Individuals with moderate to severe hand impairments may struggle to use EMG control for assistive devices.

Neurological trauma, such as stroke, traumatic brain injury (TBI), spinal cord injury, and cerebral palsy can cause mild to severe upper limb impairments. Hand impairment makes it difficult for individuals to complete activities of daily living, especially bimanual tasks. A robotic hand orthosis or hand exoskeleton can be used to restore partial function of an intact but impaired hand. It is common for upper extremity prostheses and orthoses to use electromyography (EMG) sensing as a method for the user to control their device. However some individuals with an intact but impaired hand may struggle to use a myoelectrically controlled device due to potentially confounding muscle activity. This study was conducted to evaluate the application of conventional EMG control techniques as a robotic orthosis/exoskeleton user input method for individuals with mild to severe hand impairments. Nine impaired subjects and ten healthy subjects were asked to perform repeated contractions of muscles in their forearm and then onset analysis and feature classification were used to determine the accuracy of the employed EMG techniques. The average accuracy for contraction identification across employed EMG techniques was 95.4% ± 4.9 for the healthy subjects and 73.9% ± 13.1 for the impaired subjects with a range of 47.0% ± 19.1 - 91.6% ± 8.5. These preliminary results suggest that the conventional EMG control technologies employed in this paper may be difficult for some impaired individuals to use due to their unreliable muscle control.

Modeling of Interstitial Ultrasound Ablation for Continuous Applicator Rotation With MR Validation.

The primary objective of cancer intervention is the selective removal of malignant cells while conserving surrounding healthy tissues. However, the accessibility, size and shape of the cancer can make achieving appropriate margins a challenge. One minimally invasive treatment option for these clinical cases is interstitial needle based therapeutic ultrasound (NBTU). In this work, we develop a finite element model (FEM) capable of simulating continuous rotation of a directional NBTU applicator. The developed model was used to simulate the thermal deposition for different rotation trajectories. The actual thermal deposition patterns for the simulated trajectories were then evaluated using magnetic resonance thermal imaging (MRTI) in a porcine skin gelatin phantom. An MRI-compatible robot was used to control the rotation motion profile of the physical NBTU applicator to match the simulated trajectory. The model showed agreement when compared to experimental measurements with Pearson correlation coefficients greater than 0.839 when comparing temperature fields within an area of 12.6 mm radius from the ultrasound applicator. The average temperature error along a 6.3 mm radius profile from the applicator was 1.27 °C. The model was able to compute 1 s of thermal deposition by the applicator in 0.2 s on average with a 0.1 mm spatial resolution and 0.5 s time steps. The developed simulation demonstrates performance suitable for real-time control which may enable robotically-actuated closed-loop conformal tumor ablation.

Demonstration and Experimental Validation of Plastic-Encased Resonant Ultrasonic Piezoelectric Actuator for Magnetic Resonance Imaging-Guided Surgical Robots.

Intra-operative medical imaging based on magnetic resonance imaging (MRI) coupled with robotic manipulation of surgical instruments enables precise feedback-driven procedures. Electrically powered nonferromagnetic motors based on piezoelectric elements have shown to be well suited for MRI robots. However, even avoiding ferrous materials, the high metal content on commercially available motors still cause distortions to the magnetic fields. We construct semicustom piezoelectric actuators wherein the quantity of conductive material is minimized and demonstrate that the distortion issues can be partly addressed through substituting several of these components for plastic equivalents, while maintaining motor functionality. Distortion was measured by assessing the root-mean-squared (RMS) change in position of 49 centroid points in a 12.5 mm square grid of a gelatin-filled phantom. The metal motor caused a distortion of up to 4.91 mm versus 0.55 mm for the plastic motor. An additional signal-to-noise-ratio (SNR) drop between motor off and motor spinning of approximately 20% was not statistically different for metal versus plastic (p = 0.36).

An Integrated Robotic System for MRI-Guided Neuroablation: Preclinical Evaluation.

