Simulated augmented reality-based calibration of optical see-through head mound display for surgical navigation.

PURPOSE: Calibration of an optical see-through head-mounted display is critical for augmented reality-based surgical navigation. While conventional methods have advanced, calibration errors remain significant. Moreover, prior research has focused primarily on calibration accuracy and procedure, neglecting the impact on the overall surgical navigation system. Consequently, these enhancements do not necessarily translate to accurate augmented reality in the optical see-through head mount due to systemic errors, including those in calibration. METHOD: This study introduces a simulated augmented reality-based calibration to address these issues. By replicating the augmented reality that appeared in the optical see-through head mount, the method achieves calibration that compensates for augmented reality errors, thereby reducing them. The process involves two distinct calibration approaches, followed by adjusting the transformation matrix to minimize displacement in the simulated augmented reality. RESULTS: The efficacy of this method was assessed through two accuracy evaluations: registration accuracy and augmented reality accuracy. Experimental results showed an average translational error of 2.14 mm and rotational error of 1.06° across axes in both approaches. Additionally, augmented reality accuracy, measured by the overlay regions' ratio, increased to approximately 95%. These findings confirm the enhancement in both calibration and augmented reality accuracy with the proposed method. CONCLUSION: The study presents a calibration method using simulated augmented reality, which minimizes augmented reality errors. This approach, requiring minimal manual intervention, offers a more robust and precise calibration technique for augmented reality applications in surgical navigation.

Design and Synthesis of CdHgSe/HgS/CdZnS Core/Multi-Shell Quantum Dots Exhibiting High-Quantum-Yield Tissue-Penetrating Shortwave Infrared Luminescence.

Cdx Hg1- x Se/HgS/Cdy Zn1- y S core/multi-shell quantum dots (QDs) exhibiting bright tissue-penetrating shortwave infrared (SWIR; 1000-1700 nm) photoluminescence (PL) are engineered. The new structure consists of a quasi-type-II Cdx Hg1- x Se/HgS core/inner shell domain creating luminescent bandgap tunable across SWIR window and a wide-bandgap Cdy Zn1- y S outer shell boosting the PL quantum yield (QY). This compositional sequence also facilitates uniform and coherent shell growth by minimizing interfacial lattice mismatches, resulting in high QYs in both organic (40-80%) and aqueous (20-70%) solvents with maximum QYs of 87 and 73%, respectively, which are comparable to those of brightest visible-to-near infrared QDs. Moreover, they maintain bright PL in a photocurable resin (QY 40%, peak wavelength ≈ 1300 nm), enabling the fabrication of SWIR-luminescent composites of diverse morphology and concentration. These composites are used to localize controlled amounts of SWIR QDs inside artificial (Intralipid) and porcine tissues and quantitatively evaluate the applicability as luminescent probes for deep-tissue imaging.

Radius palmar plate removal without carpal tunnel release: Correlation between plate position and median nerve symptoms.

We aimed to report the clinical results of volar plate removal without carpal tunnel release in patients with late-onset median neuropathy and to evaluate the relationship between plate position and median nerve symptoms. Part I. Twelve consecutive patients with late-onset median neuropathy treated with volar plate removal without carpal tunnel release were enrolled for analysis. Pre- and post-operative Tinel sign, Phalen and Ten test, subjective rating of tingling sensation, Mayo wrist score and Disabilities of the Arm, Shoulder and Hand (DASH) score were collected. Part II. 232 consecutive patients underwent volar plating for distal radius fracture. The relationships between median nerve symptoms and volar plate prominence on the Soong classification, fracture classification, gender and age were investigated. All cases except one showed complete symptom resolution at final follow-up, with negative Tinel sign and Ten test score of 10/10. Tingling was rated 0 at final follow-up. Mean Mayo wrist and DASH scores improved to 86.7 and 23.1, respectively. The incidence of the median nerve symptoms in our cohort was 5.6%. Even though the odds ratio in Soong grade 2 was 4.0957 (95% CI, 0.93-16.9) compared to the combination of grades 0 and 1, no statistically significant relationship was found between the median nerve symptoms and volar plate prominence (p > 0.05). Plate removal without carpal tunnel release adequately relieved symptoms of late-onset median neuropathy after volar plating in patients with distal radius fracture. LEVEL OF EVIDENCE: IV; Therapeutic.

Heterogeneous Stitching of X-ray Images According to Homographic Evaluation.

