Medical Devices with Defined Construction Are Not Hit by Section 3(i) of Patents Act: Delhi High Court Rebukes Patent Office for Misapplication of Law

“A Device Is Not A Method—Section 3(i) Does Not Bar Patent For An Extracorporeal Blood Purification Apparatus” - In a judgment that reasserts the distinct patentability of medical devices under Indian law, the Delhi High Court allowing the appeal filed by the U.S.-based company Aethlon Medical Inc. against the rejection of its Indian Patent Application No. 8139/DELNP/2008.

Justice Tejas Karia, presiding over C.A. (COMM.IPD-PAT) 251/2022, held that the rejection of Aethlon’s patent on the ground that it fell within the bar of Section 3(i) of the Patents Act, 1970 was fundamentally flawed. The Court clarified that "a medical device with defined constructional features, intended for extracorporeal blood purification, does not amount to a method of treatment" and therefore is not barred under Section 3(i).

The judgment directed the Controller General of Patents to reconsider the application afresh, including the auxiliary amended claims, and deliver a reasoned decision within six months, after granting the appellant a hearing.

“Refusal order failed to recognize the difference between a medical treatment and a device that enables it”—Court finds the objection under Section 3(i) misconceived

The patent application pertained to an invention titled “Extracorporeal Removal of Micro Vesicular Particles”, claiming a device-based blood filtration system involving multiple physical components such as:

• An intake conduit

• A matrix with a lectin-binding agent

• An output mechanism for reintroducing blood under physiologically acceptable conditions

The Patent Office rejected the application in 2017 on grounds that the invention was not patentable under Section 3(i), which bars patents on methods of medical treatment.

Justice Tejas Karia squarely rejected this reasoning, observing: “The invention under the Subject Application relates to a medical device for extracorporeal removal… and the components are clearly described… It is not a method of treatment but a tangible device.”

The Court held that the controller conflated therapeutic use with therapeutic method, which is legally untenable. Section 3(i) does not exclude inventions merely because they may be used in medical procedures, especially when the claimed invention is a device, not a method.

“Raising new objections at appellate stage violates natural justice”—Court slams belated objection regarding drawings

One of the striking aspects of the case was that the Patent Office, for the first time in its appellate reply, raised a fresh objection regarding the lack of supporting drawings. This had never been raised in the First Examination Report, hearing notice, or refusal order.

The Court condemned this late ambush: “It is important to note that the Impugned Order does not raise any such objection… Since this ground is raised at a belated stage of Reply to this Appeal, it cannot be allowed.”

The Court held that new grounds cannot be introduced at the appellate stage, particularly when the applicant had no prior opportunity to respond. This move was not just procedurally improper, but also violated the principles of natural justice.

“Auxiliary claims derived from European Patent do not broaden scope”—Court accepts proposed amendments under Section 59

Aethlon Medical had proactively submitted auxiliary amended claims, based on the already granted European Patent No. EP 1993600, seeking to limit the scope of claims by incorporating dependent features into the main claim.

The Patent Office argued that the amendments violated Section 59 of the Patents Act, which permits amendments only if they do not broaden the scope of the original disclosure.

Rejecting this objection, the Court noted: “Auxiliary Claims are acceptable as they do not broaden the scope of the unamended claims, and the subject matter... is disclosed in the Specification.”

The Court emphasized that the added limitation—mentioning an “additional agent capable of binding microvesicles”—was already disclosed and supported in the original patent specification.

This conclusion echoed earlier Delhi High Court decisions such as Nestlé v. Controller of Patents and Albemarle Corporation v. Controller of Patents, which endorsed courts’ power to allow amendments when they enhance clarity without expanding the claim’s subject matter.

“Patent Office must reconsider with an open mind”—Court remands the matter with specific directions

Setting aside the impugned refusal order, the Court remanded the matter back to the Patent Office, with an explicit instruction to consider the auxiliary claims, ignore the newly raised drawing objection, and to decide afresh after granting a hearing.

Justice Karia directed: “A fresh order be passed within six months… The Patent Office shall also not raise the issue regarding absence of drawings, as the same was not part of the Impugned Order.”

The Delhi High Court’s decision in Aethlon Medical v. Controller General of Patents marks an important clarification in Indian patent law regarding medical devices. The ruling separates the treatment of a disease from the device used to facilitate such treatment, affirming that tangible medical apparatus with defined components is not excluded under Section 3(i).

This judgment is a rebuke to overbroad interpretations of patent exclusions and a warning against procedural irregularities, such as introducing fresh objections at the appellate stage. It also champions the value of consistency with global patenting standards, acknowledging auxiliary amendments in line with European patent approvals.

For medical technology innovators, this ruling offers clarity, procedural fairness, and legal protection—confirming that India’s patent law does not close its doors to novel, well-defined medical devices even when used in therapeutic settings.

Date of Decision: 26.09.2025