scholarly journals Creating a neuroprosthesis for active tactile exploration of textures

2019 ◽  
Vol 116 (43) ◽  
pp. 21821-21827 ◽  
Author(s):  
Joseph E. O’Doherty ◽  
Solaiman Shokur ◽  
Leonel E. Medina ◽  
Mikhail A. Lebedev ◽  
Miguel A. L. Nicolelis
Keyword(s):  
Texture Features ◽  
Direct Access ◽  
Scanning Strategy ◽  
Cutaneous Sensation ◽  
Prosthetic Limbs ◽  
Spatial Frequencies ◽  
Machine Interface ◽  
Active Scanning ◽  
Somatic Sensation ◽  
Active Exploration

Intracortical microstimulation (ICMS) of the primary somatosensory cortex (S1) can produce percepts that mimic somatic sensation and, thus, has potential as an approach to sensorize prosthetic limbs. However, it is not known whether ICMS could recreate active texture exploration—the ability to infer information about object texture by using one’s fingertips to scan a surface. Here, we show that ICMS of S1 can convey information about the spatial frequencies of invisible virtual gratings through a process of active tactile exploration. Two rhesus monkeys scanned pairs of visually identical screen objects with the fingertip of a hand avatar—controlled first via a joystick and later via a brain–machine interface—to find the object with denser virtual gratings. The gratings consisted of evenly spaced ridges that were signaled through individual ICMS pulses generated whenever the avatar’s fingertip crossed a ridge. The monkeys learned to interpret these ICMS patterns, evoked by the interplay of their voluntary movements and the virtual textures of each object, to perform a sensory discrimination task. Discrimination accuracy followed Weber’s law of just-noticeable differences (JND) across a range of grating densities; a finding that matches normal cutaneous sensation. Moreover, 1 monkey developed an active scanning strategy where avatar velocity was integrated with the ICMS pulses to interpret the texture information. We propose that this approach could equip upper-limb neuroprostheses with direct access to texture features acquired during active exploration of natural objects.

scholarly journals Creating a neuroprosthesis for active tactile exploration of textures

2019 ◽  
Author(s):  
Joseph E. O’Doherty ◽  
Solaiman Shokur ◽  
Leonel E. Medina ◽  
Mikhail A. Lebedev ◽  
Miguel A. L. Nicolelis
Keyword(s):  
Texture Features ◽  
Direct Access ◽  
Cutaneous Sensation ◽  
Prosthetic Limbs ◽  
Spatial Frequencies ◽  
Machine Interface ◽  
Active Scanning ◽  
Somatic Sensation ◽  
The One ◽  
Active Exploration

AbstractIntracortical microstimulation (ICMS) of the primary somatosensory cortex (S1) can produce percepts that mimic somatic sensation and thus has potential as an approach to sensorize prosthetic limbs. However, it is not known whether ICMS could recreate active texture exploration—the ability to infer information about object texture by using one’s fingertips to scan a surface. Here we show that ICMS of S1 can convey information about the spatial frequencies of invisible virtual gratings through a process of active tactile exploration. Two rhesus monkeys scanned pairs of visually identical screen objects with the fingertip of a hand avatar, controlled via a joystick and later via a brain-machine interface, to find the one with denser virtual gratings. The gratings consisted of evenly spaced ridges that were signaled through ICMS pulses generated when the avatar’s fingertip crossed each ridge. The monkeys learned to interpret these ICMS patterns evoked by the interplay of their voluntary movements and the virtual textures of each object. Discrimination accuracy across a range of grating densities followed Weber’s law of just-noticeable differences (JND), a finding that matches normal cutaneous sensation. Moreover, one monkey developed an active scanning strategy where avatar velocity was integrated with the ICMS pulses to interpret the texture information. We propose that this approach could equip upper-limb neuroprostheses with direct access to texture features acquired during active exploration of natural objects.

scholarly journals Integrated assessment of the state of sewage mine waters based on gas-discharge radiation method

