University ophthalmologist Stephen L. Trokel first gained his confidence and then his cooperation, starting in 1983. Srini vasan says he was persuaded to help Trokel develop a method for vision correction sur gery using an excimer or far-ultraviolet laser, including the design of key apparatus for the laser. HTTP://PUBS.ACS.ORG/CEN
year. LASIK and Trokel have been lauded in press accounts worldwide. Today, Trokel's patents—their named inventorship, in particular—are central to at least two pending lawsuits that involve Visx. The company has lost or has decided to settle other lawsuits. In nearly every case, inventorship of Trokel's patents has been challenged. Last year, for example, Visx lost a case it brought before the U.S. International Trade Commission (ITC). Visx had turned to ITC seeking protection of its patent rights from ajapanese competitor, Nidek, that was attempting to sell its laser eye sur gery procedure and related equipment in the U.S. The ITC judge declared Trokel's patent invalid and said that Srinivasan should have been named as a co-inventor. Trokel is a widely respected ophthal mologist with a private practice in New \brk City In addition, he is—and has been since before obtaining his laser eye surgery patents—a clinical professor of ophthal mology at the Edward S. Harkness Eye Institute, part of the Columbia College of Physicians & Surgeons. He is also a staff member of Columbia Vision Correction, a laser eye surgery clinic in Manhattan, which is also owned and operated by Columbia University When he first met Trokel in 1983, Srini vasan was experienced in research with the excimer laser. With colleagues at the IBM T J. Watson Research Center, he had described a phenomenon known as abla tive photodecomposition (APD) (C&EN, June 13,1983, page 4). Srinivasan says APD is a photochemical process that occurs when organic material absorbs ultraviolet (193-nm) laser radia tion above a threshold power per unit area. The laser radiation breaks chemical bonds and vaporizes material without heating or charring surrounding material. It allows precision cutting or etching of material, including human tissue. AT IBM, Srinivasan's work led to a new method for photolithographic etching of computer chips. But he also investigated the use of APD for such medical proce dures as the removal of dental caries and atherosclerotic plaques. In fact, Srinivasan and coworkers obtained a patent in 1988 for IBM on the use of APD in such tissue ablation. IBM has since sold the patent to Lasersight Inc. for $15 million. Srinivasan says he and his co-inventors were each paid a bonus of $10,000 by IBM for their work. Trokel, he says, approached him in 1983 with an idea of investigating the possibilC & E N / MAY 28, 2001
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SCIENCE & TECHNOLOGY ity ofyet another medical procedure: ablat ing corneal tissue in order to change its shape and thus correct vision. Srinivasan agreed that the excimer laser would be par ticularly suited to this work, and so, he says, they began a series of experiments using the enucleated eyes of calves. Srinivasan's version of his first meeting with Trokel is supported by the recollec tions of Kenneth B. Eisenthal, professor of chemistry at Columbia. Eisenthal says he putTrokel in touch with Srinivasan after the ophthalmologist contacted him about the possibility of obtaining a YAG laser, another type of laser that had been used in medical experiments. "I told him [Trokel] that the YAG laser would not be appropriate," Eisenthal says. "I told him, 'The person you should see is Srinivasan.'" And so, the chemist and the ophthal mologist met at Srinivasan's IBM labora tory In time, Srinivasan says, they had done enough experimental work that they decided to publish their research results in the American Journal of Ophthalmology (47O)[96,710(1983)}. Srinivasan says Trokel handled writing the manuscript, while he took care of
EYES ON VISX Founded in 1986, Visx pioneered the use of excimer lasers to treat visual disor ders ranging from scars to nearsighted ness, astigmatism, and farsightedness. The procedure is known as laser in situ keratomileusis (LASIK). It involves first cutting open a flap on the cornea and then using the excimer laser to ablate the exposed corneal tissue. Visx laser systems are sold in more than 60 countries worldwide, with more than 1,200 systems installed. In the U.S., more than 2 million laser vision correc tion procedures have been performed using Visx laser systems. Visx licenses its technology on a per-procedure basis, collecting a fee for each procedure per formed using its laser system. LOCATION: Santa Clara, Calif. REVENUES IN 2000: More than $200 million NET INCOME: More than $35 million PATENTS: Owns more than 150 U.S. and foreign patents and has more than 100 patent applications pending DIRECTORS: Mark B. Logan, chairman of the board; Elizabeth H. Davila, presi dent and CEO EMPLOYEES: 320 NYSE SYMBOL: EYE
