bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Lower Limb Prosthesis Haptic Feedback System for Stair Descent
Authors: Sie Astrini , Realmuto Jonathan , Rombokas Eric 
Published: October 2017

Though there are a variety of prosthetic limbs that address the motor deficits associated with amputation, there has been relatively little progress in restoring sensation. Prosthetic limbs provide little direct sensory feedback of the forces they encounter in the environment, but “closing the loop” between sensation and action can make a great difference in performance [1].
For users of lower limb prostheses, stair descent is a difficult and dangerous task. The difficulty in stair descent can be attributed to three different factors: 1) Absence of tactile and haptic sensations at the bottom of the foot. Although force on the prosthetic socket provides some haptic feedback of the terrain being stepped on, this feedback does not provide information on the location of the staircase edge. 2) Insufficient ankle flexion of lower limb prostheses. Dorsiflexion of the physiological ankle during stair descent is about 27°. Even prostheses that provide active dorsiflexion provide less than this number, and regular prostheses provide almost no ankle dorsiflexion. The first two factors are analogous to the sensation of stair descent for someone without amputation wearing ski boots. 3) Prosthetic feet are optimized for flat-ground walking, offering undesirable energy storage at ankle flexion and energy return at toe-off. This can result in unwanted extra energy at the end of stance phase, propelling the user forward down the stairs.
Most lower limb prosthesis designs focus on flat ground walking, but there has been less progress in addressing the challenges of stair descent. One technique that users of prosthetic lower limbs can use for addressing these challenges is to employ an “overhanging toe” foot placement strategy. Under this strategy, the edge of the staircase is used as a pivot point for the foot to roll over the stair. This reduces the need for ankle flexion by allowing the knee and hip to compensate, and avoids storing energy in the prosthetic spring. This strategy is dynamic, and requires the user to know the amount of toe overhang to adjust the movement of the rest of the body. Most haptic devices built to assist individuals wearing prostheses focus on upper extremity tasks [2–4] or standing and walking [5,6]. Whereas previous lower limb sensory replacement systems have targeted standing measures, here we focus on stair descent. The system provides cues of the stair edge location via vibrotactile stimulations on the thigh.
Design of a Miniature Pump for Chronic Mechanical Circulatory Support Using Computational Fluid Dynamics and Flow Visualization
Authors: Stanfield J. Ryan , Wampler Richard K. , Wu Jingchun , Stewart James , Snyder Trevor A. , Long James W. 
Published: October 2017

Ventricular assist devices (VADs) have become an accepted method of treating end-stage heart failure over the last few decades. In recent years, the use of rotary blood pumps (RBPs) as continuous flow VADs has surged ahead, and virtually eliminated the use of pulsatile-flow or volume-displacement pumps for implantable, chronic mechanical circulatory support (MCS). As the use of RBPs has become commonplace for the treatment of end-stage heart failure, the need for an implantable right-side MCS device for adults [1] and implantable MCS for the pediatric population has increased. Development of an implantable device specific to these populations includes unique challenges of anatomic placement and fixation.
Computational Fluid Dynamics (CFD) is the use of numerical methods and algorithms to solve and analyze problems involving fluid flow. CFD has become a standard tool when designing RBPs, as it can calculate pressure-flow characteristics for a given rotary impeller speed. Additionally, through calculation of shear forces, CFD can also predict hemocompatibility by means of constitutive equations derived from empirical data. Particle image velocimetry (PIV), also known as flow visualization, is an optical measurement technique used to obtain velocity in fluids, which can be employed experimentally to verify CFD-based predictions of flow field. PIV also permits more rapid investigation of the RBP operativing range and transient conditions than can be achieved with CFD due to computational requirements.
We have developed a RBP platform for chronic use with CFD to optimize hemodynamic performance. The miniaturized device includes unique inlet geometry with a rotating impeller and a vaned-diffuser in a 7mm axial hydraulic diameter. The design scheme separates the bearing and motor region from the primary flow path to further improve hemocompatibility and reduce the pump size without compromising the hydraulic capacity.
Here we report CFD and PIV results of our device geometry optimized for right-sided MCS.
Modeling of Differences Between Body Core and Forehead Temperatures Measured by Infrared Thermometers
Authors: Vesnovsky Oleg , Li Yiyong , Topoleski L. D. Timmie , Zhu Liang 
Published: October 2017

