PAPipe: A Pipeline for Comprehensive Population Genetic Analysis.

Advancements in next-generation sequencing (NGS) technologies have led to a substantial increase in the availability of population genetic variant data, thus prompting the development of various population analysis tools to enhance our understanding of population structure and evolution. The tools that are currently used to analyze population genetic variant data generally require different environments, parameters, and formats of the input data, which can act as a barrier preventing the wide-spread usage of such tools by general researchers who may not be familiar with bioinformatics. To address this problem, we have developed an automated and comprehensive pipeline called PAPipe to perform nine widely used population genetic analyses using population NGS data. PAPipe seamlessly interconnects and serializes multiple steps, such as read trimming and mapping, genetic variant calling, data filtering, and format converting, along with nine population genetic analyses such as principal component analysis, phylogenetic analysis, population tree analysis, population structure analysis, linkage disequilibrium decay analysis, selective sweep analysis, population admixture analysis, sequentially Markovian coalescent analysis, and fixation index analysis. PAPipe also provides an easy-to-use web interface that allows for the parameters to be set and the analysis results to be browsed in intuitive manner. PAPipe can be used to generate extensive results that provide insights that can help enhance user convenience and data usability. PAPipe is freely available at https://github.com/jkimlab/PAPipe.

High-level production and purification of bioactive recombinant human activin A in Chinese hamster ovary cells.

Activin A, a member of the TGF-ß superfamily, is a homodimer of the inhibin ßΑ subunit that plays a diversity of roles in biological processes. Because of its multiple functions, significant efforts have been made to produce activin A, however, unsatisfactory results were obtained due to its low level of expression. In this study, a stable CHO cell line exhibiting high expression of rhActivin A was isolated and production of rhActivin A was achieved using the cell line from 11-day fed-batch cultures in a 7.5 L bioreactor. The production rate was 0.22 g/L, substantially higher than those reported in previous studies. The culture supernatant of the bioreactor was used to purify rhActivin A (purity: >99%, recovery rate: 47%). The purified rhActivin A exhibited biological activity, with an EC50 of 3.893 ng/mL and a specific activity of 1.38 × 103 IU/mg. The control of process-related impurities in the purified rhActivin A was successful and met the USP recommendations for use in cell therapy. Thus, our production and purification methods were appropriate for large-scale GMP-grade rhActivin A production, which can be used for various purposes including cell therapy.

Early-stage diagnosis of bladder cancer using surface-enhanced Raman spectroscopy combined with machine learning algorithms in a rat model.

Early diagnosis and accurate assessment of tumor development facilitate early bladder cancer resection and initiation of drug therapy. This study enabled an early, accurate, label-free, noninvasive diagnosis of bladder tumors by analyzing nano-biomarkers in a single drop of urine through surface-enhanced Raman spectroscopy (SERS). In a standard N-butyl-N-4-hydroxybutyl nitrosamine-induced rat model of bladder cancer, cancer stage and polyp tumor development were monitored using a small endoscope with a diameter of 1.2 mm in a minimally invasive manner without the need to kill the rats. Samples were divided into cancer-free, early-stage, and polyp-form cancer. Training data were classified according to micro-cystoscopic 5-aminolevulinic acid fluorescence diagnosis, and specimens were postmortem verified through histopathological analysis. A drop of urine from each sample group was placed on an Au-coated zinc oxide nanoporous chip to filter nano-biomaterials and selectively enhance the Raman signals of nanoscale analytes via SERS. Principal component analysis was used to reduce the dimensionality of the collected Raman spectra, and partial least squares discriminant analysis was used to find diagnostic clusters based on the labeled samples. The combination of SERS and machine learning achieved an accuracy ≥99.6% in diagnosing both early- and polyp-stage bladder tumors. With an area under the receiver operating characteristic curve greater than 0.996, the accuracy of the diagnosis in the rat model suggests that SERS-based diagnostic methods are promising when coupled with machine learning. Low-cost, label-free, and noninvasive surface-enhanced Raman spectra are ideal for developing clinically relevant point-of-care diagnostic techniques.