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preparing the tables and illustrations. The illustrations included drawings of a series of masks used to direct laser light to tar geted areas of the cornea. Developing the masks was important, Srinivasan says. Various openings on the masks meant that laser light could ablate the cornea in ways that would precisely determine its post-treatment shape. That is, the treatment could be tailored, depend ing on the severity and nature of the abnor mality the surgeon wished to correct. After Srinivasan signed off on a final draft and the manuscript was in press at the publisher of AJO, Srinivasan says, Trokel handled final corrections and changes suggested by AJO reviewers and editors. According to Srinivasan, Trokel described the changes as minor, and Srini vasan never bothered to compare the printed article with hisfinaldraft copy until months later. As their collaboration progressed, Srini vasan says, he and Trokel helped each other win visiting research appointments at their respective institutions. Trokel became a visiting researcher at IBM, for instance, and Trokel wrote letters urging the appoint ment of Srinivasan as adjunct professor of ophthalmic research at the Harkness Eye Institute. But for Trokel, there was a hitch, appar ently Srinivasan says he gave Trokel an IBM confidentiality agreement to sign. The agreement prohibited Trokel from di vulging protected company information that might be revealed to him in the course of working with Srinivasan or other IBM scientists. Trokel, he says, took the agree ment but never returned a signed copy. Srinivasan's allegation could not be con firmed with IBM. FOR HIS PART,Trokel is equally blunt. He confirms that he did some work with Srini vasan, but he declined to provide details or to answer anything but "specific ques tions" about excimer laser eye surgery Trokel insists that his idea for using the excimer laser came from a research article he came across in the early 1980s. That paper— the lead author was former U.S. Air Force physicist John Taboada—describes excimer laser experiments on the corneal tissue of rabbits [Health Phys., 4 0 , 677 (1981)]. But in a published account of his own work, Trokel noted problems that Taboada had encountered: "At the higher levels, exposures of 27.5 mj/cm 2 or greater, an immediate indentation of the corneal sur face appeared taking the shape of the beam. One hour later, the surface inden
tation would fill in" [Refractive & Corneal Surg, 6,357 (1990)]. This effect—filling in or healing of the ablated corneal tissue—was never seen in the work of Srinivasan and Trokel. Its absence, Srinivasan says, is critical to the success of the surgery In the same Refractive & Corneal Surgery article, Trokel quotes from his published work with Srinivasan: "We suggested, 'The laser can be used to reshape the corneal curvature in a manner similar to kerato mileusis excising more tissue either cen trally or peripherally The net effect would be to flatten or steepen the cornea.'" WHEN QUESTIONED byC&EN about his patents, Trokel referred all further inquiry to Visx legal counsel. The Visx lawyers, in turn, refused to comment. The rabbit-eye work Trokel mentioned is cited in the 1983 AJO article he pub lished with Srinivasan. It is mentioned in the main text and cited in the paper's list of references. Srinivasan, however, says it is a skewed reference that does not describe excimer laser work at the critical 193-nm wave length threshold—despite what is pub lished. This error, Srinivasan says, is only one of several critical changes to the AJO manuscript that he did not catch at that time because he didn't carefully check the printed copy of the article against his final draft version. Other significant changes to the AJO manuscript, Srinivasan points out, include references to his discovery of APD and other work with the excimer laser. He says they were dropped or that the references were changed to read "in press" or "unpub lished data." But the articles had, in fact, been pub lished, and they were obtainable at the time the AJO manuscript was in press. In the end, he says, "the printed [AJO] article did not have a single reference that would direct a reader to a printed article on APD." W h a t is unclear is who ordered the changes. Efforts by C&EN to obtain a manuscript file for the article—documents that might show who ordered the changes—have been unsuccessful. Last year, Visx settled a lawsuit with Taboada—who, it turns out, had sued Visx, claiming that he should have been named co-inventor on Trokel's patents. Because the case never went to trial, there has not been a ruling on Taboada's claims. He is prohibited by the terms of his settlement from disclosing the amount of money he received from Visx. Nonetheless, Taboada confirms SriniH T T P : / / P U B S . ACS.ORG/CEN
ple, he won the American Chemical Soci position to receive personal financial gain vasan's contention that the AJO article's ety Creative Invention Award for the APD directly from the laser eye surgery patents reference to his work with rabbit eyes was discovery Ironically, Srinivasan had been because his contribution—if it is ever incorrect. He says the work cited was for recommended for the award by Visx's vice acknowledged—resulted from work he laser light at 248 nm—not 193 nm—an president for research and development, performed for the company energy level below the critical threshold Terrance N. Clapham. needed to induce APD. But that situation has only left Srini vasan with more questions. For example, But Taboada dismisses Srinivasan's a law firm once agreed to file suit on his "THE ENTIRE FIELD of ultraviolet-laserreliance on APD in making his co-invenbehalf and attack Trokel's patents. The firm torship claim. Taboada says APD "is just a based ophthalmologic surgery, which is the said it would take the case on a contingency business of my company, can be directly