3D Visible Light-Based Indoor Positioning System Using Two-Stage Neural Network (TSNN) and Received Intensity Selective Enhancement (RISE) to Alleviate Light Non-Overlap Zones.

The high precision three-dimensional (3D) visible light-based indoor positioning (VLIP) systems have gained much attention recently for people or robot navigation, access tracking, etc. In this work, we put forward and present the first demonstration, up to the authors' knowledge, of a 3D VLIP system utilizing a two-stage neural network (TSNN) model. The positioning performance would degrade when the distance between the light emitting diode (LED) plane and the receiver (Rx) plane increases; however, because of the finite LED field-of-view (FOV), light non-overlap zones are created. These light non-overlap zones will produce high positioning error particularly for the 3D VLIP systems. Here, we also propose and demonstrate the Received-Intensity-Selective-Enhancement scheme, known as RISE, to alleviate the light non-overlap zones in the VLIP system. In a practical test-room with dimensions of 200 × 150 × 300 cm3, the experimental results show that the mean errors in the training and testing data sets are reduced by 54.1% and 27.9% when using the TSNN model with RISE in the z-direction, and they are reduced by 39.1% and 37.8% in the xy-direction, respectively, when comparing that with using a one stage NN model only. At the cumulative distribution function (CDF) P90, the TSNN model with RISE can reduce the errors by 36.78% when compared with that in the one stage NN model.

Using lighting design tool to simplify the visible light positioning plan and reduce the deep learning loading.

We put forward and transform the commercially available lighting design software into an indoor visible light positioning (VLP) design tool. The proposed scheme can work well with different deep learning methods for reducing the loading of training data set collection. The indoor VLP models under evaluation include second order regression, fully-connected neural-network (FC-NN), and convolutional neural-network (CNN). Experimental results show that the similar positioning accuracy can be obtained when the indoor VLP models are trained with experimentally acquired data set or trained with software obtained data set. Hence, the proposed method can reduce the training loading for the indoor VLP.

Optical camera communication (OCC) using a laser-diode coupled optical-diffusing fiber (ODF) and rolling shutter image sensor.

We demonstrate an optical-camera-communication (OCC) system utilizing a laser-diode (LD) coupled optical-diffusing-fiber (ODF) transmitter (Tx) and rolling-shutter based image sensor receiver (Rx). The ODF is a glass optical fiber produced for decorative lighting or embedded into small areas where bulky optical sources cannot fit. Besides, decoding the high data rate rolling-shutter pattern from the thin ODF Tx is very challenging. Here, we propose and experimentally demonstrate the pixel-row-per-bit based neural-network (PPB-NN) to decode the rolling-shutter-pattern emitted by the thin ODF Tx. The proposed PPB-NN algorithm is discussed. The proposed PPB-NN method can satisfy the pre-forward error correction (FEC) BER at data rate of 3,300 bit/s at a transmission distance of 35 cm. Theoretical analysis of the maximum ODF Tx angle is also discussed; and our experimental values agree with our theoretical results.

Thermal Degradation of Linalool-Chemotype Cinnamomum osmophloeum Leaf Essential Oil and Its Stabilization by Microencapsulation with ß-Cyclodextrin.

The thermal degradation of linalool-chemotype Cinnamomum osmophloeum leaf essential oil and the stability effect of microencapsulation of leaf essential oil with ß-cyclodextrin were studied. After thermal degradation of linalool-chemotype leaf essential oil, degraded compounds including ß-myrcene, cis-ocimene and trans-ocimene, were formed through the dehydroxylation of linalool; and ene cyclization also occurs to linalool and its dehydroxylated products to form the compounds such as limonene, terpinolene and α-terpinene. The optimal microencapsulation conditions of leaf essential oil microcapsules were at a leaf essential oil to the ß-cyclodextrin ratio of 15:85 and with a solvent ratio (ethanol to water) of 1:5. The maximum yield of leaf essential oil microencapsulated with ß-cyclodextrin was 96.5%. According to results from the accelerated dry-heat aging test, ß-cyclodextrin was fairly stable at 105 °C, and microencapsulation with ß-cyclodextrin can efficiently slow down the emission of linalool-chemotype C. osmophloeum leaf essential oil.

