scholarly journals A method to determine the accuracy of shape setting thin, spirally shaped Nitinol wires

2021 ◽  
Vol 7 (2) ◽  
pp. 93-96
Author(s):  
Tim Ehmann ◽  
M. Geraldine Zuniga ◽  
Thomas Lenarz ◽  
Thomas S. Rau
Keyword(s):  
Mean Squared Error ◽  
Shape Change ◽  
High Reliability ◽  
Electrode Array ◽  
Morphological Operations ◽  
Shape Error ◽  
Shape Fitting ◽  
Spiral Path ◽  
Spiral Shape ◽  
Actual Shape

Abstract Electric stimulation of the auditory nerve using a cochlear implant (CI) is presumed to be superior when the electrode array (EA) is placed close to the inner wall of the cochlea. Nitinol is investigated as an actuator that enables an intracochlear shape change of the EA from a straight configuration (also necessary for the insertion) to a spiral shape fitting to the inner wall. As shape setting of the thin Nitinol wires is crucial, a method to quantify the accuracy of the shape setting is presented. To measure the trained shape of thin Nitinol wires (ø 100 μm) a contactless, optical method was developed. For each wire, a photomicrograph was captured and processed using a custom Matlab algorithm. Threshold based segmentation followed by morphological operations to remove artefacts were applied to extract the wire’s shape. Utilizing an iterative closest point (ICP) algorithm the actual shape was registered to the desired spiral path. Finally, the root mean squared error describing the deviation between both spirals was calculated as a measure for the “shape error” (εshape). In total 147 Nitinol wires of 16 batches were analyzed to quantify the reliability of the shape setting procedure. The proposed method was successfully applied in all samples. On average εshape was 0.06 ± 0.02 mm. Deviation from the desired shape was < 0.1 mm (< 0.15 mm) in 95% (99%) of the samples. In summary, the presented method is suitable to control the trained shape of thin Nitinol wires. Furthermore, our results confirm a high reliability of the shape setting procedure used for our thin Nitinol actuators intended for future applications in CI EAs.

Optimization of Threshold Values for Estimators Based on Single-Bit Quantized Sensors Using Genetic Algorithms

2002 ◽  
Author(s):  
Nishant Unnikrishnan ◽  
Ajay Mahajan ◽  
Antonios Mengoulis ◽  
R. Viswanathan
Keyword(s):  
Genetic Algorithms ◽  
Parameter Estimation ◽  
Data Storage ◽  
Dynamic Range ◽  
Mean Squared Error ◽  
High Reliability ◽  
Sensor Data ◽  
Threshold Values ◽  
Distributed Sensors ◽  
Range Resolution

The paper considers the problem of signal parameter estimation using a collection of distributed sensors called a sensor pack. Each sensor quantizes its data to one-bit information and sends it to a fusion processor for the estimation of the parameter. Estimation of a constant signal in additive noise is considered. Estimators are formulated based on one-bit sensor data and their mean squared error (MSE) performances are evaluated through simulation studies. It is shown that selecting certain threshold values for quantizing the sensor outputs can lower the MSE. Genetic algorithms are used to find the optimal threshold values for the sensors. Results from this study show that robust estimation of parameter is possible by using a moderately large number of one-bit quantized sensor data. This work has significance in applications that demand high reliability in sensor networks in spite of sensor failures, limited sensor dynamic range, resolution, bandwidth for data transmission or even data storage.

scholarly journals A Deep Learning-Aided Detection Method for FTN-Based NOMA

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jianxiong Pan ◽  
Neng Ye ◽  
Aihua Wang ◽  
Xiangming Li
Keyword(s):  
Deep Learning ◽  
Computational Complexity ◽  
Smart City ◽  
Mean Squared Error ◽  
Detection Method ◽  
High Reliability ◽  
Detection Methods ◽  
Low Latency ◽  
Detection Accuracy ◽  
Minimum Mean Squared Error

The rapid booming of future smart city applications and Internet of things (IoT) has raised higher demands on the next-generation radio access technologies with respect to connection density, spectral efficiency (SE), transmission accuracy, and detection latency. Recently, faster-than-Nyquist (FTN) and nonorthogonal multiple access (NOMA) have been regarded as promising technologies to achieve higher SE and massive connections, respectively. In this paper, we aim to exploit the joint benefits of FTN and NOMA by superimposing multiple FTN-based transmission signals on the same physical recourses. Considering the complicated intra- and interuser interferences introduced by the proposed transmission scheme, the conventional detection methods suffer from high computational complexity. To this end, we develop a novel sliding-window detection method by incorporating the state-of-the-art deep learning (DL) technology. The data-driven offline training is first applied to derive a near-optimal receiver for FTN-based NOMA, which is deployed online to achieve high detection accuracy as well as low latency. Monte Carlo simulation results validate that the proposed detector achieves higher detection accuracy than minimum mean squared error-frequency domain equalization (MMSE-FDE) and can even approach the performance of the maximum likelihood-based receiver with greatly reduced computational complexity, which is suitable for IoT applications in smart city with low latency and high reliability requirements.