word to describe what's happening. Many basis, but only if IBM would relinquish to traced to Dr. Srinivasan's discovery in things happen with laser light [when it is Srinivasan its patent rights to the work. 1981-82 of the ablative photodecomposiapplied to material] that are still being tion of tissue," Clapham wrote in his sup investigated today" IBM refused. And company officials porting letter to ACS. "There is no doubt declined to comment on the matter to Taboada claims he first conceived of the that Dr. Srinivasan fully deserves credit for C&EN. usefulness of laser light for eye surgery in creating this remarkable industry" 1979. In fact, he says, it was a simple inven IBM officials have never given him a tion to remove corneal tissue. He says he reason, but Srinivasan wonders if its con Srinivasan says it was in December 1995 didn't attempt to patent the idea because nections to Columbia's ophthalmology that he first found out the contents of the he wanted to do more work on it first. The department play a role. '388 Patent. "I thought at first that Mark Air Force, he says, would not have objected B. Logan, the CEO ofVisx, was not aware to his filing for a patent. of the deception by Trokel. EVEN MORE PUZZLING to Srinivasan, IBM has never pursued Trokel's The ITC decision in March patents for its own financial 2 0 0 0 dealt a serious blow to gain. Since 1991, he says, the Visx. T h e price of the com company has been anxious to pany's stock dropped 4 1 % sell patents it cannot use or to when the ruling of Administra make money from its patents. tive Law Judge Debra Morriss He cites, for example, the was made public. Her ruling APD-based patent covering was later confirmed by the full medical and dental uses that commission. Visx did not was sold to Lasersight in 1998. appeal the ruling, though an At one point, in the early 1990s, appeal was a clear option. PRECISION A human hair with 50-fim notches etched by Srinivasan says, IBM consid Morriss wrote: "I conclude an excimer laser. ered donating the patent to the that Dr. Trokel acted with National Institutes of Health. It recon "I think I was right. But I was also naive deceptive intent in submitting his oath of sidered as the company entered a period of in thinking that he [Logan] would back my sole inventorship. T h e record clearly financial hardship and management demand for co-inventorship because Visx demonstrates that Dr. Trokel could not change. would then have lost its great position to possibly have in good faith believed him collect royalties," he says. self to be the sole inventor of the claims in For Visx and Trokel, the patent battles the issued 7 6 2 Patent [a continuation of continue. One of the pending lawsuits was W h e n asked for comment about the Trokel's first patent] or in the application brought by former stockholders. They ITC ruling, Columbia University officials therefor." claim that they purchased Visx stock on declined to be interviewed for this story the basis of fraudulent patent claims. A university spokesperson, however, Morriss continued: "I further note that What's more, they say, Visx managers knew answered another question: W h y was the record indicates that Dr. Trokel was the claims were fraudulent. Srinivasan's name dropped this year from suspiciously secretive with Srinivasan a university website listing adjunct fac about the 7 6 2 Patent application, such And Visx is again trying to assert its ulty? His name appeared on the listing as that, as Dr. Srinivasan testified, until the patent rights in yet another lawsuit, a con late as March 28, but by mid-April it had patent issued he was not familiar with its solidated case pending in a federal district been removed. scope. I find evidence that Dr. Trokel court in California. Visx had attempted to intentionally appropriated for use in his stop groups of doctors who were operat The spokesperson says that Srinivasan's patent application material and informa ing laser eye surgery clinics without paying appointment has expired. She was not tion from Dr. Srinivasan and/or IBM Visx per-procedure royalties. Again, the able to provide a date and she could not without authorization." validity of the Trokel patents is at issue. say if adjunct faculty appointments like Srinivasan's are limited to specific peri Despite its legal battles, Visx still claims Srinivasan, who was once a consultant ods of time. a significant market share for laser eye sur to Visx, describes his relationship with the gery in the U.S. Its stock has partly recov company before he discovered the exis Srinivasan says Columbia has not noti ered from the bruising that followed the tence of the patent: fied him of the expiration. Instead, he pro ITC ruling. duced a 1992 letter he received when he "I was treated as the inventor of UVlaser was awarded the appointment. It makes Srinivasan has given depositions in many ablation by everybody— m anagement and no mention that the appointment would of the legal cases, partly, he says, because it employees—but the '388 Patent [Trokel's someday expire. is his only recourse. More than anything first patent] was never discussed." else, he says, he would like to someday Srinivasan retired from IBM in 1990. Srinivasan was also lauded for his work receive proper credit for his work. ■ He points out that he has never been in a outside the halls ofVisx. In 1996, for exam HTTP://PUBS.ACS.ORG/CEN
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