Attachment 8-2. Dispersion and Shelf Life Test Report_V1_121125

Electrode Pad Dispersion Test and Shelf Life TestElectrode Pad Performance Test Report(For Dispersion Test and Shelf Life Test)1. Test PurposeThis testing is prepared to study the current dispersion of electrode pad during its shelf-life for medical device GYMFORM ABS-A-ROUND Fitness Belt.2. Reference Standard & GuidanceASTM F 1980-07, Standard Guide for Accelerated Aging of Sterile Barrier Systems for Medical DevicesFDA related comment for Shelf Life and Performance Test of electrode as below:- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 3. Quality Assurance Statement This testing meets the technical requirement of the applied standard. The testing lab is “Medical Device Performance Testing Laboratory” and meets with the requirements of the “Good Laboratory Practice Regulations”.4. Sample RequirementsWe have claimed that our subject device would only include one kind electrode pad in the package. The overview and size of electrode is as below: Figure 1. Big Electrode Pad1. 图中增加Unit:mm2. 原真实图片的比例不合适 Figure 2. Small Electrode PadThe testing will conduct on several new and old electrode pads as below:New electrode pad: 6 pieces (Big Electrode: Sample #1-3) (Small Electrode: Sample #4-6)Old electrode pad: 6 pieces (Big Electrode: Sample #7-9) (Small Electrode: Sample #10-12), which have been stored at temperature 40 C, relative humidity 95% for 24 months客户要求2年 by manufacturer.Conductive pad material: nonwoven fabric, the Ag electrode core and the pressure-sensitive conductive adhesive, conductive carbon black.5. Test Apparatus(1) CabinetThe cabinet should be such size that samples may be individually exposed to circulating air at the temperature and relative humidity chosen.The cabinet includes the control apparatus, which is capable of maintaining the room at the required atmospheric conditions within the tolerance limits.(2) HygrometerThe hygrometer used to indicate the relative humidity should be accurate to 62 % relative humidity. A psychrometer is used either for direct measurement of relative humidity or for checking the hygrometer.(3) ThermometerThe thermometer is used to accurately indicate the temperature to within 0.1C or 0.2F.(4) Power SourceThe power source should include at least 50Vdc, 10A for output.(5) Adjustment ResistanceMaximum 500 Ohm(6) Multimeter6. Test Protocol(1) Conduct the “Current Dispersion Test” (refer to Item 7 for test detail) on 6 pieces new electrode pads (3 big electrode pads, and 3 small electrode pads). Analyze the current dispersion through impedances on several places of the active areas of the electrode.(2) Conduct the “Accelerated Aging Test” (refer to Item 8 for test detail) on these 3 pieces new electrode pads (3 small electrode pads).(3) Conduct the “Current Dispersion Test” (refer to Item 7 for test detail) against on “Item 2” - 3 pieces new electrode pads after “Accelerated Aging Test”, and another 3 pieces old electrode pads (3 small electrode pads) after maximum life time in the highest storage temperature (normal storage, not accelerated aging).(4) Compare the impedance difference on above specified places of the active areas of the electrode. Analyze if the impedance is still complied with the acceptable criteria after its shelf life (Accelerated Aging method, and Non- Accelerated Aging method).7. Current Dispersion TestFigure 2. Test Circuit PrincipleFigure 3. Test Circuit ConnectionThis test involves the testing of impedances on several places of the active areas of the electrode to be sure it is distributing current uniformly. The testing steps are as below:(1) Connect the testing circuit as Figure 2 and 3. R1 is electrode impedance between two connections. One connecting point is metal nail, the other one is any number point listed in below Figure 4. We select 9 points to test. And “point 1”之前没有更新 is under the metal nail (“point 0”).Rx is adjustment resistance. Its maximum range is 500 Ohm.V1, V2 are both multimeters.The 10V DC power source should include range at least 50Vdc, 10A for output.Figure 4. Test Point1. 