Surgical Planning and Additive Manufacturing of an Anatomical Model: A Case Study of a Spine Surgery

3D scanning technologies have promising solutions for medical needs such as anatomical models, biocompatible implants, and orthotic/prosthetic models. Although virtual presurgical planning offers more precise results, it may not be applied in every hospital because of the high costs. The aim of this study is to assess the accuracy of the suggested low-cost and effective surgical planning method by means of additive manufacturing to increase success rate of each surgery. In this study, a full spine model of a scoliosis patient was acquired and reconstructed in MIMICS software using different filters and parameters. Therefore, a comparison in terms of geometrical errors among each model was performed based on a reference model. Subsequently, patient-specific full spine model was manufactured using a three-dimensional printing method (fused deposition modeling) and utilized before the surgery. 3D surgical model reconstruction parameters such as wrap tool, binomial blur, and curvature flow filters produced high geometrical errors, while mean filter produced the lowest geometrical error. Furthermore, similarity results of the curvature flow and discrete Gaussian filters were close to mean filter. Smooth tool and mean filter produced almost the same volume of the reference model. Consequently, an ideal protocol for surgical planning of a spine surgery is defined with measurable accuracy. Thus, success rate of a spine surgery may be increased especially for the severe cases owing to the more accurate preoperative review: operability

Research of Dosimetry Parameters in Small Electron Beams

In this study, dose distributions and outputs of circular fields with dimensions of 5 cm and smaller, for 6 and 9 MeV nominal energies from the Siemens ONCOR Linac, were measured and compared with data from a treatment planning system using the pencil beam algorithm in electron beam calculations. All dose distribution measurements were performed using the GafChromic EBT film; these measurements were compared with data that were obtained from the Computerized Medical Systems (CMS) XiO treatment planning system (TPS). Output measurements were performed using GafChromic EBT film, an Advanced Markus ion chamber, and thermoluminescent dosimetry (TLD). Although it is used in many clinics, there is not a substantial amount of detailed information in the literature about use of the pencil beam algorithm to model electron beams. Output factors were consistent; differences from the values obtained from the TPS were at maximum. When the dose distributions from the TPS were compared with the measurements from the ion chamber and GafChromic EBT films, it was observed that the results were consistent with 2 cm diameter fields and larger, but the outputs for 1 cm diameter fields and smaller were not consistent

Distributed TDMA Scheduling for Autonomous Aerial Swarms: A Self-Organizing Approach

Self-organization is a key strategy for improving the performance of an aerial swarm ad hoc network. The proliferation of low-cost VTOL drones has broadened the application domain of aerial swarms, and the need for synchronized communication among network entities has become crucial. However, existing ad hoc approaches struggle to maintain multi-hop connections in contested environments characterized by frequent topology changes and intermittent links. To overcome these limitations, we introduced STDMA protocol, which enables the self-configuration of drones without reliance on a ground controller. In continuation of the earlier work, we conduct extensive experiments to evaluate the performance of the proposed protocol. Comparative simulation experiments cover various scenarios with different network sizes, frame lengths, and traffic loads. The STDMA protocol achieves optimal access delay in highly contested environments and reduces delay by approximately 19.181%. Moreover, it exhibits improved channel utilization compared to the E-ASAP/SM protocol, with a 4.5 times increase

Evaluation of Postural Parathyroid Hormone Change in Patients with Primary Hyperparathyroidism

Purpose. In the present study, we aimed to investigate postural change of PTH in normal individuals and in patients with primary hyperparathyroidism (PHPT). Methods. Twenty-two patients with PHPT and nine healthy controls were enrolled. Following 12 h of fast, patients stayed in recumbent position for an hour and PTH and total Ca measurements were performed at the 45th and 60th minutes of resting. Afterwards, the patients resumed an upright posture for an hour and again blood samples were taken at the 45th and 60th minutes of standing. Results. In the PHPT group, mean PTH was calculated as 153.9 pg/mL in the recumbent position while it was 206.3 during upright position (Δ change was 47.7) (P<0.001). In the control group mean serum PTH was measured as 41.2 pg/mL in the recumbent position while it was 44.8 pg/mL in the upright position (Δ change was 1.7) (P=0.11). In both groups, serum Ca was higher in the upright position compared to the recumbent position (P<0.001). Conclusion. Postural change of serum PTH is significant only in PHPT group. Postural PTH test may give a clue to the clinician when the diagnosis of PHPT is equivocal

Simultaneous Determination of Cyclosporine A, Tacrolimus, Sirolimus, and Everolimus in Whole-Blood Samples by LC-MS/MS

Objectives. Cyclosporine A (CyA), tacrolimus (TRL), sirolimus (SIR), and everolimus (RAD) are immunosuppressive drugs frequently used in organ transplantation. Our aim was to confirm a robust sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determination of CyA, TRL, SIR, and RAD in whole-blood samples. Materials and Methods. We used an integrated online solid-phase extraction-LC-MS/MS system and atmospheric pressure ionization tandem mass spectrometry (API-MS/MS) in the multiple reaction monitoring (MRM) detection mode. CyA, TRL, SIR, and RAD were simultaneously analyzed in whole blood treated with precipitation reagent taken from transplant patients. Results. System performance parameters were suitable for using this method as a high-throughput technique in clinical practice. The high concentration of one analyte in the sample did not affect the concentration of other analytes. Total analytical time was 2.5 min, and retention times of all analytes were shorter than 2 minutes. Conclusion. This LC-MS/MS method can be preferable for therapeutic drug monitoring of these immunosuppressive drugs (CyA, TRL, SRL, and RAD) in whole blood. Sample preparation was too short and simple in this method, and it permits robust, rapid, sensitive, selective, and simultaneous determination of these drugs

Anomalous WW-Gamma Vertex in Gamma-p Collision

The potential of LC+HERAp based Gamma-p collider to probe WW-Gamma vertex is presented through the discussion of sensitivity to anomalous couplings and P_T distribution of the final quark. The limits of -0.04<\Delta\kappa<0.04 and -0.11<\lambda<0.11 at 95% C.L. can be reached with integrated luminosity 200(1/pb). The limit for \Delta\kappa is comparable to one which is expected from LHC. The bounds are also obtained from corresponding ep collider using Weizsacker-Williams Approximation to compare with real photons.Comment: 8 pages, 2 eps figure