bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Roll Misalignment on Vibration Response of Roll Grinder
Authors: Li Liang , Wang Liming , Yimin Shao , Yuan Yilin
Published: July 2018

The chatter marks may be caused by the roll misalignment during the grinding process of roll grinder, which can affect the quality of the roll surface of the strip steel. Based on a doubly regenerative time delay grinding model, a 2-degree-of-freedom lumped parameter model of a roll grinder with the roll misalignment fault is presented to investigate the effect of a roll misalignment on its vibration responses. A Runge-Kutta numerical integration method is applied to calculate the vibration response from the presented model. The effects of the roll misalignment and the rolling speed are investigated. Moreover, an experiment setup is presented. Numerical results from the presented model are compared with experimental results to validate the presented model. It seems that the results may provide some guidance for the detection of the misalignment fault and monitoring of the operation state of the roll grinder.
Numerical Research of Multi-Scale Coupling Simulation on Rotary Pressure Exchanger and Pipe System
Authors: Cao Z. , Deng J. Q. , Liu K.
Published: July 2018

Rotary Pressure exchanger (RPE) is an efficient device which recovers pressure energy from liquid streams in process industries. In this work, a multi-scale numerical investigation of pressure propagation in RPE and the pipeline is carried out. A system model including pipe system and RPE component is firstly presented, and is then solved by the integration of 1-D Method of characteristics (MOC) and CFD method. The simultaneous data exchange between the pipeline and RPE is enabled by making use of the existing programming interfaces. At last, the mutual effect of wave phenomenon in pipeline and RPE is evaluated by the synchronous interaction under transient operating conditions. The proposed multi-scale coupling approach in this work could either provide the internal flow details in RPE device or the dynamic behavior of the system, making the numerical simulation more reasonable with system-level accuracy and time-saving.
Everyday Life Quantification Using mDFA: Heart Health Monitoring and Structural Health Monitoring
Authors: Yazawa Toru
Published: July 2018

The aim of this study was to make a method usable in an early detection of malfunction, e.g., abnormal vibration/fluctuation in recorded signals. We conducted experimentations of heart health and structural health monitoring. We collected natural world signals, e.g., heartbeat fluctuation and mechanical vibration. For the analysis, we used modified detrended fluctuation analysis (mDFA) method that we have made recently. mDFA calculated the scaling exponent (SI, the acronym SI is derived from the scaling indices) from the time series data, e.g., R-R interval time series obtained from electrocardiograms. In the present study, peaks were identified by our own method. In every single mDFA computation, we identified ∼2000 consecutive peaks from a data: “2000” was necessary number to conduct mDFA. mDFA was able to distinguish between normal and abnormal behaviors: Normal healthy hearts exhibited an SI around 1.0, which is a phenomena comparable to 1/f fluctuation. Job-related stressful hearts and extrasystolic hearts both exhibited a low SI such as 0.7. Normally running car’s vibration — recorded steering wheel vibration — exhibited an SI around 0.5, which is white noise like fluctuation. Normally spinning ball-bearings (BB) exhibited an SI around 0.1, which belongs to the anti-correlation phenomena. A malfunctioning BB showed an increased SI. At an SI value over 0.2, an inspector must check BB’s correct functioning. Here we propose that healthiness in various cyclic vibration behaviors can be quantitatively analyzed by mDFA.
Assessment of Intra and Inter-Observer Variability of Peripheral Arterial Tonometry Measurements
Authors: Singal Ashish , Taimeh Ziad , Peichel Gretchen , Krueger Dean , Eckman Peter , Valeti Uma
Published: July 2018

Importance of repeatable and reproducible measurements in medicine cannot be understated [1]. In this investigation, we quantified repeatability (intra-observer variability) and reproducibility (inter-observer variability) while measuring peripheral arterial tonometry (PAT) signals from finger tips of healthy subjects using piezoelectric transducers. Although numerous techniques for measuring PAT have been described in literature, the repeatability and reproducibility of these measurements, and the variability in multiple probes have not been established. We hypothesize that: (1) PAT measurements would be repeatable when measured by a single operator at each time point, (2) readings would be reproducible when measured by multiple operators, and (3) there would be minimal variation between multiple probes.
Characterization of Pulsatility and Temperature Profile During Reactive Hyperemic Response
Authors: Singal Ashish , Ojo Clarence , Faizer Rumi
Published: July 2018

Patients with peripheral arterial disease (PAD) have compromised blood flow to their extremities as a result of arterial narrowing. PAD is often associated with impairment in endothelial function which is exaggerated by injury from processes related to cardiovascular risk factors such as ageing, hypertension, hyperlipidemia, diabetes, smoking, and obesity [1]. Furthermore, patients with diabetes often have calcified arteries making standard non-invasive testing non diagnostic [2]. With increase in diabetes prevalence and concomitant PAD, a new non-invasive assessment method of arterial function that has the potential to reflect both arterial tone and response to ischemia reperfusion may be valuable. We have developed a peripheral arterial tonometry (PAT) system (previously described, [3]) that is capable of measuring pulsatility in peripheral digits. We complemented our system with simultaneous peripheral temperature measurements that could not only add value in understanding PAD, but also aid in clinical diagnoses. In this investigation, we characterized our system on healthy individuals before using it on patients suffering from arterial disease in future investigations.
Weight Distribution Monitoring System for Patients With Parkinson’s Disease
Authors: Dickens Matthew , Wadekar Ameya , Bhutada Karan Subhash , Nguyen Pham Huy , Jameson Shannon , Polygerinos Panagiotis
Published: July 2018

