PubMed · 10947771
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
P K Sinha, S Arora, K K Gombar. 2000. Another teeth protector.. https://doi.org/10.1046/j.1365-2044.2000.01664-15.x
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Explore the source record for details and available documents.
BACKGROUND: The operative potential of hand-assisted laparoscopic surgery (HALS) could be enhanced by the introduction of a new generation of assisting instruments. These tools will have to meet specific requirements of shape, function, and safety of use. METHODS: Problems related to the working environment of HALS and deriving projectual restrictions of HALS instruments were analyzed in order to develop and manufacture a working prototype with grasping and dissecting properties to assist during HALS procedures. The resulting instrument was mechanically and clinically tested in 22 HALS procedures. RESULTS: The additional benefit of the new device was particularly appreciated during dissection and isolation of vascular pedicles (nephrectomies and splenectomies). It was shown to be safe and effective in providing the additional assistance it was designed for. CONCLUSION: The described grasping and dissecting instrument for HALS is of great value in assisting the surgeon during fine dissection, as required in selected procedures. New generation of HALS instruments should comply with the functional and safety issues analyzed in this report.
Quantitative determination of activity concentration has always been regarded as a goal of PET scanner design. Therefore, a linear response with respect to activity concentration is essential. To prove system linearity of response a test is proposed based on the determination of recovery coefficients (RC) for different object geometries. If all degrading effects, especially scatter and attenuation, are corrected to a sufficient degree of accuracy, the system behaves linearly resulting in a theoretical relationship between hot (HSRC) and cold spot recovery coefficients (CSRC). Therefore this relationship, applied to appropriate phantom data containing hot or cold spheres, combined with the constraints on asymptotic behaviour of RC can be used as a test of system linearity of response. After applying the system's standard corrections RC were determined using both 2D and 3D data acquisition modes. For both 2D and 3D data, HSRC directly measured showed an excellent agreement with the HSRC calculated from the CSRC. The analysis was extended to radionuclides of different positron ranges, to the effect of data smoothing, and to that of iterative reconstruction. The agreement between the RC determined under varying border conditions demonstrates the effectiveness of the corrections used in constituting system linearity. Therefore, the method proposed is used as a test of system linearity of response.