The C-arm X-ray system is a common intraoperative imaging modality used to observe the state of a fractured bone in orthopedic surgery. Using C-arm, the bone fragments are aligned during surgery, and their lengths and angles with respect to the entire bone are measured to verify the fracture reduction. Since the field-of-view of the C-arm is too narrow to visualize the entire bone, a panoramic X-ray image is utilized to enlarge it by stitching multiple images. To achieve X-ray image stitching with feature detection, the extraction of accurate and densely matched features within the overlap region between images is imperative. However, since the features are highly affected by the properties and sizes of the overlap regions in consecutive X-ray images, the accuracy and density of matched features cannot be guaranteed. To solve this problem, a heterogeneous stitching of X-ray images was proposed. This heterogeneous stitching was completed according to the overlap region based on homographic evaluation. To acquire sufficiently matched features within the limited overlap region, integrated feature detection was used to estimate a homography. The homography was then evaluated to confirm its accuracy. When the estimated homography was incorrect, local regions around the matched feature were derived from integrated feature detection and substituted to re-estimate the homography. Successful X-ray image stitching of the C-arm was achieved by estimating the optimal homography for each image. Based on phantom and ex-vivo experiments using the proposed method, we confirmed a panoramic X-ray image construction that was robust compared to the conventional methods.

Simultaneous Optimization of Patient-Image Registration and Hand-Eye Calibration for Accurate Augmented Reality in Surgery.

OBJECTIVE: Augmented reality (AR) navigation using a position sensor in endoscopic surgeries relies on the quality of patient-image registration and hand-eye calibration. Conventional methods collect the necessary data to compute two output transformation matrices separately. However, the AR display setting during surgery generally differs from that during preoperative processes. Although conventional methods can identify optimal solutions under initial conditions, AR display errors are unavoidable during surgery owing to the inherent computational complexity of AR processes, such as error accumulation over successive matrix multiplications, and tracking errors of position sensor. METHODS: We propose the simultaneous optimization of patient-image registration and hand-eye calibration in an AR environment before surgery. The relationship between the endoscope and a virtual object to overlay is first calculated using an endoscopic image, which also functions as a reference during optimization. After including the tracking information from the position sensor, patient-image registration and hand-eye calibration are optimized in terms of least-squares. RESULTS: Experiments with synthetic data verify that the proposed method is less sensitive to computation and tracking errors. A phantom experiment with a position sensor is also conducted. The accuracy of the proposed method is significantly higher than that of the conventional method. CONCLUSION: The AR accuracy of the proposed method is compared with those of the conventional ones, and the superiority of the proposed method is verified. SIGNIFICANCE: This study demonstrates that the proposed method exhibits substantial potential for improving AR navigation accuracy.

Effect of Seed of Cassia tora Extract in the Prevention of Remote Renal Reperfusion Injury.

OBJECTIVE: Renal ischemia/reperfusion (I/R) injury is characterized by the acute deterioration of renal function during ischemia and renal inflammation. Cassia tora has various effects, including antioxidant, antidiabetic, and hypolipidemic properties. In the present study, we investigated whether C tora has a renoprotective effect on I/R-induced acute kidney injury in rats. METHODS: We fed Sprague-Dawley rats either C tora (100 mg/kg/d) or saline. One week later, ischemia was induced by bilateral renal pedicle occlusion for 30 minutes, followed by reperfusion. Rats were randomized into 3 major groups, which were treated as follows: 1. the sham operation group; 2. the I/R group; and 3. the I/R-C tora group. RESULTS: Compared to the sham group, the I/R group had higher levels of blood urea nitrogen and serum creatinine in serum and lower expression of catalase, superoxide dismutase, glutathione peroxidase, antioxidant, and nitric oxide. Compared to the I/R group, the I/R-C tora group had higher expression of catalase, superoxide dismutase, glutathione peroxidase, antioxidant, and nitric oxide, as well as lower levels of blood urea nitrogen and creatinine in serum. CONCLUSIONS: These results suggest that C tora has significant therapeutic effects in ischemic renal injury.

Analysis of the hump phenomenon and needle defect states formed by driving stress in the oxide semiconductor.