Parkinson’s disease is a neurodegenerative brain disorder that occurs when a patient’s body stops producing dopamine. This chemical is essential in transferring motor commands between the substantia nigra and the corpus striatum which enables smooth, intentional movement in the body. Because this transmission line is degrading, about 68% of the Parkinson’s population reports falling [1].
A Simple Aspect Ratio Dependent Method of Patterning Microwells for Selective Cell Attachment
Authors: Zavrel Erik A. , Shuler Michael L. , Shen Xiling
Published: July 2018

3-D culture has been shown to provide cells with a more physiologically authentic environment than traditional 2-D (planar) culture [1, 2]. 3-D cues allow cells to exhibit more realistic functions and behaviors, e.g., adhesion, spreading, migration, metabolic activity, and differentiation. Knowledge of changes in cell morphology, mechanics, and mobility in response to geometrical cues and topological stimuli is important for understanding normal and pathological cell development [3]. Microfabrication provides unique in vitro approaches to recapitulating in vivo conditions due to the ability to precisely control the cellular microenvironment [4, 5]. Microwell arrays have emerged as robust alternatives to traditional 2D cell culture substrates as they are relatively simple and compatible with existing laboratory techniques and instrumentation [6, 7]. In particular, microwells have been adopted as a biomimetic approach to modeling the unique micro-architecture of the epithelial lining of the gastrointestinal (GI) tract [8–10]. The inner (lumen-facing) surface of the intestine has a convoluted topography consisting of finger-like projections (villi) with deep well-like invaginations (crypts) between them. The dimensions of villi and crypts are on the order of hundreds of microns (100–700 μm in height and 50–250 μm in diameter) [11]. While microwells have proven important in the development of physiologically realistic in vitro models of human intestine, existing methods of ensuring their surface is suitable for cell culture are lacking. Sometimes it is desirable to selectively seed cells within microwells and confine or restrict them to the microwells in which they are seeded. Existing methods of patterning microwells for cell attachment either lack selectivity, meaning cells can adhere and migrate anywhere on the microwell array, i.e., inside microwells or outside of them, or necessitate sophisticated techniques such as micro-contact printing, which requires precise alignment and control to selectively pattern the bottoms of microwells for cell attachment [12, 13].
Design of an Automated Measurement System for Episcleral Venous Pressure
Authors: Craig Trevor L. , Nelson Carl A. , Fan Shan , Gulati Vikas , Kedar Sachin , Ghate Deepta
Published: July 2018

Episcleral venous pressure (EVP) refers to the pressure in the episcleral veins. It is used by scientists in glaucoma physiology and pharmacology research to study the parameters of aqueous humor dynamics as part of the Goldmann equation [1]. The episcleral veins drain into the superior ophthalmic vein which drains into the cavernous sinus. Our previous work in a pig model [2] shows for the first time that EVP is an excellent non-invasive quantitative marker for intracranial pressure (ICP) estimation (high ICP leads to high intracranial venous pressure and high EVP). Intracranial pressure (ICP) is an important marker of outcomes in traumatic brain injury. There is an unfulfilled civilian and military need for a non-invasive ICP measurement modality. EVP could serve as a quantitative ICP biomarker, measurable by personnel with different skill levels for remote acute triage in battlefields and other urgent situations.
Design of a Modular, Partially Disposable Robot for Minimally Invasive Surgery
Authors: Nelson Nicholas , Nelson Carl A.
Published: July 2018

Most robots for minimally invasive surgery (MIS) are large, bulky devices which mimic the paradigm of manual MIS by manipulating long, rigid instruments from outside the body [1]. Some of these incorporate “wristed” instruments to place some local dexterity at or near the tool tip [2]. In contrast, a small number of MIS robot designs place all of the degrees of freedom inside the patient’s body in order to increase the local dexterity [3].
Finite Element Analysis and Experiment on Large Intestine End-to-End Anastomosis
Authors: Liao-yuan Ai , Shu-chen Ge , Jing-jing Xu , Ming-yang Li , Lin Mao , Cheng-li Song
Published: July 2018

Colorectal surgery is widely performed to re-establish the bowel, the part of which is removed because of diverticulitis, intestinal polyps, inflammatory bowel and cancer. Stapled anastomosis is a highly standardized technique and considered the standard of care. However, complications like leakage, stenosis and postoperative bleeding cannot be completely avoided [1,2]. There is limited understanding of the impact of staplers on tissue and basic mechanics of tissue stapling. According to the previous research, compression, staple height, tissue thickness, tissue compressibility, and tissue type have an effect on the patient outcomes [3]. Hence, we conducted this prospective study to analyze the effect of staple height on tissue damage and compression pressure. An attempt was made to determine the relationship between the tissue height and the optimal closed staple height.
A Device for Improving Oxygenation in Patients With Acute Respiratory Distress Syndrome
Authors: Gordon Alex , Ai Xin Jue Luo Kevin , Saab Rami , Engelberts Doreen , Kavanagh Brian , Yoshida Takeshi , Looi Thomas
Published: July 2018

In this paper we present a device for improving blood oxygenation in patients with Acute Respiratory Distress Syndrome (ARDS). ARDS is caused by lung-related illness or injury, and can occur in mechanically ventilated ICU patients due to volutrauma or barotrauma. In ARDS, the lower lung is closed resulting in impaired gas exchange, and the upper lung is easily overstretched resulting in injury. The application of continuous negative abdominal pressure (CNAP) assists in opening the lower lung by pulling the diaphragm towards the abdomen. The device, consisting of a rigid arch, a compliant patient interface, and a pressure sensor module, allows for the application of CNAP to a patient suffering from ARDS.