Hemodynamic instability following intravenous dexmedetomidine infusion for sedation under brachial plexus block: Two case reports.

BACKGROUND: Dexmedetomidine (DMED) is frequently used as a sedative in several medical fields. The benefits of DMED include enhanced quality of regional anesthesia, prolonged analgesia, and postoperative opioid-sparing when administered intravenously or perineurally in combination with regional anesthesia. Severe hemodynamic complications, such as profound bradycardia and hypotension, can occur after DMED administration in critically ill patients or overdosage; however, there are few reports of complications with DMED administration following brachial plexus block (BPB). CASE SUMMARY: We present two cases of hemodynamic instability that occurred following the initial loading of DMED under supraclavicular BPB. A healthy 29-year-old man without any medical history showed profound bradycardia after receiving a loading dose of DMED 0.9 µg/kg for 9 min. DMED administration was promptly stopped, and after receiving a second dose of atropine, the heart rate recovered. A 62-year-old woman with a history of cardiomyopathy became hypotensive abruptly, requiring the administration of inotrope and vasopressors after receiving a reduced loading dose of 0.5 µg/kg for 10 min. Half of the recommended loading dose of DMED was administered due to the underlying heart dysfunction. Decreased blood pressure was maintained despite the intravenous administration of ephedrine. With continuous infusion of dopamine and norepinephrine, the vital signs were maintained within normal ranges. Inotropic and vasopressor support was required for over 6 h after the initial loading dose of DMED. CONCLUSION: DMED administration following BPB could trigger hemodynamic instability in patients with decreased cardiac function as well as in healthy individuals.

Assessing Machine Learning Models for Predicting Age with Intracranial Vessel Tortuosity and Thickness Information.

This study aimed to develop and validate machine learning (ML) models that predict age using intracranial vessels' tortuosity and diameter features derived from magnetic resonance angiography (MRA) data. A total of 171 subjects' three-dimensional (3D) time-of-flight MRA image data were considered for analysis. After annotations of two endpoints in each arterial segment, tortuosity features such as the sum of the angle metrics, triangular index, relative length, and product of the angle distance, as well as the vessels' diameter features, were extracted and used to train and validate the ML models for age prediction. Features extracted from the right and left internal carotid arteries (ICA) and basilar arteries were considered as the inputs to train and validate six ML regression models with a four-fold cross validation. The random forest regression model resulted in the lowest root mean square error of 14.9 years and the highest average coefficient of determination of 0.186. The linear regression model showed the lowest average mean absolute percentage error (MAPE) and the highest average Pearson correlation coefficient (0.532). The mean diameter of the right ICA vessel segment was the most important feature contributing to prediction of age in two out of the four regression models considered. An ML of tortuosity descriptors and diameter features extracted from MRA data showed a modest correlation between real age and ML-predicted age. Further studies are warranted for the assessment of the model's age predictions in patients with intracranial vessel diseases.

Appropriateness of the anxiety subscale of the Hospital Anxiety and Depression Scale for Koreans to measure preoperative anxiety and the effect of preoperative anxiety on postoperative quality of recovery.

BACKGROUND: The reliability and validity of the anxiety subscale of the Hospital Anxiety and Depression Scale for Koreans (K-HADS-A) has not been studied in Korean surgical patients. This study aimed to validate the usefulness of K-HADS-A for measuring preoperative anxiety in Korean surgical patients. Additionally, the effect of preoperative anxiety on postoperative quality of recovery was evaluated. METHODS: Preoperative anxiety in 126 inpatients with planned elective surgery was measured using the K-HADS-A. The postoperative quality of recovery was measured using the Korean version of the Quality of Recovery-15. The validity and reliability of the K-HADS-A were evaluated. The differences in quality of recovery on the first and seventh day postoperatively were then compared between the anxious and non-anxious groups. RESULTS: There was a statistical correlation between the K-HADS-A and Anxiety Likert Scale. The goodness-of-fit indices of the structural equation model showed how well the data from the K-HADS-A match their concept. The Kaiser-Meyer-Olkin value was 0.848, and the P value of Bartlett's test of sphericity was < 0.001. Cronbach's alpha was high at 0.872. The K-HADS-A had an acceptable level of validity and reliability. Postoperative quality of recovery was significantly lower in the anxious group (postoperative day 1: t = 2.058, P = 0.042; postoperative day 7: t = 3.430, P = 0.002). CONCLUSIONS: The K-HADS-A is an acceptable tool for appropriately assessing preoperative anxiety in Korean surgical patients. Assessing preoperative anxiety is valuable, because preoperative anxiety affects the postoperative quality of mental and physical recovery.