The reduction in current ability accompanied by the hump phenomenon in oxide semiconductor thin-film transistors to which high DC voltages and AC drive voltages are applied has not been studied extensively, although it is a significant bottleneck in the manufacture of integrated circuits. Here, we report on the origin of the hump and current drop in reliability tests caused by the degradation in the oxide semiconductor during a circuit driving test. The hump phenomenon and current drop according to two different driving stresses were verified. Through a numerical computational simulation, we confirmed that this issue can be caused by an additional "needle", a shallow (~0.2 eV) and narrow (<0.1 eV), defect state near the conduction band minimum (CBM). This is also discussed in terms of the dual current path caused by leakage current in the channel edge.

Characterization of Lactobacillus plantarum strains isolated from black raspberry and their effect on BALB/c mice gut microbiota.

The objective of this study was to evaluate probiotic effects of two Lactobacillus plantarum strains (GBL16 and 17) isolated from black raspberry. Results revealed that the number of GBL16 was gradually decreased as bile salt concentration was increased from 0.3 to 1%. However, GBL17 did not show any difference when GBL17 was applied to 1% bile salt, and it indicates that GBL17 is more tolerant to bile salt than GBL16. GBL17 exhibited higher heat resistance and adhesion ability to Caco-2 cells than GBL16. Regarding gut microbiome, no significant change in the number of total bacteria in intestines of mice after treatment with GBLs was determined. However, the combination of GBL16 and GBL17 significantly increased the number of total bacteria in intestines of mice after they were orally administered. Therefore, the results suggest that both GBL16 and 17 strains could be one of major probiotics that can improve human gut health.

Association Between Change in Serum Aminotransferase and Mortality: A Nationwide Cohort Study in Korea.

There is little information on how the change in serum aminotransferase affects mortality. We investigated the association between changes in serum aminotransferase levels and mortality from all causes, cardiovascular disease (CVD), and liver disease.Three percent of men from the Korean National Health Insurance database were sampled randomly at the end of 2002. After excluding patients with cancer, CVD, CVD risk factors, or liver disease, those who participated in 2 consecutive rounds of the national health screening examination were included (n = 68,431). The primary outcome was CVD mortality. Secondary outcomes were liver disease mortality and all-cause mortality. Change in metabolic profiles was analyzed based on changes in liver enzyme levels. Elevated levels of serum aminotransferase were associated with CVD, liver disease, and all-cause mortality. Men who had sustained elevation of serum aminotransferase during 2 subsequent liver enzyme tests showed a significantly higher risk of CVD mortality (adjusted hazard ratio [aHR] 1.95; 95% confidence interval [CI] 1.07-3.56, 2.29; 1.27-4.12) than the sustained normal group. In contrast, the normalization group (aHR 1.52, 95% CI 0.82-2.81 for aspartate aminotransferase [AST]; aHR 1.35, 95% CI 0.70-2.61 for alanine aminotransferase [ALT]) and the new elevation group (aHR 1.27, 0.66-2.44 for AST; aHR 0.99, 95% CI 0.49-2.20 for ALT) were not different from the sustained normal group in CVD mortality.Individuals with serum aminotransferase elevation, particularly when sustained, are at higher risk of mortality, and should receive appropriate medical attention.

Association between Muscle Loss and Urinary Incontinence in Elderly Korean Women.

BACKGROUND: Incontinence and muscle loss are important senior health issues. Nevertheless, there are no available domestic or international studies on the association between urinary incontinence and muscle loss. The aim of this study was to investigate the association between muscle loss and urinary incontinence in elderly Korean woman. METHODS: Korean women (1,313) ≥65 years of age whose complete body composition data were collected using dual X-ray absorptiometry were analyzed from the Fourth Korean National Health and Nutritional Examination Surveys. Class I and II losses of the appendicular, truncal, and total muscle mass were defined using adjustments for weight and height. Each participant's incontinence status was collected using constructed questionnaires. Multiple logistic regression was performed to examine the association between muscle loss and incontinence. RESULTS: On the basis of physician-diagnosed incontinence, weight- and height-adjusted muscle loss showed no association with urinary incontinence (weight-adjusted muscle loss: class I adjusted odds ratio [aOR], 0.77; 95% confidence interval [CI], 0.34 to 1.73; class II aOR, 1.37; 95% CI, 0.59 to 3.18; height-adjusted muscle loss: class I aOR, 0.51; 95% CI, 0.18 to 1.51; class II aOR, 1.86; 95% CI, 0.22 to 15.79). Similar results were observed for truncal muscle and total muscle mass as well as self-reported urinary incontinence. CONCLUSION: Our study found no association between urinary incontinence and appendicular, truncal, and total muscle loss in elderly Korean women.

