Combining FES and Exoskeletons in a Hybrid Haptic System for Enhancing VR Experience.

Robotic technology and functional electrical stimulation (FES) have emerged as highly effective rehabilitative techniques for individuals with neuromuscular diseases, showcasting their ability to restore motor functions. Within the proposed study, we developed and tested a new hybrid controller combining an upper-limb exoskeleton with FES to enhance haptic feedback when performing task-oriented and bimanual movement, like pick-and-place, in a virtual environment. We investigated the performance of the proposed approach on eight unimpaired participants providing haptic feedback either only by the exoskeleton or by the hybrid system. The hybrid control presents two different modalities, assistive and resistive, to modulate the perception of the load. FES intensity is calibrated to the subjects' biomechanical properties and it is adjusted in real-time according to the real-time motion of the upper limbs. Experimental results highlighted the ability of the hybrid control to improve kinematic performance: in both hybrid modalities subjects reduced the target matching error(values between 0.048±0.007 m and 0.06±0.006 m) without affecting the normal motion smoothness (SPARC values in the hybrid conditions range from -2.58±0.12 to -3.30±0.13). Moreover, the resistive approach resulted in greater metabolic consumption (1.04±0.03 W/kg), indicating a more realistic experience of lifting a virtual object through FES that increased the perceived weight. The innovation in our hybrid control relies on the modulation of muscular activation during manipulation tasks, which could be a promising approach in the clinical treatment of neuromuscular diseases.

El futuro de la elaboración de medicamentos: comentarios al proyecto de modificación del RD175/2001 / The future of drug compounding: comments on the Real Decreto 175/2001 modification project

Objetivo: El 22 de marzo de 2022 la Agencia Española de Medicamentos y Productos Sanitarios y el Ministerio de Sanidad sacaron a consulta pública el proyecto de Real Decreto para modificar el RD175/2001 que regula la elaboración y control de calidad de fórmulas magistrales y preparados oficinales. Este trabajo sugiere lo que la nueva norma debería tener en cuenta para potenciar la elaboración de medicamentos bajo un estándar de calidad más elevado.Método: Se ha realizado un estudio de la situación, legislativa y práctica, de la actividad elaboradora en España, así como técnicas y conceptos de calidad empleados en la industria farmacéutica a nivel internacional.Resultados: La elaboración debe considerarse una actividad más de entre todas las que llevan a cabo los Servicios de Farmacia y por esto debe estar enmarcada dentro de todo su contexto normativo. Es conveniente ampliar los esfuerzos en la garantía de calidad para poder elaborar medicamentos con clasificaciones más abiertas, permitiendo emplear los recursos de forma más eficiente y ajustada al compromiso de cada Servicio con la actividad elaboradora.Conclusión: Por tanto, el nuevo Real Decreto debe considerar la calidad de los medicamentos que llegan al paciente como el objetivo principal de esta actividad. (AU)

Aim: In March 2022, the Spanish Agency of Medicines and Medical Devices and the Ministry of Health presented for public consultation the project of Real Decreto to modify the RD175/2001, which regulates the compounding of magistral formulas and formulations typified in the National Formulary. This work intends to signify what the new regulation should consider boosting compounding under a higher quality standard. Method: Current state of art of compounding in Spain has been studied, just as quality techniques and concepts developed in pharmaceutical industry at an international level.Results: Compounding needs to be considered as one between all the activities developed by Pharmacy Services and, hence, it must be framed inside all its regulatory context. It would be desirable to increase the efforts in quality assurance to permit a wider classification for the presentations, using resources in a more efficient way and commensurate to the commitment of each Service with compounding.Conclusion: Accordingly, the new Real Decreto should acknowledge that the quality of the medicines which reach patients should be the primal objective of this activity. (AU)

Modular one-to-many clutchable actuator for a soft elbow exosuit.

