Designed a contrast pinhole detect testing including water leak method, electrical method and improved electrical method, and concluded that the water leak method is most suitable as the arbitration method, and recommended the national standard add the requirement on electrolytic liquid filling volume of electrical test in order to improve detection accuracy.
Condoms ; Latex ; Materials Testing ; methods ; Rubber

In China, the evaluation of hemocompatibility of biomaterials is limited to hemolysis, coagulation time,and the number and morphology of platelets adhered on biomaterials. The present research, however, is aimed to establish a method for evaluating the function of sheet biomaterials in platelet activation. Platelet activation caused by glass, polyvinyl chloride or polymethylvinylsiloxane sheets was evaluated by measuring alpha-granule membrane protein (GMP-140) in platelet poor plasma, using a reasonable blood-material contact model vibrating at different speed. The result showed that the difference in platelet activation was not significantly different among the three above-mentioned materials at 140r/m or 200r/m. However, when it comes to 230r/m, significant difference was observed among these three groups, with glass > polyvinyl chloride > polymethylvinylsiloxane. But the order was reversed at 270r/m, which may be due to the different interfacial tension of different materials. Therefore, the method is suitable to evaluate platelet activation caused by sheet biomaterials, but an appropriate vibrating speed should be chosen. The interfacial tension plays an important role in the model and should be considered for results assessment.
Biocompatible Materials ; Humans ; Materials Testing ; methods ; Platelet Activation ; Surface Properties

The favorable biocompatibility of dental biomaterial is very important, which guarantees the safety and effectiveness of its clinical application. The cytotoxicity test, as one of the biological evaluation screening tests, is known to be an important and frequently used method to evaluate biocompatibility of biomaterials. This text is devoted to an overview of the cytotoxicity test for dental materials.
Biocompatible Materials ; toxicity ; Biological Assay ; methods ; trends ; Dental Materials ; toxicity ; Humans ; Materials Testing ; methods

The major idea of this article is to discuss standardization and normalization for the product standard of medical devices. Analyze the problem related to the physical performance requirements and test methods during product standard drafting process and make corresponding suggestions.
Device Approval ; Equipment and Supplies ; standards ; Materials Testing ; methods ; Weights and Measures

OBJECTIVETo investigate the impact of cuff pressure on airway leak pressure in laryngeal mask airway(LMA)Supreme and Flexible.

METHODSPatients about to have elective breast surgery were divided into Supreme group(35 cases)and Flexible group(33 cases). After general induction of anesthesia,LMA Supreme or Flexible was inserted by one anesthesiologist. We confirmed the LMA location,adjusted the cuff pressure,and recorded the peak airway leak pressures under different cuff pressures(10,20,30,40,and 50 cmH2O).

RESULTSIn Supreme group,peak airway leak pressures [(24.46±5.43),(25.11±5.51),(25.86±5.57),(26.17±5.72)cmH2O] under 20,30,40,and 50 cmH2O cuff pressure showed no significant difference(P>0.05)between each other,but significantly higher than that under 10 cmH2O cuff pressure(20.80±4.63)cmH2O(P<0.05). And in the Flexible group,peak airway leak pressures [(20.09±2.98),(20.70±3.08),(21.21±3.15)cmH2O] under 30,40,50 cmH2O cuff pressure also showed no significant difference(P>0.05)between each other,but significantly higher than those under 10 or 20 cmH2O cuff pressure [(17.52±2.39),(18.61±2.42)cmH2O]. Mean peak airway leak pressure [(25.40±5.52) cmH2O] of LMA Supreme was significantly higher than that of LMA Flexible(20.67±3.06)cmH2O(P<0.05).

CONCLUSIONSMean airway leak pressure of LMA Supreme is higher than LMA Flexible. The lowest cuff pressure to meet the tightness requirement with LMA Supreme is 20 cmH2O,which is lower than Flexible(30 cmH2O).

This paper is based on the research and analysis of the existing related measuring methods, and aimed at the characteristics of equivalent artificial soft materials, and it also proposes a new adaptable test method to measure elastic modules. The modules are based on capacitive gate transducer and micrometer which suits for soft materials. Based on this proposed method, a micro feed mechanism has been designed. The same strain of soft materials under compress test was realized, and the feasibility of this method by analyzing the test results was testified.
Biocompatible Materials ; Biomechanical Phenomena ; Biomedical Engineering ; methods ; Computer Simulation ; Elastic Modulus ; Hardness ; Materials Testing ; methods

