ABSTRACT
Background/Aims: We investigated how interactions between humans and computer-aided detection (CADe) systems are influenced by the user's experience and polyp characteristics. Methods: We developed a CADe system using YOLOv4, trained on 16,996 polyp images from 1,914 patients and 1,800 synthesized sessile serrated lesion (SSL) images. The performance of polyp detection with CADe assistance was evaluated using a computerized test module. Eighteen participants were grouped by colonoscopy experience (nurses, fellows, and experts). The value added by CADe based on the histopathology and detection difficulty of polyps were analyzed. Results: The area under the curve for CADe was 0.87 (95% confidence interval [CI], 0.83 to 0.91). CADe assistance increased overall polyp detection accuracy from 69.7% to 77.7% (odds ratio [OR], 1.88; 95% CI, 1.69 to 2.09). However, accuracy decreased when CADe inaccurately detected a polyp (OR, 0.72; 95% CI, 0.58 to 0.87). The impact of CADe assistance was most and least prominent in the nurses (OR, 1.97; 95% CI, 1.71 to 2.27) and the experts (OR, 1.42; 95% CI, 1.15 to 1.74), respectively. Participants demonstrated better sensitivity with CADe assistance, achieving 81.7% for adenomas and 92.4% for easy-to-detect polyps, surpassing the standalone CADe performance of 79.7% and 89.8%, respectively. For SSLs and difficult-to-detect polyps, participants' sensitivities with CADe assistance (66.5% and 71.5%, respectively) were below those of standalone CADe (81.1% and 74.4%). Compared to the other two groups (56.1% and 61.7%), the expert group showed sensitivity closest to that of standalone CADe in detecting SSLs (79.7% vs 81.1%, respectively). Conclusions: CADe assistance boosts polyp detection significantly, but its effectiveness depends on the user's experience, particularly for challenging lesions.
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Endotracheal suctioning is an essential but labor-intensive procedure, with the risk of serious complications. A brand new automatic closed-suction device was developed to alleviate the workload of healthcare providers and minimize those complications. We evaluated the clinical efficacy and safety of the automatic suction system in mechanically ventilated patients with pneumonia. In this multicenter, randomized, non-inferiority, investigator-initiated trial, mechanically ventilated patients with pneumonia were randomized to the automatic device (intervention) or conventional manual suctioning (control). The primary efficacy outcome was the change in the modified clinical pulmonary infection score (CPIS) in 3 days. Secondary outcomes were the frequency of additional suctioning and the amount of secretion. Safety outcomes included adverse events or complications. A total of 54 participants, less than the pre-determined number of 102, were enrolled. There was no significant difference in the change in the CPIS over 72 h (-0.13 ± 1.58 in the intervention group, -0.58 ± 1.18 in the control group, p = 0.866), but the non-inferiority margin was not satisfied. There were no significant differences in the secondary outcomes and safety outcomes, with a tendency for more patients with improved tracheal mucosal injury in the intervention group. The novel automatic closed-suction system showed comparable efficacy and safety compared with conventional manual suctioning in mechanically ventilated patients with pneumonia.
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This study proposes the use of vocal resonators to enhance cardiac auscultation signals and evaluates their performance for voice-noise suppression. Data were collected using two electronic stethoscopes while each study subject was talking. One collected auscultation signal from the chest while the other collected voice signals from one of the three voice resonators (cheek, back of the neck, and shoulder). The spectral subtraction method was applied to the signals. Both objective and subjective metrics were used to evaluate the quality of enhanced signals and to investigate the most effective vocal resonator for noise suppression. Our preliminary findings showed a significant improvement after enhancement and demonstrated the efficacy of vocal resonators. A listening survey was conducted with thirteen physicians to evaluate the quality of enhanced signals, and they have received significantly better scores regarding the sound quality than their original signals. The shoulder resonator group demonstrated significantly better sound quality than the cheek group when reducing voice sound in cardiac auscultation signals. The suggested method has the potential to be used for the development of an electronic stethoscope with a robust noise removal function. Significant clinical benefits are expected from the expedited preliminary diagnostic procedure.
