TX Q&A

Applicants should define the performance indicators related to the cooling spray function based on its mode of use, functional design, and whether it can be switched on or off. These indicators might include duration, interval time, and cooling effect. Applicants must also provide the basis for determining these indicators and the testing methods. During performance and safety testing, the cooling spray function should be considered and tested in conjunction with the cooling spray. For electromagnetic compatibility testing, the impact of activating the cooling spray function on the product should be considered, and testing should be conducted under the most adverse conditions.

After validation and confirmation that there is no reduction in the performance indicators of the product, applicants can apply for a change in the main material grade of approved products through the change registration procedure. Additionally, it is encouraged to file the main documents for implant materials such as polyetheretherketone (PEEK), alumina-zirconia composite ceramics, and highly cross-linked ultra-high molecular weight polyethylene to avoid redundant verification.

Vehicles are not managed as medical devices and are not considered part of the structural composition of imaging products used in vehicular environments.

Enzyme-linked immunosorbent assay methods are divided into "one-step" and "two-step" based on the reaction mode. The "one-step" method involves adding the test sample and enzyme-labeled antibody to the reaction well simultaneously, whereas the "two-step" method involves adding the sample first and then the enzyme-labeled antibody after the initial reaction is complete. The experimental steps of these two methods differ; the former shortens the reaction time but may reduce product performance. Therefore, it is not recommended to change the registered method from "two-step" to "one-step".

In principle, when considering clinical trials, it is necessary to take into account the working principles of the product, its scope of application, differences between models and specifications, and non-clinical research data. Additionally, factors such as the objectives of the clinical trial and the main evaluation indicators should be considered. After a comprehensive assessment, it should be confirmed whether the product tested in the clinical trial is representative and can cover all models and specifications of the product being registered.

In principle, products used in vehicle environments (when the vehicle is stationary) and products used in hospitals can be classified into the same registration unit. If there are other differences between the products besides the usage environment, they should be classified according to the principles of registration unit division.

Personalized abutment products are categorized under 17-08-02 abutments and accessories in the "Medical Device Classification Catalogue" (2017 edition). The compatibility performance studies for these products generally need to be conducted in conjunction with the implant systems they are used with. For different series, separate compatibility performance tests should be carried out. These tests should consider factors such as product taper fit, fitting gap, thread deviation, torsional resistance, and tightening torque, in accordance with the YY0315 standard.

Measurement repeatability and measurement accuracy reflect different meanings. Measurement accuracy refers to the consistency of the measurement values with the true values; measurement repeatability refers to the consistency among measurement values obtained at different times, considering systematic errors. If the test method for measurement accuracy already takes into account systematic errors over different periods, it is not necessary to consider repeatability separately.

According to the "Guidelines for Technical Review of Clinical Evaluation of Ultrasonic Soft Tissue Cutting and Hemostasis Systems," given the relatively high clinical use risks and technical challenges associated with devices capable of sealing up to 7mm vessels, it is recommended to further demonstrate their safety and effectiveness through clinical data of the product itself, in addition to in vitro burst testing and animal trials. Clinical trials conducted domestically should comply with the "Quality Management Regulations for Medical Device Clinical Trials."

The selection of sample concentrations should be a key consideration, including at least negative, weakly positive, and moderate/strongly positive samples, to investigate the stability of samples at different concentrations and their impact on detection.