One Case a Day | China: The Contribution of Use Features in Product Claims to Novelty and Inventiveness – Supreme People's Court Intellectual Property Final No. 475 (2023) Medical Device Case

Case Introduction
Wishing everyone an early happy weekend.

Whether use features in product claims can contribute to novelty and inventiveness mainly depends on whether these features have a substantial impact on the product itself. The unique aspect of today’s case is that it involves the technical field of medical devices, and whether such solutions can be protected by referencing medical use claims is addressed in this case. The case points out: discovering the mechanism by which a drug is suitable for different diseases in the human body, thereby uncovering new uses of the drug, is not comparable to a medical device acting on the human body through different physical means to be suitable for different indications. Therefore, the use of medical devices generally cannot be protected by referencing medical use claims.

Case Information

• Application Number: 201310471114.X
• Invention Title: Device for Removing Combined Thrombus Mass
• Invalidation Decision Information: No. 55824
• First-Instance Information: (2022) Jing 73 Xing Chu No. 13741
• Second-Instance Information: (2023) Supreme People's Court Intellectual Property Final No. 475
• Judgment Date: July 25, 2024

Controversial Focus
Claim 1 of the involved patent protects a self-expanding device for removing thrombus in blood vessels (Feature A). The self-expanding device includes:

A mesh structure comprising a first set of multiple meshes (23), the mesh structure having a proximal end and a distal end, wherein the distal end of the mesh structure is configured to be implanted in at least a portion of the thrombus, thereby forming a combined thrombus-device mass that can be removed from the patient's occlusion site (Feature B);

A tapered portion comprising a second set of multiple meshes (24), the tapered portion arranged toward the proximal end of the mesh structure; and

A connection point (9), where the tapered portion converges, located at the proximal end of the tapered portion,

wherein the self-expanding device is preformed to assume an expanded volume form, and in the expanded volume form, the self-expanding device takes the shape of a longitudinally open tube tapering toward the connection point (9).

Evidence 1.1 discloses a medical implant that expands and contracts in volume through shape memory alloy properties, i.e., a self-expanding device. The functional structure A with multiple mesh units (3) in Evidence 1.1 corresponds to the mesh structure comprising the first set of multiple meshes in this patent. This functional structure A has a proximal end and a distal end. The tapered proximal structure B in Evidence 1.1, comprising wider mesh units (4), corresponds to the tapered portion comprising the second set of multiple meshes in this patent. This tapered proximal structure is arranged toward the proximal end of the functional structure A (i.e., the mesh structure). The connection point (5) in Evidence 1.1 and Figure 1 disclose the connection point of this patent, where the tapered portion converges at the connection point, which is located at the proximal end of the tapered portion. The longitudinally open tube disclosed in Evidence 1.1 and the memory alloy's ability to expand and contract in volume disclose the technical feature of this patent: "the self-expanding device is preformed to assume an expanded volume form, and in the expanded volume form, the self-expanding device takes the shape of a longitudinally open tube tapering toward the connection point."

All parties acknowledge that Evidence 1.1 does not explicitly disclose the two use technical features, i.e., Feature A and Feature B.

The controversial focus of this case is: Do the above differences contribute to the novelty and inventiveness of the technical solution of Claim 1?

Views of the Parties
The patentee argued that due to the different inventive purposes and uses of the self-expanding device in this patent compared to the implant in Evidence 1.1, there are implied differences in the structure of the mesh structure, connection point, tensile strength, connection mechanism, shape during operation, physical properties, etc. The patentee also argued that this patent discovered a new use based on Evidence 1.1, and the use of medical devices should be protected by referencing medical use claims.

The first-instance court held: Feature A, "for removing thrombus in blood vessels," is a use feature limiting the subject name "self-expanding device." However, a person skilled in the art does not know what differences exist between this patent and Evidence 1.1 in terms of product structure, materials, etc. The use for removing thrombus in blood vessels is determined by the inherent properties of the self-expanding device product itself, which has the same structure as Evidence 1.1. This use feature does not imply that the product of this patent has undergone structural changes compared to Evidence 1.1. The differences in mesh structure, connection point structure, tensile strength, etc., claimed by the patentee are not recorded in the specification of this patent, and a person skilled in the art cannot directly and unambiguously determine that this patent and Evidence 1.1 have the differences claimed by the patentee in the above aspects. Therefore, the above use features do not imply that the product of this patent has undergone structural changes compared to Evidence 1.1, i.e., they do not bring substantial impact on the self-expanding device itself. These use features do not play a limiting role; they are merely descriptions of the use or method of use of the self-expanding device product and should not be considered when judging novelty and inventiveness.

