Bringing US Medical device claims to Europe
Patent co-operation treaty (PCT) applications that have been initially filed in the US have the possibility to enter into the European Regional phase before the end of the 31 month International phase. Under US patent provisions, claims towards methods of treatment by surgery or therapy by a medical device on the human or animal and are typically permitted, while in Europe such claims would be objected to under Article 53(c) EPC as exceptions to patentability.
In a field of medical devices, method claims often form a part of a US claim set – such claims typically allow all features to have patentable weight over the prior art, compared with an apparatus claim where features setting out interactions with a human or animal body might be regarded as the device “in use” or as not translating to structural features that have a limiting effect. Method claims hence may sometimes find an easier grant. However, problems arise when such claims are brought to Europe for instance via the PCT route, and the EPO (European Patent Office) Examiner sees a method step as explicitly or implicitly being on the body in the context of a treatment or diagnostic method. Because Europe has strict rules concerning basis for amendments, the method claims sometimes cannot be adapted, and the subject matter might ultimately be lost. In this article we explore how medical device method claims are examined in Europe in view of the exceptions to patentability and propose recommendations for pre-emptive steps to be taken at the US drafting stage.
How are medical device method claims examined at the EPO?
An EPO Examiner will object to a medical device method claim if the invention of the claim causes or implies a treatment by therapy or surgery or a diagnosis of a condition by steps carried out on the human or animal body. Classic examples of claims falling under the exception include:
- A method for diagnosing Alzheimer’s disease in a patient comprising measurement of EEG data from an electrode placed at position x on the patient (diagnostic step on the body)
- A method for treating or alleviating symptoms of Alzheimer’s disease in a patient comprising application of surface electrical stimulation via an electrode placed at position x of the patient (therapy step on the body).
- A method for treating or alleviating symptoms of Alzheimer’s disease in a patient comprising application of deep brain electrical stimulation via electrodes inserted at positions x, y and z of the patient (therapy and implied surgical step on the body).
The exception also applies to methods which take place within a computing environment. Where the computer-implemented method is limited to steps of receiving data and outputting data, the implied application on the human body which gives rise to a treatment or diagnosis or surgery can cause the objection. According to the EPO guidelines: “If a method claim directed to therapy is open to objection under Art. 53(c), this also applies to a corresponding claim directed to a computer-implemented therapeutic method (T 1680/08).” (EPO Guidelines G-II 188.8.131.52).
In our experience, the objection is currently broadly applied, and an Examiner will be inclined to open with an Article 53(c) EPC objection if there is even an implied excepted step on the human or animal body.
What should I add to my US draft?
The exception to patentability relates to surgical steps, methods of treatment and diagnostic methods, but not to diagnostic methods with at least one technical step not involving the body, and more notably not to product claims, hence most medical device protection in Europe is achieved through apparatus protection. A simple solution thus is a reformulation towards a product claim (e.g. device, apparatus, system). In this context it can be envisaged to consider whether all structural features of the device relating to the interaction with the human body are adequately described in the application.
The allowability of apparatus or device claims is well established in the EPO Guidelines (G II 4.2.1): “Claims to medical devices... 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 practised 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).
Similarly, claims towards 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 practised 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). (EPO Guidelines G-II 4.2.1).
However, the EPO does not allow a reformulation of a method claim to a product claim unless there is an existing basis in the specification. Hence, it is advisable to include during drafting suitable phrases which allow for later amendments.
Examples are below:
- Boiler-plate language such as:
- “A product/device/system configured to carry out one or more of the methods described herein”;
- “A computer program or computer program product having instructions which when executed by a computing device or system, cause the computing device or system to perform one or more of the methods described herein”;
- “A computer readable medium having stored thereon a computer program having instructions which when executed by a computing device or system cause the computing device or system to perform one or more of the methods described herein”;
- It can be useful to paste the US claims into a section of the description and in the same section include a statement that the boiler-plate language applies to these claims;
- Where the existing method claims contain a limitation such as “measuring signals from an electrode implanted at position X”, add also a phrase such as “processor configured to receive measurement data from an electrode implanted at position X”;
- Where the above method claim contains an additional limitation such as “injecting agent Y into the subject”, extend the phrase along the lines “processor configured to receive measurement data from an electrode implanted at position X of a subject injected with agent Y”;
- Where an action on a particular body part is referenced in the method claim, the corresponding device claim might be reformulated using functional language. For instance “attaching device A to a femoral condyle of the subject”, could be reformulated and added during drafting as “device A having a surface configured for attachment to a femoral condyle of the subject”. In Europe, a definition by reference to (use with) another entity is recognised (EPO Guidelines F-IV 4.14), and in that context such amendments can often be permitted and have a limiting effect.
