A Framework for Reasoning about Patient Safety of Emerging Computer-Based Medical Technologies

Like many industries today, the healthcare industry depends on computer-based technologies. From the digital thermometer to the magnetic resonance imaging (MRI) machine, one can find a variety of devices of different levels of complexity in any clinical environment. Mobile technologies are also driving many out-of-clinic solutions. The increasing complexity of medical technologies is improving both the diagnosis and treatment capabilities of the healthcare industry, resulting in improved patient outcomes. It is, however, also creating more opportunities for undesirable outcomes, with the primary concern being harm to the patients that these technologies are intended to help. This dissertation presents a framework for reasoning about this primary concern for computer-based medical technologies in light of this increase in complexity.

The core framework consists of a general model of patient safety based on a dynamical systems view of health and health management. It views the human body as a natural safety critical system and health as the body maintaining safe states. Doing so makes the goal of health management (where medical technologies are employed) aiding in this safety-critical function, and allows us to discuss safety of these technologies within the same framework used for discussing health. This provides a number of advantages. First, it makes the developments accessible to health practitioners. Second, it provides designers with a link between system design features and patient safety (viewed as health outcomes). Third, it provides regulators with a general framework for reasoning about the large number of instantiations of medical technologies. Most importantly, it allows all three stakeholders to reach a common understanding of patient safety for any medical technology. This makes the framework valid from a health management perspective. Casting health in safety terms makes it consistent with systems safety principles, while addressing the short-comings of existing techniques for dealing with health as a functional goal.

The ability of the framework to enabling reasoning about the complexity introduced by integration, autonomy, and mobility of emerging technologies is demonstrated by extending the core ides to one class of these technologies known as body sensor networks (BSNs). The result is a general set of hazards for BSNs based on a generic BSN model, and a proof-of concept simulation tool for BSNs embodying the features necessary for exploring issues related to safety. Realistic examples based on information from the literature are provided throughout to demonstrate the validity and applicability of the ideas.