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A preponderance of evidence, primarily from surveys, has shown that gastroenterologists suffer from overuse injuries and pain of hand/fingers, wrist, forearm, shoulder, and back due to awkward postures, high forces, and repetitive movements during endoscopy. Although flexible endoscopes are brilliantly designed compact instruments that include light and image guides, irrigation channels, suction channel, biopsy channels and are the result of many technological advancements and iterations in the last 5 decades, not much has changed in their basic functions, layout, ergonomic design, and usability. The required hand-tool interaction in order to maneuver the endoscope inside the intestinal lumen, such as stabilizing the control section while manipulating dials with the left hand while simultaneously torqueing, pushing, and/or pulling the insertion tube with the right hand, are still unchanged. It is imperative that the scope manufacturers understand the ergonomic areas of concern in the design of current endoscopes and incorporate ergonomic principles in future designs to optimize the interface between the instrument and the physician. In addition, it is as important for the physicians to be educated on ergonomic principles to minimize the risk for endoscopy-related injuries. This chapter reviews the design of current endoscopes and the ergonomic areas of concern. We review endoscope design changes that are needed to mitigate risk of injury during endoscopy, possible innovations that may improve endoscope ergonomics in the future, and barriers to implementation of any intervention that will address these shortcomings.

Platelets can be found on the surface of inflamed and ruptured atherosclerotic plaques. Thus, targeting of activated platelets may allow for molecular imaging of vulnerable atherosclerotic lesions. We here investigated microbubbles (MB) functionalized with the selectin ligand sialyl Lewisa individually (MBsLea) or dually with sLea and an antibody targeting ligand-induced binding sites of the activated GPIIb/IIIa receptor (MBDual). Assessed by in vitro flow chamber, targeted MB exhibited increased adhesion to platelets as compared to MBControl. While MBsLea rolled slowly on the platelets’ surface, MBDual enhanced the percentage of firm adhesion. In vivo, MB were investigated by ultrasound in a model of ferric chloride induced non-occlusive carotid artery thrombosis. MBsLea and MBDual revealed a higher ultrasound mean acoustic intensity than MBControl (p Dual demonstrated no additional increase in mean signal intensity as compared to MBsLea. The degree of carotid artery stenosis on histology correlated well with the ultrasound acoustic intensity of targeted MB (p in vivo models.

Objective— Antioxidative drugs continue to be developed for the treatment of atherosclerosis. Apocynin is an nicotinamide adenine dinucleotide phosphate oxidase inhibitor with anti-inflammatory properties. We used contrast-enhanced ultrasound molecular imaging to assess whether short-term apocynin therapy in atherosclerosis reduces vascular oxidative stress and endothelial activation Approach and Results— Genetically modified mice with early atherosclerosis were studied at baseline and after 7 days of therapy with apocynin (4 mg/kg per day IP) or saline. Contrast-enhanced ultrasound molecular imaging of the aorta was performed with microbubbles targeted to vascular cell adhesion molecule 1 (VCAM-1; MB V ), to platelet glycoprotein Ibα (MB Pl ), and control microbubbles (MB Ctr ). Aortic vascular cell adhesion molecule 1 was measured using Western blot. Aortic reactive oxygen species generation was measured using a lucigenin assay. Hydroethidine oxidation was used to assess aortic superoxide generation. Baseline signal for MB V (1.3±0.3 AU) and MB Pl (1.5±0.5 AU) was higher than for MB Ctr (0.5±0.2 AU; P P V : 0.3±0.1; MB Pl : 0.4±0.1; MB Ctr : 0.3±0.2 AU; P =0.6 between agents). Apocynin reduced aortic vascular cell adhesion molecule 1 expression by 50% ( P Conclusions— Short-term treatment with apocynin in atherosclerosis reduces endothelial cell adhesion molecule expression. This change in endothelial phenotype can be detected by molecular imaging before any measurable decrease in macrophage content and is not associated with a detectable change in oxidative burden.

The current International Organization for Standardization (ISO) standard (ISO 8600-3: 1997 including Amendment 1: 2003) for determining endoscope field of view (FOV) does not accurately characterize some novel endoscopic technologies such as endoscopes with a close focus distance and capsule endoscopes. We evaluated the endoscope FOV measurement method (the FOVWS method) in the current ISO 8600-3 standard and proposed a new method (the FOVEP method). We compared the two methods by measuring the FOV of 18 models of endoscopes (one device for each model) from seven key international manufacturers. We also estimated the device to device variation of two models of colonoscopes by measuring several hundreds of devices. Our results showed that the FOVEP method was more accurate than the FOVWS method, and could be used for all endoscopes. We also found that the labelled FOV values of many commercial endoscopes are significantly overstated. Our study can help endoscope users understand endoscope FOV and identify a proper method for FOV measurement. This paper can be used as a reference to revise the current endoscope FOV measurement standard.

