Canada’s Intellectual Property Firm

Patent protection for medical inventions in various jurisdictions

Authored bySally Hemming

Companies that sell products in different global markets may wish to seek patent protection for their inventions in multiple jurisdictions. Depending on the nature of the product that is to be patented, it may be possible to present the same set of patent claims in all jurisdictions in which a patent application is filed and thereby protect the same aspects of the invention in each jurisdiction. However, for products such as medical devices, there may be special considerations for patenting in various jurisdictions due to the use of such products in medical treatment methods.

Medical devices, for example, surgical tools, stents, implants or wound dressings, fall under the invention category of product. Usually there is no issue with obtaining patent protection for a product invention, assuming that the product meets the patentability requirements of being new, non-obvious and useful. Medical devices are no different. But obtaining patent protection for methods of using medical devices may be problematic in certain jurisdictions, like Canada, in which methods of medical treatment are not considered patentable.

Understanding the different types of medical treatment patent claims that are permissible in different jurisdictions before filing a patent application in those jurisdictions may help to avoid paying claim fees for claims that ultimately will not be patentable. Rather than presenting the same claim set in each jurisdiction, medical treatment patent claims can be tailored to reflect the rules relating to patentable subject matter for each specific jurisdiction.

This article briefly discusses approaches for obtaining patent protection for methods of using a medical device in the United States, Canada and Europe. For purposes of illustration, the example of a simple wound dressing is used, although the same principles apply to more complicated medical devices.

United States. In the United States, both medical devices and methods of medical treatment are considered patentable subject matter. Thus, it is possible to obtain protection for an inventive device, as well as methods of using such a device in a medical application. Examples of types of patent claims for a wound dressing that should be considered permissible in the U.S. include:

  1. A dressing comprising [essential features].
  2. A method for dressing a wound, comprising applying the dressing of claim 1 to a wound site [and any additional steps that might reflect the inventive aspect of the wound dressing].

If the wound dressing includes a pharmaceutically active compound in a coating layer (for example, a compound that reduces the risk of infection of the wound), the claim set could include an additional product claim that specifies such a feature:

  1. The dressing of claim 1 further comprising a coating layer on a wound-facing surface of the dressing, said coating layer comprising compound X.

A method that corresponds to the wound dressing of claim 3 might also be included, which relates to the function of the pharmaceutically active compound:

  1. A method of reducing infection of a wound site, comprising applying the dressing of claim 3 to the wound site.

Canada. The Canadian Patent Office, contrary to the U.S. Patent and Trademark Office, does not consider methods of medical treatment to be patentable. Thus, while claims 1 and 3 from the above U.S. claims might be considered patentable, claims 2 and 4 would be rejected as being directed to non-patentable subject matter.

Instead, the method claims can be converted to use claims, as well as product-for-use claims. In essence, use claims protect a specific purpose for which a medical device or product is to be used without reciting any actual method steps. Thus, the following patent claims should be permissible in Canada in place of claim 2 above:

  1. The dressing of claim 1, for use in dressing a wound site in a subject.
  2. Use of a dressing for dressing a wound, the wound dressing comprising [essential features].

Similarly, product-for-use and use claims can be presented in Canada to correspond to method claim 4 from the U.S. claims:

  1. The dressing of claim 3, for use in reducing infection of a wound site in a subject.
  2. Use of a dressing for reducing infection of a wound site, the wound dressing comprising [essential features of claim 3].

Europe. As in Canada, methods of medical treatment are excluded from patentability in Europe. However, the Canadian approach cannot be transferred to a claim set for filing in the European Patent Office.

European law sets out that products for use in medical treatments are patentable, even though the methods of treatment are not. Thus, device claims 1 and 3 should be considered patentable subject matter. While product-for-use claims are allowed for medical uses, the law stipulates that such claims are only permitted for substances and compositions. Thus, although claim 5 above is in product-for-use format, it likely will not be considered patentable in Europe because it is directed to a device rather than a substance or composition.

It may be possible to recast Canadian claims 7 and 8 above as acceptable subject matter in Europe by focussing upon the pharmaceutically active compound, as follows:

  1. Compound X formulated in a coating layer applied on a wound-facing surface of a dressing for use in reducing infection of a wound site.

However, if claim 9 is considered to be a "device claim in disguise," it is possible that claim 9 could be rejected as non-patentable subject matter.

The exclusion in Europe of medical treatment methods from patentable subject matter may be less of a concern for methods of using new devices, as protection can be obtained for the device itself. However, for methods that relate to new and non-obvious medical uses of a previously known medical device, patent protection may not be available in Europe.

The best approach for claiming methods of using medical device inventions may vary for other jurisdictions not listed above. When methods of using a medical device form an important part of a company's intellectual property, it is prudent to consult your Canadian patent agent regarding preferred forms of patent claims in the jurisdiction(s) of interest. Doing so prior to filing an application or paying claim fees in such jurisdictions may help to reduce costs.

The preceding is intended as a timely update on Canadian intellectual property and technology law. The content is informational only and does not constitute legal or professional advice. To obtain such advice, please communicate with our offices directly.