scholarly journals Camera-based optical palpation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rowan W. Sanderson ◽  
Qi Fang ◽  
Andrea Curatolo ◽  
Wayne Adams ◽  
Devina D. Lakhiani ◽  
...  

Abstract Optical elastography is undergoing extensive development as an imaging tool to map mechanical contrast in tissue. Here, we present a new platform for optical elastography by generating sub-millimetre-scale mechanical contrast from a simple digital camera. This cost-effective, compact and easy-to-implement approach opens the possibility to greatly expand applications of optical elastography both within and beyond the field of medical imaging. Camera-based optical palpation (CBOP) utilises a digital camera to acquire photographs that quantify the light intensity transmitted through a silicone layer comprising a dense distribution of micro-pores (diameter, 30–100 µm). As the transmission of light through the micro-pores increases with compression, we deduce strain in the layer directly from intensity in the digital photograph. By pre-characterising the relationship between stress and strain of the layer, the measured strain map can be converted to an optical palpogram, a map of stress that visualises mechanical contrast in the sample. We demonstrate a spatial resolution as high as 290 µm in CBOP, comparable to that achieved using an optical coherence tomography-based implementation of optical palpation. In this paper, we describe the fabrication of the micro-porous layer and present experimental results from structured phantoms containing stiff inclusions as small as 0.5 × 0.5 × 1 mm. In each case, we demonstrate high contrast between the inclusion and the base material and validate both the contrast and spatial resolution achieved using finite element modelling. By performing CBOP on freshly excised human breast tissue, we demonstrate the capability to delineate tumour from surrounding benign tissue.

2016 ◽  
Vol 33 (S1) ◽  
pp. S88-S89
Author(s):  
C. Wyss ◽  
K. Heekeren ◽  
A. Del Guerra ◽  
N.J. Shah ◽  
I. Neuner ◽  
...  

IntroductionThe aim of the FP7-European funded project TRIMAGE is to create a trimodal, cost-effective imaging tool consisting of PET/MR/EEG to enable effective early diagnosis of schizophrenia.ObjectiveIn the scope of this project we are interested in the multimodal assessment of response inhibition. The loudness dependence of auditory evoked potential (LDAEP) is a suitable biomarker of inhibitory action in signal processing. Variations in response inhibition can have great impact on different aspects of life. Individuals with reduced capability of inhibitory control have a tendency to impulsive behavior. Studies showed that they have stronger LDAEP values. Patients with schizophrenia may exhibit alterations in the responsiveness to sensory stimuli. Thus, a reduced LDAEP was found in these patients. However, these deviances differed in clinical features of the disorder. Therefore, we would like to further elucidate the relationship between multimodal neuroimaging methods and dimensions of symptoms, observable behavior, personality traits and general psychopathological dysfunction.MethodsA sample of 20 healthy controls and 20 patients with manifest schizophrenia will be examined with the LDAEP paradigm in a trimodal approach with customary imaging tools. PET measurements with the radiotracer [11C]-flumazenil will be used to assess the binding potentials of GABA-A receptors. MRS will provide data about GABA concentrations. Simultaneously recorded EEG-fMRI data will permit new insight in the relationship between LDAEP and impulsivity.DiscussionThe project will use alternative approaches to psychiatric classification. Response inhibition in sensory processing will be investigated from different angles (biochemical, neurophysiological, and neuroanatomical) and combined with psychological characteristic values.Disclosure of interestThe authors have not supplied their declaration of competing interest.


Author(s):  
Q. Kim ◽  
S. Kayali

Abstract In this paper, we report on a non-destructive technique, based on IR emission spectroscopy, for measuring the temperature of a hot spot in the gate channel of a GaAs metal/semiconductor field effect transistor (MESFET). A submicron-size He-Ne laser provides the local excitation of the gate channel and the emitted photons are collected by a spectrophotometer. Given the state of our experimental test system, we estimate a spectral resolution of approximately 0.1 Angstroms and a spatial resolution of approximately 0.9 μm, which is up to 100 times finer spatial resolution than can be obtained using the best available passive IR systems. The temperature resolution (<0.02 K/μm in our case) is dependent upon the spectrometer used and can be further improved. This novel technique can be used to estimate device lifetimes for critical applications and measure the channel temperature of devices under actual operating conditions. Another potential use is cost-effective prescreening for determining the 'hot spot' channel temperature of devices under normal operating conditions, which can further improve device design, yield enhancement, and reliable operation. Results are shown for both a powered and unpowered MESFET, demonstrating the strength of our infrared emission spectroscopy technique as a reliability tool.