Smartphone-Based Rigid Endoscopy Device with Hemodynamic Response Imaging and Laser Speckle Contrast Imaging.

Modern smartphones have been employed as key elements in point-of-care (POC) devices due to remarkable advances in their form factor, computing, and display performances. Recently, we reported a combination of the smartphone with a handheld endoscope using laser speckle contrast imaging (LSCI), suggesting potential for functional POC endoscopy. Here, we extended our work to develop a smartphone-combined multifunctional handheld endoscope using dual-wavelength LSCI. Dual-wavelength LSCI is used to monitor the changes in dynamic blood flow as well as changes in the concentration of oxygenated (HbO2), deoxygenated (Hbr), and total hemoglobin (HbT). The smartphone in the device performs fast acquisition and computation of the raw LSCI data to map the blood perfusion parameters. The flow imaging performance of the proposed device was tested with a tissue-like flow phantom, exhibiting a speckle flow index map representing the blood perfusion. Furthermore, the device was employed to assess the blood perfusion status from an exteriorized intestine model of rat in vivo during and after local ischemia, showing that blood flow and HbO2 gradually decreased in the ischemic region whereas hyperemia and excess increases in HbO2 were observed in the same region right after reperfusion. The results indicate that the combination of LSCI with smartphone endoscopy delivers a valuable platform for better understanding of the functional hemodynamic changes in the vasculatures of the internal organs, which may benefit POC testing for diagnosis and treatment of vascular diseases.

Fabry-Perot Interferometric Fiber-Optic Sensor for Rapid and Accurate Thrombus Detection.

We present a fiber-optic sensor based on the principles of a Fabry-Perot interferometer (FPI), which promptly, sensitively, and precisely detects blood clot formation. This sensor has two types of sensor tips; the first was crafted by splicing a tapered fiber into a single-mode fiber (SMF), where fine-tuning was achieved by adjusting the tapered diameter and length. The second type is an ultra-compact blood FPI situated on the core of a single-mode fiber. The sensor performance was evaluated via clot-formation-indicating spectrum shifts induced by the varied quantities of a thrombin reagent introduced into the blood. The most remarkable spectral sensitivity of the micro-tip fiber type was approximately 7 nm/µL, with a power sensitivity of 4.1 dB/µL, obtained with a taper fiber diameter and length of 55 and 300 µm, respectively. For the SMF type, spectral sensitivity was observed to be 8.7 nm/µL, with an optical power sensitivity of 0.4 dB/µL. This pioneering fiber-optic thrombosis sensor has the potential for in situ applications, healthcare, medical monitoring, harsh environments, and chemical and biological sensing. The study underscores the scope of optical technology in thrombus detection, establishing a platform for future medical research and application.

Reusable and Biodegradable Separation Membranes Prepared from Common Mushrooms for the Removal of Oily and Particulate Contaminants from Water.