It is difficult to test the elastic modulus of the soft bio-anthropomorphic materials by using the general stretch-strain test method. With the equipment for a hardness testing system of bio-anthropomorphic materials and millesimal gauge, we introduce in this paper a compress-strain test method and carry out the related test-data curve-fitness. The test results indicate that this kind of method can be adopted in testing the elastic modulus of the soft bio-anthropomorphic materials and help to compare and distinguish the biomechanics equivalent between the tissues.
Biocompatible Materials ; Biomedical Engineering ; methods ; Computer Simulation ; Elastic Modulus ; Elasticity ; Hardness ; Humans ; Materials Testing ; methods

This assay was aimed to evaluate the influence of different contact ways and extracting conditions on the hemolytic effect of biomaterials. Using direct contact method and extract contact method, we assessed the hemolytic effect of PDLLA and PVC. The extracting conditions included: 37 degrees C 24 h, 37 degrees C 72 h, 37 degrees C 120 h, 50 degrees C 72 h, and 70 degrees C 24 h. After the material or extract had been in contact with the diluted blood of rabbit for certain times, the hemolysis rate was calculated. The results for PDLLA showed there were some differences between direct contact and extract contact at 37 degrees C for different extraction time (P < 0.05), but the hemolysis rates, lower than 5%, were in accord with the requirements of medical devices. However, under the condition of 50 degrees C and 70 degrees C, there were significant differences when extract contact method was compared with direct method (P < 0.01). For PVC, there was no statistically significant difference under all conditions (P > 0.05). Our conclusions: (1) Under the extracting condition of 37 degrees C from 24 h to 120 h, the soluble part of PDLLA and PVC that might influence erythrocyte did not dissolve considerably. (2) Under the extracting condition of 50 degrees C and 70 degrees C, the hemolysis rate may remarkably vary with the chemical characteristics of tested materials; (3) As to an unknown material, it is advisable to adopt two methods at the same time, one for direct contact and the other for extracontact. Thus the hemolytic effect of biomaterials can be evaluated from physical and chemical angles. (4) In case that the chemical property of the sample can endure the test, the extracting condition at 50 degrees C and 70 degrees C may be of benefit to assessing the hemolytic effect of biomaterials. (5) The extract contact method as a supplemental test of direct contact method is of realistic significance.
Animals ; Biocompatible Materials ; toxicity ; Hydrolysis ; drug effects ; In Vitro Techniques ; Materials Testing ; methods ; Rabbits ; Temperature ; Time Factors

The corrosion rates of TiNi, CoCrNiW and CoCrNiMo were measured in Tyrode's solution with potentiodynamic linear polarization, fore-point weak polarization, Cao Chunan weak polarization, transient linear polarization and atomic absorption spectroscopy. Results indicated that corrosion rates of these three alloys were very low due to their excellent corrosion resistance and the corrosion resistance of CoCrNiMo was the best. Corrosion rates of TiNi, CoCrNiW and CoCrNiMo were 0.691, 0.0595, 0.0490 micron/a and 0.0528, 0.0383, 0.0387 micron/a, respectively. The results measured by the first three methods were about ten times of those by the latter two methods, this was related to the applicability of each method and the alloy surface state. Transient linear polarization technique can determine low corrosion rate conveniently and quickly. Atomic absorption spectroscopy method, determining directly the concentration of ion in solution, and thus provide reference for material biocompatibility. And these two methods are properly used in measuring corrosion rates for biomedical materials.
Biocompatible Materials ; chemistry ; Cobalt ; chemistry ; Corrosion ; Materials Testing ; methods ; Nickel ; chemistry ; Spectrophotometry, Atomic ; Titanium ; chemistry

OBJECTIVETo evaluate the performance of a new highly efficient and environment-friendly tissue cell fixatives for preserving the morphologies and properties of pleural and peritoneal effusions.

METHODSFifty-six specimens of tissue cells from pleural and peritoneal effusions were preserved using the new preservative or 95% ethanol. HE staining and Western blotting were employed to detect the morphologies and protein expression levels of CK, CEA and P53 of the cells after fixation.

RESULTSThe new preservative well preserved the morphologies of the cells from the pleural and peritoneal effusions, and the nuclei and cytoplasm were intact with little debris. The conventional preservative (95% ethanol) caused noticeable structural damage of the tissue cells, especially the cytoplasm where obvious debris were seen after fixation. CK, CEA and P53 protein expression levels in the cells were 91%, 86% and 88% after fixation with the new preservative, significantly higher than those (46%, 38% and 31%, respectively) in cells fixed with 95% ethanol (P<0.05).

CONCLUSIONThe new preservative is efficient and environment-friendly for preserving the morphologies as well as the proteins of tissue cells from pleural and peritoneal effusions well, demonstrating its potential in tissue cell fixation and preservation.