Background— Cardiac tests for diagnosing myocarditis lack sensitivity or specificity. We hypothesized that contrast-enhanced ultrasound molecular imaging could detect myocardial inflammation and the recruitment of specific cellular subsets of the inflammatory response in murine myocarditis. Methods and Results— Microbubbles (MB) bearing antibodies targeting lymphocyte CD4 (MB CD4 ), endothelial P-selectin (MB PSel ), or isotype control antibody (MB Iso ) and MB with a negative electric charge for targeting of leukocytes (MB Lc ) were prepared. Attachment of MB CD4 was validated in vitro using murine spleen CD4+ T cells. Twenty-eight mice were studied after the induction of autoimmune myocarditis by immunization with α-myosin-peptide; 20 mice served as controls. Contrast-enhanced ultrasound molecular imaging of the heart was performed. Left ventricular function was assessed by conventional and deformation echocardiography, and myocarditis severity graded on histology. Animals were grouped into no myocarditis, moderate myocarditis, and severe myocarditis. In vitro, attachment of MB CD4 to CD4+ T cells was significantly greater than of MB Iso . Of the left ventricular ejection fraction or strain and strain rate readouts, only longitudinal strain was significantly different from control animals in severe myocarditis. In contrast, contrast-enhanced ultrasound molecular imaging showed increased signals for all targeted MB versus MB Iso both in moderate and severe myocarditis, and MB CD4 signal correlated with CD4+ T-lymphocyte infiltration in the myocardium. Conclusions— Contrast-enhanced ultrasound molecular imaging can detect endothelial inflammation and leukocyte infiltration in myocarditis in the absence of a detectable decline in left ventricular performance by functional imaging. In particular, imaging of CD4+ T cells involved in autoimmune responses could be helpful in diagnosing myocarditis.

We compared GRAPPA parallel MRI (pMRI) to regular MRI (non-GRAPPA) for BOLD fMRI while keeping all other parameters fixed. We acquired both GRAPPA and non-GRAPPA images using a high resolution as well as a low resolution EPI matrix. We found significantly larger values of percent BOLD signal when comparing higher resolution acquisitions to lower resolution ones, independently of whether data were acquired with GRAPPA EPI or with regular EPI. We also demonstrated no loss of functional activation or BOLD signal when comparing GRAPPA to non-GRAPPA while keeping the same spatial resolution. We propose to use pMRI to gain the ability to perform whole-brain acquisition at higher spatial resolution with TE in the 30-40 ms range for optimal BOLD detection at 3T, or at faster scan times. To this end, we conclude that GRAPPA pMRI is advantageous for BOLD fMRI and whole-brain EPI acquisition at high spa- tial resolution.

This paper evaluates the use of electrorheological fluids (ERFs) within a magnetic resonance imaging (MRI) environment. ERF is a semiactive variable impedance material, which could be used as an alternative type of resistive force/torque generation or in combination with other actuators as a damper/clutch to modulate the output force/torque of the actuator. In this paper, an ERF damper/brake is introduced and its magnetic resonance (MR) compatibility is examined at a 3-T MR imaging environment by measuring the output performance of the damper and the SNR of the MRI images. The experimental results showed that damper's resistive force generation while positioned within the MRI is almost the same as that in normal operation. The signal-to-noise investigation was performed both with a phantom and human. The results indicated that the ERF damper did not affect the MRI images when it was operated over 30 cm away from the MRI's RF coil. We hope that the synthesis and tables presented in this paper can facilitate the choice of ERF brake actuation principle to various applications in an MR environment.

Actuators based on dielectric elastomers, a specific class of electroactive polymers, appear to be suitable candidates for new MRI-compatible technologies, due to their intrinsic material properties and working principle. This paper presents the first investigation into the MRI compatibility of a recently developed linear contractile actuator made of a silicone elastomer. The apparent absence of any degradation of both the actuator electromechanical performance in the MRI environment and the quality of images acquired from a phantom demonstrates the MRI compatibility of the actuator. These results suggest the suitability of this soft actuation technology as a possible new entry in the class of MRI-compatible mechatronic systems.