scholarly journals Magnetostrictive Actuators

1998 ◽  
Vol 120 (06) ◽  
pp. 68-70 ◽  
Author(s):  
Steven Ashley
Keyword(s):  
Low Voltage ◽  
Shape Change ◽  
High Reliability ◽  
Large Strains ◽  
Directionally Solidified ◽  
Operating Characteristics ◽  
Characterization Methods ◽  
Linear Motors ◽  
Magnetostrictive Actuators ◽  
Fail Safe

This article demonstrates that materials that change their shapes when exposed to magnetic fields can now be used to drive high-reliability linear motors and actuators. The concept of magnetostriction effect has been the focus of efforts by engineers at ETREMA Products Inc. in Ames, Iowa, to device simple, high-reliability linear motors and actuators. The development of compact, low-voltage motors will offer advantages in applications in which high-force, extended-stroke, high-precision, and fail-safe-operating characteristics are required. ETREMA researchers are looking to improve Terfenol-D using material characterization methods, schemes to enhance the available strain, and better magnetomechanical design techniques. In the Terfenol-D-actuated device, an advanced-design wing flap incorporates multiple deployment segments that would smooth the airflow over the upper surface. During manufacture, Terfenol-D is melted, cast, and directionally solidified to provide the crystalline microstructure required to produce large strains. The strain and actuation force available from Terfenol-D are superior to those of other smart shape-change materials.

Hematology and Digital Image Processing: Watershed Transform-Based Methodology for Blood Cell Counting Using the WT-MO Algorithm

2020 ◽  
Vol 4 (3) ◽  
pp. 576-576
Author(s):  
Ana Carolina Borges Monteiro
Keyword(s):  
Blood Cell ◽  
Execution Time ◽  
Laboratory Tests ◽  
Processing Time ◽  
High Reliability ◽  
Developed Countries ◽  
Cell Counting ◽  
Medical Laboratory ◽  
Morphological Operations ◽  
Watershed Transform

Background: Most diseases can be detected by routine examination, even if they are in the initial phase. Currently, one of the most requested medical laboratory tests is that which allows detecting from bacterial infections until leukemias. However, for less favored populations, this examination can be seen as having a high cost. Methods: Thus, this study introduces an algorithm of segmentation of images capable of detecting and counting red blood cells and leukocytes present in digital images of blood smear. The methodology was named by WT-MO, once it relies on the concepts of Watershed Transform and Morphological Operations. The experiments were conducted in the MATLAB software simulation environment, where 25 images were used in order to evaluate the accuracy, processing time, and execution time of the WT-MO algorithm. Results: The results show that the WT-MO methodology presents high accuracy, reaching 96% and 92% in the red blood cell and leukocyte counts, respectively; reliability and low processing time, reaching an average processing time and execution time, achieving from 0.74 to 2.17 seconds. Therefore, the WT-MO algorithm can be seen as the first step in making laboratory tests more accessible to populations in underdeveloped and developing countries. Conclusion: The WT-MO methodology helps not only disadvantaged populations gain access to low-cost, high-reliability tests but also has excellent potential for use in laboratories in developed countries.

Optimal blank shape design by the iterative sensitivity method

2002 ◽  
Vol 216 (6) ◽  
pp. 867-878 ◽  
Author(s):  
H Shim ◽  
K Son
Keyword(s):  
Moving Boundary ◽  
Shape Change ◽  
Design Stage ◽  
Shape Error ◽  
Shape Sensitivity ◽  
Initial Shape ◽  
Target Shape ◽  
Blank Design ◽  
Blank Shape ◽  
Sensitivity Method