In recent years, outbreaks of highly contagious diseases, like the Ebola virus, have motivated vigorous efforts to screen travelers entering the United States, especially at airports. Screening involves monitoring the body temperature of entering travelers, and blocking entry of those showing a fever, indicating a potential infection. Typically, screening is performed using commercially available non-contact infrared thermometers (NCITs). These thermometers require specific use protocols (e.g., working distances) to provide accurate results, which may not be followed by inspectors reluctant to approach potentially contagious travelers. Furthermore, the NCITs’ accuracy is based on an assumption that the NCIT readings from a forehead will predict the body core temperatures using a simple common one-size-fits-all correction offset. Unfortunately, the temperature detected on the forehead surface by an NCIT may not represent the true body core temperature, due to the changing conditions of the external environment and/or surface conditions of the forehead skin. It is not clear whether the correction factor is able to adjust to the thermal environment, or whether the surface condition of the forehead, including sweat and skin tone, affects the NCIT readings.
Before a clinical study is conducted to understand the differences between the forehead temperatures and the body core temperatures, a computational model to simulate temperature distribution inside and on the surface of the body is a cost-effective way to identify factors that influence the temperatures and to study the reasons for their deviations. The objectives of this study were to 1) develop a numerical whole-body model and perform computational heat transfer simulations of different body geometries and 2) perform parametric studies to evaluate the effect of environmental factors, such as air temperature and heat transfer coefficient, on the differences between the forehead temperature and body core temperature. This data can be used to evaluate correction factors or needed to use the measured forehead temperature to predict the body core temperature.
A Computational Approach Using Surface-Based Cohesive Behavior to Study Tissue Cutting With Rotation in Vacuum-Assisted Biopsy
Authors: Lan Guan-Jhong , Lin Chi-Lun 
Published: October 2017

Vacuum-assisted biopsy (VAB) is a widely used technology to sample lesion tissue for breast cancer diagnosis. The technology is designed to retrieve tougher and larger breast tissue samples.
The majority of VAB tools utilize a so-called rotational cutting method, in which the cutting needle simultaneously rotates and translates to produce both tangential and normal forces at the cutting surface of the tissue. The introduction of the tangential force can significantly reduce the cutting force measured in the axial direction. As a result, higher quality of tissue samples can be obtained as the samples are less deformed while being removed. The slice-push ratio, i.e. the ratio of the speed component parallel to the cutting edge to the speed component perpendicular to the cutting edge, was previously found to be the most important factor to influence the cutting force [1]. However, these studies only investigated the cases in low translational cutting speeds in a small-scale experiment.
In this paper, we present a finite element (FE) model based on surface-based cohesive behavior, which simulates the rotational cutting method used in VAB to predict the progressive damage and the cutting force of soft tissue phantoms. The model is validated using the experimental data provided in the previous study [1]. The validated model will allow us to explore more cutting conditions, such as higher translational speeds, larger range of slice-push ratio, and tissue properties. The model can also be used to optimize design parameters of current VAB needles and to evaluate new VAB needle designs.
Evaluation of Aerosol Leakage Sites Through Respirators Using Image-Based Modeling
Authors: D’Souza Gavin A. , Guha Suvajyoti , Myers Matthew R. , Hariharan Prasanna 
Published: October 2017

Personal protective equipment (PPE) such as respirators will form the first line of defense in the event of a public health emergency including an airborne pandemic or a bio-terror attack. The two major pathways by which virus-carrying aerosols can reach the human lungs through these PPEs are: a) the intrinsic penetration through porous layers of the PPE and b) the leakage through gaps between the PPE and a person’s face [1, 2]. The contribution from the second pathway can be significantly reduced using fit-testing i.e. by choosing the appropriately sized respirator for a specific face. Unfortunately, in case of an emergency, it would not be possible to fit-test the entire US population. In this scenario, excessive leakage can occur through the gaps. [1]. Hence, it is critical to identify the potential anatomical leak sites (gaps) and quantify the amount of aerosol leakage through surgical respirators for the average US population.
At the behest of Office of Counterterrorism and Emerging Threats, the Center for Devices and Radiological Health, US Food and Drug Administration (FDA), has been developing a comprehensive risk assessment model for determining the risk to different populations in case of an “off-label” use of such PPEs, i.e. for public emergency scenarios for which these FDA cleared respirators were not intended to be used. In order to develop the risk assessment model, establishing a correlation between the respirator gaps and aerosol leakage between the face and the respirator is critical. A previous study [3] identified the gaps of N95 surgical respirators for a large population and quantified the aerosol leak using computational fluid dynamics. However, the gap surface area, which is a key parameter required for establishing the gap-aerosol leak correlation, has not been quantified before.
In this study, gaps were identified and the gap surface areas were quantified for multiple head-respirator combinations under realistic conditions using imaging coupled with computer-aided design and modeling.
Validation of Feedback Control Approach for an Implantable Limb Lengthening Device
Authors: Zhang Bolun , Farley Daniel , Ploeg Heidi-Lynn , Zinn Michael 
Published: October 2017