2011 ◽  
Vol 14 (2) ◽  
Author(s):  
Thomas G Koch

Current estimates of obesity costs ignore the impact of future weight loss and gain, and may either over or underestimate economic consequences of weight loss. In light of this, I construct static and dynamic measures of medical costs associated with body mass index (BMI), to be balanced against the cost of one-time interventions. This study finds that ignoring the implications of weight loss and gain over time overstates the medical-cost savings of such interventions by an order of magnitude. When the relationship between spending and age is allowed to vary, weight-loss attempts appear to be cost-effective starting and ending with middle age. Some interventions recently proven to decrease weight may also be cost-effective.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 296-297
Author(s):  
Daniela M Meléndez ◽  
Sonia Marti ◽  
Luigi Faucitano ◽  
Derek B Haley ◽  
Timothy D Schwinghamer ◽  
...  

Abstract Blood metabolites are used to assess a variety of animal conditions for veterinary diagnosis and research. Concentration of metabolites in blood can be measured using a commercially-available lab-based assay or in real-time using a handheld device developed to be more time- and cost-effective than the lab-based method. Lactate is a product of anaerobic glycolysis, used in animal research as an indicator of muscle fatigue. Therefore, it has been used as an indicator of cattle response to long distance transportation. The aim of this study was to assess the relationship of L-lactate concentrations measured using a Lactate Scout+ analyzer (Lactate Scout, EFK Diagnostics, Barleben, Germany) and a lactate assay colorimetric kit (Lactate Assay Kit, Cell Biolabs Inc., San Diego, CA). Blood samples were collected by venipuncture from 96 steers (245 ± 35.7 kg BW) prior to (L1) and after 36 h, and prior to and after an additional 4 h of road transportation, and on d 1, 2, 3, 5, 14, and 28 after transport. The Lactate Scout+ analyzer strip was dipped in blood at the time of sampling, while blood samples were collected into sodium fluoride tubes for use in colorimetric analysis. Pearson correlations were calculated to determine the relationship between the experimental methods for the quantification of L-lactate concentrations. The strengths and levels of statistical significance of the correlation varied over the observed time points, r = -0.03, P = 0.75 (L1) to r = 0.75, P = < 0.0001 (d 3). The correlation for the pooled data was weak but statistically significant (r = 0.33, P < 0.001). Based on the experimental results, the Lactate Scout+ analyzer is not a suitable alternative to a lab-based assay for measuring L-lactate in transported cattle, due to variability across sampling time points and weak correlation with the traditional enzymatic method.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2217
Author(s):  
Daniela Șova ◽  
Mariana Domnica Stanciu ◽  
Sergiu Valeriu Georgescu

Investigating the large number of various materials now available, some materials scientists promoted a method of combining existing materials with geometric features. By studying natural materials, the performance of simple constituent materials is improved by manipulating their internal geometry; as such, any base material can be used by performing millimeter-scale air channels. The porous structure obtained utilizes the low thermal conductivity of the gas in the pores. At the same time, heat radiation and gas convection is hindered by the solid structure. The solution that was proposed in this research for obtaining a material with porous structure consisted in perforating extruded polystyrene (XPS) panels, as base material. Perforation was performed horizontally and at an angle of 45 degrees related to the face panel. The method is simple and cost-effective. Perforated and simple XPS panels were subjected to three different temperature regimes in order to measure the thermal conductivity. There was an increase in thermal conductivity with the increase in average temperature in all studied cases. The presence of air channels reduced the thermal conductivity of the perforated panels. The reduction was more significant at the panels with inclined channels. The differences between the thermal conductivity of simple XPS and perforated XPS panels are small, but the latter can be improved by increasing the number of channels and the air channels’ diameter. Additionally, the higher the thermal conductivity of the base material, the more significant is the presence of the channels, reducing the effective thermal conductivity. A base material with low emissivity may also reduce the thermal conductivity.


2021 ◽  
pp. 22-35
Author(s):  
Stanislav V. Pechinskii ◽  
Eduard T. Oganesyan ◽  
Anna G. Kuregyan

Molecular docking is a convenient and cost-effective tool for targeted screening of biologically active structures. This method makes it possible to reveal the relationship between structure and activity, as well as to search for new active compounds. Due to the fact that the antiviral activity of flavonoids and their derivatives has been shown experimentally and clinically, the study of their antiviral activity against SARS-CoV-2 is a promising study. In an in silico experiment, the possibility of binding 20 flavonoid ligands and the main protease SARS-CoV-2 was studied. The structural features of flavone and flavanone derivatives have been determined, which determine their ability to block the main protease of the SARS-CoV-2 virus. Structures of eight new candidates that bind the main protease SARS-CoV-2, which have the prospect of synthesis and further pharmacological research, have been proposed.


