Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 6 de 6
Filter
Add more filters










Database
Publication year range
1.
J Ophthalmol ; 2022: 1903516, 2022.
Article in English | MEDLINE | ID: mdl-35450322

ABSTRACT

Purpose: Ophthalmic endoscopy is useful in vitreoretinal surgery with opaque anterior segments or anatomically challenging structures. However, standard ophthalmic endoscopy devices are usually large and costly. Thus, the development of a portable endoscope is necessary. Methods: The portable endoscope consisted of a probe, an illumination system, a high-resolution camera module, and a universal serial bus (USB). It was connected to a laptop and applied for intraocular imaging of porcine eyes in vitro. Basic parameters and pictures of the same tissue target were compared with those of the standard Endo Optiks E4 system. Results: The retinal images were displayed on the laptop screen, which clearly showed the overall appearance of the central and peripheral retina, and the details of the retinal vasculature and ciliary body. Compared with a standard endoscope, our portable endoscope is smaller and more affordable. It can be taken anywhere for intraocular imaging and vitreoretinal surgery. Conclusion: A laptop-based portable endoscope is a promising device in vitreoretinal surgery. It provides high-resolution images of intraocular tissues that should make a noticeable difference in intraocular surgery with disordered anterior segments. With its portability and high-resolution imaging, it may promote the application of endoscopes in ophthalmology.

2.
Front Chem ; 9: 779304, 2021.
Article in English | MEDLINE | ID: mdl-34900938

ABSTRACT

As a new type of membrane material, graphene oxide (GO) can easily form sub-nanometer interlayer channels, which can effectively screen salt ions. The composite membrane and structure with a high water flux and good ion rejection rate were compared by the cross-linking of GO with three different diamine monomers: ethylenediamine (EDA), urea (UR), and p-phenylenediamine (PPD). X-ray photoelectron spectroscopy (XPS) results showed that unmodified GO mainly comprises π-π interactions and hydrogen bonds, but after crosslinking with diamine, both GO and mixed cellulose (MCE) membranes are chemically bonded to the diamine. The GO-UR/MCE membrane achieved a water flux similar to the original GO membrane, while the water flux of GO-PPD/MCE and GO-EDA/MCE dropped. X-ray diffraction results demonstrated that the covalent bond between GO and diamine can effectively inhibit the extension of d-spacing during the transition between dry and wet states. The separation performance of the GO-UR/MCE membrane was the best. GO-PPD/MCE had the largest contact angle and the worst hydrophilicity, but its water flux was still greater than GO-EDA/MCE. This result indicated that the introduction of different functional groups during the diamine monomer cross-linking of GO caused some changes in the performance structure of the membrane.

3.
Front Oncol ; 10: 568069, 2020.
Article in English | MEDLINE | ID: mdl-33194653

ABSTRACT

BACKGROUND: Patients with non-calcified hamartoma were more susceptible to surgery or needle biopsy for the tough discrimination from lung adenocarcinoma. Radiomics have the ability to quantify the lesion features and potentially improve disease diagnosis. Thus, this study aimed to discriminate non-calcified hamartoma from adenocarcinoma by employing imaging quantification and machine learning. METHODS: Forty-two patients with non-calcified hamartoma and 49 patients with adenocarcinoma were retrospentation; Manual lesion segmentation, feature quantification (e.g., texture features), and artificial neural network were performed consecutively. Independent t-test was used to conduct the inter-group comparisons of those imaging features. Receiver operating characteristic curve was performed to investigate the discriminating efficacy. RESULTS: Significantly higher contrast, cluster prominence, cluster shade, dissimilarity, energy, and entropy in non-calcified hamartoma were observed compared with lung adenocarcinoma. Texture-grey-level co-occurrence matrix showed a well discrimination between non-calcified hamartoma and adenocarcinoma as the detection sensitivity, specificity, accuracy, and the area under the curve were 87.22% ± 9.07%, 82.64% ± 8.07%, 85.11% ± 5.40%, and 0.942, respectively. CONCLUSION: Quantifying imaging features is a potentially useful tool for clinical diagnosis. This study demonstrated that non-calcified hamartoma has a heterogeneous distribution of attenuations probably resulting from its complex organizations. Based on this property, imaging quantification could improve discrimination of non-calcified hamartoma from adenocarcinoma.