Artificial neural networks improve LDCT lung cancer screening: a comparative validation study.

BACKGROUND: This study proposes a prediction model for the automatic assessment of lung cancer risk based on an artificial neural network (ANN) with a data-driven approach to the low-dose computed tomography (LDCT) standardized structure report. METHODS: This comparative validation study analysed a prospective cohort from Chiayi Chang Gung Memorial Hospital, Taiwan. In total, 836 asymptomatic patients who had undergone LDCT scans between February 2017 and August 2018 were included, comprising 27 lung cancer cases and 809 controls. A derivation cohort of 602 participants (19 lung cancer cases and 583 controls) was collected to construct the ANN prediction model. A comparative validation of the ANN and Lung-RADS was conducted with a prospective cohort of 234 participants (8 lung cancer cases and 226 controls). The areas under the curves (AUCs) of the receiver operating characteristic (ROC) curves were used to compare the prediction models. RESULTS: At the cut-off of category 3, the Lung-RADS had a sensitivity of 12.5%, specificity of 96.0%, positive predictive value of 10.0%, and negative predictive value of 96.9%. At its optimal cut-off value, the ANN had a sensitivity of 75.0%, specificity of 85.0%, positive predictive value of 15.0%, and negative predictive value of 99.0%. The area under the ROC curve was 0.764 for the Lung-RADS and 0.873 for the ANN (P = 0.01). The two most important predictors used by the ANN for predicting lung cancer were the documented sizes of partially solid nodules and ground-glass nodules. CONCLUSIONS: Compared to the Lung-RADS, the ANN provided better sensitivity for the detection of lung cancer in an Asian population. In addition, the ANN provided a more refined discriminative ability than the Lung-RADS for lung cancer risk stratification with population-specific demographic characteristics. When lung nodules are detected and documented in a standardized structured report, ANNs may better provide important insights for lung cancer prediction than conventional rule-based criteria.

Using non-contrast-enhanced magnetic resonance venography for the evaluation of May-Thurner syndrome in patients with renal insufficiency: A case report.

RATIONALE: Contrast-enhanced computed tomographic venography (CTV) or magnetic resonance venography (MRV) are usually used to detect May-Thurner syndrome (MTS). However, both are associated with contrast-induced nephrotoxicity. For patients who cannot receive contrast media, non-contrast-enhanced MRV using three-dimensional (3D) turbo spin-echo (TSE) is considered an alternative. We report a case of MTS to describe its clinical utility and advantages. PATIENT CONCERNS: A 49-year-old male experienced isolated left leg swelling and pain for half a month. He had a history of chronic renal insufficiency that made contrast-enhanced imaging studies inadequate. DIAGNOSES: A lower extremity venous Duplex scan showed a thrombus extending from the left distal femoral vein to the popliteal vein with valvular reflux, consistent with infrainguinal deep vein thrombosis (DVT). The suprainguinal DVT was evaluated by non-contrast-enhanced MRV. The results showed sandwich external compression of the left common iliac vein between the right common iliac artery and lumbar vertebrae, consistent with DVT of the left common iliac vein caused by MTS. INTERVENTIONS: The patient received angioplasty with the implantation of a balloon-expandable stent over the left common iliac vein. OUTCOMES: Excellent recanalization of the left iliac vein was noted postoperatively. LESSONS: In the evaluation of suprainguinal venous lesions, non-contrast-enhanced MRV presents the venous structure alone at high resolution without the accompanying arterial structure, which makes it an excellent diagnostic imaging tool for MTS. These findings indicate that non-contrast-enhanced MRV could be useful for detecting systemic venous pathologies in patients with renal insufficiency.

The use of non-contrast-enhanced MRI to evaluate serial changes in endoleaks after aortic stenting: a case report.

