T 1039/20 09-03-2023
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SYSTEM AND METHOD FOR CONFIGURING A RULE SET FOR MEDICAL EVENT MANAGEMENT AND RESPONSES
I. The appeal is against the decision of the examining division refusing European patent application No. 10765238.0. The examining division found that the main request complied with the requirements of Article 123(2) EPC but that it did not involve an inventive step within the meaning of Article 56 EPC.
II. The appellant requested that the decision under appeal be set aside and that a patent be granted on the basis of the main request or, as an auxiliary measure, that a patent be granted on the basis of one of auxiliary requests 4 or 5, all filed with the letter dated 12 March 2020.
III. Claim 1 of the main request reads as follows:
"A method for generating and storing a medical system algorithm for use in connection with an automated medical device (130) within a medical system, the steps of the method comprising:
providing a context free grammar to define the medical system algorithm, the grammar comprising non-terminal parameter symbols and terminal parameter symbols that are configured to be satisfied by a plurality of non-terminal medical system parameters and terminal medical system parameters, respectively, the grammar further comprising non-terminal condition symbols and terminal condition symbols that are configured to be satisfied by a plurality of non-terminal medical system conditions and terminal medical system conditions, respectively, the grammar further comprising a response symbol that is configured to be satisfied by a plurality of medical system responses;
receiving, by a rule set configuration processor (140), a first parameter selection comprising at least one of the non-terminal parameters or at least one of the terminal parameters, defined by the grammar;
receiving, by the rule set configuration processor (140), a respective first medical system condition selection corresponding to the at least one of the non-terminal parameter symbol or terminal parameter symbol for the selected first parameter selection defined by the grammar;
receiving, by the rule set configuration processor (140), a medical system response selection;
generating the medical system algorithm from the first parameter selection, the first medical system condition selection, and the medical system response selection; and
storing in a computer readable memory the generated medical system algorithm for later use by said automated medical device (130) wherein the generated medical system algorithm can be independently selectable without changing to a different protocol or personality of the automated medical device (130);
wherein each of the first parameter selection, the first medical system condition selection, and the medical system response selection may be inputted by a user via an interface (500),
receiving, by the rule set configuration processor (140), a second parameter selection comprising at least of [sic] one of the non-terminal parameter symbols or at least one of the terminal parameter symbols defined by the grammar; and
receiving, by the rule set configuration processor (140), a respective second medical system condition selection corresponding to the at least one of the non-terminal parameter symbol or terminal parameter symbol for the selected second parameter selection defined by the grammar, wherein each of the second parameter selection and the second medical system condition selection is inputted by said user via said interface (500),
wherein the first medical system parameter selection is a first alarm selection and wherein the second medical system parameter selection is a second alarm selection, different than the first alarm selection,
wherein said medical system response selection specifies switching the medical system algorithm to a second medical system algorithm generated from the second parameter selection and the second medical system condition selection."
IV. The following documents are relevant to this decision.
D1 US 2005/020886 A1
D2 US 2006/047538 A1
D3 "The syntax and semantics of the PROforma guideline modeling language", JOURNAL OF THE AMERICAN MEDICAL INFORMATICS ASSOCIATION, vol. 10, no. 5,
September 2003 (2003-09), pages 433-443, ISSN: 1067-5027, DOI: 10.1197/JAMIA.M1264
D4 VAN DER MAAS A A F ET AL: "Requirements for Medical Modeling Languages", JOURNAL OF THE AMERICAN MEDICAL INFORMATICS ASSOCIATION, vol. 8, no. 2, 1 March 2001 (2001-03-01), pages 146-162
V. The appellant's arguments which are relevant to the present decision can be summarised as follows.
Inventive step when starting from D1
The subject-matter of claim 1 was inventive when starting from D1.
D1 did not disclose a medical system response selection specifying switching the medical system algorithm to a second medical system algorithm generated from a second parameter selection and a second medical system condition selection, where first medical system parameter selection was a first alarm selection and wherein the second medical system parameter selection was a second alarm selection, different than the first alarm selection.
A technical effect from the distinguishing feature was a more efficient handling of alarms in a medical system. The objective technical problem was how to improve alarm handling efficiency in such system. Neither D1 nor any of the other documents on file taught the solution of claim 1.