Mushroom chitin membranes with controllable pore structures were fabricated through a simple process with naturally abundant Agaricus bisporus mushrooms. A freeze-thaw method was applied to alter the pore structures of the membranes, which consist of chitin fibril clusters within the glucan matrix. With tunable pore size and distribution, mushroom chitin membranes could effectively separate stable oil/water emulsions (dodecane, toluene, isooctane, and chili oil) with various chemical properties and concentrations and particle contaminants (carbon black and microfibers) from water. Chitin fibrils tightly pack with each other to form a dense membrane, leading to no permeation of contaminants or water. An increasing number of applied freeze-thaw cycles confers more tortuous pore structures throughout the mushroom chitin membranes, leading to higher flux while maintaining rejection performance. The 3D simulation constructed by the X-ray computed tomography and GeoDict software also demonstrated capturing a considerable amount of contaminants within the membranes' pores, which can be easily removed by water rinsing for further successive filtration. Furthermore, mushroom chitin membranes were almost completely biodegraded after approximately a month of being buried in the soil or kept in a lysozyme solution while possessing mechanical durability demonstrated by consistent filtration performance for repeated usage up to 15 cycles under ambient and external pressure. This research is a proof of concept that mushroom-derived chitin develops functional and biodegradable materials for environmental applications with scalability.

Medial Branch Radiofrequency Treatment for Low-Back Pain in Cancer Patients: A Case Series.

Cancer patients are increasing in number, with an increased lifespan and advances in cancer treatment. Palliative care physicians often encounter difficulties in caring for patients with pain. In addition to cancer-related pain, patients with cancer may suffer from various musculoskeletal diseases, resulting in significant functional limitations of physical activities of daily living. We present three cases illustrating methods to deal with nonspecific mechanical low-back pain in patients with advanced cancer. We provide our therapeutic experiences, focusing on the usefulness of radiofrequency treatment in palliative care in patients with cancer.

Diagnosis of Ischemic Renal Failure Using Surface-Enhanced Raman Spectroscopy and a Machine Learning Algorithm.

To diagnose renal function using a biochip capable of detecting SERS and to assess Raman measurements taken from a bilateral renal ischemia model and the feasibility of early diagnosis was done. After generating a bilateral renal ischemia rat model, blood and urine were collected. After confirming the presence of renal injury and function, liquid drops were placed onto a Raman chip whose surface had been enhanced with Au-ZnO nanorods. SERS biomarkers that diffused into the nanogaps were selectively amplified. Raman signals varied based on the severity of the renal function, and these differences were confirmed statistically. These results confirm that renal ischemia leads to renal dysfunction and that surface-enhanced Raman spectroscopy and a machine learning algorithm can be used to track signals in the urine from the release of SERS biomarkers.

Development of a scanning tunneling microscope for variable temperature electron spin resonance.

Recent advances in improving the spectroscopic energy resolution in scanning tunneling microscopy (STM) have been achieved by integrating electron spin resonance (ESR) with STM. Here, we demonstrate the design and performance of a homebuilt STM capable of ESR at temperatures ranging from 1 to 10 K. The STM is incorporated with a homebuilt Joule-Thomson refrigerator and a two-axis vector magnet. Our STM design allows for the deposition of atoms and molecules directly into the cold STM, eliminating the need to extract the sample for deposition. In addition, we adopt two methods to apply radio-frequency (RF) voltages to the tunnel junction: the early design of wiring to the STM tip directly and a more recent idea to use an RF antenna. Direct comparisons of ESR results measured using the two methods and simulations of electric field distribution around the tunnel junction show that, despite their different designs and capacitive coupling to the tunnel junction, there is no discernible difference in the driving and detection of ESR. Furthermore, at a magnetic field of ∼1.6 T, we observe ESR signals (near 40 GHz) sustained up to 10 K, which is the highest temperature for ESR-STM measurement reported to date, to the best of our knowledge. Although the ESR intensity exponentially decreases with increasing temperature, our ESR-STM system with low noise at the tunnel junction allows us to measure weak ESR signals with intensities of a few fA. Our new design of an ESR-STM system, which is operational in a large frequency and temperature range, can broaden the use of ESR spectroscopy in STM and enable the simple modification of existing STM systems, which will hopefully accelerate a generalized use of ESR-STM.

Fluorescence-Based Microendoscopic Sensing System for Minimally Invasive In Vivo Bladder Cancer Diagnosis.