OBJECTIVE: Treatment of brain tumors requires high precision in order to ensure sufficient treatment while minimizing damage to surrounding healthy tissue. Ablation of such tumors using needle-based therapeutic ultrasound (NBTU) under real-time magnetic resonance imaging (MRI) can fulfill this need. However, the constrained space and strong magnetic field in the MRI bore restricts patient access limiting precise placement of the NBTU ablation tool. A surgical robot compatible with use inside the bore of an MRI scanner can alleviate these challenges. METHODS: We present preclinical trials of a robotic system for NBTU ablation of brain tumors under real-time MRI guidance. The system comprises of an updated robotic manipulator and corresponding control electronics, the NBTU ablation system and applications for planning, navigation and monitoring of the system. RESULTS: The robotic system had a mean translational and rotational accuracy of 1.39  ± 0.64 mm and 1.27 [Formula: see text] in gelatin phantoms and 3.13  ± 1.41 mm and 5.58 [Formula: see text] in 10 porcine trials while causing a maximum reduction in signal to noise ratio (SNR) of 10.3%. CONCLUSION: The integrated robotic system can place NBTU ablator at a desired target location in porcine brain and monitor the ablation in realtime via magnetic resonance thermal imaging (MRTI). SIGNIFICANCE: Further optimization of this system could result in a clinically viable system for use in human trials for various diagnostic or therapeutic neurosurgical interventions.

Robot-assisted extended pelvic lymph node dissection in prostate cancer. When and how?

OBJECTIVE: To review the literature evaluating the role of the extended pelvic lymph node dissectione PLND during robot assisted radical prostatectomy (RARP) in the management of PCa patients, as well as the preoperative clinic pathologic factors that predict lymph node metastases (LNM). The technique and current outcomes of robotic ePLND will be presented. METHODS: Medline®/Pubmed® were searched up to august 2018 to find comparative studies of different anatomic limits of pelvic lymph node dissection (PLND) during RARP, open or pure laparoscopic surgery that reported number of nodes retrieved, oncologic outcomes and complications. The search was complemented to identify studies that evaluated diagnostic images and factors that predict LNM. Overall, 44 articles were included for full text review. RESULTS: There is not an imaging technique with an acceptable performance to select patients for PLND, the decision to perform a PLND is based on clinical characteristics described on validated nomograms. Median lymph node yield at RARP range from 5 to 21 depending on the extent of PLND, positivity rate of LN as high as 37% depending on the risk stratification of patients. Robot-assisted can be carried out to any extent with lymph node yields and safety concerns comparable to the open approach. CONCLUSION: Extended pelvic lymph node dissection is recommended to be performed at the time of RARP in intermediate and high-risk patients and cannot be replaced by other modalities. A benefit in terms of oncologic outcomes remains to be established. The robot assisted approach offers shorter length of hospital stay, lower transfusion rates and comparable outcomes compared to other surgical approaches.

ARTICULO SOLO EN INGLES.OBJETIVO: Revisar la literatura que evalúa  el papel de la linfadenectomía pélvica extendida  (LPe) durante la prostatectomía radical asistida por robot  (PRAR) en el manejo de pacientes con cáncer de próstata,  así como los factores clínico-patológicos preoperatorios  que predicen las metástasis ganglionares. Presentamos la técnica de LPe y sus resultados actuales.MÉTODOS: Se realizó una búsqueda bibliográfica en Medline®/Pubmed® hasta agosto 2018 para encontrar estudios comparativos de los diferentes límites anatómicos de la linfadenectomía pélvica duranteprostatectomía radical asistida por robot, abierta olaparoscópica que comunicaran número de ganglios,resultados oncológicos y complicaciones. La búsquedafue complementada para identificar estudios que evaluaran imágenes diagnósticas y factores predictivos demetástasis ganglionares. Finalmente, se incluyeron 44artículos. RESULTADOS: No hay una técnica de imagen que tengauna resolución aceptable para seleccionar pacientespara linfadenectomía. La decisión de practicar linfadenectomíase basa en las características clínicas descritasen nomogramas validados. La mediana del númerode ganglios obtenidos oscila entre 5 y 21 dependiendode la extensión de la linfadenectomía, y la tasa de gangliospositivos es tan alta como el 37% dependiendo dela estratificación del riesgo de los pacientes. La cirugíaasistida por robot puede realizarse con cualquier extensióncon un número de ganglios obtenidos y aspectosde seguridad comparables con el abordaje abierto. CONCLUSION: Se recomienda realizar la linfadenectomíapélvica extendida en el momento de la PRAR enpacientes de riesgo intermedio y alto y no puede reemplazarsepor otras modalidades. Sigue por establecerseun beneficio en términos de resultados oncológicos. Elabordaje asistido por robot ofrece estancias hospitalariasmás cortas, menores tasas de transfusión y resultadoscomparables en comparación con otros abordajesquirúrgicos.

