AI in healthcare inventions - uncertainty relating to processing medical data

European Patent Office (EPO) Board of Appeal decision T 1741/22 has cast doubt on the circumstances of when a mathematical method may be considered to contribute to technical character in the processing of medical data. Of particular note, this decision deviates from both an earlier decision (T 2681/16) and EPO Guidelines G-II, 3.3 (citing particular examples in the EPO Guidelines as “erroneous”), raising concerning questions as to how inventions relating to the processing of medical data, or indeed data more generally, might fare at the EPO.  

Background

In the healthcare field, use of mathematical methods to analyse and process physiological data are widely used.

Inventions relating to data analysis typically have to overcome two hurdles regarding the assessment of “technical character” before they might be considered patentable:

1. whether the claimed subject-matter relates to a mathematical method as such (i.e. a purely abstract mathematical method) and thus is excluded from patentability under Art. 52(2) and (3) EPC; and
2. whether the mathematical method contributes to the technical character of the invention for the assessment of inventive step.

In relation to the first hurdle, this is typically overcome by including use of technical means such that the claimed subject-matter has technical character as a whole so it is not excluded from patentability.

In relation to the second hurdle, EPO Guidelines G-II, 3.3 provide examples of technical contributions of a mathematical method, including in the field of healthcare, “determining the energy expenditure of a subject by processing data obtained from physiological sensors; deriving the body temperature of a subject from data obtained from an ear temperature detector” and “providing a medical diagnosis by an automated system processing physiological measurements”. 

However, Technical Board of Appeal decision T 1741/22 has cast doubt on when a mathematical method may be considered to contribute to technical character in the processing of medical data.

The decision – T 1741/22

The claim at issue relates to analysing glucose monitoring data indicative of a glucose level, where minimum and maximum glucose values are determined and displayed.

Claim 1 of Auxiliary Request 10 reads (board's labelling):

1. A system for analysing glucose monitoring data indicative of a glucose level in a bodily fluid, comprising: an input device, a data processing device, an output device, a display device, and machine-readable instructions that are executed by the data processing device,
2. [wherein the machine-readable instructions cause the data processing device to] receive continuous glucose monitoring data via the input device, the continuous glucose monitoring data indicating a glucose level sampled for a person in a bodily fluid at a plurality of sample times over a measurement time period in a continuous glucose level measurement, and comprising a plurality of continuous glucose profiles, each of the glucose profiles comprising a plurality of glucose values with a glucose value for each of the plurality of sample times over the measurement period, wherein the plurality of glucose profiles is determined on different days by sampling the glucose level on each day over the measurement period, wherein the measurement period is 24 hours;
3. [wherein the machine-readable instructions cause the data processing device to] for the plurality of continuous glucose profiles, determine a plurality of minimum glucose values and/or a plurality of maximum glucose values for a selected group or each of the plurality of respective sample times
4. [wherein the machine-readable instructions cause the data processing device to] provide first display signals representing the plurality of minimum glucose values and/or the plurality of maximum glucose values for the selected group or each of the plurality of respective sample times;
5. [wherein the machine-readable instructions cause the data processing device to] output the first display signals via the output device to the display device; and display a first graphical representation according to the first display signals on the display device.

Features (c) and (d) relating to determining and displaying minimum/maximum values were considered to be the distinguishing features over the cited art. The appellant considered the technical effect of these features was to provide an improved analysis of glucose monitoring data since these values “may correspond to medically relevant outlier values”¹.

“New data” are not “measurements”

The Board considered that features (c) and (d) do not involve the actual measurement of the respective glucose level in a bodily fluid. Instead, they process already measured glucose monitoring data to generate and display further "new data". Such subsequent processing of certain measurement data collected from the human or animal body is considered by the Board to be "predominantly of a non-technical nature…Thus, it cannot contribute to the technical character of the invention” ².

According to the Board, merely the generation of “new data” is not sufficient to contribute to the technical character of the invention since mathematical methods are supposed to generate “new data” and mathematical methods as such are excluded from patentability Art. 52(2) and (3) EPC.