An initial pig trial using the prototype device showed significant improvement in the ratio of oxygen in the blood to the fraction of inspired oxygen, PaO2/FiO2, after five minutes of −5 cmH2O pressure application. Furthermore, preliminary testing on healthy humans indicated the device was comfortable, easy to apply, and formed a consistent airtight seal. Future prototypes will focus on ease of application, rigidity, and adjustability.
Design and Validation of an Organizational Device for Endourological Surgery
Authors: Tradewell Michael , Morin Steve , Chrouser Kristin
Published: July 2018

Through a needs-based approach we sought to reduce instrument drops during endourological surgery. To this end, we designed and validated an endourology equipment organization device: the cord caddy. Iterative computer aided design and fused deposition model prototyping lead to the development of a machined functional prototype to accommodate the wide-variety of cables, cords, wires and equipment used in endourologic cases. Over 20 consecutive endourological surgeries, use of the cord caddy demonstrated that it met most of the design requirements, aside from disposability and basket/ureteroscope storage. Assessment of these requirements was precluded by the inability to test a sterile version of the device at our institution. Future plans include validating a sterile disposable device in the operating room.
Port Placement Optimization for Robotically-Assisted Minimally Invasive Surgery
Authors: Stricko Robert G. , Page Brett , Kerdok Amy E. , Itkowitz Brandon , Pile Jason
Published: July 2018

Minimally invasive surgery (MIS) requires ports to be placed through the body wall in a manner such that instruments can reach a desired area. Limitations of laparoscopic surgery include maintaining triangulation and ergonomics for the surgeon while allowing access to the anatomy with non-wristed instruments [1]. In robotically-assisted MIS, the surgeon does not stand bedside, and they have wristed instruments that the robot manipulates. Limitations of robotically-assisted MIS include range of motion (ROM) limits and decreased spatial awareness, resulting in the potential for interfering robotic components. As a result, port placement varies between laparoscopic and robotically-assisted surgery.
Waterjet Assisted Craniotome for Reduced Dural Tears
Authors: Orner Mathew , Greminger Michael , Goyal Amit
Published: July 2018

A craniotomy is a procedure where a piece of the skull is removed in order to gain access to the brain. This is commonly done to remove brain tumors, treat epilepsy, and to treat traumatic brain injury. Currently, the craniotomy procedure involves drilling one or more burr holes and then using a craniotome to complete the cut. The craniotome consists of a rotating cutting tool and a dura guard, which is intended to prevent the cutting tool from touching the dura. However, even with the dura guard, dural tears occur in approximately 20–30% of craniotomy procedures [1], [2]. There are approximately 160,000 craniotomies performed per year in the United States [3]. Dural tears add time to the craniotomy procedure due to the increased difficulty in suturing the dura and the potential need to use synthetic dura material in order to reclose the dura. Also, if the dura tears while using the craniotome, the brain is no longer protected as the craniotomy is completed. There is a strong desire among neurosurgeons to have an improved tool for craniotomies that reduces the incidence of dural tears.
SMA Wire Characterization for 3D Steerable Active Devices
Authors: Karimi Saeed , Konh Bardia , Ashrafiuon Hashem
Published: July 2018

Shape Memory Alloys (SMAs) are a unique class of smart materials that recover their deformed shapes, caused by a loading condition, through temperature changes [1]. SMAs are employed in a variety of areas including aerospace, automotive, and biomedical fields. Their Pseudoelastic characteristics, shape memory effects, and biocompatibility make them particularly suitable for medical applications.
3D Printing Realistic Endobronchial Models for Surgical Planning and Simulation
Authors: Zhao Zhuo , Coronel Baracaldo Javier , Palacio Varona Juliana , Rueda-Esteban Roberto , Tse Zion Tsz Ho
Published: July 2018

Lung cancer is the second most common cancer in both men and women globally. More than one million lung cancer cases are diagnosed worldwide each year. The leading cause of cancer death is lung cancer in the United States and worldwide [1]. According to the American Cancer Society, there were an estimated 222,500 new cases of lung cancer and 155,870 deaths from lung cancer in the United States in 2017. Early detection and diagnosis, as well as accurate localization in lung intervention, are the keys to reducing the death rate from lung cancer [1].
Obstetrical Forceps With Passive Rotation and Sensor Feedback
Authors: Beaudoin Judith M. , Chin Lillian T. , Zlotnick Hannah M. , Cervantes Thomas M. , Slocum Alexander H. , Robinson Julian N. , Lassey Sarah C.
Published: July 2018

