Medical engineering & physics
-
Intracranial pressure (ICP) elevation (intracranial hypertension, IH) in neurocritical care is typically treated in a reactive fashion; it is only delivered after bedside clinicians notice prolonged ICP elevation. A proactive solution is desirable to improve the treatment of intracranial hypertension. ⋯ A key contribution of this work is to exploit an ensemble classifier method based on extremely randomized decision trees (Extra-Trees). Experiments on a representative set of 30 patients admitted for various intracranial pressure related conditions demonstrate the effectiveness of the predicting framework on ICP pulses acquired under clinical conditions and the superior results of the proposed approach in comparison to linear and AdaBoost classifiers.
-
Plaque composition is a potentially important diagnostic feature for carotid artery stenting (CAS). The purpose of this investigation is to evaluate the reproducibility of manual border correction in intravascular ultrasound with virtual histology (VH IVUS) images. Three images each were obtained from 51 CAS datasets on which automatic border detection was corrected manually by two trained observers. ⋯ Agreement between classifications of plaque type was evaluated using the weighted Kappa statistic. There was substantial agreement between the observers based on necrotic core percentage (κ=0.63), while the agreement was moderate (κ(quadratic)=0.60) based on plaque classification. Due to the time-consuming nature of manual border detection, an improved automatic border detection algorithm is necessary for using VH IVUS as a diagnostic tool for assessing the suitability of patients with carotid artery occlusive disease for CAS.
-
Comparative Study
Protocols to compare infusion distribution of wound catheters.
Multi-holed wound catheters are increasingly used in clinical practice to administer analgesic/anaesthetic locally to the painful region. The distribution of flow infused during controlled (continuous or intermittent) administration of medication is believed to be an important issue for successful pain relief. Nevertheless, this information is not available from the literature. ⋯ Baxter, Pajunk) distribute the flow more homogeneously than catheters characterized by large size holes (e.g. I-Flow, Temena). The distribution of infused flow does not change significantly during continuous or intermittent infusion.
-
Sacral fractures from high-impact trauma often cause instability in the pelvic ring structure. Treatment is by internal fixation which clamps the fractured edges together to promote healing. Healing could take up to 12 weeks whereby patients are bedridden to avoid hindrances to the fracture from movement or weight bearing activities. ⋯ Ultrasound provides in situ monitoring of stiffness recovery but only assesses local fracture sites close to the skin surface and has only been tested on long bones. Vibration analysis can detect non-uniform healing due to its assessment of the overall structure but may suffer from low signal-to-noise ratio due to damping. Impedance techniques have been used to assess properties of non-long bones but recent studies have only been conducted on non-biological materials and more research needs to be done before it can be applicable for monitoring healing in the fixated pelvis.
-
Orthopaedic drilling operations without optimum operating parameters by surgeons may cause bone defects such as bone fracture, cracks, osteolysis and tissue loss around the drilling zone. For the sake of optimum drilling parameters, an in vitro study was performed by considering the bone mineral density, bone sex, drill tip angle, drill speed, drill force and feed-rate. The specimens were taken from the drilled sites of fresh male and female calf tibias. ⋯ The drilling temperatures of the female bovine tibias were found to be higher than that of the male tibias and the drill speed was found to be a significant parameter on the maximum temperature. Moreover, the maximum temperature increased with an increasing drill tip angle and bone mineral density. Therefore the bone quality around the drill site was found to be worse than the bone samples exposed to low temperatures.