In vitro comparative study of wall portbased high-frequency chest wall oscillation device and internal air-pulse generator device.

Owing to environmental and disease issues, the use of high-frequency chest wall oscillation (HFCWO) devices in hospitals is consistently increasing. This study proposes a cost-effective actuator-less HFCWO device that utilizes an external wall port utility in hospitals to generate the positive and negative pneumatic pressures required for HFCWO treatment instead of an embedded mechanical actuator. The manufactured prototype with the no-amplification (NO-AMP) setting contained an electric pressure regulator to enable intensity level adjustment and two solenoid valves to enable vibration frequency adjustment, whereas the prototype with the pre-amplification (PRE-AMP) setting contained an additional air reservoir and an air-pressure booster. The prototype device was tuned to output average local maximum values in the pressure waveform similar to a commercial VEST-205 device at an 8-12 Hz frequency and 2-4 pressure intensity levels. In vitro comparative experiments demonstrated that the prototype device showed similar local maximum pressures to those of the VEST-205 (mean absolute pressure difference, <3 mmH2O); in contrast, the proposed device showed significantly higher local minimum pressures than those of the VEST-205 (mean absolute pressure difference, >8 mmH2O). Additionally, the driving sound of the proposed device was 17.0-17.8 dB higher than that of VEST-205. We conclude that the proposed device has the potential to substitute for conventional HFCWO devices under the limited but most frequently used operating conditions, although more detailed modifications are necessary in future studies to improve its performance and clinical usability.

Sensing of sound pressure gradients by C. elegans drives phonotaxis behavior.

Despite lacking ears, the nematode C. elegans senses airborne sound and engages in phonotaxis behavior, enabling it to locate and avoid sound sources.1 How worms sense sound, however, is not well understood. Here, we report an interesting observation that worms respond only to sounds emitted by small but not large speakers, indicating that they preferentially respond to localized sound sources. Notably, sounds emitted by small speakers form a sharp sound pressure gradient across the worm body, while sounds from large speakers do not, suggesting that worms sense sound pressure gradients rather than absolute sound pressure. Analysis of phonotaxis behavior, sound-evoked skin vibration, and sound-sensitive neuron activities further support this model. We suggest that the ability to sense sound pressure gradients provides a potential mechanism for worms to distinguish sounds generated by their predators, which are typically small animals, from those produced by large animals or background noise. As vertebrate cochlea and some insect ears can also detect sound pressure gradients, our results reveal that sensing of sound pressure gradients may represent a common mechanism in auditory sensation across animal phyla. VIDEO ABSTRACT.

Convolutional neural network-based vocal cord tumor classification technique for home-based self-prescreening purpose.

BACKGROUND: In this study, we proposed a deep learning technique that can simultaneously detect suspicious positions of benign vocal cord tumors in laparoscopic images and classify the types of tumors into cysts, granulomas, leukoplakia, nodules and polyps. This technique is useful for simplified home-based self-prescreening purposes to detect the generation of tumors around the vocal cord early in the benign stage. RESULTS: We implemented four convolutional neural network (CNN) models (two Mask R-CNNs, Yolo V4, and a single-shot detector) that were trained, validated and tested using 2183 laryngoscopic images. The experimental results demonstrated that among the four applied models, Yolo V4 showed the highest F1-score for all tumor types (0.7664, cyst; 0.9875, granuloma; 0.8214, leukoplakia; 0.8119, nodule; and 0.8271, polyp). The model with the lowest false-negative rate was different for each tumor type (Yolo V4 for cysts/granulomas and Mask R-CNN for leukoplakia/nodules/polyps). In addition, the embedded-operated Yolo V4 model showed an approximately equivalent F1-score (0.8529) to that of the computer-operated Yolo-4 model (0.8683). CONCLUSIONS: Based on these results, we conclude that the proposed deep-learning-based home screening techniques have the potential to aid in the early detection of tumors around the vocal cord and can improve the long-term survival of patients with vocal cord tumors.

Deep learning-based monitoring technique for real-time intravenous medication bag status.