An improved tool for operative vaginal delivery can reduce maternal and fetal trauma during the delivery and recovery processes. When a delivery cannot be completed naturally due to maternal exhaustion or fetal distress, physicians must perform an operative vaginal delivery (OVD), with forceps or a vacuum, or a Cesarean section (C-section). Although C-sections are more prevalent in the United States than OVDs, they require longer maternal hospital stays and recovery time and increase risk of maternal infection and fetal breathing problems [1]. In 2015, the American College of Obstetrics and Gynecology pushed to increase the number of OVDs to limit C-section associated delivery risks [2]. However, the current tools for OVD either have steep learning curves, are unable to be used for all fetal head presentations, or have associated maternal and fetal risks [3][4]. There is a need for an easy to use, safe, and reliable tool for operative vaginal delivery.
A Device for Quantitative Analysis of the Thumb Ulnar Collateral Ligament
Authors: Cervantes Thomas , Byun Woojeong Elena , Chen Ava , Kim Kristina , Nealon Kaitlyn , Connor Jay , Slocum Alexander
Published: July 2018

A device to quantitatively assess the ulnar collateral ligament of the thumb was developed to facilitate rapid and accurate diagnosis of the ligamentous injury known as Skier’s thumb.
“Air Slicer” for Immersive Visualization of Medical Images
Authors: Dehghani Hossein , Laha Sumit , Kulkarni Pankaj , Biswas Pradipta , Bagci Ulas , Song Sang-Eun
Published: July 2018

Medical imaging plays an essential role in screening, diagnosis, and pre- and intra-procedural intervention and therapy planning. The prime imaging modalities are Ultrasound (US), Computerized Tomography (CT), Positron Emission Tomography (PET), and Magnetic Resonance Imaging (MRI). Each modality has its advantages and disadvantages, thus, an appropriate one is advised by physicians depending on clinical needs.
No-Power-Required, Touch-Activated Compression Garments for the Treatment of POTS
Authors: Granberry Rachael , Ciavarella Nicole , Pettys-Baker Robert , Berglund Mary Ellen , Holschuh Brad
Published: July 2018

Postural orthostatic tachycardia syndrome (POTS) is a clinical autonomic disorder characterized by a spike in heart rate and syncope in response to orthostasis, symptoms which then dissipate upon recumbency [1]. Additional symptoms include chronic fatigue, bloating, and nausea [2]. POTS predominately affects females (5:1) between the ages of 15 and 50 years [3]. It is estimated 1 to 3 million are affected by POTS in the United States [4]. While there is no known cure, symptom management requires a multifaceted approach, including physical exercise, counter maneuvers, high salt and fluid intake, and medications, including beta blockers and fludrocortisone [3]. Lower body compression is a core component to POTS treatment, especially during prolonged periods of upright posture. Because POTS disproportionately affects young, otherwise healthy females who have high physical and professional demands, compression garments (CG) are critical to allow this population to carry out their activities of daily living [5].
Preparing for Conjoined Twins Separation Through Virtual Reality
Authors: Juhnke Bethany , Mattson Alex , Saltzman Daniel , Azakie Anthony , Hoggard Eric , Ambrose Matthew , Iaizzo Paul , Erdman Arthur , Fischer Gwenyth
Published: July 2018

Advances in technology are making virtual reality (VR) available for many different interests. Inexpensive commercially available hardware can be setup at home [1,2], while corporations are using VR to design mechanical systems and train pilots [3,4]. However, limited application is seen in the medical field.
Robotic Platform for the Delivery of Gene Products Into Single Cells in Organotypic Slices of the Developing Mouse Brain
Authors: Shull Gabriella , Haffner Christiane , Huttner Wieland , Taverna Elena , Kodandaramaiah Suhasa B.
Published: July 2018

Microinjection of genetic components and dye into organotypic slices provides excellent single cell resolution for unraveling biological complexities, but is extremely difficult and time consuming to perform manually resulting in low yield and low use in the developmental biology field. We developed a computer vision guided platform to inject specimen with mRNA, and/or dye and investigated the efficiency of the process using organotypic slices of the mouse developing neocortex. We demonstrate that the system significantly increases yield of injection relative to manual use by an order of magnitude, allows for cell tracking over 0, 24, and 48 hours post injection in culture, and enables mRNA translation of injected product. The autoinjector platform thus can open the door to new types of experiments including investigating effects of mRNA concentration, and composition on cell fate, and tracking these effects on cell reprogramming and lineage.
Novel Design of Stabilizing Device for Tube Thoracostomy
Authors: Kim Jennifer , Joseph Grace , Cadavez Joshua , Gulachek Nicholas , Rujana Juan , Molina Marcos
Published: July 2018

Tube Thoracostomy (TT) is a surgical procedure involving the insertion of a plastic tube into the patient’s pleural cavity with the purpose of evacuating the air or fluid contents that have abnormally accumulated in this space [1]. Chest tube insertion has been identified as part of a core set of skills needed in a physician’s repertoire when caring for an injured patient [2]. Iatrogenic injuries, traumatic injuries, as well as malignancy, are the likely clinical scenarios were tube thoracotomy may be required. The presentation of these clinical events can be classified into three broad categories: pneumothorax, hemothorax, and pleural effusion, all of which lead to the abnormal accumulation of air, blood, or lymphatic fluid within the pleural space, respectively.
Contextual Design Theory Applied to Wearables That Facilitate Kangaroo Care by Interviewing Mothers of Hospitalized Infants
Authors: Clarke-Sather Abigail R. , Cobb Kelly , Maloney Catherine , Young Hannah
Published: July 2018

