We report results from a clinical trial for monitoring respiration and cardiac activity of patients during sleep using microbend fiber sensor. This sensor is used to acquire respiratory and heart beat information. We have collected reference data from standard Polysomnography and data from microbend fiber sensor on 22 patients. A new algorithm is developed to calculate breathing rate and heart rate simultaneously. The Bland-Altman analysis demonstrates the measurements have good accuracy for monitoring purposes compared with the standard Polysomnography. An accuracy of 1.06bpm for breathing rate and 3.32bpm for heart rate has been validated for 30s averaging time although there were significant signal distortions under sleep conditions.