Bladder cancer is commonly diagnosed by evaluating the tissue morphology through cystoscopy, and tumor resection is used as the primary treatment approach. However, these methods are limited by lesion site specificity and resection margin, and can thereby fail to detect cancer lesions at early stages. Nevertheless, rapid diagnosis without biopsy may be possible through fluorescence sensing. Herein, we describe a minimally invasive imaging system capable of sensing even small tumors through a 1.2 mm diameter flexible fiber bundle microprobe. We demonstrate that this new device can be used for the early diagnosis of bladder cancer in rats. Bladder cancer was induced in rats using the carcinogen N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN), and a togglable filter capable of PpIX fluorescence sensing was installed in the microendoscopic system. Following 5-aminolevulinic acid administration, tissue in the early stages of bladder cancer was successfully identified with fluorescence detection and confirmed with hematoxylin/eosin and ferrochelatase staining. Although the time required for BBN to induce bladder cancer varied between 3 and 4 weeks among the rats, the microendoscopic system allowed the minimally invasive follow-up on cancer development.

Spectral Multiplexing of Fluorescent Endoscopy for Simultaneous Imaging with Multiple Fluorophores and Multiple Fields of View.

Complex clinical procedures and small-animal research procedures can benefit from dual-site imaging provided by multiple endoscopic devices. Here, an endoscopic system is proposed which enables multiple fluorescence microendoscopes to be spectrally multiplexed on a single microscope base, enabling light sources and optical relays to be shared between endoscopes. The presented system is characterized for resolution using USAF-1951 resolution test charts and for modulation transfer function using the slanted edge method. Imaging is demonstrated both directly and with microendoscopes attached. Imaging of phantoms was demonstrated by targeting USAF charts and fiber tissues dyed for FITC and Texas Red fluorescence. Afterwards, simultaneous liver and kidney imaging was demonstrated in mice expressing mitochondrial Dendra2 and injected with Texas Red-dextran. The results indicate that the system achieves high channel isolation and submicron and subcellular resolution, with resolution limited by the endoscopic probe and by physiological movement during endoscopic imaging. Multi-channel microendoscopy provides a potentially low-cost means of simultaneous multiple endoscopic imaging during biological experiments, resulting in reduced animal harm and potentially increasing insight into temporal connections between connected biological systems.

A Wi-Fi-Based Mask-Type Laryngoscope for Telediagnosis During the COVID-19 Pandemic: Instrument Validation Study.

BACKGROUND: Owing to the COVID-19 pandemic, social distancing has become mandatory. Wireless endoscopy in contactless examinations promises to protect health care workers and reduce viral spread. OBJECTIVE: This study aimed to introduce a contactless endoscopic diagnosis system using a wireless endoscope resembling a mask. METHODS: The Wi-Fi-based contactless mask endoscopy system comprises a disposable endoscope and a controller. First, the effective force applied by the tip during insertion was evaluated in a simple transoral model consisting of a force sensor on a simulated oropharynx wall. Second, the delay in video streaming was evaluated by comparing the frame rate and delays between a movement and its image over direct and Wi-Fi connections. Third, the system was applied to a detailed laryngopharyngeal tract phantom. RESULTS: The smartphone-controlled wireless endoscopy system was successfully evaluated. The mean, maximum, and minimum collision forces against the wall of the transoral model were 296 mN (30 gf), 363 mN (37 gf), and 235 mN (24 gf), respectively. The delay resulting from the wireless connection was 0.72 seconds. Using the phantom, an inexperienced user took around 1 minute to orient the endoscope to a desired area via the app. CONCLUSIONS: Device articulation does not pose a significant risk of laryngopharyngeal wall penetration, and latency does not significantly impede its use. Contactless wireless video streaming was successful within the access point range regardless of the presence of walls. The mask endoscope can be controlled and articulated wirelessly, minimizing contact between patients and device operators. By minimizing contact, the device can protect health care workers from infectious viruses like the coronavirus.

A Portable Smartphone-Based Laryngoscope System for High-Speed Vocal Cord Imaging of Patients With Throat Disorders: Instrument Validation Study.