Robot-assisted extended pelvic lymph node dissection in prostate cancer, when and how? / Linfadenectomía pélvica extendida en cáncer de próstata. ¿Cuándo y cómo?

Objective: To review the literature evaluating the role of the extended pelvic lymph node dissection ePLND during robot assisted radical prostatectomy (RARP) in the management of PCa patients, as well as the preoperative clinic pathologic factors that predict lymph node metastases (LNM). The technique and current outcomes of robotic ePLND will be presented. Methods: Medline(R)/Pubmed(R) were searched up to august 2018 to find comparative studies of different anatomic limits of pelvic lymph node dissection (PLND) during RARP, open or pure laparoscopic surgery that reported number of nodes retrieved, oncologic outcomes and complications. The search was complemented to identify studies that evaluated diagnostic images and factors that predict LNM. Overall, 44 articles were included for full text review. Results: There is not an imaging technique with an acceptable performance to select patients for PLND, the decision to perform a PLND is based on clinical characteristics described on validated nomograms. Median lymph node yield at RARP range from 5 to 21 depending on the extent of PLND, positivity rate of LN as high as 37% depending on the risk stratification of patients. Robot-assisted can be carried out to any extent with lymph node yields and safety concerns comparable to the open approach. CONCLUSION: Extended pelvic lymph node dissection is recommended to be performed at the time of RARP in intermediate and high-risk patients and cannot be replaced by other modalities. A benefit in terms of oncologic outcomes remains to be established. The robot assisted approach offers shorter length of hospital stay, lower transfusion rates and comparable outcomes compared to other surgical approaches

Objetivo: Revisar la literatura que evalúa el papel de la linfadenectomía pélvica extendida (LPe) durante la prostatectomía radical asistida por robot (PRAR) en el manejo de pacientes con cáncer de próstata, así como los factores clínico-patológicos preoperatorios que predicen las metástasis ganglionares. Presentamos la técnica de LPe y sus resultados actuales. Métodos: Se realizó una búsqueda bibliográfica en Medline(R)/Pubmed(R) hasta agosto 2018 para encontrar estudios comparativos de los diferentes límites anatómicos de la linfadenectomía pélvica durante prostatectomía radical asistida por robot, abierta o laparoscópica que comunicaran número de ganglios, resultados oncológicos y complicaciones. La búsqueda fue complementada para identificar estudios que evaluaran imágenes diagnósticas y factores predictivos de metástasis ganglionares. Finalmente, se incluyeron 44 artículos. Resultados: No hay una técnica de imagen que tenga una resolución aceptable para seleccionar pacientes para linfadenectomía. La decisión de practicar linfadenectomía se basa en las características clínicas descritas en nomogramas validados. La mediana del número de ganglios obtenidos oscila entre 5 y 21 dependiendo de la extensión de la linfadenectomía, y la tasa de ganglios positivos es tan alta como el 37% dependiendo de la estratificación del riesgo de los pacientes. La cirugía asistida por robot puede realizarse con cualquier extensión con un número de ganglios obtenidos y aspectos de seguridad comparables con el abordaje abierto. Conclusión: Se recomienda realizar la linfadenectomía pélvica extendida en el momento de la PRAR en pacientes de riesgo intermedio y alto y no puede reemplazarse por otras modalidades. Sigue por establecerse un beneficio en términos de resultados oncológicos. El abordaje asistido por robot ofrece estancias hospitalarias más cortas, menores tasas de transfusión y resultados comparables en comparación con otros abordajes quirúrgicos

DEMONSTRATION AND EXPERIMENTAL VALIDATION OF PLASTIC-ENCASED RESONANT ULTRASONIC PIEZOELECTRIC ACTUATOR FOR MRI-GUIDED SURGICAL ROBOTS.

