Patentability Of Surgical Methods – New Insights From The EPO

This is a guest post from Dr. Stefan Danner
Patentanwalt/German Patent Attorney, European Patent Attorney

In its previous decision G1/07, the EPO Enlarged Board of Appeal (EBA) shed new light on the patentability of surgical methods, particularly those forming part of diagnostic methods. Based on this ruling the range of patentable subject matter is now limited in that methods that are surgical by nature but not necessarily by purpose are not deemed eligible for patent protection according to Article 53(c) EPC^[1]

However, after issuance of G1/07 numerous complaints have been raised that the EBA refrained from providing any workable criteria for determining whether such surgical intervention is excluded from patent protection, that is, when an invasive step constitutes a substantial physical intervention on the body that requires professional medical skills and involves a substantial health risk.

In recent decision T1695/07, the EPO Technical Board of Appeal (TBA) 3.3.07 has now given further guidance for applicants in this regard.

The case concerns European patent EP 0 781 161 B1 which was maintained during opposition proceedings in amended form. Both the patent proprietor and the opponent lodged an appeal against the decision of the EPO Opposition Division.

Claim 1 as granted reads:

A process for measuring the rate of blood flow in a shunt (12) in which blood is flowing, comprising:

continuously removing blood from a downstream location in the shunt (12) by way of an inlet (28) to an inlet side (26) of a circulating line; delivering the removed blood flowing in said circulating line by way of an outlet (34) connected to an outlet side (32) of said circulating line to an upstream location of said shunt (12), so as to cause it to travel downstream in the shunt (12) towards the inlet (28) as an admixture with the blood flow;

changing a selected physical property of the blood in said circulating line to produce a distinguishable blood characteristic at the outlet side (32) of said circulating line;

measuring the amount of change of said distinguishable blood characteristic; and

determining the rate of blood flow in said shunt (12) from the amount of change of said distinguishable blood characteristic by reference to a dilution curve of said amount of change.

According to the patent specification, the process of claim 1 is intended for measuring arterio-venous shunt blood flow during hemodialysis. The process is performed in vivo on a human or animal body, from which blood is removed and reintroduced.

Thus, it had to be decided whether the claimed process is a method for treatment of the human or animal body by surgery falling under the exception of Article 53(c) EPC.

Initially, the competent TBA pointed out that decision G1/07 indicated a new direction in which further practice and jurisprudence should develop, namely that the exclusion from patentability should apply only to methods in respect of which it is justified on grounds of public health, the protection of patients and the freedom of the medical profession to apply the treatment of choice to its patients. Each case should be assessed on its own merits. The main criteria for such assessment, as developed in G1/07, concerned the criticality of the parts of the body affected by the method, the degree of intervention, the environment in which the method is carried out, the required medical expertise, if any, and the health risks incurred,[2]

The Board further noted that the claimed process involved the continuous removal of blood from a shunt, its subsequent flowing through a circulating line of an extracorporeal circuit and the re-delivery of the blood to the shunt, where it formed an admixture with the blood flowing in the shunt. The shunt would usually be created in the lower arm but may also be situated on the hand. In any case, at least when the shunt is created by anastomosis to ensure the required access to the blood, in order to carry out hemodialysis, the shunt too cannot be regarded as an “uncritical part of the body.”

In addition, the Board concluded that the claimed process, since it involved a continuous manipulation of a large part of the flowing organ blood in an extracorporeal circuit connected to the patient, it would be far from being a “minor intervention”. Rather, the claimed process therefore involved a significant degree of intervention on the body.[3]

As a rule, hemodialysis were to be considered as to be carried out in a medical environment, i.e. hospital, clinic or dialysis center. The fact that, in some countries, hemodialysis might also be carried out at home represents rather an exception which would only be available under very specific conditions for certain kinds of patients, who nevertheless required detailed instructions and temporary assistance of medically trained personnel.