BACKGROUND: Currently, high-speed digital imaging (HSDI), especially endoscopic HSDI, is routinely used for the diagnosis of vocal cord disorders. However, endoscopic HSDI devices are usually large and costly, which limits access to patients in underdeveloped countries and in regions with inadequate medical infrastructure. Modern smartphones have sufficient functionality to process the complex calculations that are required for processing high-resolution images and videos with a high frame rate. Recently, several attempts have been made to integrate medical endoscopes with smartphones to make them more accessible to people in underdeveloped countries. OBJECTIVE: This study aims to develop a smartphone adaptor for endoscopes, which enables smartphone-based vocal cord imaging, to demonstrate the feasibility of performing high-speed vocal cord imaging via the high-speed imaging functions of a high-performance smartphone camera, and to determine the acceptability of the smartphone-based high-speed vocal cord imaging system for clinical applications in developing countries. METHODS: A customized smartphone adaptor optical relay was designed for clinical endoscopy using selective laser melting-based 3D printing. A standard laryngoscope was attached to the smartphone adaptor to acquire high-speed vocal cord endoscopic images. Only existing basic functions of the smartphone camera were used for HSDI of the vocal cords. Extracted still frames were observed for qualitative glottal volume and shape. For image processing, segmented glottal and vocal cord areas were calculated from whole HSDI frames to characterize the amplitude of the vibrations on each side of the glottis, including the frequency, edge length, glottal areas, base cord, and lateral phase differences over the acquisition time. The device was incorporated into a preclinical videokymography diagnosis routine to compare functionality. RESULTS: Smartphone-based HSDI with the smartphone-endoscope adaptor could achieve 940 frames per second and a resolution of 1280 by 720 frames, which corresponds to the detection of 3 to 8 frames per vocal cycle at double the spatial resolution of existing devices. The device was used to image the vocal cords of 4 volunteers: 1 healthy individual and 3 patients with vocal cord paralysis, chronic laryngitis, or vocal cord polyps. The resultant image stacks were sufficient for most diagnostic purposes. The cost of the device including the smartphone was lower than that of existing HSDI devices. The image processing and analytics demonstrated the successful calculation of relevant diagnostic variables from the acquired images. Patients with vocal pathologies were easily differentiable in the quantitative data. CONCLUSIONS: A smartphone-based HSDI endoscope system can function as a point-of-care clinical diagnostic device. The resulting analysis is of higher quality than that accessible by videostroboscopy and promises comparable quality and greater accessibility than HSDI. In particular, this system is suitable for use as an accessible diagnostic tool in underdeveloped areas with inadequate medical service infrastructure.

Eupatilin Inhibits Reactive Oxygen Species Generation via Akt/NF-κB/MAPK Signaling Pathways in Particulate Matter-Exposed Human Bronchial Epithelial Cells.

BACKGROUND: Eupatilin is an active flavon extracted from the Artemisia species and has properties such as antioxidant, anti-inflammatory, and anti-cancer. We examined the effect of eupatilin using fine particulate matter (FPM) and human bronchial epithelial cell line (BEAS-2B) to confirm the potential of eupatilin as a therapeutic agent for respiratory diseases caused by FPM. METHODS: Reactive oxygen species (ROS) levels were checked by flow cytometry to identify if FPM and eupatilin affect ROS production. Western blotting was performed to identify the mechanism of action of eupatilin in FPM-exposed BEAS-2B cells. RESULTS: When cells were exposed to FPM above 12.5 µg/mL concentration for 24 h, ROS production increased significantly compared to the control. When eupatilin was added to cells exposed to FPM, the ROS level decreased proportionally with the eupatilin dose. The phosphorylation of Akt, NF-κB p65, and p38 MAPK induced by FPM was significantly reduced by eupatilin, respectively. CONCLUSION: FPM cause respiratory disease by producing ROS in bronchial epithelial cells. Eupatilin has been shown to inhibit ROS production through altering signaling pathways. The ROS inhibiting property of eupatilin can be exploited in FPM induced respiratory disorders.

Infection control of operating room and anesthesia for cesarean section during the COVID-19 outbreak in Daegu, the Republic of Korea -a case series.

