Abstract
A large number of people living with type two diabetes suffer from a slow rate of wound healing. Also, some injuries, such as burns, can cause chronic wounds. Low-intensity vibrations have been investigated to promote wound healing. In authors’ previous research, a piezoelectric disc was bonded near the wound site to deliver low intensity vibration. It has been demonstrated that low intensity vibration promotes tissue perfusion, granulation tissue formation, and wound healing in diabetic mice. In this paper, a self-sensing feedback control system is designed to ensure vibration consistency. Such consistency is critical to the proposed treatment. The piezoelectric disc acts as an actuator and a sensor synchronously, i.e., a single piezoelectric disk bonded on the skin can produce vibrations and measure strain or stress simultaneously. No separate sensors are needed to deploy in the feedback control systems. Such integrated design eliminates sensors, which saves space and reduces complexity, and it is important to wearable devices. A bridge circuit is adopted in this work to enable the collocated control. The bridge circuit, piezoelectric disk, and tissue are modeled separately. Finally, a single-input single-output system model is established for the whole system, and a corresponding controller is designed. Responses based on the SISO model are simulated and analyzed. The important system parameters are investigated and discussed.
