Patent Rule Changes: Preparing a Medtech Portfolio

Posted by mddiadmin on September 1, 2006


Bookoff: Patent rule change looming

Earlier this year, the U.S. Patent and Trademark Office (PTO) proposed several changes to patent practice that could significantly alter the way in which medical device companies file and prosecute patent applications.1,2 If the final rules closely resemble the proposed changes—which many industry observers predict they will—medical device companies that fail to take appropriate action on pending applications prior to implementation of the new rules may lose the ability to obtain protection on disclosed inventions.

PTO is currently considering hundreds of written comments filed by the public about the proposed rules, and the office plans to publish final rules in late 2006. The final rules are expected to provide only a very short period between their publication and their effective date. This article discusses several of the proposed rule changes and some possible strategies medical device manufacturers can consider before rule implementation.

Continuing Applications

One of the main changes proposed by PTO would limit the filing of continuing applications. A continuing application permits an applicant to refile the disclosure of a previously filed parent application, present different and often broader claims, and receive the benefit of the filing date of the parent application. Under current practice, there is no limit to the number of continuing applications that an applicant can file. Consequently, an unlimited number of patents can stem from an original application.

Continuing applications are particularly important in the medical device industry, in which commercialization often lags well behind inventive activities as a result of lengthy clinical trials and the FDA clearance process. Unlimited use of continuing applications provides medical technology companies the benefit of being able to monitor the development of a new technology—both from their own development activities and those of their competitors—and then craft claims to cover the latest versions of that technology. Therefore, continuing applications often result in the most commercially significant patents.

Several recently enforced medical device patents might not have existed if the proposed PTO rules had been in effect at the time the companies filed their patent applications. Such cases include four patents that Masimo Corp. (Irvine, CA) successfully asserted against pulse oximeters produced by Tyco Healthcare's Nellcor division (Pleasanton, CA), as well a patent that Guidant Corp. (Indianapolis) recently successfully asserted against stents produced by Medtronic Inc. (Minneapolis).

Despite the benefits that unlimited use of continuing applications affords medical device companies, PTO considers current continuing application practice a contributor to the significant backlog of unexamined applications before the office. PTO has proposed rule changes in an attempt to address that backlog.

Proposed Changes. The PTO's proposed rule change would limit continuing applications to only one per each original application, with the narrow and uncertain exception that “second or subsequent continued examination filings. . . be supported by a showing as to why the amendment, argument, or evidence presented could not have been previously submitted.” The change would be retroactive in effect, as it would apply to any application filed on or after the final rule's effective date. If the proposed rules go into effect when a medtech company's pending application is a continuing application, the company would not be permitted to file another continuing application.

Possible Strategies for Medtech Firms. Medical technology companies should consider taking steps now to prepare their patent portfolio for potential implementation of this rule. Companies should identify pending applications that contain valuable unclaimed subject matter, and should determine whether they are candidates for continuing applications to be filed before the rule change. However, companies should note that under the proposed rules, PTO may challenge cases in which there are multiple applications with claims directed to the same invention. Therefore, filing multiple continuing applications—even before the new rules are effective—could waste resources.

To best preserve the right to a single continuing case, a medical technology company should prosecute each patent application as if it is the last case containing its disclosure. Manufacturers should discuss with their patent counsel strategies that will help narrow the gap between their applications and their patent examiners. These may include examiner interviews and presenting additional claim amendments or patentability arguments and evidence.

Following the implementation of the new rules, procedures such as appeals and a new process called a preappeal brief request for review may find greater use. The preappeal brief request for review provides for an expedited review of an application's final rejection before a company has to proceed with a costly, time-consuming appeal. The new review process may result in the allowance of a case or the reopening of a patent application's prosecution.

Divisional Applications

PTO also has proposed changes to the practice of filing divisional applications, a type of continuing application.

When a single patent application presents claims directed to multiple inventions, PTO often requires the applicant to restrict the application to one invention. Claims to the other inventions may then be prosecuted in divisional applications.

For example, in a single application, a medical device company may present separate claims for a balloon angioplasty catheter, a method of treating an arterial occlusion, and a specific balloon material suitable for such a procedure. In response to a PTO requirement for restriction, the company could elect to pursue the catheter claims in the original filing and the method and material claims in separate, later-filed divisional applications.

Proposed Changes. PTO has proposed a rule change that would allow applicants to file divisional applications only while the original application is still pending. Therefore, an applicant with a pending divisional application would have no right to file any further divisional applications if the original application had already issued as a patent. To use the previous example, if the company's application for catheter claims had issued as a patent and the method claims were being prosecuted in a pending divisional application, an application for the balloon material claims would have to be filed before rule implementation. If the company failed to do so, the company might lose the right to seek patent protection on the balloon material.

Possible Strategies for Medtech Firms. In light of the proposed rule on divisional applications, medical technology companies should identify cases in which PTO has required them to restrict the claims of a patent application covering multiple inventions. Those inventions that are excluded from an original application are potential candidates for divisional applications. Such applications should be filed before the new rules go into effect, or the company risks losing the right to seek a patent on those inventions.


Due to the nature of the medtech industry, the proposed changes to U.S. patent rules, if implemented, could have a significant effect on the patent prosecution practices of device manufacturers. However, by taking appropriate action prior to the implementation of the final rules, manufacturers may avoid losing the right to seek patent protection for important innovations.

This article does not recommend a specific strategy for any particular case or patent portfolio—every company's situation is different. The strategy each manufacturer should take to prepare for the implementation of the new PTO rules depends on a variety of business and budget considerations, as well as the company's product focus and the competitive landscape of its sector. Therefore, in light of the proposed rules, executives at medical technology companies should discuss their portfolios with their patent counsel.


1. “Changes to Practice for Continuing Applications, Request for Continued Examination Practice, and Applications Claiming Patentably Indistinct Claims,” Federal Register, 71 FR: 48–61, January 3, 2006.

2. “Changes to Practice for the Examination of Claims in Patent Applications,” Federal Register, 71 FR: 61, January 3, 2006.

Les Bookoff is a partner at Finnegan, Henderson, Farabow, Garrett & Dunner LLP (Washington, DC).

© 2006 Canon Communications LLC

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