| Electric stimulation (ES) therapy involves the use of low-energy, static, or time-varying electric and magnetic fields and associated electrical currents to stimulate a therapeutic physiological response in human tissue. The focus of this thesis is on the use of ES as an adjunctive therapy to accelerate wound healing. Broadly speaking, there are two distinct ES therapies that are used for wound healing, capacitively-coupled (CC) electrode stimulation and pulsed electromagnetic field (PEMF) therapy. The interest in these therapies has grown in recent years as bioapplications of ES have proliferated. However, despite this progress, relatively few publications describe rigorous models for predicting the electromagnetic aspects of ES therapy. In addition, the rational design for ES device development is lacking. This thesis contains an overview of wound healing, a discussion of ES as an adjunctive therapy, electromagnetic modeling of CC-based ES therapy and the design of an electrical system to power and control the therapy. The overview of wound healing includes the staging wounds and the basic physiology of the healing process. The discussion of ES therapy includes the different treatment modalities, clinical evidence of therapeutic effectiveness and the current regulatory status of the therapy. The modeling content contains a description of the development of computational models that predict the electromagnetic aspects of CC-based ES therapy. The models predict the electric field and current density distributions in tissue taking into account parameters including the stimulation frequency, electrode configuration, voltage waveforms as well as relevant tissue layers, e.g. skin, fat, muscles, and their corresponding frequency dependent properties. Finally, a design is presented of an electrical system to power and control the therapy. The computational models provide insights into ES therapy and when combined with the electrical design methodology, they enable a cogent strategy for the development of innovative, wearable and point-of-care ES wound healing therapeutic devices. |
