Wednesday, 8 February 2012

T 1695/07 – More Bloody Stuff


Both the patent proprietor and the opponent filed an appeal against the decision of the Opposition Division (OD) to maintain the patent under consideration in amended form.

Claim 1 of the main request before the Board read:
1. 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.


Obviously, the question arose whether this was a surgical method and, as such, excluded from patentability:

[5] Claim 1 is directed to a process for measuring the rate of blood flow in a shunt in which blood is flowing. It comprises the steps of “continuously removing blood from a downstream location in the shunt (12) ...” and “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), ...”.

[5.1] According to the very first paragraph of the patent in suit, the process of Claim 1 is for measuring arterio-venous shunt blood flow during haemodialysis. Still according to the patent in suit (Paragraph [0002]), haemodialysis is a process by which an artificial kidney replaces the function of a patient’s kidney. The majority of patients have an arterio-venous shunt implanted in a location having a high blood flow, to simplify the withdrawal of blood from a location close to the arterial side of the shunt and the return of the purified blood downstream of the withdrawal site, i.e. closer to the venous side of the shunt. The implanted shunt can be a native or artificial vessel that has been established surgically between a patient’s artery and vein.

[5.2] Since Claim 1 as granted is thus directed to a process that is carried out in vivo on a human or animal body, from which blood is removed and reintroduced, it has to be decided whether the claimed process is a method for treatment of the human or animal body by surgery falling under the exception clause of A 53(c).

[5.3] In this regard, the criteria developed in decision G 1/07 of the Enlarged Board of Appeal (EBA) have to be taken into consideration.

The criteria developed in G 1/07

[6] Before dealing with the criteria of G 1/07 in detail, it is necessary to deal with the proprietor appellants’ assertion that exclusions from patentability should be construed narrowly.

[6.1] According to G 1/07 [3.1], a provision containing exclusions or exceptions from patentability is to be interpreted in such a manner that it takes its effect fully and achieves the purpose for which it was designed.

[6.2] As further explained in G 1/07 [3.4.2.1-3], the broad construction of the term “treatment by surgery” as previously developed in T 182/90 and T 35/99 was no longer justified. Also, the definition given in opinion G 1/04 [6.2.1] that “any physical intervention on the human or animal body ...” is a method of surgery within the meaning of A 52(4) EPC 1973 appeared too broad.

[6.3] A “narrower understanding” of what constitutes by its nature a “treatment by surgery” within the meaning of A 53(c) was hence required. It was generally stated (Reasons [3.4.2.2]) that “such a narrower understanding rules out from the scope of the application of the exclusion clause uncritical methods involving only a minor intervention and no substantial health risks, when carried out with the required care and skill, while still adequately protecting the medical profession” [emphasis added]. In particular it was found that it “appeared hardly still justified to exclude from patentability certain, albeit invasive techniques, at least when performed on uncritical parts of the body”, which were carried out in a non-medical, commercial environment like in cosmetic salons and in beauty parlours” [emphasis added]. This was said to apply “as a rule to treatments such as tattooing, piercing, hair removal by optical radiation, micro abrasion of the skin”. On the other hand, it was required that the “definition of the term “treatment by surgery” must cover the kind of interventions which represent the core of the medical profession’s activities, i.e. the kind of interventions for which their members are specifically trained and for which they assume a particular responsibility”. These physical interventions on the body were defined as those which “require professional medical skills to be carried out and which involve health risks even when carried out with the required medical professional care and expertise” [emphasis added].

[6.4] Therefore, G 1/07 [3.4.2.4] indicates 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.

[6.5] In the present case it now has to be decided whether the process of Claim 1 as granted belongs to the kind of methods which should not be covered by the exception clause according to this “narrower understanding” of the EBA and according to the criteria developed in G 1/07. According to G 1/07 [3.4.2.6], this assessment has to be done on a case-by-case basis, with each category of cases being assessed on its own merits.

[7] The main criteria developed in G 1/07 concern 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 (as highlighted in Point [6.3], supra). These points will be considered in the following sections.

Criticality of the parts of the body affected by the method

[8] The claimed process involves 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 forms an admixture with the blood flowing in the shunt.