The continuous technological progress of magnetic resonance imaging (MRI), as well as its widespread clinical use as a highly sensitive tool in diagnostics and advanced brain research, has brought a high demand for the development of magnetic resonance (MR)-compatible robotic/mechatronic systems. Revolutionary robots guided by real-time three-dimensional (3-D)-MRI allow reliable and precise minimally invasive interventions with relatively short recovery times. Dedicated robotic interfaces used in conjunction with fMRI allow neuroscientists to investigate the brain mechanisms of manipulation and motor learning, as well as to improve rehabilitation therapies. This paper gives an overview of the motivation, advantages, technical challenges, and existing prototypes for MR-compatible robotic/mechatronic devices.

Premature atherosclerosis and thrombotic complications are major causes of morbidity and mortality in patients with systemic lupus erythematosus (SLE). However, the high incidence of these complications cannot be explained by traditional risk factors alone, suggesting direct effects of an activated immune system on hemostasis. The unexpected nucleotide sequence homology between SLE patient–derived autoantibodies against complement C1q (Fab anti-C1q) and von Willebrand factor (VWF) led us to investigate a potential interaction between the complement and hemostatic systems on the level of initiating molecules. VWF was found to bind to surface-bound C1q under static conditions. The binding could specifically be inhibited by Fab anti-C1q and C1q-derived peptides. Under shear stress the C1q–VWF interaction was enhanced, resembling the binding of VWF to collagen I. Additionally, we could show that C1q–VWF complexes induced platelet rolling and firm adhesion. Furthermore, we observed VWF binding to C1q-positive apoptotic microparticles and cholesterol crystals, as well as increased VWF deposition in C1q-positive glomeruli of SLE patients compared with control nephropathy. We show, to our knowledge for the first time, binding of VWF to C1q and thus a direct interaction between starter molecules of hemostasis and the classical pathway of complement. This direct interaction might contribute to the pathogenic mechanisms in complement-mediated, inflammatory diseases.

In hemodialysis patients, radiographic imaging with iodinated contrast medium (ICM) application plays a central role in the diagnosis and/or follow-up of disease-related conditions. Therefore, safety aspects concerning ICM administration and radiation exposure have a great impact on this group of patients. Current hardware and software improvements including the design and synthesis of modern contrast compounds allow the use of very small amounts of ICM in concert with low radiation exposure. Undesirable ICM side effects are divided into type A (predictable reactions such as heat feeling, headache, and contrast-induced acute kidney injury, for example) and type B (nonpredictable or hypersensitivity) reactions; this chapter deals with the latter. The first onset cannot be prevented. To prevent hypersensitivity upon reexposure of ICM, an allergological workup is recommended. If this is not possible and ICM is necessary, the patient should receive a premedication (H1 antihistamine with or without corticosteroids). Current imaging hardware and software improvements (e.g. such as additional filtration of the X-ray beam) allow the use of very small amount of ICM and small X-ray doses. Proper communication among the team involved in the treatment of a patient may allow to apply imaging protocols and efficient imaging strategies limiting radiation exposure to a minimum. Practical recommendations will guide the reader how to use radiation and ICM efficiently to improve both patient and staff safety.

In hemodialysis patients, radiographic imaging with iodinated contrast medium (ICM) application plays a central role in the diagnosis and/or follow-up of disease-related conditions. Therefore, safety aspects concerning ICM administration and radiation exposure have a great impact on this group of patients. Current hardware and software improvements including the design and synthesis of modern contrast compounds allow the use of very small amounts of ICM in concert with low radiation exposure. Undesirable ICM side effects are divided into type A (predictable reactions such as heat feeling, headache, and contrast-induced acute kidney injury, for example) and type B (nonpredictable or hypersensitivity) reactions; this chapter deals with the latter. The first onset cannot be prevented. To prevent hypersensitivity upon reexposure of ICM, an allergological workup is recommended. If this is not possible and ICM is necessary, the patient should receive a premedication (H1 antihistamine with or without corticosteroids). Current imaging hardware and software improvements (e.g. such as additional filtration of the X-ray beam) allow the use of very small amount of ICM and small X-ray doses. Proper communication among the team involved in the treatment of a patient may allow to apply imaging protocols and efficient imaging strategies limiting radiation exposure to a minimum. Practical recommendations will guide the reader how to use radiation and ICM efficiently to improve both patient and staff safety.

