Power is the probability that a study will reject the null hypothesis. difference between the null and alternative hypotheses. level of significance, and the null vs. alternative difference. a numeric example of power and sample size estimation for the one-sample case.
During the procedure the patient is unconscious and unaware of the need to urinate. After the procedure, however, it may not be safe for the patient to walk. They may be too sick to take care of their own bathroom needs or their surgeon may feel that a catheter is best for their particular recovery.
A catheter is a small plastic tube used to help those unable to use the bathroom urinate. The tube is inserted through the urethra and into the bladder. Urine then empties through the tube into a plastic bag. Catheters can be used both for in-home treatment and in hospitals for patients who are bedridden.