Subject(s)
Heart Auscultation , Signal Processing, Computer-Assisted , Stethoscopes , Humans , Heart Auscultation/instrumentation , Heart Auscultation/methods , Heart Auscultation/standards , Male , Female , Adult , Heart Sounds/physiology , Sound Spectrography , Equipment Design , Voice/physiology , Middle Aged , Voice Quality , Vibration , NoiseABSTRACT
Recognizing anatomical sections during colonoscopy is crucial for diagnosing colonic diseases and generating accurate reports. While recent studies have endeavored to identify anatomical regions of the colon using deep learning, the deformable anatomical characteristics of the colon pose challenges for establishing a reliable localization system. This study presents a system utilizing 100 colonoscopy videos, combining density clustering and deep learning. Cascaded CNN models are employed to estimate the appendix orifice (AO), flexures, and "outside of the body," sequentially. Subsequently, DBSCAN algorithm is applied to identify anatomical sections. Clustering-based analysis integrates clinical knowledge and context based on the anatomical section within the model. We address challenges posed by colonoscopy images through non-informative removal preprocessing. The image data is labeled by clinicians, and the system deduces section correspondence stochastically. The model categorizes the colon into three sections: right (cecum and ascending colon), middle (transverse colon), and left (descending colon, sigmoid colon, rectum). We estimated the appearance time of anatomical boundaries with an average error of 6.31 s for AO, 9.79 s for HF, 27.69 s for SF, and 3.26 s for outside of the body. The proposed method can facilitate future advancements towards AI-based automatic reporting, offering time-saving efficacy and standardization.
Subject(s)
Colonic Diseases , Deep Learning , Humans , Colonoscopy , Algorithms , Cluster AnalysisABSTRACT
BACKGROUND: Recently, we developed a chest compression device that can move the chest compression position without interruption during CPR and be remotely controlled to minimize rescuer exposure to infectious diseases. The purpose of this study was to compare its performance with conventional mechanical CPR device in a mannequin and a swine model of cardiac arrest. MATERIALS AND METHODS: A prototype of a remote-controlled automatic chest compression device (ROSCER) that can change the chest compression position without interruption during CPR was developed, and its performance was compared with LUCAS 3 in a mannequin and a swine model of cardiac arrest. In a swine model of cardiac arrest, 16 male pigs were randomly assigned into the two groups, ROSCER CPR (n = 8) and LUCAS 3 CPR (n = 8), respectively. During 5 minutes of CPR, hemodynamic parameters including aortic pressure, right atrial pressure, coronary perfusion pressure, common carotid blood flow, and end-tidal carbon dioxide partial pressure were measured. RESULTS: In the compression performance test using a mannequin, compression depth, compression time, decompression time, and plateau time were almost equal between ROSCER and LUCAS 3. In a swine model of cardiac arrest, coronary perfusion pressure showed no difference between the two groups (p = 0.409). Systolic aortic pressure and carotid blood flow were higher in the LUCAS 3 group than in the ROSCER group during 5 minutes of CPR (p < 0.001, p = 0.008, respectively). End-tidal CO2 level of the ROSCER group was initially lower than that of the LUCAS 3 group, but was higher over time (p = 0.022). A Kaplan-Meier survival analysis for ROSC also showed no difference between the two groups (p = 0.46). CONCLUSION: The prototype of a remote-controlled automated chest compression device can move the chest compression position without interruption during CPR. In a mannequin and a swine model of cardiac arrest, the device showed no inferior performance to a conventional mechanical CPR device.
Subject(s)
Cardiopulmonary Resuscitation , Heart Arrest , Male , Animals , Swine , Pilot Projects , Manikins , Heart Arrest/therapy , Pressure , HemodynamicsABSTRACT
BACKGROUND: Elastomeric pumps have a curved infusion rate profile over infusion time. Chemically driven pumps can overcome such limitations of elastomeric pumps and infuse constantly. However, studies on the pharmacokinetic benefit of chemically-driven pumps are insufficient. OBJECTIVE: This study aimed to determine effects of constant infusion with a chemically-driven pump on plasma drug concentrations compared to elastomeric pumps. METHODS: Infusion rate profiles of a chemically driven pump and two elastomeric pumps were measured in vitro tests under three height conditions of drug reservoir. Plasma drug concentrations were estimated using a pharmacokinetic model of 5-fluorouracil (5FU). RESULTS: The chemically-driven pump was more accurate than elastomeric pumps during the total infusion time (Root-mean-square-error (RMSE): 3% vs. 13%) which thus reduced its deviation of plasma 5FU concentration over time to one-fifth of that with an elastomeric pump. The chemically-driven pump had less than 5% of RMSE despite the influence of height difference. CONCLUSION: Although chemically-driven pumps maintained plasma 5FU concentration successfully and elastomeric pumps did not, both pumps were proper for 5FU infusion because the time-dependent changes in infusion rate did not affect the area under the curve. Chemically driven pumps would be more advantageous for drugs that are sensitive to their plasma concentrations.