BACKGROUND: Aortic dissection is a life-threatening syndrome that sometimes requires emergency intervention, and endovascular aortic aneurysm repair (EVAR) is a treatment option. Long-term image follow-up is also required for patients after EVAR due to possible complications. CASE PRESENTATION: We present the case of a 73-year-old male with underlying chronic renal disease diagnosed with a type A aortic dissection who underwent EVAR. Four-dimensional (three spatial dimensions combined with time) phase-contrast magnetic resonance imaging (4D PC-MRI) was performed during regular follow-up in preference to contrast-enhanced computed tomography or simple MRI while taking his poor renal function into consideration. CONCLUSIONS: We considered this preferable given his issues with renal function.

Accuracy and complications of CT-guided pulmonary core biopsy in small nodules: a single-center experience.

BACKGROUND: Computed tomography (CT)-guided pulmonary core biopsies of small pulmonary nodules less than 15 millimeters (mm) are challenging for radiologists, and their diagnostic accuracy has been shown to be variable in previous studies. Common complications after the procedure include pneumothorax and pulmonary hemorrhage. The present study compared the diagnostic accuracy of small and large lesions using CT-guided core biopsies and identified the risk factors associated with post-procedure complications. METHODS: Between January 1, 2016, and December 31, 2017, 198 CT-guided core biopsies performed on 195 patients at our institution were retrospectively enrolled. The lesions were separated into group A (< or = 15 mm) and group B (> 15 mm) according to the longest diameter of the target lesions on CT. Seventeen-gauge introducer needles and 18-gauge automated biopsy instruments were coaxially used for the biopsy procedures. The accuracy and complications, including pneumothorax and pulmonary hemorrhage, of the procedures of each group were recorded. The risk factors for pneumothorax and pulmonary hemorrhage were determined using univariate analysis of variables. RESULTS: The diagnostic accuracies of group A (n = 43) and group B (n = 155) were 83.7 % and 96.8 %, respectively (p = 0.005). The risk factors associated with post-biopsy pneumothorax were longer needle path length from the pleura to the lesion (p = 0.020), lesion location in lower lobes (p = 0.002), and patients with obstructive lung function tests (p = 0.034). The risk factors associated with post-biopsy pulmonary hemorrhage were longer needle path length from the pleura to the lesion (p < 0.001), smaller lesions (p < 0.001), non-pleural contact lesions (p < 0.001), patients without restrictive lung function tests (p = 0.034), and patients in supine positions (p < 0.003). CONCLUSION: CT-guided biopsies of small nodules equal to or less than 15 mm using 17-gauge guiding needles and 18-gauge biopsy guns were accurate and safe. The biopsy results of small lesions were less accurate than those of large lesions, but the results were a reliable reference for clinical decision-making. Understanding the risk factors associated with the complications of CT-guided biopsies is necessary for pre-procedural planning and communication.

Assessment of small hepatocellular carcinoma: perfusion quantification and time-concentration curve evaluation using color-coded and quantitative digital subtraction angiography.

To explore the role of quantitative digital subtraction angiography (QDSA) in the diagnosis of small hepatocellular carcinoma (HCC).Between November 2015 and November 2017, all patients who underwent chemoembolization for HCC were retrospectively reviewed. Patients with tumors measuring more than 5 cm or evident post-processing imaging artifacts were excluded. Images were post-processed using the QDSA technique. Regions of interest were manually drawn on proper hepatic artery (as a reference), target HCC and peritumoral liver. Time-concentration curves and flow parameters of the peak ratio, subtracted time-to-peak (TTP), and area under the curve (AUC) ratio was obtained and analyzed.A total of 146 HCCs (mean diameter, 1.6 cm) of 71 cirrhotic patients (54 men, 17 women; mean age, 67.7 years) were enrolled. Compared with liver parenchyma, HCCs showed an increased and more rapid flow (peak ratio, AUC ratio, subtracted TTP, and wash-in slope; all P <.001). Compared with untreated HCCs, chemoembolized HCCs showed a slower flow (subtracted TTP and wash-in slope, P = .004 and .002, respectively). HCCs with a typical enhancement pattern on computed tomography (CT) or magnetic resonance imaging (MRI) had a trend toward Type III (washout pattern) time-concentration curves (P <.001). Chemoembolized HCCs had a trend toward Type II (plateau pattern) time-concentration curves (P = .005).QDSA technology can be used to quantify perfusion measurements of HCC and hepatic parenchyma and to assess perfusion changes after HCC chemoembolization.