Exoskeletons have been developed for a wide range of applications, from the military to the medical field, with the aim of augmenting human performance or compensating for neuromuscular deficiencies. However, to empower the high number of degrees of freedom of the human body, they often employ a high number of motors, increasing the size, weight and power consumption of the system. We hereby present an actuation strategy to empower our elbow exosuit that adopts a single motor to drive multiple, independently actuated, degrees of freedom. This paradigm, known as One-to-many, is achieved using a modular design where each module comprises a clutchable mechanism that allows to convert a single directional motion from the prime mover to a selectable bidirectional output. Moreover, the mechanism has a locking feature that enables the wearer of the exoskeleton to hold a static load with a minimal power consumption. We present a simple controller for the clutchable unit based on a finite-state machine model, and evaluate its performance for varying input velocities. The system is shown to have a bandwidth of 1.5 Hz, sufficient for daily elbow movements, whilst retaining a compact design.

Cirugía mínimamente invasiva en la patología esofágica tumoral / Minimally invasive surgery for esophageal tumors: experience in 85 patients

Background: Minimally invasive surgery reduced the incidence of postoperative complications. Many benign or malignant esophageal diseases can be treated with this technique. Aim: To report our experience with the technique in the treatment of esophageal tumors. Material and Methods: Analysis of a cohort of 85 patients with esophageal tumors aged 28 to 82 years (59 males). Sixty seven had esophageal cancer, 14 had leiomyomas or esophageal stromal tumors and four had duplication cysts. All were subjected to minimally invasive surgery. Short and long term results were recorded. Results: Forty three percent of patients with cancer had complications and 2.9 percent died. No complications were recorded among patients with stromal tumors or duplication cysts. Conclusions: Minimally invasive surgery is a feasible and safe therapeutic approach for patients with esophageal tumors.

Introducción: En las últimas dos décadas, la implementación de técnicas quirúrgicas mínimamente invasivas ha colaborado en la reducción de las complicaciones intra y postoperatorias. Un amplio espectro de enfermedades del esófago, benignas o malignas, pueden ser tratadas por medio de estas técnicas. Objetivo: Se presenta nuestra experiencia en el tratamiento quirúrgico de la patología tumoral esofágica y se hace una revisión de las indicaciones y resultados publicados en la literatura internacional. Material y Método: Se trata de 85 pacientes operados desde 1993 a la fecha, 67 corresponden a cáncer esofágico, 14 casos operados por leiomomas o tumores estromales esofágicos y 4 pacientes con quistes de duplicación. Todos fueron sometidos a cirugía mini invasiva de acuerdo a técnicas descritas previamente. Se analizan y discuten los resultados a corto y largo plazo y se discuten los resultados a la luz de los datos de la literatura internacional. Resultados: En los pacientes sometidos a esofagectomía por cáncer, las complicaciones ocurrieron en 43 por ciento y la mortalidad actual es de un 2,9 por ciento. En pacientes operados por tumores estromales o quistes de duplicación no hubo complicaciones postoperatorias ni mortalidad. En las otras patologías hubo mínima morbilidad y no hubo mortalidad, resultados que son comparables a la literatura consultada. Conclusión: Las técnicas de cirugía mínimamente invasiva diseñadas para el abordaje de los diversos tipos de patologías que afectan al esófago, resultan por lo general, altamente factibles de realizar, con buenos resultados en cuanto a complicaciones y mortalidad postoperatoria.

EMG-based learning approach for estimating wrist motion.

This paper proposes an EMG based learning approach for estimating the displacement along the 2-axes (abduction/adduction and flexion/extension) of the human wrist in real-time. The algorithm extracts features from the EMG electrodes on the upper and forearm and uses Support Vector Regression to estimate the intended displacement of the wrist. Using data recorded with the arm outstretched in various locations in space, we train the algorithm so as to allow robust prediction even when the subject moves his/her arm across several positions in space. The proposed approach was tested on five healthy subjects and showed that a R(2) index of 63.6% is obtained for generalization across different arm positions and wrist joint angles.

Wrist rehabilitation in chronic stroke patients by means of adaptive, progressive robot-aided therapy.