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OBJECTIVES: This study evaluated suture tie-down forces and cyclic contractile forces (CCFs) after undersized tricuspid annuloplasty using a hybrid band. METHODS: Downsized tricuspid annuloplasty was planned in adult male sheep using 8 force transducers attached from the septal to the anterior annular areas of the ring (segments 1 and 2, flexible septal; segments 3 and 4, semi-rigid posterior; segments 5 and 6, semi-rigid anterior; segments 7 and 8, flexible anterior). CCFs were analysed at 3 different levels of peak right ventricular pressure (RVP): 30, 50 and 70 mmHg. RESULTS: Eight 5-year-old male Corriedale sheep (average body weight = 66.8 kg) were used. The average suture tie-down force was 4.42 [standard deviation (SD): 2.32] N. When the forces were compared, it was lowest in the flexible anterior area and highest in the flexible septal area (P < 0.001). With the RVP of 30 mmHg, the average CCFs was lowest at segment 3 [0.07 (SD: 0.07) N] and highest at segment 7 [0.15 (SD: 0.08) N]. The CCFs were 0.12 (SD: 0.1) N, 0.09 (SD: 0.12) N, 0.14 (SD: 0.1) N and 0.13 (SD: 0.09) N in the flexible septal, semi-rigid posterior, semi-rigid anterior and flexible anterior parts, respectively (P = 0.208). As the peak RVP increased to 50 and 70 mmHg, the CCFs of each area increased significantly (P < 0.001). Despite this increase, the CCFs remained low (0.1 and 0.3 N), and differences in CCFs between segments and between annular areas showed similar patterns. CONCLUSIONS: The flexible end of the hybrid band reduces the CCFs and might prevent annular tears after ring tricuspid annuloplasty, and the risk of tear would be low even in the septal area.
ABSTRACT
BACKGROUND: There is a need for development of reliable and accessible clinical biomarker for detecting cognitive dysfunction in PD. This study aimed to investigate whether involuntary head rotation during the saccade test could serve as a potential biomarker for screening cognitive dysfunction in PD. METHODS: A total of 27 PD patients and nine age- and sex-matched healthy controls were prospectively enrolled in this study. A custom-designed gyroscope was attached to the forehead of each participant, and a saccade test consisting of 20 trials was conducted. The entire test was recorded on video, and two movement disorder experts independently rated the degree of head rotation, blinded to the patients' clinical information. The peak angular velocity of head rotation was derived from the gyroscope data. Participants underwent Montreal Cognitive Assessment (MoCA) as the cognitive evaluation. Correlation analysis was performed to assess the relationship between head rotation and MoCA scores. RESULTS: The mean peak angular velocity of head rotation significantly correlated with the MoCA scores (R = -0.52, p = 0.0023) including age, sex, disease duration, and education duration as cofactors. The optimal peak angular velocity thresholds for head rotation, which aligned with the manual ratings, were determined to be 5°/s and 10°/s for raters 1 and 2, respectively. The MoCA scores exhibited significant correlations with the number of head rotations, using both the 5°/s (R = -0.36, p = 0.042) and 10°/s (R = -0.49, p = 0.0048) thresholds. Furthermore, the mean angular velocity of the head demonstrated a 100% positive predictive value and specificity for the detection of cognitive impairment (MoCA < 26), based on the cut-offs of 5°/s and 10°/s. CONCLUSION: Inability to suppress head rotation during saccades may serve as a potential clinical biomarker for screening cognitive dysfunction in PD.
Subject(s)
Cognitive Dysfunction , Parkinson Disease , Humans , Parkinson Disease/complications , Parkinson Disease/diagnosis , Saccades , Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/psychology , Mental Status and Dementia Tests , BiomarkersABSTRACT
Telemedicine data are measured directly by untrained patients, which may cause problems in data reliability. Many deep learning-based studies have been conducted to improve the quality of measurement data. However, they could not provide an accurate basis for judgment. Therefore, this study proposed a deep neural network filter-based reliability evaluation system that could present an accurate basis for judgment and verified its reliability by evaluating photoplethysmography signal and change in data quality according to judgment criteria through clinical trials. In the results, the deviation of 3% or more when the oxygen saturation was judged as normal according to each criterion was 0.3% and 0.82% for criteria 1 and 2, respectively, which was very low compared to the abnormal judgment (3.86%). The deviation of diastolic blood pressure (≥ 10 mmHg) according to criterion 3 was reduced by about 4% in the normal judgment compared to the abnormal. In addition, when multiple judgment conditions were satisfied, abnormal data were better discriminated than when only one criterion was satisfied. Therefore, the basis for judging abnormal data can be presented with the system proposed in this study, and the quality of telemedicine data can be improved according to the judgment result.