Shared decision-making on the use of hormone therapy: a nationwide survey in the Republic of Korea.

OBJECTIVE: This study aims to assess the current status of shared decision-making on instituting postmenopausal hormone therapy (HT). METHODS: Two cross-sectional nationwide surveys of postmenopausal women and primary care physicians in the Republic of Korea were conducted in 2012 via face-to-face interviews. A total of 685 women (aged 50-69 y) who with natural menopause and 250 primary care physicians were included. RESULTS: Only 56.8% of primary care physicians reported that they explain the benefits and risks of HT and leave the decision to postmenopausal women. The others usually recommended using or not using HT. Of those postmenopausal women who had discussed such therapy with physicians (147 of 685; 21.5%), not all were aware of breast cancer or cardiovascular risks (only 65.3% and 38.8% were informed, respectively). Although most physicians perceived HT as beneficial for menopausal symptom control (99.6%) and acknowledged the related risk of breast cancer (84.8%), nearly half had the impression that HT was preventive of cardiovascular diseases. The interviewed women were less informed of the benefits and risks of HT than were the physician respondents. The awareness levels of the treated and untreated women did not differ. CONCLUSIONS: Participation of postmenopausal women in deciding whether to use HT is not prevalent. Physician-woman information transfer is suboptimal, and treatment decisions often are not based on the best available evidence. The current status of shared decision-making in this setting is clearly in need of improvement.

A case of acute aortic dissection presenting with chest pain relieved by sublingual nitroglycerin.

Acute aortic dissection is an uncommon disorder which can have fatal results in the event of treatment delay or misdiagnosis. This case examines a 77-year-old woman presenting with chest pain relieved by nitroglycerin. She was referred to the emergency room with clinical suspicion of acute coronary syndrome (ACS). However, she was later diagnosed with acute aortic dissection and an emergency operation was performed with successful recovery. Aortic dissection may manifest in various ways depending on the site involved and may mimic other disorders such as ACS or pulmonary embolism. Therefore, clinicians must always be aware of aortic dissection and its different clinical manifestations must be understood.

The role of androgen in the adipose tissue of males.

Adipose tissue, where various metabolic hormones are secreted, plays a role in metabolizing different substances including androgen. Within fat tissue, enzymes such as aromatase and aldo-keto reductase 1C are responsible for metabolizing testosterone into estrogen and 5-dihydrotestosterone into inactive metabolites. Adipose tissue can also affect the secretion of gonadotropin, which influences the formation of androgen in the testes. At the same time, androgen has an impact on the distribution and proliferation of adipose tissue. The adrenoreceptors for catecholamines, which have been proven to play an essential role in controlling lipolysis, function by being up-regulated by androgens. Furthermore, androgens regulate the activity of lipoprotein lipase, a key enzyme involved in intracellular esterification of adipose tissue.

Antidepressant use and diabetes mellitus risk: a meta-analysis.

BACKGROUND: Epidemiologic studies have reported inconsistent findings regarding the association between the use of antidepressants and type 2 diabetes mellitus (DM) risk. We performed a meta-analysis to systematically assess the association between antidepressants and type 2 DM risk. METHODS: We searched MEDLINE (PubMed), EMBASE, and the Cochrane Library (through Dec 31, 2011), including references of qualifying articles. Studies concerning the use of tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), or other antidepressants and the associated risk of diabetes mellitus were included. RESULTS: Out of 2,934 screened articles, 3 case-control studies, 9 cohort studies, and no clinical trials were included in the final analyses. When all studies were pooled, use of antidepressants was significantly associated with an increased risk of DM in a random effect model (relative risk [RR], 1.49; 95% confidence interval [CI], 1.29 to 1.71). In subgroup analyses, the risk of DM increased among both SSRI users (RR, 1.35; 95% CI, 1.15 to 1.58) and TCA users (RR, 1.57; 95% CI, 1.26 to 1.96). The subgroup analyses were consistent with overall results regardless of study type, information source, country, duration of medication, or study quality. The subgroup results considering body weight, depression severity, and physical activity also showed a positive association (RR, 1.14; 95% CI, 1.01 to 1.28). A publication bias was observed in the selected studies (Egger's test, P for bias = 0.09). CONCLUSION: Our results suggest that the use of antidepressants is associated with an increased risk of DM.