In order to realize net shape manufacturing of drawn parts, determination of the optimal blank shape plays a key role in the process development stage. The sensitivity method has many successful applications of the optimal blank design. In the method, the undeformed blank shape is modified iteratively by moving boundary nodes in the initial moving direction until the deformed shape satisfies a target shape. To determine the magnitude of the movement of the nodes, both the shape error measured at the deformed shape and the shape sensitivity defined by the effect of initial shape change on the final shape are utilized. To obtain shape sensitivity for each boundary node numerically, a couple of deformation processes has been analysed at each design stage with an original blank and offset blank. Drawings of the trapezoidal cup, cross-shaped cup and oil pan have been chosen as examples to verify the sensitivity method. Both the cross-shaped cup and oil pan are examples of complicated material flow during forming while the trapezoidal cup is of a simple flow. For every case the optimal blank shape has been obtained after only a few modifications without any predetermined deformation path. With the predicted optimal blank, a corresponding experiment has been carried out. The deformed shapes of the experiment almost exactly coincide with the desired target shape in every case. Through the investigation, the sensitivity method is found to be excellent in the blank design of arbitrary shaped drawing products.

scholarly journals Histological evaluation of a cochlear implant electrode array with electrically activated shape change for perimodiolar positioning

2018 ◽  
Vol 4 (1) ◽  
pp. 145-148
Author(s):  
Thomas S. Rau ◽  
N.úha Suzaly ◽  
Nick Pawsey ◽  
Silke Hügl ◽  
Lenarz Majdani ◽  
...  
Keyword(s):  
Shape Memory ◽  
Inner Ear ◽  
Shape Change ◽  
Round Window ◽  
Small Diameter ◽  
Electrode Array ◽  
Electrical Heating ◽  
Histological Evaluation ◽  
Electrode Arrays ◽  
Nitinol Wire

AbstractFor the treatment of deafness or severe hearing loss cochlear implants (CI) are used to stimulate the auditory nerve of the inner ear. In order to produce an electrode array which is both atraumatic and reaches a perimodiolar final position a design featuring shape memory effect was proposed. A Nitinol wire with a diameter of 100 μm was integrated in a state of the art lateral wall electrode array. The wire serves as an actuator after it has been ‘trained’ to adopt the spiral shape of an average human cochlea. Three small diameter platinum-iridium wires (each 20 μm) were crimped to the Nitinol wire in order to produce thermal energy. An insertion test was pursued using a human temporal bone specimen. The prototype electrode array was cooled down by means of immersion in ice water and freeze spray to enable sufficient straightening. Thereafter, insertion into the cochlea through the round window as performed. Insertion was feasible but difficult as premature curling of the electrode occurred during the movement towards the inner ear while passing the middle ear cavity. Therefore, the insertion had to be performed faster than usual. The shape memory actuator was subsequently activated with 450mA current at 5V for 3 seconds. After insertion the specimen was embedded in epoxy resin, microgrinded and all histological slices were assessed for trauma. Perimodiolar position was achieved. No insertion trauma was observed and there were no indications of thermal damage caused by the electrical heating. To the best of our knowledge, this is the first histological evaluation of the insertion trauma caused by an electrically activated shape memory electrode array. These promising results support further research on shape memory CI electrode arrays.

Design for an Inexpensive but Effective Cochlear Implant

1998 ◽  
Vol 118 (2) ◽  
pp. 235-241 ◽  
Author(s):  
Blake S. Wilson ◽  
Stephen Rebscher ◽  
Fan-Gang Zeng ◽  
Robert V. Shannon ◽  
Gerald E. Loeb ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
High Reliability ◽  
Low Cost ◽  
Electrode Array ◽  
Sampling Strategy ◽  
Prototype System ◽  
Widespread Application ◽  
Speech Processor ◽  
Monopolar Electrodes ◽  
Implant System

Widespread application of cochlear implants is limited by cost, especially in developing countries. In this article we present a design for a low-cost but effective cochlear implant system. The system includes a speech processor, four pairs of transmitting and receiving coils, and an electrode array with four monopolar electrodes. All implanted components are passive, reducing to a minimum the complexity of manufacture and allowing high reliability. A four-channel continuous interleaved sampling strategy is used for the speech processor. The processor and transmission link have been evaluated in tests with a subject previously implanted with the Ineraid electrode array and percutaneous connector. A prototype of the link, consisting of four pairs of transmitting and external receiving coils, was used, with the outputs of the receiving coils directed to four intracochlear electrodes through the percutaneous connector. The subject achieved speech reception scores with the prototype system that were equivalent to those achieved with a standard laboratory implementation of a continuous interleaved sampling processor with current-controlled stimuli.

scholarly journals Analysis of a robust edge detection system in different color spaces using color and depth images