1. The invention
Patients can be monitored using biometric sensors including an EKG system, respiratory monitors and blood gas monitors. Medical equipment such as a medication delivery pump can also be monitored, for example to identify when an interruption of the regular operation has happened.
Systems to monitor patients and equipment provide outputs which can be used by caregivers to make various patient care decisions. They may also trigger an alarm if a deviation is detected, for example a "low blood pressure" alarm.
Conventional monitoring systems have some drawbacks, including false positive alarms and the lack of ability to require a response only when multiple monitored parameters have changed. For example, a momentary deviation such as a brief disconnection from a biometric sensor may lead to an alarm being triggered also when no action from the caregiver is needed. A false alarm may cause an improper reaction from the caregiver. Frequent false alarms may also desensitize caregivers.
The invention addresses these drawbacks by using two medical system algorithms (i.e. two rule sets). Each algorithm is generated with a respective medical system parameter selection and medical system condition selection. The medical system parameter selection of each of the two algorithms is an alarm selection, with the two alarm selections being different.
The (first) medical system algorithm is generated with a medical system response selection which specifies switching the algorithm to the second medical system algorithm.
An example of a rule set comprising parameters/alarms, conditions and responses is shown in Figure 4 of the patent application reproduced below.
FORMULA/TABLE/GRAPHIC
2. Main request - inventive step
2.1 D1 deals with patient monitoring using rule-based algorithms and defines a valid starting point for the invention of claim 1. D1 teaches that one or more rule-based algorithms can be applied to physiologic variables in order to establish one or more diagnostic interpretations.
2.2 The appealed decision identified the feature "providing a context free grammar ..." as defining the sole distinguishing feature of the claimed invention over D1. This feature was found to be a so-called non-technical feature which did not result in a technical effect serving a technical purpose. This assessment was not disputed by the appellant and the Board sees no need to address it further. However, as explained hereafter, further features distinguish the claimed method from D1.
2.3 The rule-based algorithm(s) disclosed in D1 can be regarded as the "medical system algorithm" of claim 1.
2.3.1 D1 discloses that the selection of which rule set(s) / rule-based algorithm(s) to apply can previously be done by the logic 22 (see paragraphs [0021], [0028] and claim 13 of D1). It is not fully clear from the feature analysis in the appealed decision whether the examining division regarded the rule-based algorithm(s) or their pre-selection as anticipating the "medical system algorithm" of claim 1. The Board regards the latter possibility as less appropriate for two reasons.
2.3.2 Firstly, according to claim 1, both the medical system algorithm and the second medical system algorithm are defined using symbols from a common context free grammar. However, D1 comprises no indication that the selection of which rule-based algorithm(s) to use would be represented as an algorithm using symbols from the same grammar as the rule-based algorithms themselves.
2.3.3 Secondly and more importantly, the passage of D1 relating to the physiologic variables showing a development comparable to an alarm (i.e. "drop in oxygen in a patient's blood" in paragraph [0019]) is within the context of applying the logic rules / algorithms to derive a diagnostic interpretation. D1 does not disclose that any such developments would be identified or that anything equivalent to an alarm would play any role when selecting which rule set(s) / algorithm(s) to apply.
2.4 The rule-based algorithm(s) of D1 receive physiologic variables 17 as input and generate a response such as an alarm or a diagnostic interpretation (see paragraphs [0018]-[0019] and [0030] of D1).
2.4.1 As explained in the appealed decision, the plurality of physiologic variables 17 of D1 can be regarded as anticipating the claimed "first parameter selection" , while the "first medical system condition selection" is anticipated by comparisons of the type less-than or equal-to implicitly used to establish a drop in oxygen or a drop in CO2 level, mentioned in paragraph [0019] of D1.
2.4.2 The claimed "medical system response selection" is anticipated by the alarm, diagnostic interpretation, etc. that can be the response of the rule-based algorithm according to paragraph [0030] of D1.