Intra-operative medical imaging based on magnetic resonance imaging (MRI) coupled with robotic manipulation of surgical instruments enables precise feedback-driven procedures. Electrically powered non-ferromagnetic motors based on piezoelectric elements have shown to be well suited for MRI robots. However, even avoiding ferrous materials, the high metal content on commercially available motors still cause distortions to the magnetic fields. We construct semi-custom piezoelectric actuators wherein the quantity of conductive material is minimized and demonstrate that the distortion issues can be partly addressed through substituting several of these components for plastic equivalents, while maintaining motor functionality. Distortion was measured by assessing the RMS change in position of 49 centroid points in a 12.5mm square grid of a gelatin-filled phantom. The metal motor caused a distortion of up to 4.91mm versus 0.55mm for the plastic motor. An additional SNR drop between motor off and motor spinning of approximately 20% was not statistically different for metal versus plastic (p=0.36).

Prognostic implications of the difference between left ventricular ejection fractions after stress and at rest in addition to the quantification of myocardial perfusion abnormalities obtained with gated SPECT.

BACKGROUND: The prognostic significance of the difference between poststress and at rest left ventricular ejection fraction (ΔLVEF) in patients sent for diagnostic myocardial perfusion study (MPS) is not well characterized. The purpose of this study was to prospectively evaluate the ability of ΔLVEF in further risk stratifying these patients in addition to the severity/extent of myocardial perfusion abnormalities expressed as the total perfusion deficit at stress (sTPD), according to the type of stress used. METHODS AND RESULTS: Two-day 99mTc-MIBI MPS after stress and rest were obtained for 507 patients subdivided according to the type of stress used, sTPD values, and ΔLVEF. Subsequent cardiac events were determined through a standardized questionnaire applied 1, 2, and 6 years after MPS. Independent of the type of stress used, the 6-year event rate with progressive perfusion and functional abnormalities combined was significant for total events, all-cause death, cardiac death, and revascularization but not for myocardial infarct. When ΔLVEF decreased by more than -10%, only those individuals with sTPD of 5% or less had increased 6-year total event rates [5.9% vs 15% for those submitted to treadmill test (P < 0.001) and 8.3% vs 19% when submitted to pharmacological stress (P = 0.001)]. An sTPD greater than 5% was the only variable predictive of total events when multivariate analysis was applied (P < 0.001 for treadmill exercise and P = 0.033 for dipyridamole). CONCLUSIONS: Estimation of ΔLVEF in addition to sTPD seems to improve risk stratification for future events when ΔLVEF decreases by more than -10% for those individuals with normal or near-normal myocardial perfusion (sTPD ≤ 5%). An sTPD greater than 5% was a better prognostic indicator of future events when compared with ΔLVEF for individuals with greater perfusion abnormality at stress.

Self-Etching Primer: resistência confiável na colagem de acessórios ortodônticos? Estudo clínico / Self-Etching Primer: reliable shear bonding strength of orthodontic brackets? A clinical study

O objetivo neste estudo clínico prospectivo foi quantificar a freqüência de queda de braquetes metálicos durante o tratamento ortodôntico, quando utilizado o sistema adesivo Transbond Plus – Self-Etching Primer (SEP). A amostra foi composta por 278 dentes de 17 pacientes consecutivos, que realizaram tratamento ortodôntico regular na clínica de Ortodontia da USP. Os braquetes utilizados (Victory, slot .022”, prescrição MBT, 3M-Unitek) foram colados de forma direta sobre a face vestibular dos dentes superiores e inferiores, seguindo as orientações do fabricante. Uma vez iniciado o tratamento foram monitoradas as colagens durante 30 meses e registradas as quedas, causa da queda e a posição dos dentes nas arcadas. Os resultados indicam que houve 16 quedas, que representam 5,8% do total dos dentes considerados, observando-se maior incidência nos pré-molares (8,9%), seguida dos incisivos (6,5%) e nenhuma nos caninos. As causas em termos gerais dizem respeito ao excesso de força aplicada, mordendo itens que deveriam ter sido excluídos da dieta regular, conforme orientação inicial, com balas e pirulitos, entre outros. Com base nesses resultados podemos afirmar que o transbond Plus – Self-Etching Primer apresenta comportamento clinico semelhante ao descrito na literatura para os já consagrados sistemas de condicionamento do esmalte tradicionais, portanto se confirmando a sua perfeita confiabilidade no uso clinico.

