People with spinal cord injury (SCI) are predisposed to pressure ulcers (PU). PU remain a significant burden in cost of care and quality of life despite improved mechanistic understanding and advanced interventions. An agent-based model (ABM) of ischemia/reperfusion-induced inflammation and PU (the PUABM) was created, calibrated to serial images of post-SCI PU, and used to investigate potential treatments in silico. Tissue-level features of the PUABM recapitulated visual patterns of ulcer formation in individuals with SCI. These morphological features, along with simulated cell counts and mediator concentrations, suggested that the influence of inflammatory dynamics caused simulations to be committed to "better" vs. "worse" outcomes by 4 days of simulated time and prior to ulcer formation. Sensitivity analysis of model parameters suggested that increasing oxygen availability would reduce PU incidence. Using the PUABM, in silico trials of anti-inflammatory treatments such as corticosteroids and a neutralizing antibody targeted at Damage-Associated Molecular Pattern molecules (DAMPs) suggested that, at best, early application at a sufficiently high dose could attenuate local inflammation and reduce pressure-associated tissue damage, but could not reduce PU incidence. The PUABM thus shows promise as an adjunct for mechanistic understanding, diagnosis, and design of therapies in the setting of PU.

Pressure ulcers are costly and life-threatening complications for people with spinal cord injury (SCI). People with SCI also exhibit differential blood flow properties in non-ulcerated skin. We hypothesized that a computer simulation of the pressure ulcer formation process, informed by data regarding skin blood flow and reactive hyperemia in response to pressure, could provide insights into the pathogenesis and effective treatment of post-SCI pressure ulcers. Agent-Based Models (ABM) are useful in settings such as pressure ulcers, in which spatial realism is important. Ordinary Differential Equation-based (ODE) models are useful when modeling physiological phenomena such as reactive hyperemia. Accordingly, we constructed a hybrid model that combines ODEs related to blood flow along with an ABM of skin injury, inflammation, and ulcer formation. The relationship between pressure and the course of ulcer formation, as well as several other important characteristic patterns of pressure ulcer formation, was demonstrated in this model. The ODE portion of this model was calibrated to data related to blood flow following experimental pressure responses in non-injured human subjects or to data from people with SCI. This model predicted a higher propensity to form ulcers in response to pressure in people with SCI vs. non-injured control subjects, and thus may serve as novel diagnostic platform for post-SCI ulcer formation.

Head-operated computer controls provide an alternative means of computer access for people with physical disabilities. A person's ability to use such head controls may be reduced if he or she experiences neck movement limitations. Five experimental methods of compensating for neck movement limitations were evaluated in comparison to a standard head control interface. Twenty-two subjects without disabilities and three subjects with multiple sclerosis performed icon acquisition exercises using the standard interface and each of the five experimental compensation methods. Subjects without disabilities had less tendency to overshoot the target icons when using an interface with decreased sensitivity or one in which head movements controlled cursor velocity rather than cursor position (p<0.05). Subjects with multiple sclerosis tended to be more accurate when using an interface with increased sensitivity, and had less tendency to overshoot icons when using head movements to control cursor velocity rather than cursor position. Overall, subjects tended to demonstrate faster performance when using an interface with reduced sensitivity.

The potential of modern telecommunications and computing technologies as tools in the delivery and evaluation of assistive technology (AT) has been discussed and has been termed telerehabilitation. The problems of providing AT in rural areas parallels the delivery of health care to rural areas where the proportion of people with chronic illnesses is higher and the means to pay for them is reduced. Large distances mean long travel times, increasing costs associated with any service delivery, and consuming valuable time skilled professionals could be using to provide services elsewhere. The technology available for practising telerehabilitation is significant and expanding at a rapid rate. Currently, plain old telephone systems (POTS) and broad-band videoconferencing equipment, Internet and World Wide Web, and embedded processor systems are most widely available. These technologies continue to evolve as well as emerging technologies such as wearable sensors that will have telehabilitation applications. Issues of payment, safety liability, and licensure need to be resolved, as legislation lags the development of new technologies.

Computer head controls provide an alternative means of computer access for people with disabilities. However, a person?s ability to use head controls may be reduced if his or her disability involves neck movement limitations. In this study, 15 subjects without disabilities and 10 subjects with disabilities received neck range of motion evaluations and performed computer exercises using head controls. Regression analysis was used to determine the relationship between neck range of motion and performance on computer exercises. Reduced neck range of motion was found to be correlated with reduced functional range for moving the cursor across the screen, and reduced accuracy and speed in icon selection. Fitts' Law-type models were fit to the data, indicating higher Fitts' law slopes for subjects with disabilities compared to subjects without disabilities. Results also indicate that vertical cursor movements are faster than horizontal or diagonal movements.