Despite distal arm impairment after brain injury is an extremely disabling consequence of neurological damage, most studies on robotic therapy are mainly focused on recovery of proximal upper limb motor functions, routing the major efforts in rehabilitation to shoulder and elbow joints. In the present study we developed a novel therapeutic protocol aimed at restoring wrist functionality in chronic stroke patients. A haptic three DoFs (degrees of freedom) robot has been used to quantify motor impairment and assist wrist and forearm articular movements: flexion/extension (FE), abduction/adduction (AA), pronation/supination (PS). This preliminary study involved nine stroke patients, from a mild to severe level of impairment. Therapy consisted in ten 1-hour sessions over a period of five weeks. The novelty of the approach was the adaptive control scheme which trained wrist movements with slow oscillatory patterns of small amplitude and progressively increasing bias, in order to maximize the recovery of the active range of motion. The primary outcome was a change in the active RoM (range of motion) for each DoF and a change of motor function, as measured by the Fugl-Meyer assessment of arm physical performance after stroke (FMA). The secondary outcome was the score on the Wolf Motor Function Test (WOLF). The FMA score reported a significant improvement (average of 9.33±1.89 points), revealing a reduction of the upper extremity motor impairment over the sessions; moreover, a detailed component analysis of the score hinted at some degree of motor recovery transfer from the distal, trained parts of the arm to the proximal untrained parts. WOLF showed an improvement of 8.31±2.77 points, highlighting an increase in functional capability for the whole arm. The active RoM displayed a remarkable improvement. Moreover, a three-months follow up assessment reported long lasting benefits in both distal and proximal arm functionalities. The experimental results of th- s preliminary clinical study provide enough empirical evidence for introducing the novel progressive, adaptive, gentle robotic assistance of wrist movements in the clinical practice, consolidating the evaluation of its efficacy by means of a controlled clinical trial.

Impact of minimally invasive surgery in the treatment of esophageal cancer.

BACKGROUND: Surgical treatment of esophageal cancer is associated to a high morbidity and mortality rate. The open transthoracic or transhiatal esophagectomy are considerably invasive procedures and have been associated to high rates of complications and operative mortality. In this way, minimally invasive esophageal surgery has been suggested as an alternative to the classic procedures because would produce improvement in clinical longterm postoperative outcomes. AIM: To assess survival, mortality and morbidity results of esophagectomy due to esophageal cancer submitted to minimally invasive techniques and compare them to results published in international literature. METHOD: An observational, prospective study. Between 2003 and 2012, 69 patients were submitted to a minimally invasive esophagectomy due to cancer. It was recorded postoperative morbidity and mortality according to the Clavien-Dindo classification. The survival rate was analyzed with the Kaplan-Meier method. The number of lymph nodes obtained during the lymph node dissection, as an index of the quality of the surgical technique, was analysed. RESULTS: 63.7% of patients had minor complications (type I-II Clavien Dindo), while nine (13%) required surgical re-exploration. The most common postoperative complication corresponded to leak of the cervical anastomosis seen in 44 (63.7%) patients but without clinical repercusion, only two of them required reoperation. The mortality rate was 4.34%, and reoperation was necessary in nine (13%) cases. The average survival time was 22.59 ± 25.38 months, with the probability of a 3-year survival rate estimated at 30%. The number of resected lymph nodes was 17.17 ± 9.62. CONCLUSION: Minimally invasive techniques have lower morbidity and mortality rate, very satisfactory lymphnodes resection and similar long term outcomes in term of quality of life and survival compared to results observed after open surgery.

Resultados del tratamiento quirúrgico de la patología esofágica benigna con cirugía mínimamente invasiva: experiencia en 483 pacientes / Minimally invasive surgery for benign esophageal diseases: experience in 483 patients

Background: Minimally invasive surgical techniques are increasingly used for the treatment of benign esophageal diseases. Aim: To report the results of minimally invasive surgical techniques among patients with benign esophageal diseases. Material and Methods: Four hundred eighty three patients aged 37 to 81 years (184 males), were studied. Of these, 278 had a Barret esophagus, 125 had a hiatal hernia, 75 had achalasia and five had esophageal diverticula. All patients were studied using standard protocols, operated using minimally invasive techniques and followed, registering postoperative complications and recurrence of symptoms. Results: Among patients with esophageal reflux, 85 percent had successful results on the long term. Among patients with hiatal hernia and subjected to laparoscopic surgery, 12 percent had complications and 12 percent had recurrence of symptoms which increased to 17 percent if a mesh was not used. The recurrence rate among patients with achalasia is less than 5 percent. There was no recurrence among patients with esophageal diverticula. Conclusions: Minimally invasive surgery for esophageal diseases has good success rates, with a lower incidence of complications than open surgery.