[8.1] In a medical sense, blood is a (flowing) organ of the human body, performing numerous functions which are essential to the health of the patient (T 1075/06 [2.1.1.2]). Accordingly, it can hardly be regarded as an “uncritical part of the body”.

[8.2] As regards the arterio-venous shunt, it can be created by joining an artery and a vein together through anastomosis, to bypass the capillaries, whereby a high blood flow is created in the shunt. Alternatively, an artificial vessel can be used to join artery and vein. The shunt is usually 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 haemodialysis, the shunt too cannot be regarded as an “uncritical part of the body”.

[8.3] Therefore, the claimed process is practised on body parts (blood and shunt) that are not uncritical for the health of the patient, whereby at least one of them (blood) is manipulated during the process. As mentioned in G 1/07 [3.4.2.5], “manipulating a body part is traditionally considered surgical”. The Board considers that this traditional approach still applies to “in vivo” blood manipulation, blood not being an uncritical organ of the body.

[8.4] Hence, the claimed method surgically affects a not uncritical part of the body.

Degree of intervention on the human or animal body

[9] The specification of the patent in suit neither discloses a specific amount of the blood flow rate in the circulation line, nor the duration of the process. According to D19 […], a typical flow value is 300 ml/min. Taking into account a duration of about 10 min, acknowledged as typical by the proprietor appellants […], the total quantity of blood flowing through the circulation line of the extracorporeal circuit during the measurement would be about 3 litres, i.e. more than one half of the average total blood volume of an adult patient. Even if the duration of the measurement were to be shorter, a substantial volume of blood is nevertheless being circulated during the measurement.

[9.1] Since the process of Claim 1 as granted involves a continuous manipulation of a large part of the flowing organ blood in an extracorporeal circuit connected to the patient, it is far from being a “minor intervention”. The claimed process therefore involves a significant degree of intervention on the body.

The environment (medical, non-medical, commercial)
in which the method is carried out

[10] That the process of Claim 1 as granted is performed “during haemodialysis” is not only disclosed in […] the patent in suit but also indicated in D19 […]. As a rule, haemodialysis is carried out in a medical environment, i.e. hospital, clinic or dialysis centre. The fact that, in some countries, nowadays, haemodialysis may also be carried out at home represents the exception rather than the rule, an exception which is only available under very specific conditions for certain kinds of patients, who nevertheless require detailed instructions and temporary assistance of medically trained personnel.

[10.1] Although, as ruled in opinion G 1/04 [6.3], the fact that the method steps can also be practised by the patient himself or herself is not a decisive criterion with respect to the applicability of the exception clause, the conditions under which the claimed method is carried out are nevertheless not comparable to a “commercial environment like cosmetic salons and in beauty parlours”, where certain kinds of treatment may not be excepted from patentability.

[10.2] In the Board’s view, the process of Claim 1 as granted is performed in an essentially clinical environment, i.e. in a medical environment.

Required professional medical expertise

[11] Claim 1 itself does not address haemodialysis, but as indicated above its process is carried out during haemodialysis.

[11.1] Haemodialysis is usually prescribed and supervised by nephrologists, as a consequence of a serious kidney dysfunction, i.e. of the inability of the kidneys to ensure the cleaning of the blood and the water balance in the body, resulting in accumulation of water and dangerous substances in the body, eventually leading to dysfunctions in almost all of the organs of the body. The treatment is initiated and managed by specialised medical staff specifically trained in extracorporeal blood treatment techniques, according to the detailed instructions of the physician and under his or her control and responsibility.

[11.2] In order to perform the claimed measurement process, the dialysis treatment has to be interrupted, the direction of flow in the shunt is to be reversed and the rate should be set at a specific value (e.g. 250 to 300 ml/min, see D19 […]). In the Board’s view, these steps in particular require a dedicated decision of the responsible physician. This becomes also evident from the fact that D19 […] restricts the use of the claimed measurement process to “patients under stable cardiovascular condition” and specifically excludes “unattended monitoring of conditions which could result in imminent danger to the patient”.

[11.3] Therefore, the claimed in vivo process requires “professional medical expertise”.