2020 ◽  
Vol 201 ◽  
pp. 01032
Author(s):  
Natalija Glukhova ◽  
Viktor Khilov ◽  
Yuliia Kharlamova ◽  
Mariia Isakova
Keyword(s):  
Fourier Transform ◽  
Integrated Assessment ◽  
Experimental Studies ◽  
Texture Features ◽  
Biological Properties ◽  
Gas Discharge ◽  
Mine Waters ◽  
Physical Chemical ◽  
Spatial Frequencies ◽  
The Fourier Transform

The existing environmental problems resulting from the use and subsequent discharge of water by mining and metallurgical enterprises are analyzed. The relevance of developing methods for an integrated assessment of water properties is presented, which will allow the study of not only physical-chemical, but also the biological parameters of water. Experimental studies of water samples are conducted based on the method of gas-discharge radiation. The existing methods for extracting informative features of gas-discharge radiation images of liquid-phase objects are analyzed. Histograms of gas-discharge radiation images of various types of water were constructed and studied. The expediency of dividing images into separate fragments, characterized by common texture features, is shown. The analysis of texture features is carried out based on the use of the Fourier transform. Using the Fourier transform for the corresponding luminance vectors, the spectra have been obtained of the spatial distribution of the frequencies of brightness changes, which are used as texture features to identify the specific characteristics of the gas-discharge tracks formation. It has been determined that the developed method of water analysis allows assessing its biological properties, which is based on the values of the spatial frequency range. The advantage of the proposed method over the existing ones is the possibility of quantitative assessment in the form of numerical values of the covered range of spatial frequencies. The proposed method of studying the biological properties of water can be used as part of modern environmental monitoring systems.

scholarly journals Decoding a New Neural–Machine Interface for Control of Artificial Limbs

2007 ◽  
Vol 98 (5) ◽  
pp. 2974-2982 ◽  
Author(s):  
Ping Zhou ◽  
Madeleine M. Lowery ◽  
Kevin B. Englehart ◽  
He Huang ◽  
Guanglin Li ◽  
...  
Keyword(s):  
Motor Control ◽  
Degrees Of Freedom ◽  
Clinical Success ◽  
Surface Emg ◽  
Robotic Arm ◽  
Electrode Arrays ◽  
Control Information ◽  
Targeted Muscle Reinnervation ◽  
Prosthetic Limbs ◽  
Machine Interface

An analysis of the motor control information content made available with a neural–machine interface (NMI) in four subjects is presented in this study. We have developed a novel NMI–called targeted muscle reinnervation (TMR)—to improve the function of artificial arms for amputees. TMR involves transferring the residual amputated nerves to nonfunctional muscles in amputees. The reinnervated muscles act as biological amplifiers of motor commands in the amputated nerves and the surface electromyogram (EMG) can be used to enhance control of a robotic arm. Although initial clinical success with TMR has been promising, the number of degrees of freedom of the robotic arm that can be controlled has been limited by the number of reinnervated muscle sites. In this study we assess how much control information can be extracted from reinnervated muscles using high-density surface EMG electrode arrays to record surface EMG signals over the reinnervated muscles. We then applied pattern classification techniques to the surface EMG signals. High accuracy was achieved in the classification of 16 intended arm, hand, and finger/thumb movements. Preliminary analyses of the required number of EMG channels and computational demands demonstrate clinical feasibility of these methods. This study indicates that TMR combined with pattern-recognition techniques has the potential to further improve the function of prosthetic limbs. In addition, the results demonstrate that the central motor control system is capable of eliciting complex efferent commands for a missing limb, in the absence of peripheral feedback and without retraining of the pathways involved.

scholarly journals Software description of the PID-controller algorithm in C# for use in a closed automatic control system

2020 ◽  
pp. 40-54
Author(s):  
Dmitrii Piotrovskii ◽  
◽  
Sergei Podgorny ◽  
Alexsander Kukolev ◽  
◽  
...  
Keyword(s):  
Automatic Control ◽  
Programming Language ◽  
Pid Controller ◽  
Direct Access ◽  
Central Processor ◽  
Analog To Digital ◽  
C Language ◽  
Electronic Computing ◽  
Cross Platform ◽  
Machine Interface