Effects that two different compound-angle film-hole configurations have on film cooling effectiveness are investigated. Effectiveness measurements have been made downstream of a single row of compound-angle cylindrical holes with a diameter of 7.5 mm, and a single row of compound-angle, diffuser-shaped holes with an inlet diameter of 7.5 mm. Both geometries were inclined with respect to the coverage surface at an anglea of 25 deg. The cylindrical holes, however, were oriented perpendicular to the high-temperature airflow direction while the diffuser-shaped holes had a compound angle of 45 deg with respect to the high temperature air flow direction. Both geometries were tested over a blowing ratio range of 0.7 to 4.0 Surface temperatures were measured along four longitudinal rows of thermocouples covering the downstream area between two adjacent holes. The results showed that the best overall protection over the widest range of blowing ratios was provided by the diffuser-shaped film cooling holes, particularly at high blowing ratios. The increased cross-sectional area at the shaped hole exit lead to a reduction of the momentum flux of the jet exiting the hole. Therefore, the penetration of the jet into the main flow was reduced, resulting in an increased cooling effectiveness. CFD analyses were also performed to study the film cooling effectiveness downstream of the row of holes. Comparisons between the test and numerical results showed a reasonable agreement between the two, thus CFD can be considered a viable tool to predict the cooling performance of different film cooling configurations in a parametric study. @DOI: 10.1115/1.1865222#

This experimental investigation deals with impingement on the leading edge of an airfoil with and without showerhead film holes and its effects on heat transfer coefficients on the airfoil nose area as well as the pressure and suction side areas. a comparison between the experimental and numerical results are also made. the tests were run for a range of flow conditions pertinent to common practice and at an elevated range of jet Reynolds numbers (8000–48,000). The major conclusions of this study were: (a) The presence of showerhead film holes along the leading edge enhances the internal impingement heat transfer coefficients significantly, and (b) while the numerical predictions of impingement heat transfer coefficients for the no-showerhead case were in good agreement with the measured values, the case with showerhead flow was under-predicted by as much as 30% indicating a need for a more elaborate turbulence modeling.

This Focused Section contains 14 papers (11 regular and 3 short papers) that describe recent research in robotic and mechatronic systems for MRI applications in four categories of actuators, systems, sensing technology, and human-machine interface.

Stroke is the third leading cause of mortality and a frequent cause of long-term adult impairment. Improved strategies to enhance motor function in individuals with chronic disability from stroke are thus required. Post-stroke therapy may improve rehabilitation and reduce long-term disability; however, objective methods for evaluating the specific impact of rehabilitation are rare. Brain imaging studies on patients with chronic stroke have shown evidence for reorganization of areas showing functional plasticity after a stroke. In this study, we hypothesized that brain mapping using a novel magnetic resonance (MR)-compatible hand device in conjunction with state-of-the-art magnetic resonance imaging (MRI) can serve as a novel biomarker for brain plasticity induced by rehabilitative motor training in patients with chronic stroke. This hypothesis is based on the premises that robotic devices, by stimulating brain plasticity, can assist in restoring movement compromised by stroke-induced pathological changes in the brain and that these changes can then be monitored by advanced MRI. We serially examined 15 healthy controls and 4 patients with chronic stroke. We employed a combination of diffusion tensor imaging (DTI) and volumetric MRI using a 3-tesla (3T) MRI system using a 12-channel Siemens Tim coil and a novel MR-compatible hand-induced robotic device. DTI data revealed that the number of fibers and the average tract length significantly increased after 8 weeks of hand training by 110% and 64%, respectively (p