Lower limb length discrepancy (LLD), defined by unequal length of paired lower limbs, contributes to lower back pain, osteoarthritis of the hip, and stress fractures [1–3]. The Center for Disease Control and Prevention estimated that there were approximately 700 children born with LLD each year in US [4]. Patients may receive distraction osteogenesis treatment, in which an osteotomy is performed on the shorter limb, and mechanical force is applied to gradually distract the two halves of the bone during the healing process. This stretches the bone callus during healing to achieve desired limb length upon callus consolidation [5].
The current correction devices are external fixators that leave unsightly scars and are prone to infection [6]. While recently developed intramedullary devices address many of the persistent issues with external lengthening devices, size limitations and potential damage to the bone growth plates make them impractical for use in children [7, 8]. The proposed research addresses an unmet need by developing a novel implantable extramedullary device for LLD correction that is targeted for pediatric use. The device will be implantable, submuscular, and fixed to the outside surface of the bone (extramedullary), thus allowing for use in children without concern for injury to the growth plates. The device’s function will be similar to an external fixator; however, it will not require exposed hardware, which increases risk of infection, or muscle penetration from the pins, which causes pain. Additionally, the device incorporates real-time control of the distraction rate, reducing the risk of complications arising from fixed rate distraction such as premature consolidation and non-union of the callus. [9–11].
The investigators of this study have previously designed and constructed a distraction mechanism prototype and test frame [10]. The current study aims to validate the real-time controller of the prototype.
Using Smartphone-Based Virtual Reality to Explore Internal Anatomy of 3D Heart Models
Authors: Gaasedelen Erik , Deakyne Alex , Iles Tinen , Iaizzo Paul 
Published: October 2017

The recent and rapid developments of immersive, interactive 3D environments have been critical in advancing interfaces for entertainment, design, and education. For cardiovascular research, our laboratory and others have been able to use such software tools for the construction of heart models from DICOM files. These models can then be printed in hard or soft plastic from a 3D printer. In general, such models are considered useful for surgical planning and education; these modalities are being applied as critical tools in the field of cardiovascular research.
Recently, the development of virtual reality (VR) has introduced a new modality for exploring 3D virtual structures with high resolution, high flexibility, and fast turn-around times. Until recently, the adoption of these technologies has been hindered by the high costs of VR goggles and the complexities in their setup. New developments in phone software and hardware, however, have alleviated some of these difficulties by allowing smartphone screens, graphics units, and gyroscopes to provide the necessary technologies for VR. In this way, phones can be placed inside a headset holder and used freely, without being connected to the computer.
Here we explore the utility of using this VR setup in the context of internal heart anatomy visualization.
Synthesis and Characterization of Radiopaque Shape Memory Polymers
Authors: Ezell Kendal , Nash Landon , Gordon Sonya , Maitland Duncan 
Published: October 2017

An estimated 6 million people in the United States have an unruptured cerebral aneurysm [1]. If left untreated, these aneurysms can rupture and to lead to severe brain function impairment or even death. Shape memory polymer (SMP) foams have been proposed for use to optimize endovascular embolization in place of current embolization devices [2,3].
SMPs are capable of actuating from a programmed secondary geometry to their expanded primary geometry in response to a stimulus, such as body temperature [4]. The expanded foam geometry provides an interface for embolization of the aneurysm to occur, however, treatment with these devices has limited visibility under fluoroscopy.
Previous work by Hasan et al. increased radiopacity through the incorporation of tungsten (W) nanoparticles. These composite foams showed successful x-ray visibility, but aggregate disruption of the SMP matrix led to decreased mechanical properties [5].
This work addresses limitations of composite SMP foams, namely toughness, by chemically incorporating x-ray visible monomers, such as the triodobenzene containing monomer, 5-Amino-2,4,6-triiodoisophthalic acid (AT), into the material composition. These materials enable contrast agent loading without disrupting the polymer matrix. This polymer foam system was characterized to determine the clinical relevance of the improved radiopaque SMP foam for occlusion devices.
Design of an Implantable Blood Pump for Mechanical Circulatory Support in Pediatric Patients
Authors: Snyder Trevor A. , Coghill Phillip , Azartash-Namin Kooroush , Wu Jingchun , Stanfield J. Ryan , Long James W. 
Published: October 2017