Accidents related to the administration of intravenous (IV) medication, such as drug overdose/underdose, drug/patient mis-identification, and delayed bag exchange, occur consistently in clinical fields. Several previous studies have suggested various contact-sensing and image-processing methodologies; however, most of them can increase the workload of nursing staffs during the long-term, continuous monitoring. In this study, we proposed a smart IV pole that can monitor the infusion status of up to four IV medications (patient/drug identification, and liquid residue) with various sizes and hanging positions to reduce IV-related accidents and improve patient safety with the least additional workload; the system consists of 12 cameras, one code scanner, and four controllers. Two types of deep learning models for automated camera selection (CNN-1) and liquid residue monitoring (CNN-2), and three drug residue estimation equations were implemented. The experimental results demonstrated that the accuracy of identification code-checking (60 tests) was 100%. The classification accuracy and the mean inference time of CNN-1 (1200 tests) were 100% and 140 ms. The mean average precision and the mean inference time of CNN-2 (300 tests) were 0.94 and 144 ms. The average error rates between the alarm setting (20, 30, and 40 mL) and the actual drug residue when the alarm first generated were 4.00%, 7.33%, and 4.50% for a 1,000 mL bag; 6.00%, 4.67%, and 2.50% for a 500 mL bag; and 3.00%, 6.00%, and 3.50% for a 100 mL bag, respectively. Our results suggest that the implemented AI-based prototype IV pole is a potential tool for reducing IV-related accidents and improving in-hospital patient safety. Supplementary Information: The online version contains supplementary material available at 10.1007/s13534-023-00292-w.

Cold anesthesia for pain reduction during intralesional steroid injection for nodulocystic acne.

BACKGROUND: In any dermatologic procedure, patient acceptance of treatment is heavily influenced by intraprocedural pain. Intralesional triamcinolone injections are very important in keloid scar and nodulocystic acne treatment. However, the main problem of needle-stick procedures is pain. Cryoanesthesia is ideally intended to cool only the epidermis during treatment and has advantage which did not require application time. AIMS: The aim of this study was to investigate the pain-reducing effect and safety of CryoVIVE® (newly introduced cryoanesthesia device) during triamcinolone injections for nodulocystic acne in actual clinical settings. PATIENTS/METHODS: In this two-staged, non-randomized clinical trial, a total of 64 subjects underwent intralesional triamcinolone injections for their acne lesions with cold anesthesia using CryoVIVE®. The pain intensity was assessed with Visual Analogue Scale (VAS) scores. Safety profile was also evaluated. RESULTS: The mean pain VAS scores on the lesion with and without cold anesthesia were 3.667 and 5.933, respectively (p = 0.0001). No side effects, discoloration, and scarring were observed. CONCLUSION: In conclusion, the anesthetic use of CryoVIVE® with intralesional corticosteroid injections is a practical and well-tolerated modality.

Effect of a Precision Cryotherapy Device with Temperature Adjustability on Pigmentation.

Background: Pigmentary skin disorders impair the quality of life, leading to the development of therapeutic modalities. However, these treatments should focus more on effectiveness and safety. Aims and Objectives: To evaluate the effect of a temperature-adjustable cryotherapy device on the expression of pigmentation-related biomarkers. Methods and Results: A temperature- and time-adjustable cryotherapy device was employed to improve 200 mJ UVB-induced pigmentation on mice at -5°C (for 5, 10 or 20 s), 0°C (for 5, 10 or 20 s), 5°C (for 5, 10 or 20 s), or 10°C (for 5, 10 or 20 s). Expression of pigmentation-related biomarkers, such as tyrosinase, c-kit, melanocortin 1 receptor and microphthalmia-associated transcription factor before and after treatment with the cryotherapy device was investigated with real-time polymerase chain reaction and immunohistochemistry. Results: Expression of pigmentation-related biomarkers was decreased after the treatment of the temperature-adjustable cryotherapy device. Gene expression of the pigmentation-related biomarkers was decreased under the above conditions with some exception. Protein expression of the pigmentation-related biomarkers showed decreased tendency under the conditions with some exceptions. Conclusion: The temperature-adjustable cryotherapy device used in this study reduced the expression of pigmentation-related biomarkers on mice and may be used to treat patients with skin pigmentation.

Split-face comparative trial of 785-nm picosecond neodymium:yttrium-aluminum-garnet laser and precision cryotherapy combination treatment for facial benign pigmented lesions.