Although there have been significant improvements in the treatment of cardiovascular diseases they still remain the main cause of morbidity and mortality globally. Currently available diagnostic approaches may not be adequate to detect pathologic changes during the early disease stages, which may be valuable for risk stratification and also to assess a response to a therapy. Therefore molecular imaging techniques such as Contrast Enhanced Ultrasound (CEU) molecular imaging to noninvasively image pathophysiologic processes on a molecular level have been developed. For CEU molecular imaging targeted microbubbles are used as contrast agent. However it has been shown that the targeting efficiency of microbubbles is low with retention of less than 5% of targeted microbubbles under high flow shear rate. Furthermore the application of CEU molecular imaging in assessing a response to therapeutic agents aiming at preventing cardiovascular events has not yet been studied. Therefore, in this PhD thesis first we investigated the influence of microbubble shell characteristics on targeting efficiency of microbubbles. Second we used ultrasound molecular imaging to assess the anti-inflammatory effects of statins in vascular inflammation in relevant murine models of atherosclerosis and finally we investigated the short-term effects of treatment with apocynin on endothelial inflammation and thrombogenicity in a murine model of early atherosclerosis by application of ultrasound molecular imaging. In the first part of our study we demonstrated that microbubbles with a longer PEG spacer arm, which is used for the conjugation of the targeting ligand on the microbubble surface, yield a better targeting efficiency compared to the microbubbles with a shorter PEG spacer arm. The improvement of the targeting efficiency of microbubbles with the longer PEG spacer arm could be due to better accessibility of the conjugated ligands on the microbubble surface to their endothelial target and also due to more stable bonds formed between ligands presented by longer PEG spacer arms to their target under flow conditions. In addition the targeting efficiency of microbubbles was influenced by the degree to which the endothelial target was projected away from the endothelial surface. The attachment efficiency was low for short molecular targets, which were hidden in the glycocaylyx. This observation could have implications for the selection of potential molecular imaging targets. Moreover as the interaction of targeted microbubbles with their endothelial target occurs in the presence of the endothelial glycocalyx the thickness of the glycocalyx in the vessels may have an important influence on microbubble attachment efficiency. In the second project we could show that CEU molecular imaging can assess the impact of therapy on endothelial inflammation in a murine model of early atherosclerosis where high frequency ultrasound imaging of the aortic wall was unable to show the effects of treatment on the atherosclerotic plaques. In atherosclerosis endothelial expression of the inflammatory cell adhesion molecule Vascular Cell Adhesion Molecule- 1 (VCAM-1) plays an important role in the initiation and progression of atherosclerosis. CEU molecular imaging by targeting microbubbles to VCAM-1 demonstrated a selective signal enhancement for these microbubbles compared to control microbubbles in non- treated animals but not in atorvastatin treated animals. Therefore given that phenotypic changes on the endothelial surface are responsible for the initiation of atherosclerosis, this method could be used for assessing treatment effects during the initial stages of atherosclerosis. Lastly, We were able to demonstrate that short-term treatment with apocynin, an antioxidant, anti-inflammatory agent, in a mouse model of early atherosclerosis results in reduced aortic endothelial inflammation presented as a reduced expression of endothelial VCAM-1 and platelet adhesion. However, these anti-inflammatory effects were not associated with measurable reductions in vascular NADPH oxidase activity or superoxide content. Our findings from CEU molecular imaging demonstrated that there is a lower attachment of microbubbles targeted to endothelial VCAM-1 and also activated platelets to aortic endothelial cells after treatment with apocynin compared to the group which were imaged at baseline and a group which received saline treatment as a control group. However, apocynin therapy did not reduce ROS content or superoxide generation. These effects of apocynin are probably due to ROS- independent mechanisms in the early stages of atherosclerotic plaque development. In conclusion CEU molecular imaging could be useful in the future for assessing the effects of drug treatment in individual patients, but also for screening of the effects of novel drug classes in preclinical field.

Background In biologic systems, the arrest of circulating cells is mediated by adhesion molecules projecting their active binding domain above the cell surface to enhance bond formation and tether strength. Similarly, molecular spacers are used for ligands on particle-based molecular imaging agents. The aim of this study was to evaluate the influence of tether length for targeting ligands on ultrasound molecular imaging agents. Methods Microbubbles bearing biotin at the end of variable-length polyethylene glycol spacer arms (MB 2000 and MB 3400 ) were prepared. To assess in vivo attachment efficiency to endothelial counterligands that vary in their distance from the endothelial cell surface, contrast-enhanced ultrasound (CEU) molecular imaging of tumor necrosis factor–α–induced P-selectin (long distance) or intercellular adhesion molecule–2 (short distance) was performed with each agent in murine hind limbs. To assess the influence of the glycocalyx on microbubble attachment, CEU molecular imaging of intercellular adhesion molecule–2 was performed after degradation of the glycocalyx. Results CEU molecular imaging targeted to P-selectin showed signal enhancement above control agent for MB 2000 and MB 3400 , the degree of which was significantly higher for MB 3400 compared with MB 2000 . CEU molecular imaging targeted to intercellular adhesion molecule–2 showed low overall signal for all agents and signal enhancement above control for MB 3400 only. Glycocalyx degradation increased signal for MB 3400 and MB 2000 . Conclusions Microbubble targeting to endothelial ligands is influenced by (1) the tether length of the ligand, (2) the degree to which the endothelial target is projected from the cell surface, and (3) the status of the glycocalyx. These considerations are important for designing targeted imaging probes and understanding potential obstacles to molecular imaging.