Author(s):  
Filiz Güldaval ◽  
Ceyda Anar ◽  
Mine Gayaf ◽  
Gulru Polat ◽  
Merve Ayık Türk ◽  
...  

Objective: Various studies have reported that the neutrophil-to-lymphocyte ratio in the serum (sNLR) may serve as a cost-effective and useful prognostic factor in patients with various cancer types. We investigated the clinical impact of NLR as a prognostic factor in malign pleural effusion (MPE) and sNLR on prognosis in MPE. Method: We retrospectively reviewed all of the patients who were diagnosed MPE. The relationship between sNLR and neutrophil-to-lymphocyte ratio in the malign pleural effusion (mNLR) value, age, Eastern Cooperative Oncology Group (ECOG), histopathologic type, serum albumin and lactate dehydrogenase (LDH) with survival were investigated. Results: A total of 222 patients with a mean age of 65.7±11.5 were included in the study. Patients with a mNLR value ≥0.42 and a serum NLR value ≥4.75 had a shorter survival (p: 0.000). Multivariate analysis, which showed that survival was significantly related mNLR value > 0.42 and/or sNLR value > 4.75 (Odds Ratio (OR): 2.66, %95 CI, 1,65-4,3 p: 0.001), serum LDH > 210 (OR = 1.8, %95 CI, 1,33-2,46 p: 0.001) and age > 65 (OR = 1.9, %95 CI, 1,41-2,55 p = 0.001). Conclusion: sNLR and mNLR may act as a simple, useful, and cost-effective prognostic factor in patients with MPE. Furthermore, these results may serve as the cornerstone of further research into the mNLR in the future. Although further studies are required to generalize our results, this information will benefit clinicians and patients in determining the most appropriate therapy for patients with MPE.


2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Sabelo Nick Dlamini ◽  
Jonas Franke ◽  
Penelope Vounatsou

Many entomological studies have analyzed remotely sensed data to assess the relationship between malaria vector distribution and the associated environmental factors. However, the high cost of remotely sensed products with high spatial resolution has often resulted in analyses being conducted at coarse scales using open-source, archived remotely sensed data. In the present study, spatial prediction of potential breeding sites based on multi-scale remotely sensed information in conjunction with entomological data with special reference to presence or absence of larvae was realized. Selected water bodies were tested for mosquito larvae using the larva scooping method, and the results were compared with data on land cover, rainfall, land surface temperature (LST) and altitude presented with high spatial resolution. To assess which environmental factors best predict larval presence or absence, Decision Tree methodology and logistic regression techniques were applied. Both approaches showed that some environmental predictors can reliably distinguish between the two alternatives (existence and non-existence of larvae). For example, the results suggest that larvae are mainly present in very small water pools related to human activities, such as subsistence farming that were also found to be the major determinant for vector breeding. Rainfall, LST and altitude, on the other hand, were less useful as a basis for mapping the distribution of breeding sites. In conclusion, we found that models linking presence of larvae with high-resolution land use have good predictive ability of identifying potential breeding sites.


2017 ◽  
Vol 43 (4) ◽  
pp. 281-288 ◽  
Author(s):  
Catherine Rachel Morgan ◽  
Hanhua Liu

BackgroundReducing unplanned pregnancy in Scotland is a key government objective. Long-acting reversible contraception (LARC) is a cost-effective way to reduce unintended pregnancy. Abortion and teenage pregnancy rates are highest in the most deprived areas. One possible explanation could be contraceptive prescribing inequality. This study examined the relationship between area deprivation measured by the Scottish Index of Multiple Deprivation and LARC prescription.MethodsUsing Scottish electronic prescribing data from primary care and sexual and reproductive health clinics, this study analysed female Lothian residents with a valid postcode aged 16–49 years who received a contraceptive prescription from 1 April 2012 to 31 March 2014. Prescription of LARC (intrauterine, implant or injectable contraceptive) compared with non-LARC (oral pill, patch, ring or diaphragm) was examined. Logistic regression was performed adjusting for age group and prescription location.ResultsA total of 90 150 women were included; 21.1% of prescriptions were LARC and 15.3% vLARC (intrauterine method or implant). Women residing in the most deprived quintile (Q1) and prescribed contraception received a significantly higher proportion of LARC than quintiles 2–5 (Q2–5). Odds ratios compared with Q1 were: Q2 0.86, Q3 0.77, Q4 0.59 and Q5 0.51. Women in quintile 1 were also significantly more likely to receive vLARC than quintiles 2–5.ConclusionWomen in the most deprived quintile in Lothian who are prescribed contraception are significantly more likely to receive LARC and vLARC compared with women in less deprived quintiles.


Sign in / Sign up

Export Citation Format

Share Document