Jorge Larrey Ruiz

Efficacy and safety of dipyrone versus tramadol in the management of pain after hysterectomy: A randomized, double-blind, multicenter study

Background and Objectives We assessed the efficacy and safety of dipyrone in comparison with tramadol in the relief of early postoperative pain following abdominal hysterectomy. Methods A total of 151 women between 18 and 60 years of age undergoing abdominal hysterectomy during general anesthesia participated in a randomized, double-blind, controlled, multicenter study. Seventy-three patients received dipyrone and 78 received tramadol. Patients received an intravenous loading dose of the study drug immediately after operation followed by intravenous (IV) maintenance infusion and IV on-demand boluses up to a maximum number of predetermined doses/day of 8 g dipyrone and 500 mg tramadol. The duration of the study was 24 hours. Results The mean (SD) number of boluses in the dipyrone group was 3.8 (2.4) and 3.5 (2.5) in the tramadol group (95% confidence interval, −0.455 to 1.175), and the percentage of patients requiring rescue IV morphine (dipyrone 26.9%, tramadol 26.8%) was not statistically significant. Other analgesic efficacy parameters, such as pain intensity differences, sum of pain intensity differences, pain relief assessed by the patient, or patients who required the maximum number of demand doses, were not different between treatment groups. A significantly higher percentage of adverse gastrointestinal effects was found in patients given tramadol (42.1%) than in patients given dipyrone (20.2%) (P < .05). Also, a significantly higher number of tramadol-treated patients required ondansetron to control nausea and vomiting at 1 hour (19% v 7%), 2 hours (26% v 11%), and 24 hours (46% v 29%) (P < .05) after surgery. Patients and the investigators reported similar tolerability for both study arms. Conclusions Dipyrone and tramadol showed similar efficacy for early pain relief after abdominal hysterectomy. Nausea and vomiting, possibly caused by the tramadol, occurred more frequently in those patients. In this group, the need of the antiemetic drug ondansetron was also higher.

Frequency implementation of the Euler-Lagrange equations for variational image registration

In this letter, a novel theoretical framework defined in the frequency domain for variational nonparametric image registration is proposed. It provides more efficient implementations than existing theoretical approaches for the most common registration techniques. The presented frequency domain analysis adds simplicity to the variational image registration implementations and allows for an easy extension to higher dimensions by using the multidimensional Fourier transform of multidimensional signals.

Characterization of Artificial Muscles Using Image Processing

Artificial muscles are bio-inspired devices formed by several layers of conducting polymers. These devices have the ability of transform electrical energy into mechanical energy through an electrochemical reaction, which is produced by an oxidation or reduction of the polymer due to an electric current. Since the device have a strip shape, this reaction results in a macroscopic swelling and shrinking movement. This movement is similar to the biological muscles and it has several applications as motor prostheses and as part of complex biomaterials. In this paper we describe a computer vision system developed to analyze and characterize these devices through their cycle of life. The method includes cameras for tracking the movement of the muscle from different angles and a set of algorithms to characterize the motion of the device through its use. By means of active contours it is determined the instantaneous position of the muscle in the space. From these contours other parameters like the parametric motion and energy of curvature are calculated. These data are compared with the physical parameters of the device, like the tension and energy consumption, providing a way for performing automatic testing on the research of artificial muscles.Artificial muscles are bio-inspired devices formed by several layers of conducting polymers. These devices have the ability of transform electrical energy into mechanical energy through an electrochemical reaction, which is produced by an oxidation or reduction of the polymer due to an electric current. Since the device have a strip shape, this reaction results in a macroscopic swelling and shrinking movement. This movement is similar to the biological muscles and it has several applications as motor prostheses and as part of complex biomaterials. In this paper we describe a computer vision system developed to analyze and characterize these devices through their cycle of life. The method includes cameras for tracking the movement of the muscle from different angles and a set of algorithms to characterize the motion of the device through its use. By means of active contours it is determined the instantaneous position of the muscle in the space. From these contours other parameters like the parametric motion and energy of curvature are calculated. These data are compared with the physical parameters of the device, like the tension and energy consumption, providing a way for performing automatic testing on the research of artificial muscles.