The aim of this study was to investigate functional reorganization of motor systems by probing connectivity between motor related areas in chronic stroke patients using functional magnetic resonance imaging (fMRI) in conjunction with a novel MR-compatible hand-induced, robotic device (MR_CHIROD). We evaluated data sets obtained from healthy volunteers and right-hand-dominant patients with first-ever left-sided stroke ≥ 6 months prior and mild to moderate hemiparesis affecting the right hand. We acquired T1-weighted echo planar and fluid attenuation inversion recovery MR images and multi-level fMRI data using parallel imaging by means of the GeneRalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) algorithm on a 3 T MR system. Participants underwent fMRI while performing a motor task with the MR_CHIROD in the MR scanner. Changes in effective connectivity among a network of primary motor cortex (M1), supplementary motor area (SMA) and cerebellum (Ce) were assessed using dynamic causal modeling. Relative to healthy controls, stroke patients exhibited decreased intrinsic neural coupling between M1 and Ce, which was consistent with a dysfunctional M1 to Ce connection. Stroke patients also showed increased SMA to M1 and SMA to cerebellum coupling, suggesting that changes in SMA and Ce connectivity may occur to compensate for a dysfunctional M1. The results demonstrate for the first time that connectivity alterations between motor areas may help counterbalance a functionally abnormal M1 in chronic stroke patients. Assessing changes in connectivity by means of fMRI and MR_CHIROD might be used in the future to further elucidate the neural network plasticity that underlies functional recovery in chronic stroke patients.

This paper presents the design, fabrication, control and testing of the third generation prototype of a novel, one degree of freedom (DOF) Variable Resistance Hand Device (VRHD) that was designed for isotonic, isokinetic, and variable resistance grasp and release exercises. Its principle functionality is derived from an electro-rheological fluid based controllable damper that allows continuously variable modulation of dynamic resistance throughout its stroke. The VRHD system consists of the patient actuated device, the control electronics and software, the practitioner graphical interface and the patient's virtual reality game software. VRHD was designed and experimentally shown to be fully Magnetic Resonance Imaging (MRI) compatible so that it can be used in brain MR imaging during handgrip rehabilitation.

The aim of this study was to investigate functional reorganization of motor systems by probing connectivity between motor related areas in chronic stroke patients using functional magnetic resonance imaging (fMRI) in conjunction with a novel MR-compatible hand-induced, robotic device (MR_CHIROD). We evaluated data sets obtained from healthy volunteers and right-hand-dominant patients with first-ever left-sided stroke > or =6 months prior and mild to moderate hemiparesis affecting the right hand. We acquired T1-weighted echo planar and fluid attenuation inversion recovery MR images and multi-level fMRI data using parallel imaging by means of the GeneRalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) algorithm on a 3 T MR system. Participants underwent fMRI while performing a motor task with the MR_CHIROD in the MR scanner. Changes in effective connectivity among a network of primary motor cortex (M1), supplementary motor area (SMA) and cerebellum (Ce) were assessed using dynamic causal modeling. Relative to healthy controls, stroke patients exhibited decreased intrinsic neural coupling between M1 and Ce, which was consistent with a dysfunctional M1 to Ce connection. Stroke patients also showed increased SMA to M1 and SMA to cerebellum coupling, suggesting that changes in SMA and Ce connectivity may occur to compensate for a dysfunctional M1. The results demonstrate for the first time that connectivity alterations between motor areas may help counterbalance a functionally abnormal M1 in chronic stroke patients. Assessing changes in connectivity by means of fMRI and MR_CHIROD might be used in the future to further elucidate the neural network plasticity that underlies functional recovery in chronic stroke patients. Neuroimage

Schwannomas are slow-growing nerve sheet neoplasms which are rarely found in the female genital system. In this article, we present a patient with Antony A congenital plexiform schwannoma of the clitoris. A 6-year-old girl was brought to our hospital with the history of a firm non-cystic clitoral mass from birth, which had been growing more rapidly during the previous year. The patient was scheduled for surgery. Histological studies revealed plexiform schwannoma of the clitoris post-operatively. Therefore, schwannoma should be considered in the differential diagnosis of clitoral masses.

This paper presents the design, fabrication, and testing of a novel, one degree-of-freedom, magnetic resonance compatible smart hand interfaced rehabilitation device (MR_CHIROD v.2), which may be used in brain magnetic resonance (MR) imaging during handgrip rehabilitation. A key feature of the device is the use of electrorheological fluids (ERFs) to achieve computer controlled, variable, and tunable resistive force generation. The device consists of three major subsystems: 1) an ERF based resistive element, 2) handles, and c) two sensors, one optical encoder and one force sensor, to measure the patient induced motion and force. MR_CHIROD v.2 is designed to resist up to 50% of the maximum level of gripping force of a human hand and be controlled in real time. Our results demonstrate that the MR environment does not interfere with the performance of the MR_CHIROD v.2, and, reciprocally, its use does not cause fMR image artifacts. The results are encouraging in jointly using MR_CHIROD v.2 and brain MR imaging to study motor performance and assess rehabilitation after neurological injuries such as stroke.