2.5 However, D1 does not disclose that the "first [medical system] parameter selection" is a "first alarm selection".
2.5.1 In respect of this feature the appealed decision refers to the alarm of paragraph [0030] or to the physiologic variables 17. Neither of the approaches is convincing:
2.5.2 The alarm is disclosed in D1 as a possible response of the rule-based algorithm, not as a possible parameter.
2.5.3 As regards the physiologic variables 17, the decision indicates that they could show a development such as a drop in oxygen in a patient's blood which is equivalent to an alarm. However, as also argued in the appealed decision, this is done in D1 in the context of what would be the "medical system condition selection", i.e. the algorithm's parameters in D1 are the physiologic variables and any such development equivalent to an alarm could only be implied by the algorithm's conditions/comparisons. It follows that the plurality of physiologic variables 17 may anticipate a "first parameter selection" within the meaning of claim 1, but this first parameter selection is not a "first alarm selection".
2.6 Moreover, the last feature of claim 1 ("wherein said medical system response selection specifies switching the medical system algorithm to a second medical system algorithm ...") is not disclosed in D1 either.
2.6.1 The examining division construed said feature as encompassing the possibility of merely prompting a user to perform the switching to a second algorithm (see point 2.2.2 of the appealed decision). The Board construes the feature differently. The feature relates to the response/action provided by the generated medical system algorithm of claim 1. Switching to another algorithm is not the same response as merely prompting the user to switch to another algorithm, nor does the former encompass the latter.
2.6.2 A different interpretation is not supported by the description either. The most relevant passage seems to be the second sentence of paragraph [0060], which reads as follows:
This change [to the second rule set] could be automatic, in the case where the response specifies that the rule set be switched, or it could merely be suggested in the case where the rule set is configured to suggest to the caregiver that he or she switch rule sets.
The algorithm's response as defined in claim 1 is "switching" to a second medical system algorithm, corresponding to the first alternative in the sentence above. This sentence can thus not support that "switching" in claim 1 encompasses the second alternative of providing a suggestion.
2.6.3 The possible responses of the rule-based algorithm(s) of D1 are recited in paragraph [0030] and do not include switching to a different algorithm. Hence, the last feature of claim 1 represents a further difference in view of D1.
2.7 It follows that the last two features of claim 1 define additional distinguishing features over D1.
2.8 These two features allow the generated algorithm to switch to a different algorithm if the conditions on the first parameter selection which is a first alarm selection are met. Thereby, successive algorithms / rule sets may be linked. This may be used for example with two algorithms having a different sensitivity to externally generated alarms (see the penultimate sentence of paragraph [0060] of the patent application).
2.9 The Board agrees with the appellant that the technical effect can be seen as achieving a more efficient handling of parameters/alarms in a medical system. The objective technical problem may thus be regarded as how to provide an algorithm which improves parameter handling efficiency.
2.10 The person skilled in the art starting from D1 finds no hint in the available prior art towards the solution of claim 1.
2.10.1 D2 deals with monitoring the therapy delivered to a patient. Alarms may be issued if the monitored information does not fall within an acceptable range according to certain rules (see paragraphs [0020] and [0026] of D2). D2 acknowledges that not all alarms are equally important and addresses this issue by applying further rules to an alarm to determine whether or not the alarm should be communicated to care givers (see paragraphs [0111]-[0112]).
2.10.2 Even assuming that the person skilled in the art starting from D1 and trying to solve this problem would consider the teaching of D2, he or she would not arrive at the claimed solution. Following the teaching of D2 he/she would use the alarm which may be provided as response of a (first) rule-based algorithm (see paragraph [0030], 3rd sentence, of D1) as a parameter for a second rule-based algorithm and would also specify switching to this second rule-based algorithm as part of the response of the first rule-based algorithm. This would lead to a first rule-based algorithm which has physiologic variables as parameters and a second rule-based algorithm which has an alarm selection as parameter. Hence, even with these modifications, the "first parameter selection" would not be a "first alarm selection", so that the penultimate feature of claim 1 would not be anticipated. It follows that starting from D1 and in view of D2 the person skilled in the art would not arrive at a method anticipating the subject-matter of claim 1.
2.10.3 D3 and D4 deal with modeling languages for clinical applications without addressing the problem indicated above.
2.11 It follows that the subject-matter of claim 1 involves an inventive step.
For these reasons it is decided that:
1. The decision under appeal is set aside.
2. The case is remitted to the examining division with the order to grant a patent on the basis of the main request filed with the letter dated 12 March 2020 and a description to be adapted thereto.