Cryotherapy (or cryosurgery) has been performed to treat various skin lesions in the field of dermatology; however, to the best of our knowledge, no study has investigated its efficacy and safety for benign pigmented lesions. Therefore, we conducted a split-face study to evaluate the efficacy and safety of cryotherapy in the treatment of benign pigmented lesions. A total of five subjects were included. Picosecond laser therapy was performed to treat the whole face and cryotherapy for half the face. Four weeks after completing the treatment sessions, patients showed more clinical improvement on the laser and cryotherapy combination treatment side than on the laser-only side, with no adverse events. Our study demonstrated that cryotherapy is a potential adjuvant therapeutic modality for benign pigmented lesions.

Cooling Anesthesia for Intravitreal Injection: Results of the Prospective Open-Label, Dose-Ranging COOL-1 Trial.

PURPOSE: To evaluate the safety and efficacy of a novel medical device to provide cooling anesthesia to the eye as local anesthesia for intravitreal injections. STUDY DESIGN: First in human, open-label study of 43 subjects assessed at three different doses: -10°C for 20 seconds (group 1), -15°C for 15 seconds (group 2), and -15°C for 20 seconds (group 3). Main outcome measures were safety and pain of injection using a numeric rating scale (NRS). RESULTS: Cooling anesthesia did not result in any serious ocular adverse events. One grade 1 adverse event was a vasovagal response during cooling administration which resolved immediately after cooling. Mean NRS scores at the time of injection for each group ranged from 2.5 to 4.3 There was a statistically significant difference between pain scores of the 3 groups at injection in aggregate but not in pairwise comparisons (P value = 0.047). There was a statistically significant decrease in pain from injection to 5 minutes post injection in all groups (P value = 0.00008, 0.003, 0.0005 for groups 1, 2, 3, respectively) as well as from 5 minutes to 24-48 hours (P value = 0.00001, 0.018, and 0.0545 for groups 1, 2, 3, respectively). CONCLUSION: The rapid cooling anesthesia device was well tolerated for achieving local anesthesia among patients receiving intravitreal injections with no serious ocular adverse events.

Combined Effects of Zeta-potential and Temperature of Nanopores on Diffusioosmotic Ion Transport.

Diffusioosmosis (DO) results from ion transport near charged surfaces in the presence of electrolyte gradients and is critical in nanofluidic systems. However, DO has not yet been comprehensively studied because nanofabrication materials have limitations of low throughput and difficult quantification. Herein, we describe a self-assembled particle membrane (SAPM)-integrated microfluidic platform that can modulate the material properties (e.g., zeta-potential) and transport flux of nanopores. We quantify the effect of the zeta-potential on DO by measuring the electrical signals across three different nanopores/nanochannels of the SAPM. We then empirically quantify the effects of the temperature and ionic strength of the electrolytes on DO and reveal a nonlinear relationship with DO-driven ion transport; the ionic strengths govern the DO- or diffusion-effective ion transport phenomena. Finally, we demonstrate DO-driven electric power generation with enhanced performance as a potential application under optimized experimental conditions.

Automated laryngeal mass detection algorithm for home-based self-screening test based on convolutional neural network.

BACKGROUND: Early detection of laryngeal masses without periodic visits to hospitals is essential for improving the possibility of full recovery and the long-term survival ratio after prompt treatment, as well as reducing the risk of clinical infection. RESULTS: We first propose a convolutional neural network model for automated laryngeal mass detection based on diagnostic images captured at hospitals. Thereafter, we propose a pilot system, composed of an embedded controller, a camera module, and an LCD display, that can be utilized for a home-based self-screening test. In terms of evaluating the model's performance, the experimental results indicated a final validation loss of 0.9152 and a F1-score of 0.8371 before post-processing. Additionally, the F1-score of the original computer algorithm with respect to 100 randomly selected color-printed test images was 0.8534 after post-processing while that of the embedded pilot system was 0.7672. CONCLUSIONS: The proposed technique is expected to increase the ratio of early detection of laryngeal masses without the risk of clinical infection spread, which could help improve convenience and ensure safety of individuals, patients, and medical staff.

Enhanced Mechanical and Antibacterial Properties of Nanocomposites Based on Poly(vinyl Alcohol) and Biopolymer-Derived Reduced Graphene Oxide.