Aim of this clinical prospective study was to quantify metallic bracket bonding failure during orthodontic treatment when used the adhesive system transbond Plus – Self-Etching Primer (SEP). 278 teeth of 17 consecutive patients undergoing regular orthodontic treatment in the orthodontics department of the University of Sao Paulo composed the sample. The brackets used in this study (Victory, slot 0.022”, MBT prescription, 3M-Unitek) were bonded directly on the buccal surface of the upper and lower teeth following the instructions given from the producer. Once the treatment started, the bonding of the bracket was monitored during 30 months. When the failure occurred, the cause and the position of the tooth were recorded. The results indicate that 16 brackets failure occurred, representing 5.8% of the 278 teeth, being the major bracket bonding failure percentage on the premolars (8.9%) followed by the incisors (6.5%). No bonding failure occurred on the cuspids. The main cause of the bonding failure was related to excess of force applied on the bracket chewing hard aliments (sweets) that should have been eliminated, as asked at the beginning of the treatment, from the regular diet. Based on these results we can state that Transbond Plus – self-Etching Primer shows a clinical behavior similar to the one described in the literature for the traditional bonding systems based on conventional acid etching of the enamel, confirming though is perfect reliability for the clinical use.

Influência da época de colheita e do genótipo de cana-de-açúcar sobre a infestação de Mahanarva fimbriolata (Stal) (Hemiptera: Cercopidae) / Effect of harvest period and sugarcane variety on Mahanarva fimbriolata (Stal) (Hemiptera: Cercopidae) infestation

O efeito da época de colheita e dos genótipos de cana-de-açúcar sobre a infestação da cigarrinha das raízes, Mahanarva fimbriolata (Stal), foi avaliado em um campo experimental, contendo 18 genótipos e no qual as colheitas foram efetuadas em três épocas: maio, agosto e outubro. As maiores infestações das cigarrinhas ocorreram no campo em que a cana-de-açúcar foi colhida em maio, provavelmente porque durante o verão, quando o ataque das cigarrinhas das raízes foi mais intenso, a cultura colhida em maio apresentou plantas maiores que aquelas colhidas em agosto ou outubro, o que contribuiu para o melhor sombreamento do terreno e, consequentemente, maior umidade no solo, favorecendo significativamente o desenvolvimento da praga. Entre os genótipos avaliados, IAC83-2396, SP80-1842 e RB825336 foram severamente atacados, sendo considerados os preferidos pela praga. As cultivares RB72454, RB835486 e IAC86-2210 apresentaram níveis populacionais de M. fimbriolata um pouco menores que aqueles encontrados nos genótipos anteriores, porém também elevados. Entre os genótipos menos infestados pela cigarrinha das raízes podem ser citados IAC82-3092, IAC87-3187 e PO86-1107.

The objective of this work was to study the effect of harvest period and sugarcane genotypes on Mahanarva fimbriolata (Stal) infestation. Under field conditions, 18 genotypes were harvested in three periods: May, August and October. The highest root froghoppers populations were obtained in the field were sugarcane was harvested in may, probably because, during summer, when the root froghopper attack is more intensive, the plants were more grown. In consequence, the soil was more shaded and humid, favouring the root froghopper development. The genotypes IAC83-2396, SP80-1842 and RB825336 were severely attacked and were preferred by the pest. The cultivars RB72454, RB835486 e IAC86-2210 also presented high populational levels. IAC82-3092, IAC87-3197 and PO86-1107 presented the smallest pest infestations.

Colestase neonatal - atraso no encaminhamento de crianças para diagnótico diferencial / Neonatal cholestasis: The delay in referring patients for differential diagnosis

Objetivo: O tratamento eficaz da atresia de vias biliares extra-hepáticas exige que a diferenciaçäo diagnóstica entre colestase neonatal de causa intra e extra-hepática seja realizada antes das primeiras oito semanas de vida. o objetivo do presente estudo foi avaliar a idade dos pacientes com colestase neonatal iternados em um hospital geral para diferenciaçäo diagnóstica da icterícia colestática. Métodos: Foram estudadas 49 crianças no Serviço de Pediatria do Hospital de Clínicas de Porto Alegre entre 1984 e 1991. O protocolo para esclarecimento diagnóstico seguido neste hospital inclui realizaçäo de cintilografia de vias biliares com Tc-99m DISIDA e posterior biópsia hepática, em cunha ou percutânea dependendo do resultado do teste cintilográfico...