While the use of pulsatile- and continuous-flow ventricular assist devices (VADs) has become widely accepted as an acceptable treatment for end-stage heart failure in adults over the last three decades, the technology development for pediatric-specific patients is lagging behind that of adult devices. Only one pulsatile-flow VAD has been approved for use in pediatric patients in the U.S., just five years ago [1]. One continuous-flow device was approved specific to this population under Humanitarian Device Exemption (HDE), but is not in clinical use today [2]. As continuous-flow rotary blood pumps (RBPs) have become commonplace for mechanical circulatory support (MCS) in adults due to smaller size and greater reliability, significant resources have gone into the development of RBPs for pediatric use [3]. Further, RBPs designed for adult MCS have been used off-label in pediatric patients [4]. Development of an implantable device specific to a pediatric population includes challenges of anatomic placement and fixation.
We have developed a RBP for adult MCS specific to right heart failure using computational fluid dynamics (CFD) and flow visualization [5]. The miniaturized device includes a rotating impeller and a vaned-diffuser in a 7 mm axial hydraulic diameter. As seen in Figure 1, the hydrodynamic characteristics suitable for a right-VAD (RVAD) may also be suitable for pediatric patients. Currently, the only approved device is placed extracorporeal due to size constraints in the intended population [1]. This report shows results of computational simulations for anatomic fit and fluid flow studies of our device geometry in pediatric patients.
Safety and Feasibility of a Novel Gait Training Device Using a “Spacesuit” to Support Body Weight
Authors: Brenteson Charlotte , Hauck John , Wigness Bruce , Johnson Doug 
Published: October 2017

In the U.S. alone, 7.5 million individuals have survived stroke, traumatic brain injury, and spinal cord injury, and over a million new patients are diagnosed every year [1]. Most of these patients will need gait rehabilitation. Body weight supported gait training is a widely used rehabilitation therapy to improve gait function [2]. Commonly, a physical therapist provides assistance using a gait belt to support the patient. Sometimes two or three therapists may be needed for severely impaired patients. Bodyweight supported treadmill training uses a harness attached to an overhead lift to support body weight [2], however harness systems often cause discomfort and may take significant time to set up and take down.
Lite Run Corporation has developed a system for the treatment of patients with gait and balance difficulties that uses differential air pressure inside a specially designed suit to reduce up to 50 percent of a patient’s body weight. The suit facilitates patient ambulation using technology like that in astronaut spacesuits to achieve comfort and flexibility. Potential benefits include longer therapy sessions due to greater comfort and greater unweighting, as well as the therapeutic benefits of being upright and walking for subjects unable to stand independently.
The suit is used in conjunction with the Gait Trainer device shown in Figure 1 which provides air pressure to the suit and support for the patient. Gait Trainer features include: 1) electro-mechanical and pneumatic controls to support the suit and patient when rising from sitting to standing and ambulating during therapy — so that a single therapist can safely transfer a patient from a wheelchair and practice gait therapy; 2) an open design that permits access to patient’s body and legs by the therapist; 3) a compact profile that provides easy maneuverability; 4) a “base spread” function that permits positioning close to a patient when seated in wheel chair, bed or therapy table. Together these features provide safety and stability for the patient and reduced physical burden on the therapist.
The objectives for the current study were to establish the safety and feasibility of the Gait Trainer, validate user design requirements, and to test the hypothesis that the rate of perceived exertion when using the device is significantly less than during unaided walking therapy.
Determining counselling communication strategies associated with successful quits in the National Health Service community pharmacy Stop Smoking programme in East London: a focused ethnography using recorded consultations
Authors: Rivas Carol , Sohanpal Ratna , MacNeill Virginia , Steed Liz , Edwards Elizabeth , Antao Laurence , Griffiths Chris , Eldridge Sandra , Taylor Stephanie , Walton Robert 
Published: October 2017

ObjectivesTo determine communication strategies associated with smoking cessation in the National Health Service community pharmacy Stop Smoking programme.Setting11 community pharmacies in three inner east London boroughs.Participants9 stop smoking advisers and 16 pairs of smokers who either quit or did not quit at 4 weeks, matched on gender, ethnicity, age and smoking intensity.Method1–3 audio-recorded consultations between an adviser and each pair member over 5–6 weeks were analysed using a mixed-method approach. First a content analysis was based on deductive coding drawn from a theme-oriented discourse analysis approach and the Roter Interaction Analysis System. Core themes were identified through this quantification to explore in detail the qualitative differences and similarities between quitters and non-quitters.ResultsQuantitative analysis revealed advisers used a core set of counselling strategies that privileged the ‘voice of medicine’ and often omitted explicit motivational interviewing. Smokers tended to quit when these core strategies were augmented by supportive talk, clear permission for smokers to seek additional support from the adviser between consultations, encouragement for smokers to use willpower. The thematic analysis highlighted the choices made by advisers as to which strategies to adopt and the impacts on smokers. The first theme ‘Negotiating the smoker–adviser relationship’ referred to adviser judgements about the likelihood the smoker would quit. The second theme, ‘Roles of the adviser and smoker in the quit attempt’, focused on advisers’ counselling strategies, while the third theme, ‘Smoker and adviser misalignment on reasons for smoking, relapsing and quitting’, concerned inconsistencies in the implementation of National Centre for Smoking Cessation and Training recommendations.DiscussionAdvisers in community pharmacies should use the advantages of their familiarity with smokers to ensure appropriate delivery of patient-centred counselling strategies and reflect on the impact on their counselling of early judgements of smoker success.