原真实图片的比例不合适2. 实物在截图时为什么不处于中间的位置。(2) First, adjust the Rx = 0 Ohm, and make the output of DC power source to be 10V constant on electrode R1. Confirm the voltage V1 by multimeter.(3) Then, increase the Rx until the V1 = V2 = 5V. After that, cut off the Rx with circuit connection, and test the resistance of Rx.(4) Test all the resistances of 9 points on the electrode repeat above step (2) (3).(5) Test all the samples repeat above step (1) (4).8. Shelf Life Test之前作为备注的内容，客户已经做出回答。修改后，应该删掉。(1) Select the Q10 value.Q10 = an aging factor for 10C increase or decrease in temperature.It states that a 10C increase or decrease in temperature of a homogeneous process results in, approximately, a two times or 12-time change in the rate of a chemical reaction (Q10).We set “Q10 = 2” as common by using the Arrhenius equation.(2) Define the desired shelf life of the electrode, such as, marketing needs, product needs, and so forth.We define the desired shelf life of the electrode is 2 years (730 days).(3) Define aging test time intervals, including time zero.Please refer to “Item 10 - Test Record”.(4) Define test conditions, room temperature (TRT), and accelerated aging temperature (TAA).We define TRT = 40 C, TAA = 60 C.(5) Decide if humidity conditions will be used in the aging study. If used, define the relative humidity (RH) conditions and allowable tolerances to be utilized around a targeted value.We define RH = 90%, allowable tolerances 5%.(6) Calculate the test duration using the Q10, TRT, and TAA.Where:Q10 = aging factor = 2TAA = accelerated aging temperature = 60CTRT = ambient temperature = 40CDesired (RT) = desired real-time aging = 730 daysSo:AAF = 4AAT (Accelerated Aging Time) = 182.5 days(7) Define the electrode material properties, sample sizes, and acceptance criteria.Please refer to “Item 4, 9”.(8) Age samples at TAA. In parallel, age samples at real-life aging conditions (TRT).Age samples #46 at TAA. Age samples #79 at TRT.(9) Evaluate the electrode performance after accelerated aging relative to the initial electrode requirements.Please refer to “Item 6 - Dispersion Test” for system performance test method.Please refer to “Item 10 - Test Record and Result” for test result.(10) Evaluate the electrode after real time aging relative to their initial design requirements. The initial AAF method is a simple and conservative technique for evaluating the long-term affects on the materials, however, like all accelerated aging techniques; it must be confirmed by real time aging data.Please refer to “Item 10 - Test Record and Result” for detail.9. Acceptable CriteriaThe impedance change after “Accelerated Aging Test” should not exceed 20% of initial average impedance.10. Test Record and Result(1) Electrode Impedance Test Result (before Aging Test)Test Date: 2012-4-30Test Result:Test PointBig Electrode Resistance (Ohm) Left PartSample #1Sample #2Sample #3Average161261461061227967947957953623620626623481081281481256406466436436790792794792764264464064287957987957969638634633635Test PointBig Electrode Resistance (Ohm) Right PartSample #1Sample #2Sample #3Average161861461361527967947957953623620626623481081281481256406466436436790792794792764264464064287957987957969638634633635Test PointSmall Electrode Resistance (Ohm)Sample #4Sample #5Sample #6Average161261461061227967947957953623620626623481081281481256406466436436790792794792764264464064287957987957969638634633635From above test result, we can see that Small Electrode resistance is similar to Big Electrode left part resistance and right part resistance. So, we only use Small Electrode for the following Aging Test. (2) Electrode Impedance Test Result after “Accelerated Aging Test”Test Date: 2012-5-1 to 2012-11-1 (Total: 183 days) Test Result: Test PointElectrode Resistance (Ohm)Sample #4Sample #5Sample #6AverageVariety from “before aging”1539542536539-12%2666670668668-16%3527531532530-15%4662665661666-18%5527530524527-18%6676670673673-15%7584574576578-10%8657661665661-17%9544545549546-14%-Total Average:-15%(3) Electrode Impedance Test Result after “Normal Aging Test”Test Date: 2010-11-1 to 2