When considering how to design medical devices considering the needs of the patient and hospital staff may seem sufficient. Hospitalized infants are patients who cannot speak or advocate for their needs; the parents and the hospital staff caring for infant patients have different roles that together are integral to an infant’s recovery. Figure 1 shows how mothers, nurses, and infants form a system of care to promote infant patient healing. In particular caregiver behaviors such as kangaroo care (KC), are dependent upon the involvement of family. KC, defined as bare skin-to-skin contact between an infant and an adult caregiver, is usually done chest-to-chest. The design of wearables for the caregivers holding the infant patient can make KC easier and be part of wearable medical device design that improves infant patient outcomes.
Interaction Force Modeling for Joint Misalignment Minimization Toward Bio-Inspired Knee Exoskeleton Design
Authors: Li Yanjun , Chang Shuo-Hsiu , Francisco Gerard , Su Hao
Published: July 2018

Roboticists have developed a diverse array of powered exoskeletons for human augmentation and rehabilitation over the last few decades. One of the key design objectives is to minimize the discomfort to enhance the user experience. The high inertia and joint misalignment of conventional rigid exoskeletons are two key factors that cause these problems. Different types of control algorithms have been developed to compensate the inertia and render low impedance to the wearers [1–2].
A Modular Approach for Lightweight Humanoid Hand Design Using High Torque Density Electric Actuators
Authors: Cui Haotian , Yu Shuangyue , Yan Xunge , Chang Shuo-Hsiu , Francisco Gerard , Fu Qiushi , Su Hao
Published: July 2018

The human hand has extraordinary dexterity with more than 20 degrees of freedom (DOF) actuated by lightweight and efficient biological actuators (i.e., muscles). The average weight of human hand is only 400g [1]. Over the last few decades, research and commercialization effort has been dedicated to the development of novel robotic hands for humanoid or prosthetic application towards dexterous and biomimetic design [2]. However, due to the limitations of existing electric motors in terms of torque density and energy efficiency, the design of humanoid hands has to compromise between dexterity and weight. For example, commercial prosthetic terminal devices i-Limb [3] and Bebionic [4] prioritize the lightweight need (450g) and use 5-DOF motors to under-actuated 11 joints, which is only able to realize a few basic grasp postures. On the other hand, some humanoid robot hand devices like DLR-HIT I & II hands [5] prioritize the dexterity need (15 DOF), but weigh more than four times than their biological counterpart (2200g and 1500g, respectively).
Study of the Adsorption of Glibenclamide/Metformine in Hydrogels Using PM6 Model
Authors: Rangel-Vázquez Norma-Aurea , Delgadillo-Armendariz Nancy , Kalla Jonathan
Published: July 2018

In the present work the physical-chemical and energetic properties of the molecules of hydrogels about chitosan crosslinking with genipin were studied in the adsorption process of Metformine and Glibenclamide. The analysis was done by means of PM6 model in order to obtain the necessary data base to establish their potential use as transdermal controlled release systems. Currently, the drugs (metformine and glibenclamide) are administered orally, however, there are already several oral medications that have been presented as transdermal administration systems (SAT), with great advantages, such as patient comfort and zero order release. Drugs before mentioned, are especially important in chronic diseases such as type 2 diabetes.
Force Myography Signal-Based Hand Gesture Classification for the Implementation of Real-Time Control System to a Prosthetic Hand
Authors: Ha Nguon , Withanachchi Gaminda Pankaja , Yihun Yimesker
Published: July 2018

This study is aimed at exploring the prediction of the various hand gestures based on Force Myography (FMG) signals generated through piezoelectric sensors banded around the forearm for the implementation of a control system in a prosthetic hand. Matlab, Simulink software has been utilized for the analysis and classification. Several classification and recognition models have been considered, and the Tree Decision Learning (TDL) and Support Vector Machine (SVM) have shown high accuracy results. Both of these estimated models generate above ninety five percentage of accuracy in terms of classification. As the classification showed a distinct feature in the signal, a realtime control system based on the threshold value has been implemented in the prosthetic hand. The hand motion has been recorded through Virtual Motion Glove (VMD) to establish dynamic relationship between the FMG data and the different gestures through system identification. The classification of the hand gestures based on FMG signal will provide a useful foundation for future research in the interfacing and utilization of medical devices.
Developing a Novel Gait Training Device Using a Minimally-Required-Assistance Principle
Authors: Liu Wen
Published: July 2018

The purpose of this report is to propose a new principle of minimally-required-assistance in the design of assistive devices for sensorimotor training in patients with neurological disorders. We illustrate the implementation of the principle in design and development of a novel assistive device for gait training in stroke survivors. Specific aims of this report are three folds including a brief review of literature on gait training after stroke, revision of movement specifics during gait in the context of task-specific training, and design of a novel assistive device for gait training.
Combination Product Patient Training: How Are Patients Trained and Who Conducts the Training?
Authors: Lang Virginia A. , Nalan David
Published: July 2018