We monitored brain activation after chronic stroke by combining functional magnetic resonance imaging (fMRI) with a novel MR-compatible, hand-induced, robotic device (MR_CHIROD). We evaluated 60 fMRI datasets on a 3 T MR system from five right-handed patients with left-sided stroke >/=6 months prior and mild to moderate hemiparesis. Patients trained the paretic right hand at approximately 75% of maximum strength with an exercise ball for 1 hour/day, 3 days/week for 4 weeks. Multi-level fMRI data were acquired before, during training, upon completion of training, and after a non-training period using parallel imaging employing GeneRalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) while the participant used the MR_CHIROD. Training increased the number of activated sensorimotor cortical voxels, indicating functional cortical plasticity in chronic stroke patients. The effect persisted four weeks after training completion, indicating the potential of rehabilitation in inducing cortical plasticity in chronic stroke patients. Open Neuroimag J

New actuators are greatly demanded today in order to develop magnetic resonance imaging (MRI)-compatible mechatronic systems capable of extended and improved capabilities. They are particularly needed for MRI-guided interventional or rehabilitation procedures. Actuators based on dielectric elastomers, a specific class of electroactive polymers, appear as suitable candidates for new MRI-compatible technologies, due to their intrinsic material properties and working principle. This paper presents the first investigation on the MRI compatibility of a recently developed linear contractile actuator made of a silicone elastomer. The assessed absence of any degradation of both the actuator electromechanical performance in the MRI environment and the quality of images acquired from a phantom demonstrated the MRI compatibility of the actuator. These results suggest the suitability of this soft actuation technology as a possible new entry in the class of MRI compatible mechatronic systems.

We monitored brain activation after chronic stroke by combining functional magnetic resonance imaging (fMRI) with a novel MR-compatible, hand-induced, robotic device (MR_CHIROD). We evaluated 60 fMRI datasets on a 3 T MR system from five right-handed patients with left-sided stroke � 6 months prior and mild to moderate hemiparesis. Patients trained the paretic right hand at approximately 75% of maximum strength with an exercise ball for 1 hour/day, 3 days/week for 4 weeks. Multi-level fMRI data were acquired before, during training, upon completion of training, and af- ter a non-training period using parallel imaging employing GeneRalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) while the participant used the MR_CHIROD. Training increased the number of activated sensorimotor corti- cal voxels, indicating functional cortical plasticity in chronic stroke patients. The effect persisted four weeks after training completion, indicating the potential of rehabilitation in inducing cortical plasticity in chronic stroke patients.

This paper presents the design, fabrication and testing of a novel, one degree of freedom (DOF) magnetic resonance compatible smart hand interfaced rehabilitation device (MR_CHIROD v.2), which may be used in brain magnetic resonance (MR) imaging during handgrip rehabilitation. The device consists of three major subsystems: a) an ERF based resistive element; b) handles and c) two sensors, one optical encoder and one force sensor, to measure the patient induced motion and force. MR_CHIROD v.2 is designed to resist up to 50% of the maximum level of gripping force of a human hand and be controlled in real time. Our results demonstrate that the MR environment does not interfere with the performance of the MR_CHIROD v.2, and, reciprocally, its use does not cause fMR image artifacts. The results are encouraging in jointly using MR_CHIROD v.2 and brain MR imaging to study motor performance and assess rehabilitation after neurological injuries such as stroke.

The authors present the first design, fabrication and testing results from an electrohydrodynamic (EHD) micropump on a flexible Parylene-C substrate. Parylene-C membranes with their excellent properties are rarely used yet are very promising candidates as flexible substrates. Low power on-chip micropumps are needed in various fields including biotechnology and cryogenic cooling. Furthermore, being fabricated on a flexible Parylene substrate, they can be utilized in commercial applications including wearable textiles. Pumping pressures of up to 490Pa (@30 Volts) with a flow velocity of 190mm/min (@20 Volts) is measured using isopropanol (IPA) fluid. The micropump has no moving parts and occupies a volume of only 5mmtimes7mmtimes80mum. This is the first instance of a low power EHD micropump fabricated on a flexible Parylene-C substrate.