Short bowel syndrome caused by laparoscopic loop enterostomy of the jejunum in an adult with undiagnosed intestinal malrotation: A case report.

RATIONALE: Failure to recognize intestinal malrotation in adults can cause complications during surgeries, especially those with a limited operative field. We report a case of short bowel syndrome caused by mistaken creation of a loop enterostomy in the jejunum due to undiagnosed intestinal malrotation. PATIENT CONCERNS: A 72-year-old man underwent a laparoscopic right hemicolectomy and ileocolostomy because of complicated diverticulitis. Six days after the surgery, he received laparoscopic exploration because of anastomotic leak, and a laparoscopic loop ileostomy was also performed as a protective diversion stoma. One month after surgery, he complained of severe diarrhea from the enterostomy after food and water intake. An upper gastrointestinal and small bowel series revealed that the duodenojejunal junction (DJJ) did not cross the midline and there was a short distance between the DJJ and the enterostomy in the right lower quadrant. DIAGNOSES: Short bowel syndrome caused by mistaken creation of a loop enterostomy in the jejunum due to undiagnosed intestinal malrotation. INTERVENTIONS: Total parental nutrition was used and the loop enterostomy was closed 3 months after the initial surgery. OUTCOMES: The patient was discharged uneventfully 2 weeks after the loop enterostomy. LESSONS: Intestinal malrotation in adults is often encountered during routine radiological examinations. However, it may cause complications during surgery if ignored. Radiologists should keep in mind that complications may occur if a complete presurgical evaluation of intestinal malrotation is not performed, and surgeons should take caution when performing surgeries, especially those with a limited operative field.

Hepatocellular carcinoma with thoracic metastases presenting as hemothorax: A case report and literature review.

RATIONALE: Hemothorax caused by metastasis or direct invasion of hepatocellular carcinoma (HCC) in the chest is rare. We report a case of hemothorax caused by metastasis in the mediastinum and treated with transcatheter arterial embolization (TAE). PATIENT CONCERNS: A 60-year-old woman with HCC was admitted to receive chemotherapy. Two days after admission, she complained of dyspnea, and a chest X-ray revealed right pleural effusion. Thoracentesis confirmed the diagnosis of hemothorax. Computed tomography (CT) angiography showed lung, pleural, and mediastinal metastases and contrast extravasation from the right lower mediastinal mass. DIAGNOSES: Hemothorax caused by spontaneous rupture of mediastinal metastasis of hepatocellular carcinoma. INTERVENTIONS: During emergent angiography, contrast extravasation from the right T10 intercostal artery was observed and we performed embolization with lipiodol and gelatin sponge particles. After embolization, no active bleeding was observed. OUTCOMES: The patient died because of sepsis and multiple organ failure 22 days after admission. LESSONS: We reviewed 21 cases of HCC with metastasis or direct invasion in the chest presenting hemothorax. The results revealed that male sex and right hemothorax were predominant in these cases. The average age of the patients was 61.24±10.82 years. The most common symptoms were dyspnea, chest wall pain, and shock. Thoracentesis can confirm the diagnosis, and CT angiography can help identify the location of contrast extravasation before TAE. The reported bleeding arteries were the intercostal, inferior phrenic, bronchial, hepatic, and superficial cervical arteries. TAE with embolic agents is a feasible treatment. The overall outcomes in these cases were poor.

Adult renal neuroblastoma: A case report and literature review.