2019 ◽  
Vol 43 (4) ◽  
pp. 632-646
Author(s):  
S.M.H. Mousavi ◽  
V. Lyashenko ◽  
V.B.S. Prasath
Keyword(s):  
Edge Detection ◽  
Mean Squared Error ◽  
Detection System ◽  
Detection Methods ◽  
Morphological Operations ◽  
Color Spaces ◽  
Detection Techniques ◽  
Depth Data ◽  
Depth Images ◽  
Different Color

Edge detection is very important technique to reveal significant areas in the digital image, which could aids the feature extraction techniques. In fact it is possible to remove un-necessary parts from image, using edge detection. A lot of edge detection techniques has been made already, but we propose a robust evolutionary based system to extract the vital parts of the image. System is based on a lot of pre and post-processing techniques such as filters and morphological operations, and applying modified Ant Colony Optimization edge detection method to the image. The main goal is to test the system on different color spaces, and calculate the system’s performance. Another novel aspect of the research is using depth images along with color ones, which depth data is acquired by Kinect V.2 in validation part, to understand edge detection concept better in depth data. System is going to be tested with 10 benchmark test images for color and 5 images for depth format, and validate using 7 Image Quality Assessment factors such as Peak Signal-to-Noise Ratio, Mean Squared Error, Structural Similarity and more (mostly related to edges) for prove, in different color spaces and compared with other famous edge detection methods in same condition. Also for evaluating the robustness of the system, some types of noises such as Gaussian, Salt and pepper, Poisson and Speckle are added to images, to shows proposed system power in any condition. The goal is reaching to best edges possible and to do this, more computation is needed, which increases run time computation just a bit more. But with today’s systems this time is decreased to minimum, which is worth it to make such a system. Acquired results are so promising and satisfactory in compare with other methods available in validation section of the paper.

scholarly journals Combining Interior Orientation Variables to Predict the Accuracy of Rpas–Sfm 3D Models

2020 ◽  
Vol 12 (17) ◽  
pp. 2674 ◽  
Author(s):  
Alessandra Capolupo ◽  
Mirko Saponaro ◽  
Enrico Borgogno Mondino ◽  
Eufemia Tarantino
Keyword(s):  
Mean Squared Error ◽  
High Reliability ◽  
Low Cost ◽  
3D Models ◽  
Time Data ◽  
Prediction Function ◽  
The One ◽  
Processing Techniques ◽  
Predictive Functions ◽  
Aerial Systems

Remotely piloted aerial systems (RPAS) have been recognized as an effective low-cost tool to acquire photogrammetric data of low accessible areas reducing collection and processing time. Data processing techniques like structure from motion (SfM) and multiview stereo (MVS) techniques, can nowadays provide detailed 3D models with an accuracy comparable to the one generated by other conventional approaches. Accuracy of RPAS-based measures is strongly dependent on the type of adopted sensors. Nevertheless, up to now, no investigation was done about relationships between camera calibration parameters and final accuracy of measures. In this work, authors tried to fill this gap by exploring those dependencies with the aim of proposing a prediction function able to quantify the potential final error in respect of camera parameters. Predictive functions were estimated by combining multivariate and linear statistical techniques. Four photogrammetric RPAS acquisitions were considered, supported by ground surveys, to calibrate the predictive model while a further acquisition was used to test and validate it. Results are preliminary, but promising. The calibrated predictive functions relating camera internal orientation (I.O.) parameters with final accuracy of measures (root mean squared error) showed high reliability and accuracy.

Role of spectrin in membrane fusion and in shape change of human erythrocyte ghost

1978 ◽  
Vol 36 (2) ◽  
pp. 328-329
Author(s):  
Hideo Hayashi ◽  
Yoshikazu Hirai ◽  
John T. Penniston
Keyword(s):  
Conformational Changes ◽  
Human Erythrocyte ◽  
Shape Change ◽  
Membrane Surface ◽  
Slight Modification ◽  
Active Role ◽  
Main Role ◽  
Bank Blood ◽  
Human Erythrocyte Ghost

Spectrin is a membrane associated protein most of which properties have been tentatively elucidated. A main role of the protein has been assumed to give a supporting structure to inside of the membrane. As reported previously, however, the isolated spectrin molecule underwent self assemble to form such as fibrous, meshwork, dispersed or aggregated arrangements depending upon the buffer suspended and was suggested to play an active role in the membrane conformational changes. In this study, the role of spectrin and actin was examined in terms of the molecular arrangements on the erythrocyte membrane surface with correlation to the functional states of the ghosts.Human erythrocyte ghosts were prepared from either freshly drawn or stocked bank blood by the method of Dodge et al with a slight modification as described before. Anti-spectrin antibody was raised against rabbit by injection of purified spectrin and partially purified.

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