Functionalized graphene-polymer nanocomposites have gained significant attention for their enhanced mechanical, thermal, and antibacterial properties, but the requirement of multi-step processes or hazardous reducing agents to functionalize graphene limits their current applications. Here, we present a single-step synthesis of thermally reduced graphene oxide (TrGO) based on shellac, which is a low-cost biopolymer that can be employed to produce poly(vinyl alcohol) (PVA)/TrGO nanocomposites (PVA-TrGO). The concentration of TrGO varied from 0.1 to 2.0 wt.%, and the critical concentration of homogeneous TrGO dispersion was observed to be 1.5 wt.%, below which strong interfacial molecular interactions between the TrGO and the PVA matrix resulted in improved thermal and mechanical properties. At 1.5 wt.% filler loading, the tensile strength and modulus of the PVA-TrGO nanocomposite were increased by 98.7% and 97.4%, respectively, while the storage modulus was increased by 69%. Furthermore, the nanocomposite was 96% more effective in preventing bacterial colonization relative to the neat PVA matrix. The present findings indicate that TrGO can be considered a promising material for potential applications in biomedical devices.

A general approach to composites containing nonmetallic fillers and liquid gallium.

We report a versatile method to make liquid metal composites by vigorously mixing gallium (Ga) with non-metallic particles of graphene oxide (G-O), graphite, diamond, and silicon carbide that display either paste or putty-like behavior depending on the volume fraction. Unlike Ga, the putty-like mixtures can be kneaded and rolled on any surface without leaving residue. By changing temperature, these materials can be stiffened, softened, and, for the G-O-containing composite, even made porous. The gallium putty (GalP) containing reduced G-O (rG-O) has excellent electromagnetic interference shielding effectiveness. GalP with diamond filler has excellent thermal conductivity and heat transfer superior to a commercial liquid metal-based thermal paste. Composites can also be formed from eutectic alloys of Ga including Ga-In (EGaIn), Ga-Sn (EGaSn), and Ga-In-Sn (EGaInSn or Galinstan). The versatility of our approach allows a variety of fillers to be incorporated in liquid metals, potentially allowing filler-specific "fit for purpose" materials.

Convolutional neural network-based ambient light-independent panel digit surveillance technique for infusion pumps.

For effective patient therapy and improved patient safety, it is critical to administer medication accurately in accordance with doctor's prescription. However, accidents owing to the erroneous programing of infusion pumps caused by users have been consistently reported in several documents. In this study, the authors propose a novel surveillance technique for infusion pumps to continuously monitor the variations in panel digits using a convolutional neural network model, and evaluate the performance of the implemented technique. During the experimental evaluation, 1st-step ROIs and 2nd-step ROIs were successfully extracted from the frame images regardless of the ambient lighting conditions. The final accuracies of the implemented CNN model are 99.9% for both the training (172,800 images) and validation (1080 images) dataset while the final losses for the training and validation datasets are 0.48 and 0.45 after 13th epoch, respectively. In the 24-h continuous monitoring test, the accuracy of the model for volume recognition considering all the 1440 measurements (960 for day-lighting and 480 for night-lighting) is 95.5%, whereas in day-lighting and night-lighting modes the accuracies of the model are 98.2% and 90.0%, respectively. Based on these experimental results, the proposed surveillance technique incorporating infusion pumps is expected to improve the safety of patients who need long-term treatments via infusion pumps, reducing the burden on the nurses and hospitals.

Multi-modal infusion pump real-time monitoring technique for improvement in safety of intravenous-administration patients.

Intravenous (IV) medication administration processes have been considered as high-risk steps, because accidents during IV administration can lead to serious adverse effects, which can deteriorate the therapeutic effect or threaten the patient's life. In this study, we propose a multi-modal infusion pump (IP) monitoring technique, which can detect mismatches between the IP setting and actual infusion state and between the IP setting and doctor's prescription in real time using a thin membrane potentiometer and convolutional-neural-network-based deep learning technique. During performance evaluation, the percentage errors between the reference infusion rate (IR) and average estimated IR were in the range of 0.50-2.55%, while those between the average actual IR and average estimated IR were in the range of 0.22-2.90%. In addition, the training, validation, and test accuracies of the implemented deep learning model after training were 98.3%, 97.7%, and 98.5%, respectively. The training and validation losses were 0.33 and 0.36, respectively. According to these experimental results, the proposed technique could provide improved protection functions to IV-administration patients.

Photoactive Antiviral Face Mask with Self-Sterilization and Reusability.