Today, automatic control is increasingly associated with the capabilities of electronic compu-ting. If at the stage of the origin of the control theory, regulators were mainly mechanical de-vices with the simplest kinematics, now most regulators in production are electronic computing devices containing a Central processor, analog - to - digital converters, amplifiers, auxiliary switching equipment, peripheral devices as part of a human-machine interface. Responsibility for the correct and trouble-free operation and operation of such equipment is assigned to soft-ware that is a program code written in a specific programming language (Java, Python, C++, Pascal). Certain languages are adapted for specific purposes that determine their prevalence. Developed in 1998–2001 by Microsoft specialists, the object-oriented C# language has now gained considerable popularity due to its expressive syntax and ease of learning. The syntax of the language aims to level the complexity of C++, providing such impressive features as the use of lambda expressions, delegates, as well as providing direct access to memory. The number of applications written to date written in C# is incalculable due to the cross-platform nature of the .NET Core. For this reason, the authors attempted to consider the possibility of writing a software algorithm for a classical PID controller in the chain of the simplest first-order aperiodic link using this programming language.

scholarly journals A way to Calibrate a Colour Texture Feature

2020 ◽  
Vol 2020 (28) ◽  
pp. 150-155
Author(s):  
Hermine Chatoux ◽  
Noël Richard ◽  
Hela Jebali ◽  
François Lecellier ◽  
Christine Fernandez-Maloigne
Keyword(s):  
Texture Feature ◽  
Texture Features ◽  
Image Databases ◽  
Texture Descriptor ◽  
Spatial Frequencies ◽  
Reference Images

Several colour descriptors are presented each year. The existing protocols to evaluate and compare these descriptors are restricted to the use of image databases without information about the spatio-chromatic content. In this article, we present a first answer to calibrate a colour texture descriptor. By calibration, we intend evaluate the capacity of the descriptor to discriminate the non-uniform aspect according to different scales of samples. In order to assess all the possibilities in term of spatial frequencies and colour content, we propose to use reference images based on a fractal vector colour model. Three texture features are compared from this protocol allowing to express the interest of the proposed calibration sequence.

The Imaging of Crystal Structures and Crystal Defects

1978 ◽  
Vol 36 (3) ◽  
pp. 207-217
Author(s):  
J.M. Cowley
Keyword(s):  
Electron Microscope ◽  
Crystal Structures ◽  
Phase Contrast ◽  
Crystal Defects ◽  
Atom Density ◽  
Lack Of Information ◽  
Spatial Frequencies

The problem of "understandinq" electron microscope imaqes becomes more acute as the resolution is improved. The naive interpretation of an imaqe as representinq the projection of an atom density becomes less and less appropriate. We are increasinqly forced to face the complexities of coherent imaqinq of what are essentially phase objects. Most electron microscopists are now aware that, for very thin weakly scatterinq objects such as thin unstained bioloqical specimens, hiqh resolution imaqes are best obtained near the optimum defocus, as prescribed by Scherzer, where the phase contrast imaqe qives a qood representation of the projected potential, apart from a lack of information on the lower spatial frequencies. But phase contrast imaqinq is never simple except in idealized limitinq cases.

X-Ray Replication of Submicrometer Linewidth Patterns

1977 ◽  
Vol 35 ◽  
pp. 136-137
Author(s):  
Henry I. Smith ◽  
D.C. Flanders
Keyword(s):  
Electron Beam Lithography ◽  
Cross Sectional ◽  
X Ray ◽  
Electron Backscattering ◽  
Spatial Frequencies ◽  
Cross Sectional Profile ◽  
Carbon Foils ◽  
Sectional Profile ◽  
And Control ◽  
Soft Radiation

Scanning electron beam lithography has been used for a number of years to write submicrometer linewidth patterns in radiation sensitive films (resist films) on substrates. On semi-infinite substrates, electron backscattering severely limits the exposure latitude and control of cross-sectional profile for patterns having fundamental spatial frequencies below about 4000 Å(l),Recently, STEM'S have been used to write patterns with linewidths below 100 Å. To avoid the detrimental effects of electron backscattering however, the substrates had to be carbon foils about 100 Å thick (2,3). X-ray lithography using the very soft radiation in the range 10 - 50 Å avoids the problem of backscattering and thus permits one to replicate on semi-infinite substrates patterns with linewidths of the order of 1000 Å and less, and in addition provides means for controlling cross-sectional profiles. X-radiation in the range 4-10 Å on the other hand is appropriate for replicating patterns in the linewidth range above about 3000 Å, and thus is most appropriate for microelectronic applications (4 - 6).

