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The following test is to demonstrate the functionality of the system. If any test fails, adjustments will be made accordingly to system.
LVAD Simulation Signal Test
Before testing the proposed prototype with the current LVAD set-up, a test simulating signals entering and leaving the designed transceivers will be conducted. Agilent 33120A Function/Arbitrary Waveform Generator will be used to simulate signals entering the device, and HP54602B Oscilloscope will be used to measure the output of the transceivers, and compare it to the input. The goal is to make sure that the signals are processed correctly, and that the propagation delay is within specification.
Results: The electirical Test has been summarizing in the following document: Electical Testing Data and Results
Electronics Functionality Test
The specifications above will be tested by plugging in the proposed device in two ways for a period of 6 hours to check the functionality of the device. One method is to test functionality of the new electronics with current system components; the second, is to test functionality with the design of the P10021 Senior Design Miniaturization team. To test functionality of the new electronics, we must have access to the current system components’ signals needed to test our design. Required signals are outlined in high-level design schematics and in specifications. Upon collaboration with P10021 Senior Design team, several criteria was agreed upon to allow for testing of both designs simultaneously for a period of 15 minutes. Observations will be made at 5 minute time intervals to ensure that the electronics are working properly, without any need for adjustments.
No Result were found due to Un -operating electical systems.
To fulfill engineering specifications #33, the drop test is designed to test for damage prevention due to any accidental drops of the outside casing. The inner casing will also be tested by a similar method to ensure that if the package can withstand this type of impact, it can withstand other kinds of unintentional impacts. To simulate best an average fall, a person would drop the casing from a height of 1.5 meters onto a standard concrete surface (Carpeted for internal component), and any damage to the casing will be observed and recorded. If the casing is severely damaged, it shall be redesigned and re-fabricated.
To prepare for the drop tests of the inside and outside components the electronic and mechanical packages had to be assembled. The outside package started with the circuit board which was mounted inside the aluminum case. The board was secured using heat sink foam as cushions on all sides. The foam was installed using electrical tape which was also used to completely separate the electrical board from the aluminum. This tape barrier is extremely important because the exposed metal could easily short out the board. The o ring was then installed on the box and the top was secured using the screws. The next and final layer was the neoprene cover to protect the aluminum. The cover was constructed with a zipper to be easily removable and durable. Once the neoprene cover was installed on the case the drop test was performed. The case with cover and electronic board was dropped three times from a height of one meter onto a hard floor. Each drop was to ensure it could withstand a drop onto a different side, top, bottom, and an edge. The case was then opened and the board examined. The board was found to be in an unchanged condition, and the aluminum was not damaged or marred. Thus the drop test for the external component was a success. The drop test for the internal box was very similar, but this case does not have a neoprene cover. The board was again installed and held in place with foam and electrical tape. The case was screwed shut with the o ring installed and the case was dropped. The case was also dropped three times onto different edges, but this time it was dropped onto a thin carpet laid over a concrete floor. This case was also opened up and it was found that all components were in perfect condition and the entire package survived the drop test with no damage. In conclusion both of our cases are capable of protecting electronics and surviving drops from one meter without damage.
Pressure and Leak Test
This test is designed to fulfill customer need #14, corresponding to engineering specification #32 and #34, where the casing and the wire connections must withstand slightly higher pressures and be leak resistant under 1 meter of water. The casing and the cables will be submerged in a tank under 1 meter of water, corresponding to pressure of 10 kPa. For this test the electronics will be removed and wire samples will be put in the connectors to simulate the actual wires in place. We will ensure complete submersion, and keep the components underwater for 15 minutes.
A series of tests were conducted to ensure that the electronics cases were both watertight. For these tests the goal was to prove that the two cases were completely waterproof as designed. It was proposed that silicone material would be used on the o rings to seal the boxes completely; however for the testing this material was not used. The boxes relied on just the o ring seal, and if successful the test would prove that the design was a complete success. The boxes were loaded with paper to absorb and show if any water was able to leak into the cases. The o rings were made by measuring o ring cord and super gluing the two cut ends together. The cord grips were sealed by inserting sections of wire that were super glued sealed at the ends to ensure water could not leak through the wire jacked itself. The lids were then screwed down to get firm seals from the o rings. Testing was conducted in three stages. First the cases were submerged in six inches of water for fifteen minutes. There were no observed air bubbles and disassembly confirmed absolutely no leakage. The second test involved exposing the cases to the direct impact of the water coming from a faucet as the sink filled with water, where they were submerged for another fifteen minutes. This test had the same result, no leakage. The final test was conducted at a depth of .75 meters, just shy of the 1 m depth proposed. To compensate for the shallower depth the cases were exposed to water jets in the tub for a full 90 minutes. Disassembling the cases again showed absolutely no water was able to leak in. It can be concluded that the case design is completely effective in making a watertight environment for the electronics. Future upgrades to ensure added reliability may be the use of silicone sealant and the use of a proper o ring splicing system which are available.
Heat TestThis test is designed to ensure that the heat produced by the electronics dissipated quickly, and in a manner that the surface temperature does not increase by more than 6.4 oC over ambient. Also, the electronics must function properly and should not overheat if the system is implanted into the human body. Simulating internal body fluid condition is a tedious process, therefore, for feasibility reasons; the final product casing will be tested in water for a 3 hour period. A thermocouple will be used to measure temperature of electronics inside the casing and on the surface of the case.
No Result were found due to Un -operating electical systems.
Flexibility Test- Stiffness
This test is designed to quantify the stiffness of each cable using two methods. The test design is applying a constant force on all the cables and measuring the deflection. The second test design is using the Taber Stiffness testing from the RIT Packaging Science Materials Laboratory.