TX Q&A

The product specifications should clearly define the maximum load (if it has a supporting function), the method of connection with the system (if applicable), and the equivalent attenuation. Performance indicators should be established based on the specific circumstances of the accessory, such as requirements for maximum load, equivalent attenuation, etc.

The structural design description of personalized abutment products should include the interface and the restorative part. The type and dimensions of the interface should be fixed values, while the restorative part can be within a personalized machining range. The interface section should clearly define the type of interface, interface dimensions (such as anti-rotational opposite side height/width, taper, screw channel diameter, compatible central screw size, etc.), compatible implants, and specific structural design features compatible with these implants (such as connection fixation method, anti-rotational structure, internal connection taper design, screw channel structure, specific structure of the compatible central screw, etc.). The restorative section should specify the transgingival height, restorative height, abutment angle, abutment diameter, shoulder design, and the thinnest cutting thickness.

The applicant should specifically analyze whether the changes to the delivery system affect the product's performance and clinical safety. It is also crucial to focus on whether preclinical study data are sufficient to support that the differences do not impact the product's safety and effectiveness. If the analysis and evaluation are acceptable, and if non-clinical data and clinical data from similar products with the same improvements abroad can support this, the applicant may choose the same product type pathway for clinical evaluation.

Firstly, according to the "Guidance on the Division of Medical Device Registration Units," for the substances being tested in the multiplex test, they must have synergistic diagnostic significance for specific indications; otherwise, multiplex testing is not recommended. Secondly, confirm the consistency of the product with those listed in the non-clinical trial exemption catalog. The targets being tested should match those specified in the non-clinical trial exemption catalog and the product description, and the combination testing should not expand the product's intended use scope. Under these conditions, the multiplex test product may be exempt from clinical trials.

Passive accessories for imaging equipment like CT and MRI, such as supports, pads, cradles, straps, frames, and boards, which are used to fix and support the patient's position during imaging, can be declared together with the imaging equipment.

Ceramic materials for dental restorations require consideration of chemical properties, basic properties, physical and mechanical properties, sintering-related properties, and machining performance studies. Chemical properties include chemical composition and percentage content, type, radioactivity, and chemical solubility. Basic properties cover appearance, uniformity, dimensions, and density. Physical and mechanical properties include glass transition temperature, coefficient of thermal expansion, flexural strength, Weibull modulus, hardness, and fracture toughness. Sintering-related properties involve pre- and post-sintering density and shrinkage. Machining performance includes edge stability and edge precision.

Performance studies for citric acid disinfectant solutions used for heat disinfection of internal pipelines in hemodialysis machines should at least include: appearance, pH value, fill volume, main active ingredients (e.g., citric acid content), shelf life, metal corrosivity, and microbial kill indicators. If the main active ingredients contain special substances or functions not found in other similar marketed products, the corresponding substance composition, content, and usage performance should be specified.

The rated burst pressure indicator for balloon dilatation catheters should be established in the product technical requirements according to the standards outlined in YY 0285.4-2017 "Intravascular Catheters - Sterile and Single-Use Catheters - Part 4: Balloon Dilatation Catheters." The requirement states that "the pressure at which the balloon bursts should not be less than the nominal rated burst pressure." Since the mode of balloon failure affects the safety of the product, performance study data must also investigate both the rated burst pressure and the failure mode. It is essential to observe and assess the balloon's failure mode, which should ideally be an axial failure mode. If other failure modes occur, a thorough evaluation of their impact on product safety should be conducted. This approach ensures that the balloon dilatation catheters operate safely under the expected conditions of use and that any potential failure modes are well understood and mitigated.

Applicants should conduct research on the declared product, taking into consideration factors such as key dimensions and structural design that may affect product performance, and it is necessary to select samples representing the worst-case scenario for performance studies. For different performance studies, the model specifications chosen for the worst-case scenario might vary. It is recommended to consider the selection of the worst-case scenario for the declared product in conjunction with the performance test methods. Even if the declared product and the already marketed product have the same scope of application, indications, and intended use (for example, if there is a previous generation product and the declared product only differs in product structure composition), the principles mentioned should still be applied even after proving equivalence through equivalence testing. This approach ensures that the product's performance under the most challenging conditions is understood and meets the necessary safety and efficacy standards.

The "Guidelines for the Review of Medical Device Software Registration (2022 Revised Edition)" specifies that measurement functions (also known as quantification or quantitative functions) can be divided into graphical measurement functions and objective physical measurement functions. The former indirectly reflects the measurement results of objective entities based on graphics, while the latter directly reflects the measurement results of objective entities. Regardless of the type of measurement function, factors such as measurement error and uncertainty must be considered, and measurement accuracy indicators such as linearity, precision, repeatability, reproducibility, range limits, and display error must be clearly defined. Applicants for registration must provide research data on measurement accuracy and inform users about it in the instructions for use. Additionally, objective physical measurements must specify accuracy indicators in the product technical requirements, and graphical measurements must provide warnings about measurement accuracy in the instructions for use. These details are crucial to ensure that the software functions correctly and reliably, and that users are fully informed about the potential limitations and accuracy of the measurements provided by the software.