Patients are frequently prescribed a medication that must be administered either by a nasal spray, an inhaler, or a self-injection device. These devices are classified as combination devices by the Food and Drug Administration (FDA) and the Medical Device Regulations (MDR). However, there has been an issue of who and how do these patients get trained. It has long been the stance of the pharmaceutical companies they will not provide training because they provide an Information for Use (IFU) and/or a demo on their website. The issues with either of these means is that neither the FDA, nor the MDR permit them as mitigation for use errors. And, in human factors testing there are considerable numbers of use errors when patients attempt to use the devices.
Real-Time Robust 3D Plane Extraction for Wearable Robot Perception and Control
Authors: Duan Ran , Yu Shuangyue , Yue Guang , Foulds Richard , Feng Chen , Tian Yingli , Su Hao
Published: July 2018

Wearable environment perception system has the great potential for improving the autonomous control of mobility aids [1]. A visual perception system could provide abundant information of surroundings to assist the task-oriented control such as navigation, obstacle avoidance, object detection, etc., which are essential functions for the wearers who are visually impaired or blind [2, 3, 4]. Moreover, a vision-based terrain sensing is a critical input to the decision-making for the intelligent control system. Especially for the users who find difficulties in manually achieving a seamless control model transition.
Design of a Stitched Textile-Based Thermal Actuator Garment to Attenuate Peripheral Microclimate Experience
Authors: Gagliardi Nika , Foo Esther , Dupler Ellen , Ozbek Simon , Dunne Lucy
Published: July 2018

Temperature is an important influencer of homeostatic comfort for humans, and its influence extends beyond life-preservation functions into cognitive and emotional effects. To augment metabolic processes in cold climates, many on-body heating solutions are currently available in the commercial market, ranging from chemical heat packs to electrically heated accessories and clothing. These products typically prioritize heating the body core in extreme conditions. By contrast, the experience of thermal comfort in the band around homeostatic comfort temperatures is much more strongly driven by experience of temperature in the body’s periphery: the hands, feet, and face [1]. Thermal sensitivity is highest in the distal extremities and has been established as the best correlate of overall perception of thermal comfort [2], [3]. In the medical context, this is especially significant in treating vasospastic disorders such as Raynaud’s Syndrome, where a spastic vascular response in peripheral vessels results in an over-reaction to cold temperatures proximal to the thermoneutral zone [4].
Using WebGL for Teaching Bone Identification
Authors: Holm Mikayle A. , Gaasedelen Erik , Iaizzo Paul A.
Published: July 2018

Newly developed interactive tutorials and applications which teach human anatomy are often set up as pay-to-play websites. Examples of these include the Visible Body app1 and the 3D Organon Anatomy2. Though these applications can be very educational, they may be costly, thus many students and members of the education community will not access these programs because of the upfront charges. These teaching programs are also frequently anatomically limited because they utilize idealized models, like KineMan3, instead of renderings or imaging data sets obtained from humans (clinical or from cadavers). This characteristic may make them useful study tools, but will not best prepare future doctors, nurses, and other health professionals for true, variable patient anatomies they will encounter in their various practices. Further, such students would likely gain more by studying 3D objects of real human anatomies instead of 2D images. We have designed a strategy to bring 3D human anatomies from real cadavers to the scientific and education communities completely open source (free of charge). Our interactive application is geared toward students of all ages (grade school to medical school) or by anyone interested in learning more about human bone anatomy.
Numerical Investigations on the Use of Multi-Element Airfoils for Vertical Axis Wind Turbine Configurations
Authors: Bah Elhadji A. A. , Sankar Lakshmi N. , Jagoda Jechiel I.
Published: July 2018

Vertical axis wind turbines (VAWT) have a relatively simple, rugged construction compared to HAWTs. However, vertical-axis wind turbines have numerous challenges that may hinder their performance. For instance they are strongly affected by dynamic stall at low tip speed ratios. A significant part of the kinetic energy contained in the oncoming wind is lost in swirl and vortices. As a result, VAWTs have a lower power production and efficiency compared to HAWTs. In an effort to alleviate the adverse effects of dynamic stall phenomena, the present study explores the use of two-element airfoils. A comparative study of single element and dual element VAWT configurations for representative VAWT turbines is given. The benefits of dual-element configurations are analyzed through a detailed flow visualization study of the single and two-element VAWT configurations at various azimuthal locations for a representative tip speed ratio. Analysis of these qualitative phenomena is complemented by a discussion on quantitative data for torque, surface pressure distributions, and airloads.
Fundamental Combustion Calculations With DARS and CHEMKIN™ Software Packages: A Comparison
Authors: Nori Venkata , Xu Fang
Published: July 2018