[11.4] Referring to G 1/07 and T 663/02, the patent proprietor appellants argued that “professional medical expertise can only be considered to be the expertise of a doctor or ‘physician’”, which was to be distinguished from the care and skill of a “duly trained and qualified nurse or paramedical professional” to whom a physician may delegate minor routine interventions not implying a substantial health risk for the patient. Since the claimed method was routinely carried out by a nurse or dialysis technician, i.e. paramedical personnel, it represented a delegated act which could not be considered as belonging to the “core of medical activities” and should thus not fall under the exception clause.

[11.5] The Board cannot follow this approach for the following reasons. It is true that G 1/07 [3.4.2.3] states that “any definition of the term treatment by surgery must cover the kind of interventions which represent the core of the medical profession’s activities”. This positively formulated requirement, however, does not imply that interventions which do not represent the core of the medical profession’s activities do not generally fall under the exception.

[11.6] Moreover, G 1/07 uses the definition of “the core of the medical profession’s activities, i.e. the kind of interventions for which its members are specifically trained and for which they assume a particular responsibility”. The term “medical profession” cannot be regarded as being restricted to medical doctors and physicians, i.e. academically trained personnel. It appears that the broad term “medical profession” was chosen to cover all health care providers who professionally practise medical acts, thus also physicians under training, nurses and other paramedical professionals, who are undoubtedly “specifically trained” and assume “a particular responsibility” for the interventions they perform. Any other interpretation would run against the purpose of the exception provision which is, as set out by the EBA, to free the medical profession from constraints which would be imposed on them by patents granted on methods for surgical treatments, because also paramedical staff act in the interest of public health and patients.

[11.7] This understanding is consistent with the choice of the similarly broad term “medical or veterinary practitioner” used in Opinion G 1/04 with respect to diagnostic methods, which was explicitly distinguished from the more specific term “physician” (Reasons, point [2]). In point [6.3] of the Reasons of this Opinion, it is clearly stated that
“whether or not a method is a diagnostic method within the meaning of Article 52(4) EPC [1973] should neither depend on the participation of a medical or veterinary practitioner, by being present or by bearing the responsibility, nor on the fact that all method steps can also, or only, be practised by medicinal or non-medicinal support staff, the patient himself or herself or an automated system”.

[11.8] Accordingly, no distinction is to be made between a delegating physician and paramedical (or even non-medical) support staff with respect to the performance of diagnostic methods, and it cannot be derived from G 1/07 that such a distinction should apply for surgical methods. On the contrary, the approach taken in G 1/04 is explicitly confirmed by G 1/07 [3.4.1] as follows:
“Whether or not a method is excluded from patentability under A 53(c) cannot depend on the person carrying it out. The findings of the EBA in point [6.3] of the Reasons of G 1/04 relate to diagnostic methods, but they quite generally deal with the exclusion from patentability under A 52(4) EPC 1973 and are thus equally valid with respect to the other exception conditions contained in A 53(c)”.
[11.9] Therefore, the present Board does not follow the approach (“paramedical profession”) suggested in T 663/02 [3.2.4].

Health risks

[12] In the extracorporeal circuit, the blood is 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 are usually installed within the circuit in order to exclude the presence of air in the re-delivered blood which could lead to embolisms. Moreover, leakages resulting in blood losses have to be avoided. Blood clotting due to shear stresses and contact with artificial surfaces represents a serious risk since it may lead to thrombosis. This usually requires the addition of an anticoagulant, i.e. a medicament. Further problems and health risks might arise from the fact that the shunt, where flow is to be measured, can already be partially stenosed and that the inverted flow of blood therein causes blood clots to be dislodged into the patient’s circulatory system. All these conditions must be continuously monitored and carefully controlled, and in cases of deviations and problems, immediate action must be taken to prevent danger for the patient (who is normally already in an impaired health state due to chronic renal failure, thus particularly sensitive to treatment). This requires the attendance of specially qualified and medically trained personnel, and, as a rule, the presence of a physician who at least supervises the procedure. Moreover, the necessary emergency equipment and personnel must be available. Most of the above-mentioned aspects also become directly evident from page 3 of D19. It is therefore 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.

[12.1] The proprietor’s argument that they were not aware of any complications or health risks, these only being hypothetical and not based on any evidence or reports, is not convincing.

