scholarly journals Prospective study for commercial and low-cost hyperspectral imaging systems to evaluate thermal tissue effect on bovine liver samples

Author(s):  
Mohamed Aref ◽  
Abdallah Hussein ◽  
Abou-Bakr Youssef ◽  
Ibrahim Aboughaleb ◽  
Amr Sharawi ◽  
...  

Thermal ablation modalities, for example radiofrequency ablation (RFA) and microwave ablation, are intended to prompt controlled tumour removal by raising tissue temperature. However, monitoring the size of the resulting tissue damage during the thermal removal procedures is a challenging task. The objective of this study was to evaluate the observation of RFA on an ex vivo liver sample with both a commercial and a low-cost system to distinguish between the normal and the ablated regions as well as the thermally affected regions. RFA trials were conducted on five different ex vivo normal bovine samples and monitored initially by a custom hyperspectral (HS) camera to measure the diffuse reflectance (Rd) utilising a polychromatic light source (tungsten halogen lamp) within the spectral range 348–950 nm. Next, the light source was replaced with monochromatic LEDs (415, 565 and 660 nm) and a commercial charge-coupled device (CCD) camera was used instead of the HS camera. The system algorithm comprises image enhancement (normalisation and moving average filter) and image segmentation with K-means clustering, combining spectral and spatial information to assess the variable responses to polychromatic light and monochromatic LEDs to highlight the differences in the Rd properties of thermally affected/normal tissue regions. The measured spectral signatures of the various regions, besides the calculation of the standard deviations (δ) between the generated six groups, guided us to select three optimal wavelengths (420, 540 and 660 nm) to discriminate between these various regions. Next, we selected six spectral images to apply the image processing to (at 450, 500, 550, 600, 650 and 700 nm). We noticed that the optimum image is the superimposed spectral images at 550, 600, 650 and 700 nm, which are capable of discriminating between the various regions. Later, we measured Rd with the CCD camera and commercially available monochromatic LED light sources at 415, 565 and 660 nm. Compared to the HS camera results, this system was more capable of identifying the ablated and the thermally affected regions of surface RFA than the side-penetration RFA of the investigated ex vivo liver samples. However, we succeeded in developing a low-cost system that provides satisfactory information to highlight the ablated and thermally affected region to improve the outcome of surgical tumour ablation with much shorter time for image capture and processing compared to the HS system.

Author(s):  
J. Kang ◽  
I. Lee

Sophisticated indoor design and growing development in urban architecture make indoor spaces more complex. And the indoor spaces are easily connected to public transportations such as subway and train stations. These phenomena allow to transfer outdoor activities to the indoor spaces. Constant development of technology has a significant impact on people knowledge about services such as location awareness services in the indoor spaces. Thus, it is required to develop the low-cost system to create the 3D model of the indoor spaces for services based on the indoor models. In this paper, we thus introduce the rotating stereo frame camera system that has two cameras and generate the indoor 3D model using the system. First, select a test site and acquired images eight times during one day with different positions and heights of the system. Measurements were complemented by object control points obtained from a total station. As the data were obtained from the different positions and heights of the system, it was possible to make various combinations of data and choose several suitable combinations for input data. Next, we generated the 3D model of the test site using commercial software with previously chosen input data. The last part of the processes will be to evaluate the accuracy of the generated indoor model from selected input data. In summary, this paper introduces the low-cost system to acquire indoor spatial data and generate the 3D model using images acquired by the system. Through this experiments, we ensure that the introduced system is suitable for generating indoor spatial information. The proposed low-cost system will be applied to indoor services based on the indoor spatial information.


2021 ◽  
Vol 7 (2) ◽  
pp. 020306
Author(s):  
Mohamed Aref ◽  
Ramy Abdlaty ◽  
Mohamed Abbass ◽  
Ibrahim Aboughaleb ◽  
Ayman Nassar ◽  
...  

Background and Objective: Thermal ablation modalities such as Radiofrequency ablation (RFA) / Microwave ablation (MWA) are deliberately used for marginally invasive tumor removal by escalating tissue temperature. For precise tumor extinguish, thermal ablation outcomes need routine monitoring for tissue necrosis in a challenging research task. The study aims to exploit hyperspectral imaging (HSI) to evaluate the impact of the liver tissue ablation. Materials and Methods: RFA with temperature range (≥80 °C) was accomplished on the ex vivo animal liver and evaluated using a spectral camera (400~1000 nm). The spectral signatures were extracted from the HSI data after the following processing steps: capturing three spectral data cubes for each liver sample with total 7-samples (before ablation, after ablation, and after ablation with sample slicing) using an HSI optical configuration. The custom HSI processing comprises “Top-hat and Bottom-hat transform” combined with “watershed transform” image segmentation to increase the intensity for a region of interest (ROI) of the investigated tissue, linking spectral and spatial data. Additionally, statistical analysis for HSI data was performed to exclusively select the best spectral band that discriminates between the normal, thermally-damaged, and ablated liver regions. Results: The variation of the optical parameters for the investigated liver samples provides variable interaction with the light diffuse reflection (Ŗd) over the spectrum range (400~1000 nm). Where, the extracting spectral information of the various tissue zones from the induced RFA linked to the hemoglobin, methemoglobin, and water permits variations. The generated spectral image after image enhancement utilizing “Top-hat and Bottom-hat transform” followed by “watershed segmentation”, showed high contrast between normal and thermal regions at a wavelength (600 nm). However, the wavelength (900 nm) shows a high variance between the normal and ablated regions. Finally, delineation of the thermal and ablated regions on the complemented enhanced image. Conclusion: HSI is considered a promising optical noninvasive technique for monitoring the RFA toward enhancing the ablation-based treatment for liver tumor outcomes.


