The EPO Enlarged Board of Appeal handed down its decision relating to the interpretation of the exclusion for patentability under article 53(c) EPC “method for treatment of the human or animal body by surgery”. Questions were asked to the Enlarged Board in a case about a medical imaging method, whereby a contrast agent was injected into the heart. The referring Board questioned whether this essentially diagnostic method involving a step consisting in a physical intervention was nevertheless excluded from patentability.

The appeal proceedings before the referring Board concern the appellant’s appeal against the decision of the Examining Division of 17 April 2003 refusing European patent application No. 99918429.4. The Examining Division decided that the claimed methods according to the requests then on file constituted diagnostic methods practiced on the human or animal body and thus were excluded from patent protection pursuant to Article 52(4) EPC 1973. Furthermore, the claimed methods comprised the step of administering polarized 129Xe as an imaging agent to a subject, either by inhalation or by injection. Insofar as the delivery of the imaging agent was done by injection, the claimed methods were excluded from patent protection pursuant to Article 52(4) EPC 1973 as involving a surgical step.

The application relates to magnetic resonance methods for imaging the pulmonary and/or cardiac vasculature and evaluating blood flow using dissolved polarized 129Xe.  The imaging methods of the present invention may precede surgery or a drug therapy for treating pulmonary or cardiac vasculature problems. During surgery, they may provide real-time feedback for verifying success, for example surgically induced variations in blood perfusion. During a drug therapy, they may allow the effects of the drug to be determined.

The wording of claims 1, 11 and 17, underlying the referring decision reads as follows:

1. A method for MRI imaging the pulmonary and/or cardiac vasculature using dissolved-phase polarized 129Xe, comprising the steps of: positioning a patient in an MRI apparatus having a magnetic field associated therewith; delivering polarized 129Xe gas to a predetermined region of the patient’s body, the polarized gas having a dissolved imaging phase associated therewith; exciting a predetermined region of the patient’s body, having a portion of the dissolved phase polarized gas therein with at least one large flip angle RF excitation pulse; and acquiring at least one MR image associated with the dissolved phase polarized gas after said exciting step.

11. A method for deriving a spectroscopic signal representative of a blood volume or a blood flow rate of a patient, comprising the steps of: positioning a subject in an MR spectroscopy system capable of detecting spectroscopic signals in a subject having a pulmonary vasculature; delivering gaseous polarized 129Xe to the subject; dissolving a portion of the gaseous polarized 129Xe into the pulmonary vasculature having an associated blood flow path; exciting the dissolved portion of the 129Xe with an MR spectroscopy RF excitation pulse; and deriving a spectroscopic signal associated with the dissolved phase 129Xe representing a blood volume or blood flow rate.

17. A cardiac imaging method, comprising the steps of: positioning a subject having a cardiac blood flow path in an MRI system; delivering polarized 129Xe to the subject; dissolving at least a portion of the polarized 129Xe into the subject’s cardiac blood flow path; exciting dissolved polarized 129Xe in a target region along the blood flow path with at least one large angle RF excitation pulse; and generating an MR image associated with the excited dissolved polarized 129Ke.

The Enlarged Board answered the following questions:

Q. 1.    Is a claimed imaging method for a diagnostic purpose (examination phase within the meaning given in G 1/04), which comprises or encompasses a step consisting in a physical intervention practiced on the human or animal body (in the present case, an injection of a contrast agent into the heart), to be excluded from patent protection as a “method for treatment of the human or animal body by surgery” pursuant to Article 52(4) EPC if such step does not per se aim at maintaining life and health?

A. 1. A claimed imaging method, in which, when carried out, maintaining the life and health of the subject is important and which comprises or encompasses an invasive step representing 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, is excluded from patentability as a method for treatment of the human or animal body by surgery pursuant to Article 53(c) EPC.

2.    If the answer to question 1 is in the affirmative, could the exclusion from patent protection be avoided by amending the wording of the claim so as to omit the step at issue, or disclaim it, or let the claim encompass it without being limited to it?

2a.    A claim which comprises a step encompassing an embodiment which is a “method for treatment of the human or animal body by surgery” within the meaning of Article 53(c) EPC cannot be left to encompass that embodiment.

2b.    The exclusion from patentability under Article 53(c) EPC can be avoided by disclaiming the embodiment, it being understood that in order to be patentable the claim including the disclaimer must fulfill all the requirements of the EPC and, where applicable, the requirements for a disclaimer to be allowable as defined in decisions G 1/03 and G 2/03 of the Enlarged Board of Appeal.

2c.    Whether or not the wording of the claim can be amended so as to omit the surgical step without offending against the EPC must be assessed on the basis of the overall circumstances of the individual case under consideration.

3.    Is a claimed imaging method for a diagnostic purpose (examination phase within the meaning given in G 1/04) to be considered as being a constitutive step of a “treatment of the human or animal body by surgery” pursuant to Article 52(4) EPC if the data obtained by the method immediately allow a surgeon to decide on the course of action to be taken during a surgical intervention?

3. A claimed imaging method is not to be considered as being a “treatment of the human or animal body by surgery” within the meaning of Article 53(c) EPC merely because during a surgical intervention the data obtained by the use of the method immediately allow a surgeon to decide on the course of action to be taken during a surgical intervention.

The entire opinion is here: Medi-Physics/Treatment by Surgery G107 Board Opinion

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