Introducción: En este artículo se presenta la experiencia de nuestro grupo de trabajo de los resultados obtenidos en el tratamiento quirúrgico con técnicas mínimamente invasivas en patología esofágica benigna. Material y Método: Se analizan los resultados en pacientes sometidos a cirugía antirreflujo por enfermedad por reflujo gastroesofágico, esófago de Barrett, tratamiento de las hernias hiatales, acalasia esofágica y diver-tículos esofágicos. Resultados: Los resultados obtenidos por nuestro grupo son comparables a los que señala la literatura internacional, con mínima morbilidad y sin mortalidad. En pacientes con reflujo gastroesofágico, los resultados a largo plazo presentan una tasa de éxito en el 85 por ciento de los casos. En pacientes con hernia hiatal operados por vía laparoscópica las complicaciones son cercanas al 12 por ciento y la recurrencia es de un 12 por ciento en promedio, pero se eleva al 17 por ciento cuando no se usa malla. En Acalasia por otro lado, la tasa de recurrencia es menor a un 5 por ciento. Los pacientes operados por divertículos esofágicos no presentan recidiva. Conclusiones: Las técnicas de cirugía mínimamente invasiva diseñadas para el abordaje de los diversos tipos de patologías que afectan al esófago, resultan por lo general, altamente factibles de realizar por cuanto reproducen los resultados de la cirugía abierta pero con menor tasa de complicaciones.

Rol de la cirugía mínimamente invasiva en la patología esofágica benigna: reporte de una serie de casos / Laparoscopic surgery for benign esophageal diseases

Background: Minimally invasive surgery has the advantage of a lower rate of complications and can be used for benign esophageal diseases. Aim: To report a single surgeon experience with laparoscopic surgery for benign esophageal diseases. Material and Methods: Prospective analysis of 421 patients (160 males) with benign esophageal disease, who were subjected to laparoscopic surgery by a single surgeon. Immediate mortality, surgical complications and long term results in terms of symptoms recurrence, were analyzed. Results: The underlying diagnoses of the operated patients were Barrett's esophagus or esophagitis in 257, hiatal hernia in 91, achalasia in 68 and esophageal diverticula in five. Surgery obtained successful results in 90% of patients with Barrett's esophagus. Among patients with hiatal hernia, there was a 12% rate of complications and a 30% recurrence, when a mesh was not used. Among patients with achalasia the recurrence rate was less than 5%. Conclusions: Laparoscopic surgery has a fair success rate in benign esophageal diseases, with a lower rate of complications.

[Laparoscopic surgery for benign esophageal diseases]. / Rol de la cirugía mínimamente invasiva en la patología esofágica benigna: reporte de una serie de casos.

BACKGROUND: Minimally invasive surgery has the advantage of a lower rate of complications and can be used for benign esophageal diseases. AIM: To report a single surgeon experience with laparoscopic surgery for benign esophageal diseases. MATERIAL AND METHODS: Prospective analysis of 421 patients (160 males) with benign esophageal disease, who were subjected to laparoscopic surgery by a single surgeon. Immediate mortality, surgical complications and long term results in terms of symptoms recurrence, were analyzed. RESULTS: The underlying diagnoses of the operated patients were Barrett's esophagus or esophagitis in 257, hiatal hernia in 91, achalasia in 68 and esophageal diverticula in five. Surgery obtained successful results in 90% of patients with Barrett's esophagus. Among patients with hiatal hernia, there was a 12% rate of complications and a 30% recurrence, when a mesh was not used. Among patients with achalasia the recurrence rate was less than 5%. CONCLUSIONS: Laparoscopic surgery has a fair success rate in benign esophageal diseases, with a lower rate of complications.

Wrist Coordination in a Kinematically Redundant Stabilization Task.