An investigation was conducted within Honeywell to assess the speed, accuracy, and robustness of DARS for performing basic combustion calculations. In this study, the results for the fundamental combustion characteristics from DARS are compared with those obtained by CHEMKIN, the most well known and widely used software for combustion chemistry calculations. These characteristics include the adiabatic flame temperature, flame speed, ignition delay and extinction strain rate. The operating conditions (pressure and temperature) are chosen that are relevant to aircraft gas turbine combustors. For the ignition delay studies, Jet-A is used whereas Methane is the fuel for the other simulations. Well validated reaction mechanisms for Jet-A and Methane are used for the study. Temperature and species values (profiles) are presented and compared between DARS and CHEMKIN, wherever applicable. In general, very good agreement has been found between the results of DARS and CHEMKIN. The features provided by both tools with an emphasis on gas turbine combustion application were assessed. In conclusion, it was found that DARS has equivalent accuracy and capability as CHEMKIN for this type of application.
Manufacturing of a Radial Inflow Turbine for Microgas Turbine in a 3 Axis CNC Milling Machine
Authors: Varadarajan M. N. , Sundaram M. E. Mohana , Sampath K.
Published: July 2018

A micro gas turbine impeller is a highly challenging component to fabricate given the stringent tolerance requirements. This paper highlights and reports a novel process to machine and fabricate a SS 304 impeller using a 3 axis cnc milling machine with minimum usage of job overhead. The impeller chosen to demonstrate this process is a 12 vaned impeller with outside diameter of 110 mm with an elliptical hub surface and constant radius circular shroud surface. The blade thickness varies from 1.6 mm at tip and 3.5 mm at hub. The intersection region of the blade with the disk has a uniform fillet radius of 1.5 mm. The blade exit height is 16 mm. Blades are not perpendicular to the hub surface, intersecting angle is changing as you move down the blades. The height of the blade varies from exducer to inducer is 4.5 times. It is seen that a considerable saving in time and effort without a compromise on the dimensional tolerances is obtained with the above procedure.
Development of Cavity Shapes of Labyrinth Seals Through CFD Analysis
Authors: Ramanadham Mohana Rao , Gaja Balakrishna , Kanchanapally Sravan Kumar
Published: July 2018

Axial flow compressors of Gas turbines use labyrinth seals to prevent the backflow of the working fluid. However some fluid will leak through the seals due to the clearance provided between the stationery and rotating components and due to the pressure difference across the seals, which affects the efficiency. The geometric shape of the seal plays an important role in influencing the fluid flow through the seals and the leakage rate.

The flow through the seals consists of the primary flow and the secondary flow. The secondary flow is the flow through the cavity which is associated with vortex currents and tends to obstruct the primary flow. The geometric shape of the cavity is varied to study its effect on the vortex and resultant leakage flow through the seals.

The curvatures of the seal and the distance of the seal tip to the end of the seal are the main parameters considered to arrive at the desired cavity which helps to create the required whirling action and to reduce the velocity of the leakage flow.

Gambit software is used for modeling the geometry and Fluent software is used for the analysis. Axi-symmetric pressure based analysis is carried out using the standard κ-ε turbulence. The results of the standard cavity are compared with different variants.

The flow velocity and mass flow is studied at different locations of the seal. The results indicate that by optimizing the shape of the seal cavity, the leakage through the labyrinth seal can be reduced.
Probabilistic Assessment of Thermodynamic Output of an Intercooled-Reheated-Regenerative Brayton Cycle Coupled to Variable Temperature Heat Reservoirs
Authors: Anand Vishal , Nelanti Krishna
Published: July 2018

The gas turbine engine works on the principle of Brayton cycle. One of the ways to improve the thermal efficiency of gas turbine engine is to make changes in the Brayton cycle. These changes may include intercooling, reheating, regeneration etc. The aim of the present study is to do a probabilistic assessment of the thermal efficiency and the dimensionless power of an intercooled, reheated, regenerative Brayton cycle coupled to variable temperature heat reservoirs. The Spearman’s rank coefficient has been used to find the design parameters which most affect the thermal efficiency and the dimensionless power. The design parameters, such as the effectiveness of the different heat exchangers, the efficiency of turbines and compressors and the heat capacitance rates of the external and the working fluids; have been listed with their relative impact on the thermal efficiency and the dimensionless power. The probabilistic assessment gives us a new insight into the sensitivity of the thermal efficiency and the dimensionless power of the Brayton Cycle with respect to these parameters. It will help the designers/decision makers to allocate the limited resources in a better way with the ultimate aim of making more efficient power plants.
Reduced Order Modelling of Combustion Instability in a Backward Facing Step Combustor
Authors: Krishna C. Vamsi , Hemchandra Santosh
Published: July 2018

This paper develops a fully coupled time domain Reduced Order Modelling (ROM) approach to model unsteady combustion dynamics in a backward facing step combustor. The acoustic field equations are projected onto the canonical acoustic eigenmodes of the systems to obtain a coupled system of modal evolution equations. The heat release response of the flame is modelled using the G-equation approach. Vortical velocity fluctuations that arise due to shear layer rollup downstream of the step are modelled using a simplified 1D-advection equation whose phase speed is determined from a linear, local, temporal stability analysis of the shear layer, just downstream of the step. The hydrodynamic stability analysis reveals a abrupt change in the value of disturbance phase speed from unity for Re < Recrit to 0.5 for Re > Recrit, where Recrit for the present geometry was found to be ≈ 10425. The results for self-excited flame response show highly wrinkled flame shapes that are qualitatively similar to those seen in prior experiments of acoustically forced flames. The effect of constructive and destructive interference between the two contributions to flame surface wrinkling results in high amplitude wrinkles for the case when Kc → 1.
A Comparative Study on the Synthesis and Properties of Yttria Stabilized Zirconia (YSZ) and Lanthana Doped YSZ Plasma Sprayed Thermal Barrier Coatings
Authors: Aruna S. T. , Balaji N. , Paligan B. Arul
Published: July 2018

