High-Frequency Acoustic Imaging Using Adhesive-Free Polymer Transducer

The piezoelectric polymer PVDF and its copolymers have a long history as transducer materials for medical and biological applications. An efficient use of these polymers can potentially both lower the production cost and offer an environment-friendly alternative for medical transducers which today is dominated by piezoelectric ceramics containing lead. The main goal of the current work has been to compare the image quality of a low-cost in-house transducers made from the copolymer P(VDF-TrFE) to a commercial PVDF transducer. Several test objects were explored with the transducers used in a scanning acoustic microscope, including a human articular cartilage sample, a coin surface, and an etched metal film with fine line structures. To evaluate the image quality, C- and B-scan images were obtained from the recorded time series, and compared in terms of resolution, SNR, point-spread function, and depth imaging capability. The investigation is believed to provide useful information about both the strengths and limitations of low-cost polymer transducers.

Download Full-text

Assessing Image Quality of Low-Cost Laparoscopic Box Trainers: Options for Residents Training at Home

Simulation in Healthcare The Journal of the Society for Simulation in Healthcare ◽

10.1097/sih.0b013e31821cdb68 ◽

2011 ◽

Vol 6 (5) ◽

pp. 292-298 ◽

Cited By ~ 7

Author(s):

Daniel J. Kiely ◽

Kirk Stephanson ◽

Sue Ross

Keyword(s):

Image Quality ◽

Low Cost ◽

Box Trainers ◽

At Home

Download Full-text

A Dry Trenching Diaphragm Wall in Soft Soil

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.170-173.666 ◽

2012 ◽

Vol 170-173 ◽

pp. 666-669

Author(s):

Zheng Sheng Zou ◽

Xin Liu ◽

Wen Qing Zhang ◽

Qing Hua Kong

Keyword(s):

Environmental Pollution ◽

Water Consumption ◽

High Efficiency ◽

Low Cost ◽

Soft Soil ◽

Construction Cost ◽

Diaphragm Wall ◽

Environment Friendly ◽

A New Technique

Generally, it is difficult to control the trench stability and panel joint permeability in the construction of a diaphragm wall. The high construction cost is inevitable because of the environmental pollution due to the slurry, waste of water consumption, and debris disposal treatment. A new technique, called the dry trenching diaphragm wall with self-guided double-rectangular-casing, is thereafter developed in the current study to avoid these problems. In this technique, two pieces of rectangular steel casing are driven in sequence and guided each other. The trench is made by squeezing into the soft soil. The panel alignment and straightness are assured without any joints due to the dry concrete pouring instead of the influences of the slurry. Compared to the regular diaphragm wall, the technique is an environment-friendly, less emissive and energy-conserved one by eliminating the slurry pollution with the low cost. It shows that the quality of panel connection is reliable, and the permeation-proof performance is superior with high efficiency in wall-forming due to non-joint interlocking.

Download Full-text

Replacing critical point drying with a low-cost chemical drying provides comparable surface image quality of glandular trichomes from leaves of Millingtonia hortensis L. f. in scanning electron micrograph

Applied Microscopy ◽

10.1186/s42649-020-00035-6 ◽

2020 ◽

Vol 50 (1) ◽

Cited By ~ 1

Author(s):

Raktim Bhattacharya ◽

Sulagna Saha ◽

Olga Kostina ◽

Lyudmila Muravnik ◽

Adinpunya Mitra

Keyword(s):

Image Quality ◽

Critical Point ◽

Low Cost ◽

Glandular Trichomes ◽

Electron Micrograph ◽

Scanning Electron Micrograph ◽

Critical Point Drying ◽

Surface Image ◽

Scanning Electron

Download Full-text

Learning curve evaluation upskilling retinal imaging using smartphones

Scientific Reports ◽

10.1038/s41598-021-92232-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Linus G. Jansen ◽

Payal Shah ◽

Bettina Wabbels ◽

Frank G. Holz ◽

Robert P. Finger ◽

...

Keyword(s):

Image Quality ◽

Low Cost ◽

Field Studies ◽

Field Of View ◽

Retinal Images ◽

Fundus Imaging ◽

Resource Limited ◽

Examination Time ◽

Significant Difference

AbstractSmartphone-based fundus imaging (SBFI) is a low-cost approach for screening of various ophthalmic diseases and particularly suited to resource limited settings. Thus, we assessed how best to upskill alternative healthcare cadres in SBFI and whether quality of obtained images is comparable to ophthalmologists. Ophthalmic assistants and ophthalmologists received a standardized training to SBFI (Heine iC2 combined with an iPhone 6) and 10 training examinations for capturing central retinal images. Examination time, total number of images, image alignment, usable field-of-view, and image quality (sharpness/focus, reflex artifacts, contrast/illumination) were analyzed. Thirty examiners (14 ophthalmic assistants and 16 ophthalmologists) and 14 volunteer test subjects were included. Mean examination time (1st and 10th training, respectively: 2.17 ± 1.54 and 0.56 ± 0.51 min, p < .0001), usable field-of-view (92 ± 16% and 98 ± 6.0%, p = .003) and image quality in terms of sharpness/focus (p = .002) improved by the training. Examination time was significantly shorter for ophthalmologists compared to ophthalmic assistants (10th training: 0.35 ± 0.21 and 0.79 ± 0.65 min, p = .011), but there was no significant difference in usable field-of-view and image quality. This study demonstrates the high learnability of SBFI with a relatively short training and mostly comparable results across healthcare cadres. The results will aid implementing and planning further SBFI field studies.