BACKGROUND: The coronavirus disease-19 (COVID-19) was first reported in Wuhan, China, with Korea being subsequently exposed. In Korea, COVID-19 screening guidelines have been established in every hospital as an attempt to prevent its spread. There has been a previous report of a successful cesarean section of a confirmed mother; however, there remain no guidelines for suspected mothers. Cesarean section is often urgently operated without sufficient infection evaluations. We would like to suggest anesthetic management guidelines for cesarean section patients suspected of COVID-19. CASE: Our hospital, which is located in Daegu, Korea, was designated as a quarantine and delivery facility for suspected mothers. We performed the cesarean section on seven suspected mothers and one confirmed mother. CONCLUSIONS: This case report presents guidelines for infection control during surgery and anesthesia for cesarean section of mothers with suspected COVID-19 involving operating room preparation and protection strategy.

The experience of infection prevention for coronavirus disease 2019 (COVID-19) during general anesthesia in an epidemic of COVID-19: including unexpected exposure case - Two cases report.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has been an epidemic in the Republic of Korea since the first patient who came in China was confirmed as having the disease on January 19, 2020. Therefore, surgery for COVID-19-related patients is expected to increase. CASE: We experienced two cases of COVID-19-related patients who underwent surgery for femur fracture under general anesthesia. In one case, infection control to prevent transmission was achieved, while in the second case, healthcare workers were exposed to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). CONCLUSIONS: In areas where there is COVID-19 epidemic, SARS-CoV-2 real-time polymerase chain reaction should be performed before surgery in patients with symptoms of respiratory infection such as fever, cough, and sputum, or for those in whom the possibility of COVID-19 cannot be completely excluded. Efforts should be made to prevent healthcare worker's exposure and the contamination of the operating room.

Cost-Effective Smartphone-Based Articulable Endoscope Systems for Developing Countries: Instrument Validation Study.

BACKGROUND: Endoscopes are widely used for visualizing the respiratory tract, urinary tract, uterus, and gastrointestinal tracts. Despite high demand, people in underdeveloped and developing countries cannot obtain proper access to endoscopy. Moreover, commercially available endoscopes are mostly nonarticulable as well as not actively controlled, limiting their use. Articulating endoscopes are required for some diagnosis procedures, due to their ability to image wide areas of internal organs. Furthermore, actively controlled articulating endoscopes are less likely to harm the lumen than rigid endoscopes because they can avoid contact with endothelial tissues. OBJECTIVE: The study aimed to demonstrate the feasibility and acceptability of smartphone-based wide-field articulable endoscope system for minimally invasive clinical applications in developing and less developed countries. METHODS: A thin articulable endoscope system that can be attached to and actively controlled by a smartphone was designed and constructed. The system consists of a flexible endoscopic probe with a continuum mechanism, 4 motor modules for articulation, a microprocessor for controlling the motor with a smartphone, and a homebuilt app for streaming, capturing, adjusting images and video, and controlling the motor module with a joystick-like user interface. The smartphone and motor module are connected via an integrated C-type On-The-Go (OTG) USB hub. RESULTS: We tested the device in several human-organ phantoms to evaluate the usability and utility of the smartphone-based articulating endoscope system. The resolution (960 × 720 pixels) of the device was found to be acceptable for medical diagnosis. The maximum bending angle of 110° was designed. The distance from the base of the articulating module to the tip of the endoscope was 45 mm. The angle of the virtual arc was 40.0°, for a curvature of 0.013. The finest articulation resolution was 8.9°. The articulating module succeeded in imaging all 8 octants of a spherical target, as well as all 4 quadrants of the indices marked in human phantoms. CONCLUSIONS: The portable wide-field endoscope was successfully controlled using a smartphone, yielding clear images with a resolution of 960 × 720 pixels at realistic focal distances. Actively and precisely controlled articulating movements have resulted in minimally invasive monitoring in the narrow space of internal organs providing a wide-area view. We found our smartphone-based active articulated endoscope to be suitable for point-of-care applications in developing and less developed countries.