Ceramic thermal barrier coatings (TBCs) have been used for decades to extend the life of combustors and high temperature turbine stationary and rotating components to increase the operating temperature and in turn the performance of gas turbines or diesel engines can be increased. At present, thermal barrier coatings (TBCs) of Y2O3 partially stabilized ZrO2 (YSZ) films are widely used. In recent years ceramic compositions useful in thermal barrier coatings having reduced thermal conductivity are being explored to further increasing the operating temperature of gas turbines and improve the engine efficiency. In the present study, a comparison of the properties of state-of-the art 8wt% yttria stabilized zirconia (YSZ) and lanthana doped YSZ plasma sprayed coatings is presented. Plasma sprayable powders were prepared in the laboratory by a single step precipitation method and characterized. Both the powders had good flowability. These powders were plasma sprayed at identical critical plasma spray parameters. The coatings were characterized for phase, microstructure and thermal conductivity. Both the powders and coatings exhibited tetragonal form of zirconia and no traces of lanthana were observed. Both the coatings exhibited similar porosity levels. Microstructure of the coatings revealed porous coating with good adhesion of the bondcoat with the topcoat. Plasma sprayed 8wt% YSZ and lanthana doped YSZ exhibited thermal conductivity values of 0.88 and 0.67 W m−1 K−1 respectively which is lower than that reported in literature. This study shows that lanthana doping in YSZ helps in lowering the thermal conductivity and hence this coating may be a potential candidate for TBC application.
An Assessment of Turbulence Models for S-Duct Diffusers With Flow Control
Authors: Bhat S. P. , Sullerey R. K.
Published: July 2018

The selection of a turbulence model for a problem is not trivial and has to be done systematically after comparison of various models with experimental data. It is a well known fact that there is no such turbulence model which fits all problems ([3], [13]). The flow in S-duct diffuser is a very complex one where both separation and secondary flow coexist. Previous work by the author on CFD analysis of S-duct diffuser was done using k-ε-Standard model [1], however it has been seen that choosing other turbulence model may result in better capturing of the physics in such a problem. Also flow control, to reduce energy losses, is achieved using a technique called Zero Net Mass Flow (ZNMF), in which suction and vortex generation jets (VGJ) are combined and positioned at optimum location. A proper turbulence model has to be chosen for capturing these phenomena effectively. Extensive experimental data is available on this problem and ZNMF technique from previous work done by one of the authors which is used for validating the CFD results. Here the focus is on choosing the best turbulence model for the S-duct diffuser.

Numerical (CFD) analysis is carried out using Ansys Fluent 13.0 with six turbulence models for the geometry with (ZNMF) and without (Bare duct) flow control and then compared with the experimental results. The turbulence models used are Spalart-Allmaras, three variants of k-ε – Standard, RNG and Realizable and two variants of k-ω – Standard and SST model. All the parameters of comparison are non-dimensionalized using the free stream properties, so that the results are applicable to a wider range of problems. This work is limited to incompressible flow analysis, as the experimental data is only available for low Mach number flows. Comparison of all these models clearly shows that results obtained using k-ω-SST model are very comparable to the experimental results for the bare duct (without flow control) and flow controlled duct both in terms of distribution of properties and aggregate results. Compressible flow analysis can be attempted to achieve reliable results in future with ZNMF using the best turbulence model based on this study.
Numerical Studies on the Effect of Tip Clearance and Tip Cooling Flow on Endwall Losses of an Unshrouded Axial Turbine Rotor
Authors: Asgar Ali K. , Nagpurwala Quamber H. , Nassar Abdul , Ramanamurthy S. V.
Published: July 2018

This paper deals with the numerical investigations on a low pressure axial turbine stage to assess the effect of variation in rotor tip clearance and tip coolant ejection rate on the end wall losses. The rotor, along with the NGV, was modeled to represent the entire turbine stage. The CFX TASCflow software was used to perform steady state analysis for different rotor tip clearances and different tip coolant ejection rates. The locations of the cooling slots were identified on the blade tip and the coolant ejection rate was specified at these areas. The simulations were carried out with tip clearances of 0%, 1% and 2% of blade height and ejection flow rates of 0.5%, 0.75% and 1% of main turbine flow rate. It is shown that the size and strength of the leakage vortex is directly related to the tip clearance. The reduction in efficiency is not in linearity with the tip clearance owing to the effect of boundary layer growth on the end walls. Introduction of the tip coolant flow shows increased total–total efficiency compared to that of the uncooled tip. This is attributed to a reduction in the strength of the leakage vortex due to reduced cross-flow over the tip clearance from pressure surface to suction surface. At a coolant flow rate of 0.75% of the main flow rate, there is significant increase in efficiency of about 0.5%. Optimum tip clearance and coolant flow rate are obtained based on the results of the present analysis.