RATIONALE: Adult renal neuroblastoma (NB) is extremely rare, and there have been only a few cases previously described in the literature. We report a case of adult renal NB and summarize the clinical and imaging features of the reported cases. PATIENT CONCERNS: A 41-year-old female was admitted to our hospital with a chief complaint of gross hematuria that had persisted for a month. Nonenhanced computed tomography (CT) revealed a hypodense right renal mass without calcification. Enhanced CT showed an infiltrative, heterogeneously enhancing right renal mass with retrocaval lymphadenopathy and right renal vein thrombus. Magnetic resonance imaging (MRI) revealed that the right renal mass was isointense relative to the renal parenchyma on nonenhanced T1-weighted images; it showed mixed hypointensity and hyperintensity on T2-weighted images, and heterogeneous enhancement with a hyperintense rim on fat-saturated, enhanced T1W images. The initial impression was renal cell carcinoma (RCC). DIAGNOSES: Adult renal neuroblastoma. INTERVENTIONS: Right nephroureterectomy with lymph node dissection was performed. The pathology and immunohistochemistry confirmed the diagnosis of renal NB with retrocaval lymphadenopathy and retroperitoneal metastasis. OUTCOMES: After surgery, the patient received 6 courses of chemotherapy, and no recurrence was observed during a 24-month follow-up period. LESSONS: The clinical picture of adult renal NB is that of a 44-year-old woman, presenting with an abdominal or renal mass about 13cm in size, accompanied by hypertension, hematuria, or pain. In contrast to CT features described in previous literature, no tumor calcification is mentioned in these adult renal NB cases. It is difficult to differentiate renal NB from RCC based on CT or MRI. However, biopsy, urinary catecholamine levels, and metaiodobenzylguanidine (MIBG) scan may aid in presurgical diagnosis.

Influences of cardiac motion on computed tomography-guided biopsy of lung nodules located near the heart.

Computed tomography (CT)-guided lung biopsy of nodules located near the heart may be associated with potential complications. To understand the influences of cardiac motion on lung parenchyma during biopsy, we processed the cardiac phase images of coronary CT angiography (CCTA) and noticed shifts in mediastinum lung margin (MLM) at different zones.Thirty eight CCTA (27 men and 11 women) were retrospectively evaluated. Image processing was done with Fiji (an open source Java image processing program by Fiji contributors) using 10% to 90% phase images of CCTA; and tissue displacement (MLM shift) was shown on the resulting images.The participants were 58.29 ± 9.87 years old; their height was 166.32 ±â€Š7.57 cm while their weight was 74.18 ±â€Š13.59 kg. The mean values of MLM shifts in Zones 1 to 9 ranged from 1.98 to 7.76 mm. Large MLM shifts were observed in the free wall of the left ventricle (LV). MLM shift of the upper free wall of the LV was 6.98 ±â€Š1.99 mm and that of the lower free wall of the LV was 7.76 ±â€Š3.26 mm. The largest MLM shift among all patients was 16.05 mm, found in the lower free wall of the LV. The age factor had a weak positive correlation with the wall of the pulmonary artery (r = 0.350, P = .031) and that of the right atrial appendage (r = 0.418, P = .009). In contrast, a weak negative correlation of age factor was observed with the lower free wall of the LV (r = -0.336, P = .039).In conclusion, we suggest that physicians observe caution when performing lung biopsy if the distance between the lung lesion and the MLM is 1 to 2 cm. CT-guided lung biopsy should be avoided if the distance is <1 cm. Physicians should pay special attention to lung lesions near the LV.

Hemopericardium caused by a mobile retained epicardial pacing wire after ventricular septal defect repair: A case report.