Author(s):  
J. Kang ◽  
I. Lee

Sophisticated indoor design and growing development in urban architecture make indoor spaces more complex. And the indoor spaces are easily connected to public transportations such as subway and train stations. These phenomena allow to transfer outdoor activities to the indoor spaces. Constant development of technology has a significant impact on people knowledge about services such as location awareness services in the indoor spaces. Thus, it is required to develop the low-cost system to create the 3D model of the indoor spaces for services based on the indoor models. In this paper, we thus introduce the rotating stereo frame camera system that has two cameras and generate the indoor 3D model using the system. First, select a test site and acquired images eight times during one day with different positions and heights of the system. Measurements were complemented by object control points obtained from a total station. As the data were obtained from the different positions and heights of the system, it was possible to make various combinations of data and choose several suitable combinations for input data. Next, we generated the 3D model of the test site using commercial software with previously chosen input data. The last part of the processes will be to evaluate the accuracy of the generated indoor model from selected input data. In summary, this paper introduces the low-cost system to acquire indoor spatial data and generate the 3D model using images acquired by the system. Through this experiments, we ensure that the introduced system is suitable for generating indoor spatial information. The proposed low-cost system will be applied to indoor services based on the indoor spatial information.


2020 ◽  
Vol 1 (2) ◽  
pp. 22-23
Author(s):  
Rafika Andari

Abstrak Objektif. Penggunaan sel surya silikon saat ini masih tergolong mahal serta juga menggunakan bahan kimia yang berbahaya pada proses pembuatannya. Oleh karena itu perlu dikembangkan sel surya alternatif yang berbahan dasar murah dan ramah lingkungan, seperti DSSC (Dye Sensitized Solar Cell). Penggunaan DSSC sangat bagus dikembangkan dikarenakan proses pembuatan yang sederhana, biaya murah serta berbahan dasar organik.. Berdasarkan hal tersebut, perlu adanya pengembangan DSSC menggunakan dye dari ekstrak antosianin dari bahan alam yang banyak terdapat dilingkungan.  Material and Metode. Penelitian ini bertujuan mengetahui karakteristik DSSC menggunakan ekstrak bunga rosella dengan variasi jarak sumber cahaya terhadap DSSC. Karakteristik yang diukur adalah nilai arus dan tegangan serta efisiensi sel.  Sebagai sumber cahaya digunakan adalah lampu halogen 150 watt. Sumber cahaya diletakkan pada jarak 10 cm, 20 cm dan 30 cm. Hasil. Karakterisasi nilai tegangan dan arus DSSC menggunakan cahaya lampu halogen dengan jarak 10 cm terhadap DSSC lebih besar dibandingkan dengan jarak 20 cm dan 30 cm. Hasil pengujian menunjukkan bahwa efisiensi sel yang berjarak 10 cm terhadap DSSC merupakan hasil terbaik arus maksimal (Imax) 0,08 mA, tegangan maksimal (Vmax) 121,7 mV. Kesimpulan. Kinerja dari DSSC dipengaruhi oleh jarak sumber cahaya yang digunakan terhadap sel. Perbedaan nilai efisiensi ini disebabkan oleh besar intensitas cahaya terhadap sel, semakin dekat jarak sumber cahaya semakin besar intensitas cahaya sehingga menghasilkan nilai efisiensi yang besar. Abstrack Objective. The use of silicon solar cells is still relatively expensive and also uses harmful chemicals in the manufacturing process. Therefore it is necessary to develop alternative solar cells that are based on inexpensive and environmentally friendly, such as DSSC (Dye-Sensitized Solar Cell). The use of DSSC is very well prepared because of the simple manufacturing process, low cost, and organic-based. Based on this, the development of DSSC requires the use of dye from anthocyanin extracts from natural materials that are widely available in the environment. Materials and Methods. This study aims to determine the characteristics of DSSC using rosella flower extracts with variations in the distance of the light source to DSSC. The trademarks measured are current and voltage values ​​and cell efficiency. As the light source used is a 150-watt halogen lamp. Light sources are placed at a distance of 10 cm, 20 cm, and 30 cm. Results. Characterization of DSSC voltage and current values ​​using a halogen lamp with a distance of 10 cm to DSSC is more significant than a length of 20 cm and 30 cm. The test results show that the efficiency of cells within 10 cm of DSSC is the best result of maximum current (Imax) of 0.08 mA, maximum voltage (Vmax) of 121.7 mV. Conclusion. The performance of DSSC is influenced by the distance of the light source used against the cell. This difference in efficiency value is caused by the higher intensity of the light to the battery, the closer the distance of the light source, the higher the depth of the sun to produce an immense efficiency value.