Download Full-text

Efficacy of Composites for Fabrication of Orthotic Calipers

Emergent Research on Polymeric and Composite Materials - Advances in Chemical and Materials Engineering ◽

10.4018/978-1-5225-3023-7.ch012 ◽

2017 ◽

pp. 267-286

Author(s):

Nisha Kumari ◽

Kaushik Kumar

Keyword(s):

Composite Materials ◽

Low Cost ◽

Volume Ratio ◽

Research Field ◽

Environment Friendly ◽

Lower Weight ◽

Low Weight ◽

Alternative Material

Composites based materials are becoming more important in the field of aerospace, automobile, medicine, sports, energy etc. The principal quality of composite materials is their higher strength, firmness, resistant to corrosion and comparatively low weight when compared to the metals. The main aim of the work is to replace the presently used orthotic calipers with the proposed polymeric based composites as in last few years composites have generated broad research in engineering and research field due to its smaller density, low cost, recyclable, environment friendly and capable of being decomposed. Here, the authors have proposed two polymeric based composites (thermoplast and thermoset) as an alternative material of construction and hence their various properties were investigated. The authors after performing the experiment unveil that the strength and firmness of thermoset based composites (Epoxy + Carbon) is higher and have lower weight- to- volume ratio than that of the presently used (Aluminum based) orthotic calipers.

Download Full-text

IMAGE QUALITY IMPROVEMENTS IN LOW-COST UNDERWATER PHOTOGRAMMETRY

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-2-w10-135-2019 ◽

2019 ◽

Vol XLII-2/W10 ◽

pp. 135-142 ◽

Cited By ~ 2

Author(s):

F. Neyer ◽

E. Nocerino ◽

A. Gruen

Keyword(s):

Coral Reef ◽

Image Quality ◽

Low Cost ◽

Chromatic Aberration ◽

Bundle Adjustment ◽

Quality Improvements ◽

Free Network ◽

Processing Steps

<p><strong>Abstract.</strong> This study presents an evaluation of a cheap consumer-grade camera used for modelling a coral reef section. We evaluate the quality of a reconstructed coral reef using GoPro cameras and a high-end camera with data from an actual coral reef dataset. We also investigate components of the processing pipeline (like image quality) separate from the final results. Because our GoPro images suffer from severe chromatic aberration, we apply different image pre-processing steps to improve their quality and show its effects on the reconstructed object points. Bundle adjustment is carried out as free networks in all cases, with a follow-up rigid 3D Helmert transformation onto a geodetic control network, carried out to define the common datum and to remove the bias from the free network results.</p>

Download Full-text

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100064189 ◽

1971 ◽

Vol 29 ◽

pp. 26-27

Author(s):

K. Shibatomi ◽

T. Yamanoto ◽

H. Koike

Keyword(s):

Electron Microscope ◽

Image Quality ◽

Scanning Electron Microscope ◽

Chromatic Aberration ◽

Image Contrast ◽

Objective Lens ◽

Thick Specimen ◽

Transmission Electron ◽

Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

Download Full-text

Effect of Computerized Auditory Training on Speech Perception of Adults With Hearing Impairment

Perspectives on Aural Rehabilitation and Its Instrumentation ◽

10.1044/arri20.3.91 ◽

2013 ◽

Vol 20 (3) ◽

pp. 91-106 ◽

Cited By ~ 6

Author(s):

Rachel Pizarek ◽

Valeriy Shafiro ◽

Patricia McCarthy

Keyword(s):

Hearing Loss ◽

Speech Perception ◽

Literature Review ◽

Low Cost ◽

Experimental Designs ◽

Auditory Training ◽

Hearing Impairments ◽

Communicative Disorders ◽

And Training

Computerized auditory training (CAT) is a convenient, low-cost approach to improving communication of individuals with hearing loss or other communicative disorders. A number of CAT programs are being marketed to patients and audiologists. The present literature review is an examination of evidence for the effectiveness of CAT in improving speech perception in adults with hearing impairments. Six current CAT programs, used in 9 published studies, were reviewed. In all 9 studies, some benefit of CAT for speech perception was demonstrated. Although these results are encouraging, the overall quality of available evidence remains low, and many programs currently on the market have not yet been evaluated. Thus, caution is needed when selecting CAT programs for specific patients. It is hoped that future researchers will (a) examine a greater number of CAT programs using more rigorous experimental designs, (b) determine which program features and training regimens are most effective, and (c) indicate which patients may benefit from CAT the most.

Download Full-text