BACKGROUND: Epicardial pacing wires (EPWs) are commonly employed for diagnosis and treatment of arrhythmia in the acute phase after cardiac surgery. Although rare, retained EPWs may cause mild-to-catastrophic complications. The present case demonstrates hemopericardium caused by a mobile retained EPW. METHODS: A 49-year-old woman presented to our emergency department with clinical signs of impending cardiac tamponade. She had undergone ventricular septal defect repair 7 years before this admission. An initial computed tomography (CT) scan revealed hemopericardium with suspicion of a possible intracardiac lesion. Review of the first and second CT scans, however, revealed a mobile retained EPW penetrating the pericardium in the first scan, which had moved out of the pericardium in the second scan. RESULTS: Because cardiac injury by the EPW was suspected, the patient was transferred to another medical center for further treatment. CONCLUSION: According to our experience with this case, diagnosis may be incorrect if CT is unable to obtain decisive images of the mobile EPW at the correct time. Multiplanar reconstruction and volume rendering can increase diagnostic accuracy. In conclusion, if hemopericardium is present without clear etiology in a patient with a retained EPW, a nearby mobile EPW may be the cause.

A computed tomography phantom study of foam earplugs: Uncommon but potentially hazardous foreign body ingestion in children.

Ingestion of a foreign body is common among children. However, ingestion of foam earplugs (FEPs) has not been reported previously. A 7-month-old female infant presented with small bowel obstruction, which was finally proved to be a case of FEP ingestion.Computed tomography (CT) phantom study was performed to examine the imaging features of FEPs. We studied the following dry and fully wet FEPs, FEPs squeezed in pure water to varying degrees, and FEPs with different degrees of compression in the dry and wet states from day 0 to 6 and all scanned with a CT scanner.The density of a dry FEP is -843.5 ±â€Š4.5 Hounsfield units (HU) and it increases to 0.76 ±â€Š9.3 HU when fully wet. The densities of FEPs ranged from -844.2 to 1.0 HU with different water/air ratios, and some showed a heterogeneous geographic pattern. The densities of FEPs increase due to compression and gradual water absorption.FEPs can be potentially hazardous objects to children. Owing to the special foam structure of the FEP, it can mimic a fatty lesion if the density ranges from -100 to -50 HU; moreover, it can hide in the water if fully wet. However, it should not be mistaken as air, as the density of a dry FEP is -843.5 HU, and the contour can be observed if the window level is set appropriately. Because of its soft texture, the surgeon should be careful not to miss an FEP during the operation. Moreover, radiologists should be familiar with the CT features of FEPs so that they can be identified before surgery.

Developing barbed microtip-based electrode arrays for biopotential measurement.

This study involved fabricating barbed microtip-based electrode arrays by using silicon wet etching. KOH anisotropic wet etching was employed to form a standard pyramidal microtip array and HF/HNO3 isotropic etching was used to fabricate barbs on these microtips. To improve the electrical conductance between the tip array on the front side of the wafer and the electrical contact on the back side, a through-silicon via was created during the wet etching process. The experimental results show that the forces required to detach the barbed microtip arrays from human skin, a polydimethylsiloxane (PDMS) polymer, and a polyvinylchloride (PVC) film were larger compared with those required to detach microtip arrays that lacked barbs. The impedances of the skin-electrode interface were measured and the performance levels of the proposed dry electrode were characterized. Electrode prototypes that employed the proposed tip arrays were implemented. Electroencephalogram (EEG) and electrocardiography (ECG) recordings using these electrode prototypes were also demonstrated.

Chlorido[hydridotris(pyrazol-1-yl-κN)borato](1H-pyrazole-κN)(triphenyl-phosphine-κP)ruthenium(II).

In the title compound, [Ru(C(9)H(10)BN(6))Cl(C(3)H(4)N(2))(C(18)H(15)P)], the Ru(II) atom is coordinated by an N,N',N''-tridentate hydrido-trispyrazolylborate (Tp) ligand, a pyrazole (HPz) mol-ecule, a chloride ion and a triphenyl-phosphine ligand, resulting in a distorted RuClPN(4) octa-hedral coordination for the metal ion: the tridentate N atoms occupy one octa-hedral face and the Cl and P atoms are cis. One of the phenyl rings is disordered over two orientations in a 0.547 (10):0.453 (10) ratio, and a weak intra-molecular N-H⋯Cl hydrogen bond generates an S(5) ring.