Meta-analysis: selective serotonin reuptake inhibitors and colon cancer.

OBJECTIVE: To perform meta-analyses using observational studies to assess the association between the use of selective serotonin reuptake inhibitors (SSRIs) and the risk of colorectal cancer. METHODS: A systematic search of relevant studies published through February 2012 was carried out using the Medline (PubMed), Embase, and Cochrane Library databases. We reviewed the observational studies that were associated with our subject and carried out a meta-analysis. RESULTS: Out of 324 screened articles, six observational studies were included in the final analyses. According to this meta-analysis, the use of SSRIs was not associated with an increased risk of colorectal cancer in pooled analyses (adjusted odds ratio 0.89, 95% confidence interval 0.79-1.01). This finding was consistently observed in subgroup analyses of study area, location of colorectal cancer, duration of SSRI use, study quality, adjustment for NSAID use, and the prevalence of overweight. CONCLUSION: Our research shows that the use of SSRIs does not increase the risk of colorectal cancer. Further studies are needed to confirm the association between SSRIs and colorectal cancer.

Use of selective serotonin reuptake inhibitors and risk of fracture: a systematic review and meta-analysis.

Previous studies have reported inconsistent findings regarding the association between the use of selective serotonin reuptake inhibitors (SSRIs) and the risk of fracture. We identified relevant studies by searching three electronic databases (MEDLINE, EMBASE, and the Cochrane Library) from their inception to October 20, 2010. Two evaluators independently extracted data. Because of heterogeneity, we used random-effects meta-analysis to obtain pooled estimates of effect. We identified 12 studies: seven case-control studies and five cohort studies. A meta-analysis of these 12 observational studies showed that the overall risk of fracture was higher among people using SSRIs (adjusted odds ratio [OR] = 1.69, 95% confidence interval [CI] 1.51-1.90, I(2 ) = 89.9%). Subgroup analysis by adjusted number of key risk factors for osteoporotic fracture showed a greater increased fracture risk in those adjusted for fewer than four variables (adjusted OR = 1.83, 95% CI 1.57-2.13, I(2) = 88.0%) than those adjusted for four or more variables (adjusted OR = 1.38, 95% CI 1.27-1.49, I(2) = 46.1%). The pooled ORs anatomical site of fracture in the hip/femur, spine, and wrist/forearm were 2.06 (95% CI 1.84-2.30, I(2 ) = 62.3%), 1.34 (95% CI 1.13-1.59, I(2 ) = 48.5%), and 1.51 (95% CI 1.26-1.82, I(2 ) = 76.6%), respectively. Subgroup analysis by exposure duration revealed that the strength of the association decreased with a longer window of SSRI administration before the index date. The risk of fracture was greater within 6 weeks before the index date (adjusted OR = 3.83, 95% CI 1.96-7.49, I(2 ) = 41.5%) than 6 weeks or more (adjusted OR = 1.60, 95% CI 0.93-2.76, I(2 ) = 63.1%). Fracture risk associated with SSRI use may have a significant clinical impact. Clinicians should carefully consider bone mineral density screening before prescribing SSRIs and proper management for high-risk populations.

Sensor fusion of phase measuring profilometry and stereo vision for three-dimensional inspection of electronic components assembled on printed circuit boards.

Automatic optical inspection (AOI) for printed circuit board (PCB) assembly plays a very important role in modern electronics manufacturing industries. Well-developed inspection machines in each assembly process are required to ensure the manufacturing quality of the electronics products. However, generally almost all AOI machines are based on 2D image-analysis technology. In this paper, a 3D-measurement-method-based AOI system is proposed consisting of a phase shifting profilometer and a stereo vision system for assembled electronic components on a PCB after component mounting and the reflow process. In this system information from two visual systems is fused to extend the shape measurement range limited by 2pi phase ambiguity of the phase shifting profilometer, and finally to maintain fine measurement resolution and high accuracy of the phase shifting profilometer with the measurement range extended by the stereo vision. The main purpose is to overcome the low inspection reliability problem of 2D-based inspection machines by using 3D information of components. The 3D shape measurement results on PCB-mounted electronic components are shown and compared with results from contact and noncontact 3D measuring machines. Based on a series of experiments, the usefulness of the proposed sensor system and its fusion technique are discussed and analyzed in detail.