Hence, the Board ruled: A blood manipulation process involving the continuous removal of blood from a patient, its subsequent flowing through a circulating line of an extracorporeal circuit and its re-delivery to the patient is a method of treatment of the human body by surgery excepted from patentability under Article 53(c) EPC. It does not belong to the kind of methods which should not be covered by the exception clause according to the “narrower understanding” suggested by the EBA in decision G1/07 because the process is not performed in a “non-medical, commercial environment” and cannot be considered as a “minor intervention” being performed on “uncritical parts of the body.”[4]

The TBA further held that hemodialysis would usually be prescribed and supervised by nephrologists, as a consequence of a serious kidney. In order to perform the claimed measurement process, the dialysis treatment would have to be interrupted, the direction of flow in the shunt to be reversed, and the rate to be set at a specific value. In the Board’s view, these steps in particular require a dedicated decision of the responsible physician.[5]

The Board concluded: Such an in vivo process (i.e., as the claimed one) requires “professional medical expertise” and belongs to the kind of interventions representing the “core of the medical profession’s activities”, even when performed by paramedical support staff.[6]

With regard to the assessment of the health risks associated with the claimed process, the TBA pointed out that in the extracorporeal circuit, the blood would be subjected to conditions of a non-natural environment quite different from the vasculature within the patient’s body. In order to avoid deleterious effects on the blood in the extracorporeal circuit and resulting negative side effects on the patient upon its re-delivery, a number of measures and precautions must be taken. In particular, sterility must be maintained in order to avoid infections, and the temperature and the blood flow rate be properly controlled. Bubble traps would usually be installed within the circuit in order to exclude the presence of air in the redelivered blood which could lead to embolisms.

Moreover, leakages resulting in blood losses must be avoided. Blood clotting due to shear stresses and contact with artificial surfaces would represent a serious risk since it could result in thrombosis (thus, usually requiring the addition of an anticoagulant). Further problems and health risks might arise from the fact that the shunt, where flow is to be measured, could already be partially stenosed. All these conditions must be continuously monitored and carefully controlled to prevent danger for the patient. In the Board’s opinion, it is thus clear that the patient is subjected to a number of health risks, even when the process is carried out with the required medical professional care and expertise. Some of these risks are certainly “substantial,” even though the likelihood of their occurrence may be rare.[7]

The Board concluded: even when a process is carried out with the required medical professional care and expertise, it involves “substantial health risks” for the patient. A health risk is considered to qualify as “substantial” whenever it goes beyond the side effects associated with the treatments such as tattooing, piercing, hair removal by optical radiation, micro-abrasion of the skin as mentioned in G1/07. A factual analysis of absolute and relative risks and of their likelihood of occurrence based on objective evidence is hardly feasible and should therefore not be required.[8]

 

Conclusions

Hence, in view of the above considerations the claimed method does not belong to the type of methods which should not be covered by Article 53(c) EPC according to the criteria developed in EBA decision G1/07. The method steps are considered invasive and represent a substantial physical intervention on the body which requires professional medical expertise to be carried out and which entails a substantial health risk even when carried out with the required professional care and expertise.

According to the established EPO jurisprudence, a multi-step method already falls under the exception clause of Article 53(c) EPC, if it includes at least one feature that constitutes a method step for the treatment of the human body by surgery (cf. for reference, e.g., G1/04 (point 6.2.1 of the reasoning) and G1/07 (point 3.2.5 of the reasoning)).

Even though the present decision provides some guidance for applicants how to interpret the criterions laid down in G1/07, the very limited “post-G1/07” case law currently available still includes some uncertainties. In decision T1075/06, TBA 3.2.02 considered a method for blood processing comprising a venipuncture to represent a substantial physical intervention on the body which requires professional medical expertise to be carried out and which entails a substantial health risk even when carried out with the required professional care and expertise. On the other hand, TBA 3.4.01 ruled in decision T663/02 that all potential complications associated with the step of intravenously injecting a contrast agent during a method for imaging an artery are reversible and not associated with substantial health risks.

Accordingly, applicants are advised to carefully analyzed any subject matter relating to methods involving a step of “surgical intervention” (e.g., the removal and/or manipulation of a blood sample) as to whether the criterions defined in EBA decision G1/07 are fulfilled. It is strongly recommended to include at least in the description alternative claim wordings/embodiments as potential fallback positions should the original claim wording be objected as not patentable.

Currently, it is also speculated about a further referral to the EBA being directed to surgical treatment methods in order to provide further clarification of Article 53(c) EPC.

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