208 research outputs found
Workspace Derivation of Arthroscope Using Morphological Data and Standard Portal Placement Method for Shoulder Arthroscopy
No full textRobotic arthroscopy is a potential alternative surgery method because the use of robotic arthroscope manipulators could ensure a constant quality of view that would enhance the workflow of the operator. To achieve this advancement, a workspace derivation for the movement of the arthroscope in the human joint is needed. There is a key requirement for workspace derivation of the arthroscope: the workspace should incorporate all the essential observation sites to ensure a suitable field of view during an arthroscopic surgery for various patients. The workspace could be delineated via workspace measurements on various patients or cadavers; however, this would be an arduous process. Herein, we propose a workspace derivation using morphological measurement data of various human shoulder joints for arthroscopic rotator cuff repair, which is a typical operation in arthroscopy. First, we present the geometrical modeling of the human shoulder joint using morphological parameters and standard portal placement methods. Second, the morphological measurement data of the human joint are substituted for the parameters to determine the workspace required for arthroscopic rotator cuff repair. As a result, we obtain the location of each portal and the workspace of the arthroscope via the portals that incorporate all the essential observation sites. We verify the derived workspace through several cadaveric tests. For all the experimental results, it was confirmed that the 95th percentile of the range of motion was formed within the workspace obtained using the proposed method. The results verify that the proposed method is feasible for arthroscopy.
Design of Microdisk-Shaped Ge on Si Photodetector with Recess Structure for Refractive-Index Sensing
Get PDFIn this paper, we introduce a disk-shaped Ge-on-Si photodetector for refractive-index difference sensing at an operating wavelength of 1550 nm. For the implementation of a small-scale sensor, a Ge layer was formed on top of a Si layer to increase the absorption coefficient at the expense of the light-detection area. Additionally, the sensor had a ring waveguide structure along the edge of the disk formed by a recess into the inner part of the disk. This increased the interaction between the dominant optical mode traveling along the edge waveguide and the refractive index of the cladding material to be sensed, and conclusively increased detection sensitivity. The simulation results show that the proposed sensor exhibited a detection sensitivity of >50 nm/RIU (Refractive Index Unit), a quality factor of approximately 3000, and a minimum detectable refractive index change of 0.95 × 10−2 RIU with a small disk radius of 3 μm. This corresponds to 1.67 times the sensitivity without a recess (>30 nm/RIU)
Networked SSD: Flash Memory Interconnection Network for High-Bandwidth SSD
No full textAs the flash memory performance increases with more bandwidth, the flash memory channel or the interconnect is becoming a bigger bottleneck to enable high performance SSD system. However, the bandwidth of the flash memory interconnect is not increasing at the same rate as the flash memory. In addition, current flash memory bus is based on dedicated signaling where separate control signals are used for communication between the flash channel controller and the flash memory chip. In this work, we propose to exploit packetized communication to improve the effective flash memory interconnect bandwidth and propose packetized SSD (pSSD) system architecture. We first show how packetized communication can be exploited and the microarchitectural changes required. We then propose the Omnibus topology for flash memory interconnect to enable a packetized network SSD (pnSSD) among the flash memory - a 2D bus-based organization that maintains a 'bus' organization for the interconnect while enabling direct communication between the flash memory chips. The pnSSD architecture enables a new type of garbage collection that we refer to as spatial garbage collection that significantly reduces the interference between I/O requests and garbage collection. Our detailed evaluation of pnSSD shows 82% improvement in I/O latency with no garbage collection (GC) while improving I/O latency by 9.71× when GC occurs in parallel with I/O operation, through spatial garbage collection
The Virtual Reality Brain-Computer Interface System for Ubiquitous Home Control
No full textThis paper presents a virtual reality brain computer interface (BCI) system which allows the user to interact physical objects in the ubiquitous home. The system is designed for motion disabled people to control real home facilities by a simple motor imagery and minimal physical body movements. While BCI research has mostly focused on improving classification algorithm, our BCI system uses a simple BCI classification method and the additional locking mechanism to compensate the BCI classification error. This paper describes the design, implementation, and user evaluation of our virtual reality BCI system for ubiquitous home control. The user study results showed the locking mechanism helped to improve user controllability which made the system more feasible and reduced user undesired BCI decision error rates
BebeCODE