4.
BMC Ophthalmol ; 17(1): 89, 2017 Jun 13.
Article in English | MEDLINE | ID: mdl-28610611

ABSTRACT

BACKGROUND: We modified and reconstructed a high image quality portable non-mydriatic fundus camera and compared it with the tabletop fundus camera to evaluate the efficacy of the new camera in detecting retinal diseases. METHODS: We designed and built a novel portable handheld fundus camera with telemedicine system. The image quality of fundus cameras was compared to that of existing commercial tabletop cameras by taking photographs of 364 eyes from the 254 patients. In all 800 fundus images taken by two camera types, 400 images per camera, were graded with the four image clarity classifications. RESULTS: Using the portable fundus camera, 63% (252/400) images were graded as excellent overall quality, 20.5% (82/400) were good, 11.75% (47/400) were fair, and 4.75% (19/400) were inadequate. Using the tabletop fundus camera, 70.75% (283/400) images were graded as excellent overall quality, 20.4% (51/400) were good, 13.25% (53/400) were fair, and 3.25% (13/400) were inadequate. Common retinal diseases were easily identified from fundus images obtained from the portable fundus camera. CONCLUSION: The new type of non-mydriatic portable fundus camera was qualified to have professional quality of fundus images. The revolutionary screening camera provides a foundational platform which can potentially improve the accessibility of retinal screening programmes.


Subject(s)
Image Processing, Computer-Assisted/instrumentation , Mass Screening/methods , Photography/instrumentation , Retina/pathology , Retinal Diseases/diagnosis , Telemedicine/methods , Adolescent , Adult , Aged , Aged, 80 and over , Child , Equipment Design , Female , Humans , Male , Middle Aged , Mydriatics , Reproducibility of Results , Young Adult
5.
IEEE Trans Med Imaging ; 35(4): 1046-55, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26672033

ABSTRACT

Telemedicine and the medical "big data" era in ophthalmology highlight the use of non-mydriatic ocular fundus photography, which has given rise to indispensable applications of portable fundus cameras. However, in the case of portable fundus photography, non-mydriatic image quality is more vulnerable to distortions, such as uneven illumination, color distortion, blur, and low contrast. Such distortions are called generic quality distortions. This paper proposes an algorithm capable of selecting images of fair generic quality that would be especially useful to assist inexperienced individuals in collecting meaningful and interpretable data with consistency. The algorithm is based on three characteristics of the human visual system--multi-channel sensation, just noticeable blur, and the contrast sensitivity function to detect illumination and color distortion, blur, and low contrast distortion, respectively. A total of 536 retinal images, 280 from proprietary databases and 256 from public databases, were graded independently by one senior and two junior ophthalmologists, such that three partial measures of quality and generic overall quality were classified into two categories. Binary classification was implemented by the support vector machine and the decision tree, and receiver operating characteristic (ROC) curves were obtained and plotted to analyze the performance of the proposed algorithm. The experimental results revealed that the generic overall quality classification achieved a sensitivity of 87.45% at a specificity of 91.66%, with an area under the ROC curve of 0.9452, indicating the value of applying the algorithm, which is based on the human vision system, to assess the image quality of non-mydriatic photography, especially for low-cost ophthalmological telemedicine applications.


Subject(s)
Diagnostic Techniques, Ophthalmological , Fundus Oculi , Image Processing, Computer-Assisted/methods , Algorithms , Humans , Machine Learning , ROC Curve
6.
Nan Fang Yi Ke Da Xue Xue Bao ; 34(7): 1016-9, 1024, 2014 Jun.
Article in Chinese | MEDLINE | ID: mdl-25057075

ABSTRACT

OBJECTIVE: To study the incidence of implantation metastasis of breast cancer in vacuum-assisted breast biopsy (VABB) needle tract in Chinese patients and evaluate the effect of neoadjuvant chemotherapy on needle tract metastasis following VABB. METHODS: The breast cancer patients with established diagnosis by VABB were divided into two groups to receive open surgery or neoadjuvant chemotherapy prior to open surgery. The incidence of needle tract metastasis, disease-free survival (DFS) and overall survival (OS) were compared between the two groups. RESULTS: A total of 214 patients were enrolled, among whom 94 directly underwent surgeries and 120 had neoadjuvant chemotherapy before surgery. The two groups showed no significant differences in the incidence of needle tract metastasis (3.2% vs 0.8%, P=0.206), DFS (P=0.221), or OS (P=0.531). CONCLUSION: The incidence of needle tract metastasis is low after VABB, and neoadjuvant chemotherapy does not increase this risk.


Subject(s)
Biopsy, Needle/methods , Breast Neoplasms/pathology , Neoadjuvant Therapy , Neoplasms, Second Primary/drug therapy , Breast , Disease-Free Survival , Female , Humans , Incidence , Needles , Vacuum
SELECTION OF CITATIONS
SEARCH DETAIL
...