In their reasoning, the Board places a distinction on whether generation of “new data” involves a “measurement” in contrast to generating (and displaying) further data by an evaluation or interpretation of these measurements. Specifically, the Board considers that “a prerequisite for a "measurement" with technical character, within the meaning of the jurisprudence of the Boards of Appeal, is an interaction with "physical reality" for the calculation of the physical state of an object, even if the measurement may be carried out indirectly, e.g. by means of measurements of another physical entity (see G 1/19, Reasons 99)” ³.

In coming to this conclusion, the Board explicitly deviates from both  T 2681/16 and the example provided in the EPO Guidelines.   In T 2681/16 the distinguishing features related to an algorithm to process already acquired, i.e. measured blood glucose data points. The present Board disagrees with the finding in T 2681/16 that “providing an overall "measure" of the glucose variability and a prediction of glycemic events amounts to a technical effect” ⁴. In the Board’s view, the term “measure(ment)” is used too liberally by applicants to give inventions “the veneer of technicality”. 

In the present case and in the case underlying T 2681/16, the Board considers that “the interaction with the physical reality [patient’s blood] ends once blood glucose measurements are carried out, directly on the relevant physical entity "blood", or indirectly e.g. on another bodily fluid. The provision of overall glucose variability and a prediction of glycemic events are mathematical steps or intellectual activities which take place in the absence of this interaction with the physical reality and are therefore not "measurements" in this sense”⁵.

Moreover, referring to the example in the Guidelines of “providing a medical diagnosis by an automated system processing physiological measurements” as an example of technical contributions of a mathematical method, the Board held this example to be “clearly erroneous” since “providing medical diagnosis…is devoid of any technical character (see e.g. G 1/04, Reasons 5.3 and 6.3)” ⁶.

Future of claims to processing data at the EPO?

Following this reasoning, it would appear that this Board considers that a claim to processing medical data would not have technical character. To achieve grant, applicants would need to include “measurement” steps or an “interaction with a physical reality” (either directly or indirectly).  What would constitute such an indirect interaction is not entirely clear.

In line with this, in a separate decision (T 1423/22) published at a similar time, the claim in question was directed to a method of estimating glomerular filtration rate comprising the steps of measuring concentrations of SDMA and creatinine in a blood sample and “(iii) comparing a value resulting from an equation comprising the product of the concentration of creatinine and the concentration of free SDMA to one or more standard values that correlate to glomerular filtration rate in the animal subject”. The Board held that step (iii) was the distinguishing feature, but despite the fact that it relates to a “mathematical operation” and to” a mental act”⁷ (and so was “non-technical”⁸), found that “step (iii) hence contributes, together with the technical steps (i) and (ii) of measuring the blood sCr and SDMA concentrations, to providing a method for estimating the clinical parameter GFR in an animal subject and hence contributes to the technical character of the claimed method” ⁹.

However, for applicants in the bioinformatics and software space, claims including “measurement” steps or an “interaction with a physical reality” are likely to only be indirectly infringed in the scenario where one entity carries out the “measurements” and another entity processes the data, and so such claims might be of significantly less value.

The present decision is in line with previous decisions from the same Board (3.3.05) e.g. T 1910/20 (see our previous commentary) but has created divergence from both the Board (3.2.02) in T 2681/16, as well as the EPO Guidelines.  It remains to be seen how both Examiners and different Boards of Appeal might apply this case law going forward¹⁰, especially since these two Boards mainly hear cases in different technical areas (Board 3.3.05 mainly hears cases with the IPC classification code ‘G-Physics’, whereas Board 3.2.02 mainly hears cases with the IPC classification code ‘A-Human necessities’). However, since this decision was categorised with a ‘B’ distribution code, its distribution has been to all Chairpersons and Members of the Boards of Appeal.

It is, as yet, unclear whether this decision will change how inventions relating to the processing of medical data, or indeed data more generally, fare at the EPO. Given the diverging Board of Appeal decisions, a referral to the Enlarged Board of Appeal on this matter may well be required.

[1] T1741/22, r2.2

[2] T1741/22, r2.3.3

[3] T1741/22, r2.3.6

[4] T1741/22, r2.3.6

[5] T1741/22, r2.3.6

[6] T1741/22, r2.3.7

[7] T 1423/22, r12

[8] T 1423/22, r18

[9] T 1423/22, r22

[10] This decision has not yet been cited by any other Boards of Appeal since it was published in September 2024.