We investigated how the control of a compliant object is realized by the redundancy of wrist anatomy. Subjects had to balance a one degree-of-freedom inverted pendulum using elastic linkages controlled by wrist flexion/extension (FE) and forearm pronation/supination (PS). Haptic feedback of the interaction forces between the pendulum and the wrist was provided by a robotic interface. By tuning the mechanical properties of the virtual pendulum and the stiffness of the elastic linkages it was possible to study various dynamical regimes of the simulated object. Twenty subjects (divided in two groups) were tested in four days performing the same task but with different presentation order. The stabilization strategy adopted by the subjects was characterized by primarily using the PS DoF when the pendulum was linked to stiff springs and characterized by a relatively fast dynamic response; in contrast, the stabilization task was shared by both DoFs in case of lower spring stiffness and slower dynamics of the virtual object.

Necrosis cutánea por tratamiento anticoagulante oral: caso clínico / Cutaneous necrosis caused by acenocumarol: case report

Cutaneous necrosis is a rare but serious complication, among patients treated with warfarin or acenocumarol derivatives. We report a 71 years old female with a history of deep venous thrombosis, receiving acenocumarol for three months. The treatment was discontinued, but had to be restarted, due to a new episode of thrombosis. Three days after restarting acenocumarol, the patient consulted for ecchymosis and pain of the right foot. At physical examination, there was distal cyanosis and absence of distal pulses. The patient was subjected to an embolectomy with the suspicion of an acute arterial occlusion, but no emboli were found. Due to the possibility of a cutaneous necrosis caused by Acenocumarol, the medication is discontinued. The cutaneous lesions progressed and eight days after the failed embolectomy, a gangrene of the right foot was diagnosed. The patient did not accept amputation dying fourteen days after the first intervention.

A propósito un caso registrado, se resume la historia clínica y se revisa la literatura, dada la escasa frecuencia de esta complicación derivada del tratamiento por anticoagulantes orales. La necrosis cutánea es un evento adverso raro, pero serio, de la anticoagulación con derivados de acenocumarol o warfarina. Se comunicó por primera vez en 1943. La incidencia de la necrosis cutánea inducida por anticoagulantes orales es de 0,01 al 0,1 por ciento de los pacientes tratados. El número de casos publicados en el mundo es de aproximadamente 300, y menos de 100 en lengua inglesa en las últimas tres décadas. Este trabajo reporta el caso de una paciente que presenta necrosis cutánea en hombro izquierdo y pierna derecha.

A novel mechatronic system for measuring end-point stiffness: mechanical design and preliminary tests.

Measuring arm stiffness is of great interest for many disciplines from biomechanics to medicine especially because modulation of impedance represents one of the main mechanism underlying control of movement and interaction with external environment. Previous works have proposed different methods to identify multijoint hand stiffness by using planar or even tridimensional haptic devices, but the associated computational burden makes them not easy to implement. We present a novel mechanism conceived for measuring multijoint planar stiffness by a single measurement and in a reduced execution time. A novel mechanical rotary device applies cyclic radial perturbation to human arm of a known displacement and the force is acquired by means of a 6-axes commercial load cell. The outcomes suggest that the system is not only reliable but allows obtaining a bi-dimensional estimation of arm stiffness in reduced amount of time and the results are comparable with those reported in previous researches.

Úlcera tuberculosa intestinal como causa de hemorragia digestiva baja masiva exanguinante / Intestinal tuberculosis causing a severe gastrointestinal bleeding: report of one case

We report a 27 years old woman presenting with hematochezia. An upper endoscopy and colonoscopy did not reveal the bleeding site. Due to persistence of bleeding, the patient was operated, finding a fibrinous secretion surrounding bowel loops and a hyper vascularized concentric papular lesion. The involved bowel loop was excised. The pathological study of the surgical piece revealed intestinal tuberculosis. The patient started treatment for extra pulmonary tuberculosis.

Reportamos el caso de una paciente de 27 años con tuberculosis extrapulmonar gastrointestinal que se manifestó clínicamente como una hemorragia digestiva baja masiva exanguinante requiriendo cirugía de urgencia, donde se realizó laparotomía exploradora con entero y colonoscopía intraoperatoria localizando lesión a nivel de intestino delgado, resecando segmento comprometido con anastomosis primaria, evolución satisfactoria sin complicaciones postoperatorias.