Background Functional magnetic resonance imaging (fMRI) has been widely used in studying human brain functions and neurorehabilitation. In order to develop complex and well-controlled fMRI paradigms, interfaces that can precisely control and measure output force and kinematics of the movements in human subjects are needed. Optimized state-of-the-art fMRI methods, combined with magnetic resonance (MR) compatible robotic devices for rehabilitation, can assist therapists to quantify, monitor, and improve physical rehabilitation. To achieve this goal, robotic or mechatronic devices with actuators and sensors need to be introduced into an MR environment. The common standard mechanical parts can not be used in MR environment and MR compatibility has been a tough hurdle for device developers. Methods This paper presents the design, fabrication and preliminary testing of a novel, one degree of freedom, MR compatible, computer controlled, variable resistance hand device that may be used in brain MR imaging during hand grip rehabilitation. We named the device MR_CHIROD ( M agnetic R esonance C ompatible Smart H and I nterfaced R ehabilitation D evice). A novel feature of the device is the use of Electro-Rheological Fluids (ERFs) to achieve tunable and controllable resistive force generation. ERFs are fluids that experience dramatic changes in rheological properties, such as viscosity or yield stress, in the presence of an electric field. The device consists of four major subsystems: a) an ERF based resistive element; b) a gearbox; c) two handles and d) two sensors, one optical encoder and one force sensor, to measure the patient induced motion and force. The smart hand device is designed to resist up to 50% of the maximum level of gripping force of a human hand and be controlled in real time. Results Laboratory tests of the device indicate that it was able to meet its design objective to resist up to approximately 50% of the maximum handgrip force. The detailed compatibility tests demonstrated that there is neither an effect from the MR environment on the ERF properties and performance of the sensors, nor significant degradation on MR images by the introduction of the MR_CHIROD in the MR scanner. Conclusion The MR compatible hand device was built to aid in the study of brain function during generation of controllable and tunable force during handgrip exercising. The device was shown to be MR compatible. To the best of our knowledge, this is the first system that utilizes ERF in MR environment.

This paper presents the design, fabrication and preliminary tests of a novel, one degree of freedom, MR compatible, computer controlled, variable resistance hand device that will be used in fMRI studies of the brain and motor performance during rehabilitation after stroke. The device consists of four major subsystems: a) the electro-rheological fluid (ERF) resistive element; b) the gearbox; c) the handles and d) the sensors: one optical encoder and one force sensor attached to the ERF resistive element's shaft to measure the patient induced motion and force, respectively. A key feature of the device is the use of electro theological fluids (ERF) to achieve resistive force generation. ERFs are fluids that experience dramatic changes in rheological properties, such as viscosity or yield stress, in the presence of an electric field. Using the electrically controlled rheological properties of ERFs, compact resistive elements with an ability to supply high resistive torques in a controllable and tunable fashion, have been developed. Our preliminary tests demonstrate that the device can apply, on a human hand holding the device handles, resistive forces that exceed 150 N. In addition the activated ERF maintain its properties in the magnetic environment without creating degradation of the MR images. The results are encouraging in combining functional magnetic resonance imaging methods, with MR compatible robotic devices for improved effectiveness of rehabilitation therapy.

This experimental investigation deals with impingement on the leading-edge of an airfoil with and without showerhead film holes and its effects on heat transfer coefficients on the airfoil nose area as well as the pressure and suction side areas. A comparison between the experimental and numerical results are also made. The tests were run for a range of flow conditions pertinent to common practice and at an elevated range of jet Reynolds numbers (8000–48000). The major conclusions of this study were: a) the presence of showerhead film holes along the leading edge enhances the internal impingement heat transfer coefficients significantly, and b) while the numerical predictions of impingement heat transfer coefficients for the no-showerhead case were in good agreement with the measured values, the case with showerhead flow was underpredicted by as much as 30% indicating a need for a more elaborate turbulence modeling.Copyright © 2005 by ASME

This paper presents the design, fabrication and testing of a novel, one degree of freedom, magnetic resonance (MR) compatible, computer controlled, variable resistance hand device that will be used in fMRI studies of the brain and motor performance during rehabilitation after stroke. The device consists of four major subsystems: a) the Electro-Rheological Fluid (ERF) resistive element; b) the gearbox; c) the handles and d) the sensors: one optical encoder and one force sensor was implemented into the device design to measure the patient induced motion and force, respectively. A key feature of the device is the use of electro rheological fluids (ERF) to achieve resistive force generation. ERFs are fluids that experience dramatic changes in rheological properties, such as viscosity or yield stress, in the presence of an electric field. Using the electrically controlled rheological properties of ERFs, compact resistive elements with an ability to supply high resistive torques in a controllable and tunable fashion, have been developed. The hand device is designed to resist up to 50% of maximum level of gripping force of a human hand and be controlled in real time. Our study demonstrates that there is neither an effect from MR environment on the ERF properties and performance of the sensors, nor significant degradation on MR images by the introduction of ERF driven hand device in the MR environment. The results are encouraging in combining functional Magnetic Resonance Imaging methods, with MR compatible robotic devices for improved effectiveness of rehabilitation therapy.