A simple way for producing holographic filters suitable for image improvement

1978 ◽  
Vol 36 (1) ◽  
pp. 226-227
Author(s):  
K.-H. Herrmann ◽  
E. Reuber ◽  
P. Schiske
Keyword(s):  
Transfer Functions ◽  
Diffraction Order ◽  
Lateral Position ◽  
Simple Method ◽  
Spatial Frequencies ◽  
Resolution Electron ◽  
Wiener Filters ◽  
Image Improvement ◽  
Optical Reconstruction ◽  
Set Up

Aposteriori deblurring of high resolution electron micrographs of weak phase objects can be performed by holographic filters [1,2] which are arranged in the Fourier domain of a light-optical reconstruction set-up. According to the diffraction efficiency and the lateral position of the grating structure, the filters permit adjustment of the amplitudes and phases of the spatial frequencies in the image which is obtained in the first diffraction order.In the case of bright field imaging with axial illumination, the Contrast Transfer Functions (CTF) are oscillating, but real. For different imageforming conditions and several signal-to-noise ratios an extensive set of Wiener-filters should be available. A simple method of producing such filters by only photographic and mechanical means will be described here.A transparent master grating with 6.25 lines/mm and 160 mm diameter was produced by a high precision computer plotter. It is photographed through a rotating mask, plotted by a standard plotter.

New challenges to image processing posed by cryo-Electron microscopy of single particles

1991 ◽  
Vol 49 ◽  
pp. 422-423
Author(s):  
Joachim Frank
Keyword(s):  
Electron Microscopy ◽  
Phase Contrast ◽  
Particle Orientation ◽  
Single Particles ◽  
Contrast Transfer Function ◽  
Virtual Absence ◽  
Cryo Electron Microscopy ◽  
Spatial Frequencies ◽  
New Challenges ◽  
Particle Images

Compared with images of negatively stained single particle specimens, those obtained by cryo-electron microscopy have the following new features: (a) higher “signal” variability due to a higher variability of particle orientation; (b) reduced signal/noise ratio (S/N); (c) virtual absence of low-spatial-frequency information related to elastic scattering, due to the properties of the phase contrast transfer function (PCTF); and (d) reduced resolution due to the efforts of the microscopist to boost the PCTF at low spatial frequencies, in his attempt to obtain recognizable particle images.

Audiology Service Models in a Family Physician Practice Setting

2010 ◽  
Vol 6 (1) ◽  
pp. 24-32 ◽  
Author(s):  
Sridhar Krishnamurti
Keyword(s):  
Pediatric Patients ◽  
Practice Patterns ◽  
Healthcare Delivery ◽  
Direct Consequence ◽  
Direct Access ◽  
Practice Setting ◽  
Pediatric Populations ◽  
Family Practice Physicians ◽  
Primary Focus ◽  
Balance Problems

This article illustrates the potential of placing audiology services in a family physician’s practice setting to increase referrals of geriatric and pediatric patients to audiologists. The primary focus of family practice physicians is the diagnosis/intervention of critical systemic disorders (e.g., cardiovascular disease, diabetes, cancer). Hence concurrent hearing/balance disorders are likely to be overshadowed in such patients. If audiologists get referrals from these physicians and have direct access to diagnose and manage concurrent hearing/balance problems in these patients, successful audiology practice patterns will emerge, and there will be increased visibility and profitability of audiological services. As a direct consequence, audiological services will move into the mainstream of healthcare delivery, and the profession of audiology will move further towards its goals of early detection and intervention for hearing and balance problems in geriatric and pediatric populations.

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