How to Determine the Test Conditions for β2-Microglobulin Clearance Rate in High-Flux Hemodialysis Product Clearance Rate Testing
Clearance rate is a primary functional parameter of dialyzers and a key indicator for evaluating the quality of dialyzers. Commonly used indicators for evaluating the clearance performance of dialyzers include urea, creatinine, phosphate, and vitamin B12. For high-flux dialyzers, performance testing and clinical evaluation data for β2-microglobulin clearance should also be provided. According to the mandatory industry standard YY 0053 "Blood Dialysis and Related Treatments: Blood Dialyzers, Blood Dialysis Filters, Blood Filters, and Blood Concentrators," high-flux hemodialysis should evaluate the β2-microglobulin clearance rate at clinically common blood flow rates, and a single blood flow rate can be selected for this assessment.
How to Consider Heat Treatment Processes for Metal Materials Used in Additive Manufacturing for Dental Restoration
For metal materials used in additive manufacturing processes such as laser selective melting, it is crucial to first clarify the methods and parameters of heat treatment. The suitability of these heat treatment methods should be assessed and verified. This includes establishing the basis for determining heat treatment parameters, such as heating time, holding time, and holding temperature. Additionally, criteria for the acceptability of the results after heat treatment should be clearly defined.
How to select the worst-case scenario samples for the mechanical performance of intervertebral fusion devices
When selecting the worst-case scenario samples for the mechanical performance of intervertebral fusion devices, consider the impact of various factors such as the size of the bone grafting area, side hole dimensions, angle, length, width, and height of different models and specifications of the fusion devices. Additionally, the model and specifications of the worst-case scenario samples may vary depending on the mechanical performance indicators, such as compression, compressive shear, and torsion. Considerations should be made in conjunction with the methods and loading modes of dynamic and static mechanical performance tests for cervical and thoracolumbar intervertebral fusion devices, to comprehensively determine the selection of the worst-case scenario samples.
Can products made from materials compliant with YY 0341.1 Appendix B be exempt from biological evaluation?
Biological evaluation cannot be exempted outright. However, equivalence comparisons can be used to demonstrate that the product under application has the same biocompatibility as an already marketed product, thereby potentially reducing or exempting the need for biological testing of the application product. Even though materials compliant with YY 0341.1 Appendix B are clinically proven to be acceptable, equivalence comparisons are still necessary. For instance, it should be demonstrated whether the manufacturing process introduces new biological risks. This includes comparing both products' manufacturing processes, such as processing, sterilization, and packaging, as production processes can introduce new harmful substances, such as residues from sterilants, processing aids, or release agents. If the evaluation determines that the manufacturing process does not introduce new biological risks, then biological testing may be exempted.
How to Consider the Compatibility of Metal Powders for Dental Restoration with Additive Manufacturing Parameters
When considering the compatibility of metal powders with printing parameters, it is essential to take into account the powder production process and the key process parameters of the printing equipment. Taking laser selective melting as an example, it is necessary to submit the key process principles and the basis for selection, such as electrode induction melting gas atomization, plasma inert gas atomization, vacuum induction melting gas atomization, and plasma rotating electrode atomization. Verification data for key process parameters should also be submitted, including gas pressure, flow rate, temperature, inner diameter and spray angle of the atomization nozzle, pressure and oxygen content in the atomization tower, current, and rotation speed of the rotating electrode atomization process. Compatibility with the key process parameters of the printing equipment should consider factors such as laser power, spot diameter, scanning speed, scanning distance, powder layer thickness, printing direction, atmospheric protection, support structures, and the temperature of the forming chamber.
Can the grade of the main raw materials of orthopedic products be changed through a modification registration application?
Yes, applicants can change the grade of the main raw materials of approved products through the modification registration procedure, provided that the product's performance indicators are not reduced after verification and confirmation. Additionally, it is encouraged to record the primary documents of implant materials such as polyetheretherketone (PEEK), alumina-zirconia composite ceramics, and highly cross-linked ultra-high molecular weight polyethylene to avoid redundant verification.
When do intravascular catheters need to provide flow study data?
(1) If the product documentation, labels, or other materials of the intravascular catheter mention a nominal flow rate, relevant flow study data must be provided. (2) For catheters used for infusing medication into the body, such as central venous catheters, it is necessary to specify the flow rate/speed, and requirements for flow rate/speed should be set in the technical specifications. (3) Flow testing methods can refer to YY0285.1 "Intravascular catheters - Sterile and single-use catheters - Part 1: General requirements." If the declared product's infusion pressure exceeds 10 kPa, the applicant may establish an applicable test method.
What special precautions are needed for contact lens care products claimed to be suitable for silicone hydrogel contact lenses?
Given the unique physicochemical properties of silicone hydrogel contact lenses compared to regular hydrogel lenses, the following special precautions are necessary: 1. Compatibility Testing: According to YY 0719.5 "Ophthalmic optics - Contact lens care products - Part 5: Determination of physical compatibility with contact lenses," it is required to conduct separate compatibility tests for the care products with silicone hydrogel contact lenses. 2. Representative Lens Selection: In the compatibility testing, select representative, commercially available silicone hydrogel contact lenses for the study and provide verification data. 3. Technical Requirements: The technical specifications of the product must clearly indicate that silicone hydrogel contact lenses have been tested. Submit either a self-inspection report or an inspection report issued by a qualified medical device inspection agency as supporting documentation.
When using biological test data from already marketed similar devices for biological evaluation, what factors might affect the biocompatibility risk?
(1) The main factors affecting biocompatibility risk include: the chemical composition of the product's materials (including the proportions of each component material), the physical structure of the product, surface characteristics, manufacturing processes, sterilization methods, raw material suppliers, and technical specifications, and for liquid products or products preserved in a wet state, the internal packaging materials must also be considered. (2) If there are inconsistencies between the test item and the declared product regarding the factors listed above that may affect biocompatibility risk, sufficient rationale and evidence must be provided to support the applicability of the submitted test report to the declared product. When necessary, additional biological evaluation data should be supplemented, such as leachable analysis and toxicological risk assessment data, and supplementary tests for related biological test items.
When setting performance indicators for tensile strength and elongation at break for hernia repair patches, what aspects should be considered?
(1) If the material design, weaving process, or other factors cause the patch's tensile strength to be anisotropic, separate standards for longitudinal and transverse tensile strength should be established. (2) It is recommended to establish the elongation at break under the maximum abdominal wall tension that may be encountered under physiological conditions in the human body. The acceptance criteria for elongation at break should be formulated based on the natural elongation rate of the human abdominal wall and the actual measured data of the patch.