Stabilizing unstable object by means of kinematic redundancy.

The paper aims to investigate how humans deal with unstable objects under the possibility of choosing different strategy of interaction. The presented task consisted in balancing a 1 degree of freedom (DoF) elastic inverted pendulum by means of 2 DoF of the wrist (fexion/extension and pronation/supination). The pendulum was simulated using a virtual environment and the haptic feedback was generated by a robotic wrist device. The task is a redundant because the subject can choose how to use the 2 DoF in order to move and stabilize a 1 DoF simulated mechanical system: the inverted pendulum. Six subjects volunteered to participate and were tested in four different days performing the same task but experiencing different mechanical systems (pendulum) characterized by lower or higher dynamics due to the possibility to tune the stiffness of the pendulum. Subjects were asked to balance the inverted pendulum maintaining it in a vertical position for a required amount of time. It was found the adopted stabilization strategy was mainly characterized by using only one of the 2 available DoFs of their wrist when the pendulum was stiffer, while in case of lower stiffness of the pendulum (slower dynamic) wrist input redundancy was a more suitable strategy to perform the balancing task.

Abnormal adaptation in children affected by cerebral palsy to robot generated dynamic environment.

This paper aims to investigate how robotic devices can be used to understand the mechanism of sensorimotor adaptation in pediatric subjects affected by hemiparetic cerebral palsy. Previous studies showed how healthy adults, after training in presence of a systematic structured disturbing force field, show an "after effect" and therefore they highly adapt and compensate the external disturbance. An open issue is whether this adaptive capability is preserved or disrupted in pediatric impaired subjects when they experience a robot generated dynamic environment. Fourteen pediatric Cerebral Palsy subjects (CP group), and age-matched control group were exposed to a robot generated speed-dependant force field; during familiarization (no forces generated by the robot) the movement of the CP subjects were more curved, displaying greater and variable directional error; in the force field phase both the groups showed an after-effect, but the CP group had a non significant adaptation rate. This outcome suggests the CP subjects have reduced ability to learn external force and they make greater aiming error because of an inefficient anticipatory strategy during visuomotor task.

The impact of robotic rehabilitation in children with acquired or congenital movement disorders.

AIM: The aim of this study was to evaluate if the robot-mediated therapy (RMT) can yield positive outcomes in children with acquired or congenital upper extremity movement disorders. METHODS: This was an uncontrolled pilot study with pre-post treatment outcome comparison carried out by the Pediatric Rehabilitation Department of a Children's Hospital. The study enrolled 12 children, aged 5 to 15 years, suffering from acquired (at least 12 months post-onset) or congenital upper limb motor impairment. ETIOLOGY: 4 stroke, 6 traumatic brain injuries, and 2 hemiplegic cerebral palsy. RMT was provided 3 times a week for an hour during 6 weeks for a total of 18 robot therapy sessions. The Melbourne Scale (MS) and the upper-extremity subsection of the Fugl-Meyer Assessment (FMA) were used for measurement of impairment. Secondary outcome measurements were made through the Modified Ashworth Scale (MAS); the Reaching Performance Scale (RPS); Parent's Questionnaire, and robot-based evaluation measurements. Specifically, authors compared the smoothness, as measured by the jerk metric, and average speed of unconstrained reaching movements. RESULTS: Pre-post clinical evaluation revealed statistically significant gains for all primary and secondary metrics. In addition, significant improvement of robot-based metrics was observed. The primary outcome measurement mean (SEM) gains were 6.71 (1.29) for MS and 3.33 (0.80) for the FMA. RMT led to spasticity decreases in chronic cases, as shown by the reduction of MAS. It led to improved trunk-upper extremity postural attitude as demonstrated by improved RPS, and it was well accepted by parents and children as observed in the Parent's Questionnaire. CONCLUSIONS: This study suggests that RMT may hold rehabilitative benefits in children suffering from acquired and congenital hemiparesis.

Design and Characterization of Hand Module for Whole-Arm Rehabilitation Following Stroke.

