Verification Testing

Testing Frame

Through the verification and validation testing of the Epley Maneuver System, we were given the opportunity to create a complementary tool exclusively for testing this device and ensuring that it works as stated. The frame is easily adjustable and manipulated to mimic the position of a person performing the Epley maneuver.

Design Input 1 – Verification

  • Device was positioned so error conditions in position and time occur
    • Similar process to that of Design Input 3
  • Device positioned just outside of target angle so errors would occur
  • Difference between this angle and the target angle recorded
  • No resolution for this spec
    • Device is still able to accurately measure errors within the range of 10 to 11 degrees
  • One tailed one sample t-test used
  • When time error occurred also recorded
    • < 30s and > 120s
  • Device reported errors within the expected time frame
  • One tailed t-test compared with 30s and 120s respectively

Design Input 2 – Verification

  • Device weight was 0.58 lbs
    • Weighed 3 times and averaged
  • One tailed one sample t-test done
    • Compared to max weight of 4 lbs
    • P < 0.05
  • Device weight significantly different than 4lbs
    • Passes verification

Design Input 3 – Verification

  • Simulated Head used to record different angles
  • 100 data points recorded
  • 0, 90, 180° on x-axis
  • -50, 85, 245° on y-axis
  • 65, 145, 225° on z-axis
  • Difference between target angle and recorded angle taken
Example testing procedure for Design Input 3
  • Angles chosen 20 degrees past range of Epley Maneuver and middle
  • Wilcoxon test used
    • Data not normally distributed
    • Compared to see if difference was less than 1
  • All angles pass with p < 0.05
  • Device is able to measure target angles within 1 degree

Average difference from target angle with error bars and target values (p < 0.05)

Design Input 4 – Verification

  • Device positioned or timed into different error conditions
    • Utilizing simulated head similar to design input 3
    • Time taken for feedback to be administered recorded (n = 10)
  • Values averaged
    • One tailed one sample t-test performed
    • Compared to hypothetical mean of 3 seconds
  • Less than 1/10th the time per step in the maneuver
  • Passes verification for design input 4

Design Input 6 – Verification

  • Baud rate of 9600 confirmed to be used in Arduino
    • Corresponds to 960 bytes/s
    • 7.68 kbps
  • Fails verification for design input 6
  • Due to the nature of how Arduino transmits data this was unable to be reached
  • Using a different microcontroller chosen in the future would fix this

Design Input 7 – Verification

  • Device was powered on either for five hours or until battery died
  • Power lasted for the full five hour period
  • Device passes verification for design input 7

Design Input 8 – Verification

  • Minimum and maximum adjustable values measured (n = 3)
    • Done for head circumference and bitragion coronal arch
  • One tailed one sample t-test performed for minimum and maximum values
  • Device passes verification for design input 8

Design Input 10 – Verification

  • Leakage current testing done in accordance with IEC 60601
    • Minimum earth leakage current: 5 mA
    • Minimum touch current: 0.1 mA
  • 5 Measurements taken each
  • One tailed one sample t-test performed

Body model used to test touch current