Feature B, "the distal end of the mesh structure is configured to be implanted in at least a portion of the thrombus, thereby forming a combined thrombus-device mass that can be removed from the patient's occlusion site," is a limitation on the function or effect of the distal end of the mesh structure. That is, the difference between Claim 1 of this patent and Evidence 1.1 is merely a difference in functional limitation. Article 3.2.1 of Chapter 2, Part II of the "Patent Examination Guidelines" stipulates that functional technical features in claims should be understood as covering all implementation methods capable of achieving the stated function. The specification of this patent records that the method of this patent can use any suitable self-expanding device, such as the self-expanding device in Evidence 1.1. In other words, the self-expanding device in Evidence 1.1 can objectively achieve the function of Feature B, solve the same technical problem of removing thrombus in blood vessels, and achieve the same technical effect. This is an inherent property function of the product in Evidence 1.1. The scope of protection of the technical solution of Claim 1 of this patent already completely covers the self-expanding device in Evidence 1.1. Based on the disclosed content of this patent, it is also difficult for a person skilled in the art to directly and unambiguously conclude that the technical solution of Claim 1 of this patent includes other structures that perform the same function compared to Evidence 1.1.

Second-Instance Court
Regarding the impact of Feature A on novelty determination:

For product claims containing use limitations in the subject name, the use limitation should be considered when determining the scope of protection of the product claim. However, its actual limiting effect depends on what impact it has on the product itself being protected. If the use limitation does not affect the product or device itself being protected but is merely a description of the use or method of use of the product or device, it generally cannot play a substantive role in determining whether the product or device possesses novelty.

In this case, Claim 1 is a product claim, and Feature A is its subject name "a self-expanding device for removing thrombus in blood vessels," which includes a use limitation. Therefore, when judging novelty and inventiveness, the impact of this use limitation on the product itself being protected should be considered. The patentee argued in the first instance that this use limitation implied structural differences, including differences in mesh structure, connection point structure, tensile strength, connection mechanism, shape during operation, physical property requirements, etc. In the second instance, the patentee mainly emphasized that Evidence 1.1, as a medical implant, should have a detachable connection point where the tapered portion converges, whereas this patent, as a device for removing thrombus, has an undetachable connection point. However, the above structures are not necessarily structural differences between a device for removing thrombus and a device as a medical implant. For example, whether the connection point of this patent is detachable does not necessarily correspond to its function of removing thrombus; constructing the connection point as detachable does not necessarily affect its effective performance in removing thrombus. The specification of this patent also explicitly states that Evidence 1.1 can be "incorporated herein by reference in its entirety," indicating that the structure of Evidence 1.1 can be fully used in this patent. Therefore, the patentee's claim that Feature A implies structural limitations and thus constitutes a difference from Evidence 1.1 lacks sufficient basis.

Furthermore, based on the analysis of novelty determination methods, when a person skilled in the art can determine that substantially the same technical solution is applicable to the same technical field, solves the same technical problem, and has the same expected effect, it cannot be concluded that it does not constitute the same invention or utility model merely because it is written for a different use. In this case: First, the use limitation in Feature A is a limitation on therapeutic use. According to Article 25(1)(3) of the Patent Law, methods for the diagnosis and treatment of diseases cannot be granted patent rights. When the only difference between a medical device product claim and the prior art is the therapeutic use, granting a patent right for this reason would similarly raise ethical issues such as restricting doctors' freedom. Therefore, limitations on therapeutic use should not be considered as features that have a substantive impact on the determination of novelty and inventiveness of product claims. The patentee argued that the use of medical devices should be protected by referencing medical use claims, but medical devices and drugs are different and cannot be simply compared. Discovering the mechanism by which a drug is suitable for different diseases in the human body, thereby uncovering new uses of the drug, is not comparable to a medical device acting on the human body through different physical means to be suitable for different indications. Therefore, the use of medical devices generally cannot be protected by referencing medical use claims. Second, Evidence 1.1 has already disclosed all the structural features of Claim 1 of this patent. A person skilled in the art, with general knowledge, can determine that the technical solutions of Evidence 1.1 and this patent are applicable to the same technical field, solve the same technical problem, and have the same expected effect. Other cited documents referenced in the challenged decision's discussion of inventiveness can also corroborate this.

Regarding the impact of Feature B on novelty determination:

For product claims containing use features, it should be considered whether the use feature implies that the product being protected has a specific structure and/or composition. If the use is determined by the inherent properties of the product itself, and the use feature does not imply changes in the structure and/or composition of the product, then the product claim limited by the use feature generally lacks novelty compared to the product in the prior art document. The above criteria also apply to the comparison judgment of whether such technical features are the same in inventiveness determination.

In this case, Feature B in Claim 1 does not imply changes in product structure. Based on reasons similar to Feature A, Feature B also cannot affect the novelty determination of this patent.

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