Biomedical engineers play a crucial role in medical innovation, designing devices that save lives and improve patient care. One remarkable example is the biomimetic “python teeth” rotator cuff repair device, which mimics the biological way in which python teeth grip prey without tearing flesh. Used alongside traditional sutures, or stitches, this device provides a more secure grip on tendons, significantly increasing the strength of rotator cuff repairs and reducing the risk of re-tears. Surgeons, supported by medical device experts, are incorporating this breakthrough into procedures to improve outcomes for patients with shoulder injuries.
3.1 Marina is a medical device expert who works closely with surgeons to incorporate the “python teeth” device into rotator cuff surgeries. Shown at left is her schedule for a typical workday. How much of her workday (from 7:30 a.m. to 3:30 p.m.) is spent assisting surgeries? Express your answer as a common fraction.
3.2 The biomimetic “python teeth” device Marina promotes reduces failure rates for rotator cuff repairs. Before using the device, the failure rate for younger patients was 20%. The device reduces failure rates by 50% for all patients. What is the probability that a rotator cuff repair will fail in a younger patient using the device? Express your answer as a percent.
3.3 After the “python teeth” device was introduced, the failure rate for elderly patients decreased to 47%. What was the original failure rate for elderly patients before using the device? Express your answer as a percent.