In 1991, a novel robot named MIT-MANUS was introduced as a test bed to study the potential of using robots to assist in and quantify the neurorehabilitation of motor function. It introduced a new modality of therapy, offering a highly backdrivable experience with a soft and stable feel for the user. MIT-MANUS proved an excellent fit for shoulder and elbow rehabilitation in stroke patients, showing a reduction of impairment in clinical trials with well over 300 stroke patients. The greatest impairment reduction was observed in the group of muscles exercised. This suggests a need for additional robots to rehabilitate other target areas of the body. Previous work has expanded the planar MIT-MANUS to include an antigravity robot for shoulder and elbow, and a wrist robot. In this paper we present the "missing link": a hand robot. It consists of a single-degree-of-freedom (DOF) mechanism in a novel statorless configuration, which enables rehabilitation of grasping. The system uses the kinematic configuration of a double crank and slider where the members are linked to stator and rotor; a free base motor, i.e., a motor having two rotors that are free to rotate instead of a fixed stator and a single rotatable rotor (dual-rotor statorless motor). A cylindrical structure, made of six panels and driven by the relative rotation of the rotors, is able to increase its radius linearly, moving or guiding the hand of the patients during grasping. This module completes our development of robots for the upper extremity, yielding for the first time a whole-arm rehabilitation experience. In this paper, we will discuss in detail the design and characterization of the device.

Atypical hepatic hemangiomas with intense arterial enhancement and early fading.

BACKGROUND: Our purpose is to analyze the prevalence and characteristics of the enhancement patterns of hemangiomas. METHODS: Fifty-five proven hemangiomas studied with a dynamic single-slice T1-weighted spoiled gradient echo sequence (50/13/65 degrees) were retrospectively selected. Fifteen images of the tumor in 5 min were obtained after a bolus of gadolinium. A temporal planar reconstruction image was generated to analyze the dynamic evolution of a line of interest through the tumor. RESULTS: Most hemangiomas (60%) had a typical progressive pattern with hyperintensity on late images. Of these, 34.6% had an intense enhancement pattern with the highest slope close to the arterial or portal phases of perfusion and 25.5% had a less intense enhancement with a more constant rate. In 10.9% of cases, the enhancement was slowly progressive with late isointensity and 7.3% had a very slow progressive pattern with late hypointensity; all had a globular peripheral initial enhancement pattern. There were 12 hemangiomas (21.8%) with intense arterial enhancement and early fading; eight of 12 (66.7%) showed peripheral globular enhancement, with all 12 hemangiomas remaining hyperintense to the liver at the end of the dynamic study. In four cases, the initial enhancement was diffuse throughout the entire lesion. CONCLUSIONS: Hemangiomas can have early intense enhancement with early fading and diffuse intense enhancement.

Differentiation of healthy from cirrhotic livers. Evaluation of parametric images after contrast administration in magnetic resonance imaging.

RATIONALE AND OBJECTIVES: The authors describe a method to differentiate healthy from cirrhotic livers by the analysis of their behavior after paramagnetic contrast administration on magnetic resonance imaging. METHODS: A dynamic single-slice spoiled-gradient recalled echo magnetic resonance imaging after contrast administration was performed on 67 patients (36 healthy livers and 31 cirrhotic livers). Three parametric images (averaged-enhancement, maximum-enhancement, and maximum-velocity) were reconstructed from the temporal dynamic images. Liver values were quantified by means of a region-of-interest procedure. RESULTS: Relative averaged-enhancement and maximum-enhancement values were significantly different ( P < 0.05) between cirrhotic and normal livers. There was a significant correlation between the parametric values and the Child-Turcotte index of hepatic chronic insufficiency (P < 0.05). CONCLUSIONS: Parametric images allow characterization of the signal-versus-time pixel-by-pixel variations in dynamic magnetic resonance imaging. The averaged-enhancement and maximum-enhancement values can be used to differentiate healthy from cirrhotic livers with accuracy. The higher values found in cirrhotic patients may reflect an overall increase in the amount of extracellular contrast present with respect to healthy livers. The degree of liver brightness in cirrhotic patients probably is related to an increased amount of interstitial space, an indirect measurement of hepatic necrosis.