Since the emergence of the COVID-19 pandemic outbreak, the increasing demand and disposal of surgical masks has resulted in significant economic costs and environmental impacts. Here, we applied a dual-channel spray-assisted nanocoating hybrid of shellac/copper nanoparticles (CuNPs) to a nonwoven surgical mask, thereby increasing the hydrophobicity of the surface and repelling aqueous droplets. The resulting surface showed outstanding photoactivity (combined photocatalytic and photothermal properties) for antimicrobial action, conferring reusability and self-sterilizing ability to the masks. Under solar illumination, the temperature of this photoactive antiviral mask (PAM) rapidly increased to >70 °C, generating a high level of free radicals that disrupted the membrane of nanosized (∼100 nm) virus-like particles and made the masks self-cleaning and reusable. This PAM design can provide significant protection against the transmission of viral aerosols in the fight against the COVID-19 pandemic.

Compression injury of the circular stapler for gastrointestinal end-to-end anastomosis: preliminary in-vitro study.

PURPOSE: This preliminary in-vitro study was designed to evaluate the risk factors of compression injury from use of a circular stapler for end-to-end anastomosis. METHODS: Transparent collagen plates were prepared in dry and wet conditions. Physical properties of collagen plates and porcine colon tissue were examined using a rheometer. Adjustable and fixed-type circular staplers were applied on the collagen plates and the gap distance and compressive pressure were measured during anvil approximation. Tissue injury was evaluated using a compression injury scale. Compression properties were accessed to optimal or overcompression based on gap distance. RESULTS: Unacceptable injuries were rarely observed on the dry collagens, regardless of compression device. In the adjustable compression, the compressibility ratio was similar between dry and wet collagen. Overcompression and unacceptable injury increased on the wet collagens. In the fixed compression, the compressibility ratio increased significantly and unacceptable injuries were observed in more than 50% of wet collagens. Peak pressure was significantly higher in the fixed-compression types than those of adjustable type. On bivariate correlation analysis, fixed-compression type and wet collagens were respectively associated with overcompression. On multivariate analysis, edematous collagen condition was the most important risk factor and proximal anvil side, fixed compression type, and overcompression were also independent risk factors for unacceptable compression injury. CONCLUSION: In the edematous tissue condition, unintentional overcompression could be increased and result in tissue injury on the compression line of the circular stapler.

Low cost synthesis of reduced graphene oxide using biopolymer for influenza virus sensor.

A biocompatible, cost-effective, and scalable reduced graphene oxide (rGO) film was obtained from shellac using thermal treatment and its structural, chemical, and electrical properties were investigated. This thermally-decomposed rGO (TrGO) film exhibited good crystallinity, low sheet resistance, and high carbon content. TrGO flakes obtained from the film were dispersed and drop cast onto indium tin oxide/glass electrodes to fabricate label-free electrochemical immunosensors for the quantitative detection of the influenza virus H1N1 via electrochemical impedance spectroscopy. These sensors exhibited high stability and reproducibility, both possibly ascribable to the high adhesion of TrGO due to its phenolic-OH moiety; the limits of detection were 26 and 33 plaque-forming units, respectively, in phosphate-buffered saline and diluted saliva. These cost-effective TrGO-based sensors showed great potential as reliable and robust nanomaterial-based biosensors for widespread clinical applications.

High Efficiency Doping of Conjugated Polymer for Investigation of Intercorrelation of Thermoelectric Effects with Electrical and Morphological Properties.

Intercorrelation of thermoelectric properties of a doped conjugated semiconducting polymer (PIDF-BT) with charge carrier density, conductive morphology, and crystallinity are systematically investigated. Upon being doped with F4-TCNQ by the sequential doping method, PIDF-BT exhibited a high electrical conductivity over 210 S cm-1. The significant enhancement of electrical conductivity resulted from a high charge carrier density, which is attributed to the effective charge-transfer-based integer doping between PIDF-BT and dopant molecules. Based on the systemic characterization on the optical, electrical, and structural properties of doped PIDF-BT annealed at different temperatures, we investigated the characteristic correlations between thermoelectric properties of PIDF-BT films and their four-probe electrical conductivity, charge carrier density, and charge carrier mobility obtained from AC Hall effect measurements. This study revealed that exercising fine control over the crystallinity and conductive migration of the conjugated polymer films can be a strategic approach to suppressing the degradation of the Seebeck coefficient at high charge carrier density and ultimately to maximizing the power factors of organic thermoelectric devices.