Use of the Resection Map system as guidance during hepatectomy

Industrial DesignIndustrial Design Engineerin

Surgical wayfinding and navigation processes in the human body

Design EngineeringIndustrial Design Engineerin

Visualization tool for improved accuracy in needle placement during percutaneous radio-frequency ablation of liver tumors

The European research network “Augmented reality in Surgery” (ARIS*ER) developed a system that supports percutaneous radio frequency ablation of liver tumors. The system provides interventionists, during placement and insertion of the RFA needle, with information from pre-operative CT images and real-time tracking data. A visualization tool has been designed that aims to support (1) exploration of the abdomen, (2) planning of needle trajectory and (3) insertion of the needle in the most efficient way. This work describes a first evaluation of the system, where user performances and feedback of two visualization concepts of the tool – needle view and user view – are compared. After being introduced to the system, ten subjects performed three needle placements with both concepts. Task fulfillment rate, time for completion of task, special incidences, accuracy of needle placement recorded and analyzed. The results show ambiguous results with beneficial and less favorable effects on user performance and workload of both concepts. Effects depend on characteristics of intra-operative tasks as well as on task complexities depending on tumor location. The results give valuable input for the next design steps.Human Information Communication DesignIndustrial Design Engineerin

Nelfinavir and lenalidomide/dexamethasone in patients with lenalidomide-refractory multiple myeloma. A phase I/II Trial (SAKK 39/10).

The antiretroviral agent nelfinavir has antimyeloma activity and can overcome resistance to bortezomib. Our phase I/II trial investigated whether adding nelfinavir to lenalidomide-dexamethasone can overcome lenalidomide resistance in lenalidomide-refractory multiple myeloma (MM). Twenty-nine patients were included (high-risk cytogenetic aberrations 31%; ≥2 prior therapy lines 93%; lenalidomide-bortezomib double-refractory 34%). Twenty-four patients (83%) had prior bortezomib and 10 (34%) were lenalidomide-bortezomib double-refractory. They received four cycles of nelfinavir 2500 mg/day with standard-dose lenalidomide (25 mg days 1-21) and dexamethasone (40/20 mg days 1, 8, 15, 22). Minor response or better was achieved in 16 patients (55%; 95% CI 36-74%), including 40% of those who were lenalidomide-bortezomib double-refractory, and partial response or better in nine patients (31%; 95% CI 15-51%). Median progression-free survival was 3.4 (95% CI 2.0-4.9) months and median overall survival 21.6 (13.0-50.1) months. Lenalidomide-related pneumonitis, pneumonia, and neutropenic fever occurred, but there were no unexpected adverse events. Peripheral blood mononuclear cells showed a 45% (95% CI 40-51%) reduction in total proteasome activity from baseline and significant induction of unfolded protein response and autophagy. Thus, nelfinavir-lenalidomide-dexamethasone is an active oral combination in lenalidomide-refractory MM

Manipulation of mental models of anatomy in interventional radiology and its consequences for design of human–computer interaction

Interventional radiology procedures require extensive cognitive processing from the physician. A set of these cognitive functions are aimed to be replaced by technology in order to reduce the cognitive load. However, limited knowledge is available regarding mental processes in interventional radiology. This research focuses on identifying mental model–related processes, in particular during percutaneous procedures, useful to improve image guidance during interventions. Ethnographic studies and a prototype-based study were conducted in order to perform a task analysis and to identify working strategies and cognitive processes. Data were compared to theories from visual imagery. The results indicate a high level of complexity of mental model construction and manipulation, in particular when mentally comparing mental model knowledge with radiology images on screen (e.g., to steer a needle correctly). Regarding current interface support, most difficult is the interpretation and selection of oblique views. New interface principles are needed to bring cognitive demands within reasonable human range, and also accompanying cognitive work strategies should be developed.Design EngineeringIndustrial Design Engineerin