IP Diagnosis: Is my medical invention patentable? Part 4

At a glance: In the present blog series a guide on patenting medical inventions is provided. Part 4 deals with the distinction between surgical and therapeutic methods. The criteria for surgical and therapeutic methods must not be confused.

What’s the matter?

While both types of methods, surgical on the one hand and therapeutic on the other hand, are excluded from patent protection, the ways of assessing whether a method is a surgical method or a therapeutic method differ quite a lot.

Why is it important?

When trying to determine whether a method might be a medical method and thus excluded from patent protection, it is important to use the right assessment steps, i.e., either the steps for surgical methods or the steps for therapeutic methods.

What’s the critical point?

If you choose the wrong method type, your method claim might, although the assessment for the chosen method type was positive, still be rejected since it indeed relates to subject-matter that is excluded from patentability.

What needs to be kept in mind?

An objective determination whether the method is from the surgical or the therapeutic type (or both), is particularly important before drafting and filing a patent application for a medical invention including method steps.

Overview

The following flowchart provides some guidance for assessing whether a medical invention is excluded from patentability. Each step of the flowchart will be discussed one by one in the present series of blog posts. Revised flowchart

Step 3.1: Surgical or therapeutic method?

In the previous blog post the distinction between surgical/therapeutic methods and diagnostic methods have been discussed (here). Surgical methods and therapeutic methods practised on the human or animal body are excluded from patent protection according to the German Patent Act (PatG) and the European Patent Convention (EPC)[1].

In both cases just one surgical step or one therapeutic step suffices to qualify the method as surgical method or therapeutic method, respectively. Nevertheless, a clear distinction between both types of medical methods must be made, since the steps for assessing whether a method step indeed is a surgical step or a therapeutic step differ significantly: Any physical activity or action[2] having a curative, therapeutic or prophylactic effect/purpose or which alleviates symptoms of a disease is a diagnostic step and qualifies the respective method as therapeutic method (will be discussed in a subsequent blog article). Any step entailing a substantial physical intervention on the human/animal body is a surgical step and qualifies the respective method as surgical method (will be discussed in a subsequent blog article).

However, a surgical step does not have to include a curative/therapeutic purpose[3]. Vice versa, a therapeutic step does not have to entail a substantial physical intervention (any physical activity or action).

Thus, if the type of a method relating to a medical invention is incorrectly determined, wrong assessment criteria will be used and eventually a method may erroneously not be qualified as medical method. Moreover, a method can even be a combination of surgical and therapeutic (and diagnostic) methods, such that the assessment for each method type must be completed, since the overall teaching of the invention as given in the application is decisive for establishing what the invention is and whether it is excluded from patentability[4].

Case law example: Enzymatic activity (T 1213/10)

Amended claim 1 of the underlying patent application EP 1 997 425 A1 related to a:

Method of measuring an enzymatic activity, […]
said substrate is caused by a penetration device (5) to penetrate to a site where said enzyme is present, […]

The “site” includes the liver, brain, kidney, muscles etc. and is penetrated with the penetration device (5), e.g. an endoscope. Consequently, the respective step might qualify as surgical step.

In the discussion about the surgical character of said step, which undeniably entails a substantial health risk (endoscopic procedure on inner organs), the Applicant emphasised that the method was not performed for the immediate health of a patient and especially the step of penetrating the substrate to a site where the enzyme was present did not achieve any curative benefit, but simply enhanced the accuracy and resolution of the measurement.

The common usage of the term “surgery” might indeed suggest that a curative/therapeutic purpose is a mandatory characteristic. However, since having a curative benefit is not a perquisite for qualification as surgical step/method, but for qualification as therapeutic step/methods, the argument of the Applicant was not successful.

Summary

You should not neglect a thorough analysis of the whole method when planning to protect a medical invention. Assumptions or arguments pertaining to the wrong type of medical method might lead to the refusal of the respective method claims. Instead try to identify the parts and aspects of the medical invention that are most likely excluded from patent protection and then direct the patent application to the parts and aspects that are not in conflict with the provisions of the EPC or PatG.