If a particular method claim be can written out as a full product claim, all the more advantageous. It allows a clear separation of device elements from the method steps, and purely method elements can be reformulated as functional features. We can assist applicants in this aspect.
On a side note, while product claims are allowable and form the vast majority of medical device claims, a caveat is that the product will fall under the exception if it can only be produced by performing a surgical or therapeutic step (decision of the Technical Board of Appeal T1731/12). The exception of a surgically/therapeutically defined product is confirmed in the EPO Guidelines (G II 4.2): “However, a method of manufacturing an endoprosthesis outside the body, but requiring a surgical step to be carried out for taking measurements, would be excluded from patentability under Art. 53(c) (see T 1005/98).” This type of objection could be overcome by including during drafting other ways to non-surgically configure an apparatus, e.g. based on medical imaging and modelling.
When should I amend my US claims?
Amendments to the claims for searching can generally be made upon entry into the EP regional phase or in response to the Rule 161(2) and 162 EPC communication. Assuming the International Searching Authority was not the EPO, the amended claims will be searched, and a supplementary European Search Report issued. The applicant is given an opportunity to comment on the supplementary European Search Report and file amendments and correct deficiencies within a period (6m). Any further amendments will be allowed only at the discretion of the Examiner, however, if such amendments would be driven by an Article 53(c) EPC objection, we estimate most Examiners would admit them.
Take care that after the supplementary European Search Report has been issued, future amendments that extract subject matter from the description (and not the dependent claims) might not be allowed if the subject matter only appears in the description, the search division did not find it appropriate to extend the search to this subject-matter, and it does not combine with the originally claimed and searched invention or group of inventions to form a single general inventive concept (EPO guidelines GL H IV 4.1.2). Apart from a refusal to admit amendments, a finding of lack of unity may ensue. Thus, to avoid a non-admittance of amendments, it is recommended to include strong fall back positions already in the claim set prior to searching.
Typically, the optimal time to file an initial amendment is in response to the Rule 161(2) and 162 EPC communication because the 6 month reply period gives applicants more time to formulate a suitable claim set, within the same period any extra claim fees can be paid or avoided by reducing the number of claims 15 or less, and this claim set will be subjected to the EPO’s search.
Other differences between US and EP
A potentially contentious area of difference also often relevant to medical devices concerns the use of units. According to EPO practice, physical values must be expressed in the units recognised in international practice, which is generally in the metric system, using SI units. Any values not meeting this requirement must also be expressed in the units recognised in international practice. Values expressed in the system of imperial units (e.g. inches/pounds) or in units having local character (e.g. pint), in general, do not meet the criterion "recognised in international practice" (EPO guidelines F-II, 4.13). Ranges in a patent application expressed in imperial units hence need to be converted into SI units in the description and the claims. Caution has to be exercised not to extend the scope of protection beyond that of the patent application as filed. The conversion often produces a large number of significant digits, which can extend the scope of the protection when only a limited number of those significant digits are used in the amendment. To avoid a possible point of opposition, it is advised to express values in both the usual (imperial) units and SI units in the application as filed.
There are many other well known more general differences between US and EP practices which are briefly and non-exhaustively listed below, some of which may need to be taken into account during drafting. In EP practice:
- Reference signs are required in the claims – may be added during examination;
- Strong basis in the description required for any amendments to the claims;
- Multiply dependent claims and multiple-on-multiple dependencies are allowed – claim fees are based on the claim count not on dependencies. There are no claims fees for 15 claims or less;
- Only one independent claim per category (product, method) is allowed, except where inter-related (e.g. plug and socket);
- No incorporation by reference in the description unless specific – general statements thereto may be deleted during examination;
- Two-part form of the independent claims is often requested; can be implemented just prior to allowance;
- Description is brought in line with amended claims during examination;
- Prior filed but later published EP applications are prior art for novelty but not inventive step;
- No grace period.
Patent examination before the EPO applies strict rules regarding basis for amendments to the claims. US-style medical method claims falling under the exception for patentability sometimes cannot be adapted into product claims for that reason. We reviewed herein some of the general additional language that can be included during the drafting phase. In cases where a straightforward product conversion seems inappropriate, we can assist in analysing a claim to determine product features that both avoid the exception and carry patentable weight under EPO practice. Our team of experienced patent attorneys can assist during drafting and in prosecution to find solutions to these types of objections. For more information, please do not hesitate to contact us at firstname.lastname@example.org.