This study successfully demonstrates the potential of biodegradable PLLA as a high-performance piezoelectric material for biomedical sensor applications. By employing a combination of uniaxial stretching and thermal annealing, we achieved significant enhancements in PLLA's piezoelectric properties. The processed films displayed exceptional piezoelectric performance across various testing scenarios, including cyclic strain, tapping, bending, and force-and frequency-sweep experiments. Notably, the ring-like strain sensor developed in this work could detect mechanical deformation under physiological pressures in an in vitro setup simulating the left-heart dynamic. This ability to operate under realistic hemodynamic loads-spanning systolic/diastolic pressures of 92/51, 123/78, and 164/114 mmHg -underscores the sensor's potential for real-time biomechanical and physiological monitoring. The sensor exhibited a clear correlation between applied pressures and electrical outputs, demonstrating stable and periodic signals even under dynamic and pulsatile conditions. These results represent an important step forward in supplementing current annuloplasty monitoring and dynamic assessment methods. The initial results presented indicate the potential of this sensor in capturing biomechanical actions during physiological conditions.