Technology and health care : official journal of the European Society for Engineering and Medicine
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Technol Health Care · Jan 2012
ReviewMerits and capabilities of helicopter emergency medical service (HEMS) in traumatized patients.
Since the introduction of helicopter emergency medical service (HEMS) into the civilian rescue system, there is an ongoing discussion on its potential benefits in terms of time- and cost-effectiveness as well as clinical outcome improvement. Currently, the use of HEMS seems to provide a survival benefit in traumatized patients due to several aspects compared to ground emergency medical service (GEMS). ⋯ However, these aspects should be considered carefully as specific circumstances referring to rescue teams, on-scene management as well as preclinical durations, triaging of trauma patients and subsequent treatment at different hospitals have to be attended. In the present review current aspects of HEMS compared to GEMS are discussed.
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Technol Health Care · Jan 2012
ReviewOn the efficiency of FES cycling: a framework and systematic review.
Research and development in the art of cycling using functional electrical stimulation (FES) of the paralysed leg muscles has been going on for around thirty years. A range of physiological benefits has been observed in clinical studies but an outstanding problem with FES-cycling is that efficiency and power output are very low. The present work had the following aims: (i) to provide a tutorial introduction to a novel framework and methods of estimation of metabolic efficiency using example data sets, and to propose benchmark measures for evaluating FES-cycling performance; (ii) to systematically review the literature pertaining specifically to the metabolic efficiency of FES-cycling, to analyse the observations and possible explanations for the low efficiency, and to pose hypotheses for future studies which aim to improve performance. ⋯ Performance assessments should be carried out at a well-defined operating point, i.e. under conditions of well controlled work rate and cadence, because these variables have a strong effect on energy expenditure. Future work should focus on the two main factors which affect FES-cycling performance, namely: (i) unfavourable biomechanics, i.e. crude recruitment of muscle groups, non-optimal timing of muscle activation, and lack of synergistic and antagonistic joint control; (ii) non-physiological recruitment of muscle fibres, i.e. mixed recruitment of fibres of different type and deterministic constant-frequency stimulation. We hypothesise that the following areas may bring better FES-cycling performance: (i) study of alternative stimulation strategies for muscle activation including irregular stimulation patterns (e.g. doublets, triplets, stochastic patterns) and variable frequency stimulation trains, where it appears that increasing frequency over time may be profitable; (ii) study of better timing parameters for the stimulated muscle groups, and addition of more muscle groups: this path may be approached using EMG studies and constrained numerical optimisation employing dynamic models; (iii) development of optimal stimulation protocols for muscle reconditioning and FES-cycle training.
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Technol Health Care · Jan 2012
Ultrasound-based computer navigation: an accurate measurement tool for determining combined anteversion?
The present feasibility study examined the use of an ultrasound-based navigation system (UNS) for reliability of measurement the positions of both the femoral and acetabular components, a prerequisite to adjust the combined anteversion with sufficient accuracy when using a femur-first approach in total hip arthroplasty. ⋯ Our investigations suggest that the anteversion of stem and cup can be measured with accuracy sufficient enough to utilize the concept of combined anteversion using UNS. Hence, the advantage of utilizing UNS's in a femur-first approach is the ability to intraoperatively compensate for deviations from the targeted anteversion of the stem (which is often difficult to control) by adjusting the acetabular anteversion in the final step of the implantation. In doing so, the placement of the components follows the concept of combined anteversion. Avoiding extreme anteversion values of combined anteversion could be an important step towards reducing post-operative complications following total hip arthroplasty (THA).
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Femoral malrotation is a common complication after internal fixation of a femoral shaft fracture. The only valid, objective monitoring method is computer tomography-assisted torsion measurement between the proximal and distal femur; unfortunately, this can only be carried out postoperatively. A difference of 15° compared to the contralateral femur is seen as an indication for revision. ⋯ These methods also allow for navigation-assisted definition of the optimal incision site, intramedullary access, femoral nail and interlocking. The main problem lies in the extra time of surgery, which is due to performing all the steps of the surgery navigated. The solution for this problem is "hybrid navigation", in which the surgeon can select the steps he needs from the navigation system, depending on his experience or surgical technique.
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Technol Health Care · Jan 2012
Impact of enterococcus on immunocompetent and immunosuppressed patients with perforation of the small or large bowel.
The role of enterococcus in intraabdominal infection remains controversial. A retrospective study of 473 patients with bowel perforation was conducted to assess the impact of enterococci on outcome of patients with perforation of the small and large bowel. ⋯ Enterococci seem to play a minor role in uncomplicated intraabdominal infections. Our results suggest that enterococci play a role in the severity of postoperative complications. In particular, detection of enterococci in patients with anastomotic leakage are suggested to be an indicator of severe illness. We found significantly higher rates of E. faecium than described before, but no significant differences in clinical outcome between E. faecalis and E. faecium. When empirical therapy against enterococci is recommended, E. faecalis and E. faecium should both be covered.