2007 ◽  
Vol 40 (11) ◽  
pp. 53
Author(s):  
BRUCE K. DIXON
Keyword(s):  
Low Cost ◽  

Author(s):  
Ramin Sattari ◽  
Stephan Barcikowski ◽  
Thomas Püster ◽  
Andreas Ostendorf ◽  
Heinz Haferkamp

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 671
Author(s):  
Ana Osuna ◽  
Anna Ulldemolins ◽  
Hector Sanz-Fraile ◽  
Jorge Otero ◽  
Núria Farré ◽  
...  

This paper describes the design, construction and testing of an experimental setting, making it possible to study the endothelium under different pathophysiological conditions. This novel experimental approach allows the application of the following stimuli to an ex vivo vessel in a physiological bath: (a) a realistic intravascular pressure waveform defined by the user; (b) shear stress in the endothelial layer since, in addition to the pressure waveform, the flow through the vessel can be independently controlled by the user; (c) conditions of hypo/hyperoxia and hypo/hypercapnia in an intravascular circulating medium. These stimuli can be applied alone or in different combinations to study possible synergistic or antagonistic effects. The setting performance is illustrated by a proof of concept in an ex vivo rabbit aorta. The experimental setting is easy to build by using very low-cost materials widely available. Online Supplement files provide all the technical information (e.g., circuits, codes, 3D printer drivers) following an open-source hardware approach for free replication.


2021 ◽  
Vol 7 ◽  
pp. 205951312098853
Author(s):  
Dana M Hutchison ◽  
Amir A Hakimi ◽  
Avin Wijayaweera ◽  
Soohong Seo ◽  
Ellen M Hong ◽  
...  

Introduction: Scar treatments aim to address pathologic collagen deposition; however, they can be expensive or difficult to control. Electrochemical therapy (ECT) offers a simple alternative treatment. The purpose of this study is to examine the acid-base and histological changes in ex vivo human abdominal skin following ECT. Methods: Forty-two ex vivo human panniculus tissue sections collected from six individuals were tumesced with normal saline. ECT was performed by inserting two platinum needle electrodes connected to a DC power supply into each specimen. Voltage was varied (3–6 V) and applied for 5 minutes. Each specimen was sectioned across both electrode insertion sites and immediately stained with pH sensitive dye. The width of dye color change for each dosimetry pair was calculated. Hematoxylin and eosin staining was used to evaluate samples. Results and Discussion: ECT caused a spatially localised and dose-dependent increased area of acidic and basic pH around the anode and cathode, respectively. A significantly greater mean width of pH change was generated at the cathode compared to the anode in all treatment groups. Histological evaluation displayed broad condensation and hyalinisation of dermal collagen. Conclusion: ECT triggered dermal pH alterations and changed the underlying structural framework of the specimen. This technology may serve as a low-cost, minimally invasive local soft-tissue remodeling technique with potential application in scar management. Level of Evidence: 5 Lay Summary Electrochemical therapy is a novel treatment that causes spatially selective dermal injury in areas of interest. This study measures the effects of electrochemical therapy when applied to abdominal skin. Electrochemical therapy appears to have beneficial effects by causing a highly localised reduction in collagen content or local softening of tissue, which is consistent with other studies on scar therapies, including chemexfoliation, radiofrequency technologies, and lasers. However, electrochemical therapy can be performed at a fraction of the costs of these aforementioned modalities.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Istvan Grexa ◽  
Akos Diosdi ◽  
Maria Harmati ◽  
Andras Kriston ◽  
Nikita Moshkov ◽  
...  

AbstractRecent statistics report that more than 3.7 million new cases of cancer occur in Europe yearly, and the disease accounts for approximately 20% of all deaths. High-throughput screening of cancer cell cultures has dominated the search for novel, effective anticancer therapies in the past decades. Recently, functional assays with patient-derived ex vivo 3D cell culture have gained importance for drug discovery and precision medicine. We recently evaluated the major advancements and needs for the 3D cell culture screening, and concluded that strictly standardized and robust sample preparation is the most desired development. Here we propose an artificial intelligence-guided low-cost 3D cell culture delivery system. It consists of a light microscope, a micromanipulator, a syringe pump, and a controller computer. The system performs morphology-based feature analysis on spheroids and can select uniform sized or shaped spheroids to transfer them between various sample holders. It can select the samples from standard sample holders, including Petri dishes and microwell plates, and then transfer them to a variety of holders up to 384 well plates. The device performs reliable semi- and fully automated spheroid transfer. This results in highly controlled experimental conditions and eliminates non-trivial side effects of sample variability that is a key aspect towards next-generation precision medicine.


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