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Purpose
This paper presents new quantitative data on a signal-to-noise ratio (SNR) study, distortion study, and targeting accuracy phantom study for our patient-mounted robot (called Arthrobot). Arthrobot was developed as an MRI-guided needle placement device for diagnostic and interventional procedures such as arthrography.Methods
We present the robot design and inverse kinematics. Quantitative assessment results for SNR and distortion study are also reported. A respiratory motion study was conducted to evaluate the shoulder mounting method. A phantom study was conducted to investigate end-to-end targeting accuracy. Combined error considering targeting accuracy, respiratory motion, and structure deformation is also reported.Results
The SNR study showed that the SNR changes only 2% when the unpowered robot was placed on top of a standard water phantom. The distortion study showed that the maximum distortion from the ground truth was 2.57%. The average error associated with respiratory motion was 1.32 mm with standard deviation of 1.38 mm. Results of gel phantom targeting studies indicate average needle placement error of 1.64 mm, with a standard deviation of 0.90 mm.Conclusions
Noise and distortion of the MR images were not significant, and image quality in the presence of the robot was satisfactory for MRI-guided targeting. Combined average total error, adding mounting stability errors and structure deformation errors to targeting error, is estimated to be 3.4 mm with a standard deviation of 1.65 mm. In clinical practice, needle placement accuracy under 5 mm is considered sufficient for successful joint injection during shoulder arthrography. Therefore, for the intended clinical procedure, these results indicate that Arthrobot has sufficient positioning accuracy.Background
Preoperative anemia and allogeneic blood transfusions (ABTs) may affect outcomes in cancer surgery. The prevalence of anemia, the use of ABTs, the risks of transfusions, lengths of stay and mortality of oncological patients undergoing radical cystectomy were investigated in three University Hospitals in Germany.Patients and Methods
Hospital records of 220 consecutive patients undergoing radical cystectomy from 2010 to 2012 were retrospectively analyzed for independent risk factors of ABT and unfavorable outcomes (readmission, increased length of stay (LOS) or death) using multivariate regression analysis.Results
Preoperative anemia was present in 40%. 70% of patients received blood transfusions. Low preoperative and intraoperative nadir hemoglobin levels were associated with receipt of ABT (OR 1.33, P?=?0.04 and OR 2.94, P?<?0.001 respectively). Transfusion of ten or more red blood cell units (RBCs) during the entire hospital stay was a predictor of an increased LOS (P?<?0.001) and death (OR 52, 95%CI [5.9, 461.3], P?<?0.001), compared to non-transfused patients. Preoperative ABT and ASA scores were associated with ≥10RBCs.Conclusion
Anemic patients undergoing radical cystectomy had a high risk to receive ABTs. Preoperative transfusions and transfusion of ≥10RBCs during the entire hospital stay may increase patient`s mortality.Prospective, randomized controlled studies have to follow this study. 相似文献Objectives: We aim to identify the chemical constituents and quantification of eight cases of reported “Black Mamba” use in order to further understand the clinical variability in patients presenting for emergency stabilization.
Methods: We report data from eight cases of reported “Black Mamba” use prospectively captured through the Colorado site of the Psychoactive Surveilance Consortium and Analysis Network (P SCAN). P SCAN is a geographically representative group of academic hospitals that capture clinical presentation, outcome, and biologic samples from patients that present for emergency stabilization following NPS use. Serum and urine samples were analyzed and quantified by liquid chromatography-quadrupole time-of-flight mass spectrometry after a qualitative screen for over 600 unique NPS compounds.
Results: In the reported eight cases, the median age was 28 years old. There were four male and four females. Four patients had agitation/delirium and four patients had chest pain. Normal saline, benzodiazepines and ondansetron were the common treatment provided in the emergency department (ED). Two patients were discharged from the ED and six patients being admitted for emergency observation with a median length of stay (LOS) of six hours. No deaths were reported. Confirmatory testing revealed that only five patients (62.5%) had SCs found in blood or urine samples. Cocaine, NRG-3, 3-methoxyphencyclidine hydrochloride (MeO-PCP), and methamfetamine were identified in other presentations.
Conclusions: The wide range of clinical presentations from “Black Mamba” use may be explained by the wide variability of chemical constituents found by laboratory analysis. 相似文献
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