[12.2] In the Board’s view, the wording “entails” or “involves a substantial health risk” used in G 1/07 cannot be understood as requiring a factual risk analysis based on objective evidence for the following reasons.

[12.2.1] Firstly, any risk is “hypothetical” by its very nature. In principle, it may be possible to quantify the likelihood of occurrence of a certain risk in absolute terms, taking into account statistical data. However, in many situations, significant and reliable data are not available. This applies in particular to the evaluation of health risks for patients undergoing a medical treatment. Since the treatment is generally adapted to the individual patient, comparable and thus reliable data are difficult to obtain. For new kinds of treatment, such as are frequently the subject of patent applications, e.g. the reversal of blood flow in a shunt in the present case, such data as a rule do not yet exist at all.

[12.2.2] Moreover, what would seem relevant is not a risk analysis on an absolute scale, but a relative evaluation of the health risks for the patient. This implies a consideration of the physical state of the individual patient and a judgement of the health risks in relation to the potential benefit to be achieved by the intervention. This judgement or balance itself would require “professional medical expertise” and belongs to the “core of the medical profession’s activities”.

[12.2.3] For the above reasons, the Board is of the opinion that an objective and concrete analysis of the absolute or relative risks, which is hardly feasible, cannot have been intended by the EBA and should therefore not be required. Accordingly, the present Board has not followed the approach (“risk matrix”) suggested in T 663/02 [3.2.5].

[12.2.4] The assessment of the “risk-criterion” is therefore limited to a more abstract basis, i.e. to the questions “Is a certain health risk present?” and “Is it substantial?”. A health risk is considered to qualify as “substantial” whenever it goes beyond the side effects associated with the treatments mentioned in G 1/07 (piercing, tattooing, etc.) which are generally limited to harmless infections of superficial tissues due to non-sterile working conditions.

[12.2.5] In contrast thereto, the above-mentioned health risks of the claimed method, which are objectively present, are undoubtedly “substantial”.

Conclusion

[13] It follows from the above that the claimed process does not fall under the “narrower understanding”, i.e. does not belong to the kind of methods which should not be covered by the exception clause according to the criteria developed in G 1/07.

[13.1] Claim 1 comprises the steps of “continuously removing blood from a downstream location in the shunt (12) ...” and “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), ...”.

[13.2] It has been established that these steps are 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 (G 1/07 [headnote 1, 3.4.2.7, last §]).

[13.3] According to the established jurisprudence of the Boards of Appeal, a multi-step method falls under the exception clause of A 53(c), if it includes at least one feature that constitutes a method step for the treatment of the human body by surgery (G 1/04 [6.2.1]; G 1/07 [3.2.5]).

[13.4] The possible technical contribution of the invention as mentioned by the proprietor appellants is not a criterion to be taken into consideration in this context.

[13.5] The present case is quite different from that underlying T 329/94, referred to by the proprietor appellants, which related to a blood extraction assistance method for facilitating sustained venous blood flow through a human limb towards a venous blood extraction point. In that case the blood extraction itself did not form part of the claimed subject-matter. If that had been the case, it was stated that withdrawal of blood would have fallen under the exclusion clause of A 52(4) EPC 1973 three times, namely as treatment by therapy and surgery and as a diagnostic method (point [4] of the Reasons). With respect to the last two aspects it must be noted, however, that decision G 1/07 and opinion G 1/04 have subsequently been issued by the EBA and the criteria developed therein must now be taken into consideration.

[13.6] Therefore, Claims 1 to 8 of the Main Request are directed to a method for treatment of the human body by surgery which is excepted from patentability under A 53(c).

Should you wish to download the whole decision, just click here.

The file wrapper can be found here.

More post-G 1/07 decisions can be found here, here and here.

2 comments:

sambassoon said...

Many thanks for posting several post-G 1/07 and G 1/04 decisions. As a supplement to the "Case Law Bible", your site is worth far more than $137.

Sam Bergstrom
US Patent Attorney
EPA Trainee

oliver said...

Thank you, Sam.

It is always good to hear that the blog proves useful to my readers.

NB: As a physicist, I am happy with the $137 price tag - it reminds me of the good old times when the fine-structure constant was a close friend.