No full textContinuous tracking young children's development is important for parents because early detection of developmental delay can lead to better treatment through early intervention. Screening tests, often based on questions answered by a parent, are used to assess children's development, but responses from only one parent can be subjective and even inaccurate due to limited memory and observations. In this work, we propose a collaborative child development tracking system, where screening test responses are collected through collaboration between parents or caregivers. We implement. BebeCODE, a mobile system that encourages parents to independently answer all developmental questions for a given age and resolve disagreements through chatting, image/video sharing, or asking a third person. A 4-week deployment study of BebeCODE with 12 families found that parents had approximately 22% disagreements about questions regarding their children's developmental and BebeCODE helped them reach a consensus. Parents also reported that their awareness of their child's development, increased with BebeCODE
Direct Observation of Off-Stoichiometry-Induced Phase Transformation of 2D CdSe Quantum Nanosheets
No full textCrystal structures determine material properties, suggesting that crystal phase transformations have the potential for application in a variety of systems and devices. Phase transitions are more likely to occur in smaller crystals; however, in quantum-sized semiconductor nanocrystals, the microscopic mechanisms by which phase transitions occur are not well understood. Herein, the phase transformation of 2D CdSe quantum nanosheets caused by off-stoichiometry is revealed, and the progress of the transformation is directly observed by in situ transmission electron microscopy. The initial hexagonal wurtzite-CdSe nanosheets with atomically uniform thickness are transformed into cubic zinc blende-CdSe nanosheets. A combined experimental and theoretical study reveals that electron-beam irradiation can change the stoichiometry of the nanosheets, thereby triggering phase transformation. The loss of Se atoms induces the reconstruction of surface atoms, driving the transformation from wurtzite-CdSe(112 over bar 0) to zinc blende-CdSe(001) 2D nanocrystals. Furthermore, during the phase transformation, unconventional dynamic phenomena occur, including domain separation. This study contributes to the fundamental understanding of the phase transformations in 2D quantum-sized semiconductor nanocrystals.11Nsciescopu
PARK MANAGEMENT GIS INTERN IN NEW YORK CITY DEPARTMENT OF PARK & RECREATION
Get PDFMy park management GIS internship with New York City Department of Parks & Recreation took place during June and August 2015, where I primarily worked under the guidance of Terese Flores, the park manager for the borough of Manhattan. My internship responsibility was assisting the Park Manager with park improvement project that primarily involved asset mapping for park properties, field data collecting and entry, budget devising as well as park staff coordinating. According to the requirement of GISDE program at Clark University, the content of this report mainly covers three aspects of this internship: the introduction for the mission and structure of this governmental organization, details of projects I involved in during summer time and an overall assessment of the 3-month internship experience
The Development of an IMU Integrated Clothes for Postural Monitoring Using Conductive Yarn and Interconnecting Technology
Get PDFSpinal disease is a common yet important condition that occurs because of inappropriate posture. Prevention could be achieved by continuous posture monitoring, but most measurement systems cannot be used in daily life due to factors such as burdensome wires and large sensing modules. To improve upon these weaknesses, we developed comfortable “smart wear” for posture measurement using conductive yarn for circuit patterning and a flexible printed circuit board (FPCB) for interconnections. The conductive yarn was made by twisting polyester yarn and metal filaments, and the resistance per unit length was about 0.05 Ω/cm. An embroidered circuit was made using the conductive yarn, which showed increased yield strength and uniform electrical resistance per unit length. Circuit networks of sensors and FPCBs for interconnection were integrated into clothes using a computer numerical control (CNC) embroidery process. The system was calibrated and verified by comparing the values measured by the smart wear with those measured by a motion capture camera system. Six subjects performed fixed movements and free computer work, and, with this system, we were able to measure the anterior/posterior direction tilt angle with an error of less than 4°. The smart wear does not have excessive wires, and its structure will be optimized for better posture estimation in a later study
Metal‐Like Stretchable Nanocomposite Using Locally‐Bundled Nanowires for Skin‐Mountable Devices
No full text\Stretchable conductive nanocomposites have been intensively studied for wearable bioelectronics. However, development of nanocomposites that simultaneously feature metal-like conductivity(> 100 000 S cm(-1)) and high stretchability (> 100%) for high-performance skin-mountable devices is still extremely challenging. Here a material strategy for such a nanocomposite is presented by using local bundling of silver nanowires stabilized with dual ligands (i.e., 1-propanethiols and 1-decanethiols). When the nanocomposite is solidified via solvent evaporation under a highly humid condition, the nanowires in the organic solution are bundled and stabilized. The resulting locally-bundled nanowires lower contact resistance while maintain their percolation network, leading to high conductivity. Dual ligands of 1-propanethiol and 1-decanethiol further boost up the conductivity. As a result, a nanocomposite with both high conductivity of approximate to 122,120 S cm(-1) and high stretchability of approximate to 200% is obtained. Such superb electrical and mechanical properties are critical for various applications in skin-like electronics, and herein, a wearable thermo-stimulation device is demonstrated.N
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