Newsletter
New Medical Technology Series (3) – Patent Drafting Practice in the Field of Radiation Therapy (China Example)
In the previous article, Taiwan’s patenting practice is presented as an example to illustrate how to draft BNCT related patent applications. Related patent drafting practices in China will now be introduced.
China’s Patent Law sets forth in Article 25.1.3 that “disease diagnosis and treatment methods” are ineligible for patent protection. In the Patent Examination Guidelines (hereinafter “Guidelines”) issued by the CNIPA, diagnostic methods are defined as processes of identifying, investigating and determining causes or lesion states of diseases in living human or animal bodies. The Guidelines also make it clear that a technical solution of an invention is classified as a disease diagnostic method only if it meets both of the following conditions: (a) being practiced on a living human or animal body as subject; and (b) being practiced for the immediate purpose of acquiring disease diagnosis results or health conditions. An invention may still be excluded from patent eligibility if it is directed to a subject that seems to be an in vitro sample in terms of literal expression but still actually serves the immediate purpose of acquiring the disease diagnosis results or health conditions of the subject. Where a method may include a diagnosis step, or a detection step rather than a diagnosis one, the Examiner may still tend to conceive that the method serves the immediate purpose of acquiring disease diagnosis results or health conditions as long as a person skilled in the art can obtain disease diagnosis results or health conditions directly from the diagnosis or detection information based on the disclosed patent application. In such situation, the patent application will be blocked during prosecution.
China’s Patent Law expressly excludes diagnostic methods from patent eligibility, yet does not impose restrictions on the patenting of related products. Therefore, an applicant who intends to seek patent protection in China may consider converting diagnostic methods into products. For example, a diagnostic method may be converted into the substances or materials used in the diagnostic method, or into the devices or systems carrying out the diagnostic method. In addition, for the inventions related to medical imaging diagnosis and analysis methods based on computer technology, it is advisable to describe such methods as computer processing systems for medical imaging. One area that needs special attention is that such medical imaging product inventions should not be directed to computer programs per se. That is, sensitive terms such as “program,” “instruction,” “programming” or “software” should not appear in the subject matters of the claimed products. Another key is to avoid simply changing the subject matter of a claim into a physical device or apparatus while still having the subject matter defined by limitations such as the workflows and the functions that the programs perform, because both workflows and functions are expressly excluded from patent eligibility. For medical imaging products based completely on computer workflows, it should be kept in mind that such products are products in form but in essence a virtual functional module framework. The key to the patentability of such products lies in whether they employ technical means to solve a technical problem and bring about a technical effect, or whether the solution representing a technical improvement is constituted by technical contents in conformity with the laws of nature.
Additionally, the ineligible subject matter prescribed in Article 25.1.5 of China’s Patent Law was changed from “substances obtained by methods for nuclear transformation” to “methods for nuclear transformation and substances obtained thereby” in the 2020 amendments to the Patent Law. As defined in the Guidelines issued by the CNIPA, “a method for nuclear transformation refers to the process of splitting or fusing one or multiple nuclei to form one or multiple new nuclei, for example, a magnetic mirror trap method for completing nuclear fusion reaction, a closed trap method for completing nuclear fusion reaction, and various methods for realizing nuclear fission” and “Substances obtained by methods for nuclear transformation mainly refer to various radioisotopes produced and manufactured by accelerators, reactors and other nuclear reaction devices.” The techniques related to methods for nuclear transformation and substances obtained thereby are associated with material interests in national economy, defense, scientific research and daily life, and therefore should not be monopolized by organizations or individuals. Such concerns are the main reason why barriers are set up to prevent such technical subjects from being patented. However, it is further clarified in the Guidelines that particle acceleration methods (e.g., electron traveling-wave acceleration, electron standing-wave acceleration, electron collision, electron circular acceleration, or the like) that increase particle energy for the purpose of nuclear transformation are not classified as methods for nuclear transformation and thus are patent-eligible subject matters; various equipment, instruments and parts thereof for implementing the methods for nuclear transformation are all deemed patent-eligible subject matters. Furthermore, although the isotopes obtained by methods for nuclear transformation are by themselves excluded from patent eligibility, their uses as well as the instruments and equipment for obtaining them are patent-eligible subject matters.
Given the legal background explained above, when medical radiological physics-related technologies, such as BNCT, are to be patented in China, it is necessary not only to take into account patent eligibility limitations on “disease diagnosis and treatment methods” but also to adopt an appropriate method of drafting the patent if the technical disclosure includes technological innovations related to methods for nuclear transformation, so as to circumvent the restrictions on patent-eligible subject matters. For instance, where the technical solution of a claimed invention involves a method for nuclear transformation, it is advisable to protect the invention in the form of a device by combining the steps of the method with a system or device carrying out these steps, to which partial method descriptions may be added. Concerning an invention involving a method for manufacturing radioisotopes, for another example, if the steps related to “nuclear transformation” are not the inventive parts of the invention, it is suggested to delete the aforesaid steps from the method claim and emphasize instead other processes, such as chemical isolation or purification.
To conclude, if an invention is directed to a therapeutic method, the drafting of the claims must be adjusted to conform to local requirements, as certain countries or regions impose limitations on the patenting of medical-related inventions. In principle, as stated in the Guidelines for Examination in the European Patent Office, “Claims to medical devices, computer programs and storage media which comprise subject matter corresponding to that of a method for treatment of the human or animal body by surgery or therapy or to that of a diagnostic method practiced on the human or animal body are not to be objected to under Art. 53(c), because only method claims may fall under the exception of Art. 53(c).” That is, as long as the claimed invention is defined as a medical device, a computer program, or a storage medium whose uses are not limited to surgery or treatment/diagnosis methods, the medical device, computer program or storage medium is, in principle, exempt from the strict limitations on surgeries or treatment/diagnosis methods. As a result, there is a good chance for such products to be deemed as patent-eligible subject matters.
Apart from patent drafting practice, attention should also be paid to certain aspects associated with technology export controls with respect to BNCT-related industries. In the next article, the author's relevant practical experiences will be shared and patenting under technology export controls will be discussed.