Drugdu.com expert's response:

Under the framework of the EU MDR (Medical Device Regulation), proving the equivalence of medical devices requires constructing an argumentation system from three major dimensions: technical characteristics, biological characteristics, and clinical characteristics, to ensure that there are no significant differences in safety, performance, and clinical effectiveness between the declared device and the already-marketed device. Here are the specific requirements and analyses:

I. Technical Characteristics: Ensuring Consistency in Functional Principles and Usage Conditions

Similarity in Usage Conditions

The declared device and the already-marketed device must be used under similar conditions, meaning there are no significant clinical differences in safety and clinical performance. For example, blood glucose meters should maintain consistent measurement accuracy and stability in different medical institutions (such as tertiary hospitals and community clinics) or when used by different patient groups (such as elderly and young diabetic patients).
Regulatory Basis: The MDR requires compliance with the MEDDEV 2.7.1 Rev4 guideline, which clarifies the standards for similarity in usage conditions regarding technical characteristics.
Software Algorithm Equivalence
If the device includes software (such as algorithms that drive or affect the device's use, or independent medical software), it is necessary to prove that its functional principles, clinical performance, and intended purpose are similar to those of the already-marketed device. For example, a smart cardiac monitoring device can meet equivalence requirements if it is based on the same heart rate monitoring algorithm, even if the hardware configurations differ.
Exception: Software used solely for device configuration for non-medical purposes (such as device configuration tools) does not require proof of equivalence, but it must be ensured that it does not negatively impact safety or performance.

II. Biological Characteristics: Dual Verification of Material Safety and Release Characteristics

Material and Substance Consistency

The declared device must use the same materials or substances as the already-marketed device, and the type of tissue or body fluid in contact, the mode of contact, and the duration of contact should be similar. For example, the material composition of surgical sutures or cardiac stents must be identical.

Substance Release Characteristics: Similar degradation products and leachable characteristics are required. Even if the raw materials are the same, differences in processing, design, or usage environment may lead to variations in release characteristics, which need to be verified through testing.

Biological Safety Assessment Standards

Biological evaluation should be conducted using the ISO 10993 series of standards, covering long-term risk assessment tests such as cytotoxicity, post-implantation local reactions, and genotoxicity. For example, implantable devices must pass post-implantation local reaction tests to ensure material biocompatibility.

Special Requirements: For devices composed of substances intended to be introduced into the human body (such as absorbable sutures), the substances must be identical and comply with the provisions of Annex I of Directive 2001/83/EC.

III. Clinical Characteristics: Precise Matching of User Capabilities and Clinical Conditions

Consistency in User Types

The declared device and the already-marketed device must target the same types of users, including healthcare professionals or non-professionals (such as patients for self-use). The impact of user capabilities or knowledge on safety and clinical performance needs to be assessed. For example, home medical devices should consider the ease of use for non-professional users.
Equivalence in Clinical Conditions and Purpose

They must meet the criteria of "the same medical conditions, gender, and usage duration," including similarity in disease severity, stage, site of use, and population characteristics (such as age, anatomy, and physiology). For example, devices for treating urinary system diseases should be designed according to anatomical differences between men and women and verify consistent clinical effectiveness.

Similarity in Key Performance: It is necessary to prove that there are no significant differences between the declared device and the already-marketed device in terms of expected clinical effectiveness and related key performance indicators (such as treatment success rate and complication rate).

Additional Requirements for Special Scenarios

Medicinal Product-Containing Medical Devices (Class III)

If the declared device contains an auxiliary drug, a contract must be signed with the manufacturer of the already-marketed device to ensure continuous and comprehensive access to technical documentation for verifying drug release characteristics and safety.

Equivalence of Combined Medical Devices

The declared device cannot claim equivalence by combining features from different devices; it must be fully consistent with each equivalent device in terms of technical, biological, and clinical characteristics.

Core Logic of Equivalence Proof

No Significant Clinical Differences: All arguments must revolve around "no significant differences in safety and performance between the declared device and the already-marketed device." Any differences must be justified with scientific data (such as preclinical trials or literature data).
Completeness of Documentation: Technical specifications, design drawings, biological assessment reports, clinical data, and other documents must be provided to form a complete evidence chain to support the equivalence declaration.

Summary

The EU MDR ensures the scientific validity and compliance of medical device equivalence through rigorous argumentation on technical, biological, and clinical characteristics. Manufacturers need to systematically identify differences between their products and already-marketed devices based on specific product characteristics and prove no significant clinical differences through standardized testing and data analysis, thereby meeting MDR compliance requirements and successfully entering the EU market.