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Little is known about the myopic characteristics of lamina cribrosa (LC) curvature. As such, we investigated nasal and temporal LC curvatures in myopia. In this retrospective, cross-sectional study, 144 myopic eyes (refraction < - 2D) and 88 non-myopic eyes (refraction > - 0.5D) underwent swept-source optical coherence tomography scanning of the LC. The anterior border of LC curvature was delineated with 17 points and interpolated with the "cardinal spline" curve-fitting method. The average curvature indices of the temporal and nasal sides were presented as the temporal and nasal curvatures. Myopic eyes had a mean refraction of - 6.7 ± 2.8D, while for non-myopic eyes, the value was 0.3 ± 1.0D. Nasal LC curvature was visible in 54 myopia (37.5%) and 42 non-myopia (47.7%) cases (P = 0.126), and temporal LC curvature was visible in 142 myopia (98.6%) and 68 non-myopia (77.3%) cases (P = 0.001). The nasal LC curvature was significantly larger in myopia than in non-myopia (P < 0.001). Contrastingly, the temporal LC curvature was significantly smaller in myopia than in non-myopia (P < 0.001). Axial length was associated with larger nasal LC curvature, smaller temporal LC curvature, and larger nasal-temporal LC curvature difference (all P's < 0.05). In myopic relative to non-myopic eyes, LC curvature was decreased temporally and increased nasally.
Subject(s)
Myopia , Cross-Sectional Studies , Eye , Humans , Myopia/complications , Retrospective Studies , Tomography, Optical Coherence/methodsABSTRACT
Thermal damage and inflammatory responses of the sphincter and neurovascular bundles (NVBs) are responsible for post-prostatectomy incontinence and erectile dysfunction. Intraoperative hypothermia in the pelvic cavity may reduce the occurrence of these complications. We evaluated the feasibility of a novel rectal cooling system using an animal model. A novel rectal cooling system consisting of a cooling console and a multi-lumen rectal balloon was developed. We conducted animal tests on male pigs to evaluate the efficacy and safety of the system. The primary endpoint was to maintain the temperature of the NVBs at 25â (±5â) during and after the electrocauterization of the bladder neck for 10 seconds. The safety endpoint was device-related complications or significant changes in the core body temperature of the pigs. The NVB temperature was below 30â within 3 minutes of activation of the rectal balloon. The temperature of the proximal NVB was consistently maintained below 25â in all cases. The temperature 1 cm from the bladder neck did not rise above 38â and dropped to the initial level within 1 minute after electrocauterization. During cooling, the minimum temperature at the apex of the prostate was reduced to 10.1â. There were no device-related complications or significant changes in core body temperature throughout the experiment. Animal tests suggest the feasibility and safety of this novel rectal cooling system. A first-in-human trial to assess the safety and efficacy of this system during radical prostatectomy is warranted.
Subject(s)
Hypothermia, Induced , Hypothermia , Animals , Feasibility Studies , Hypothermia/surgery , Male , Prostate/surgery , Prostatectomy/adverse effects , SwineABSTRACT
BACKGROUND: Autologous fat grafting is one of the most common procedures used in plastic surgery to correct soft tissue deficiency or depression deformity. However, its clinical outcomes are often suboptimal, and lack of metabolic and architectural support at recipient sites affect fat survival leading to complications such as cyst formation, calcification. Extracellular matrix-based scaffolds, such as allograft adipose matrix (AAM) and poly(lactic-co-glycolic) acid (PLGA), have shown exceptional clinical promise as regenerative scaffolds. Magnesium hydroxide (MH), an alkaline ceramic, has attracted attention as a potential additive to improve biocompatibility. We attempted to combine fat graft with regenerative scaffolds and analyzed the changes and viability of injected fat graft in relation to the effects of injectable natural, and synthetic (PLGA/MH microsphere) biomaterials. METHODS: In vitro cell cytotoxicity, angiogenesis of the scaffolds, and wound healing were evaluated using human dermal fibroblast cells. Subcutaneous soft-tissue integration of harvested fat tissue was investigated in vivo in nude mouse with random fat transfer protocol Fat integrity and angiogenesis were identified by qRT-PCR and immunohistochemistry. RESULTS: In vitro cell cytotoxicity was not observed both in AAM and PLGA/MH with human dermal fibroblast. PLGA/MH and AAM showed excellent wound healing effect. In vivo, the AAM and PLGA/MH retained volume compared to that in the only fat group. And the PLGA/MH showed the highest angiogenesis and anti-inflammation. CONCLUSION: In this study, a comparison of the volume retention effect and angiogenic ability between autologous fat grafting, injectable natural, and synthetic biomaterials will provide a reasonable basis for fat grafting.
Subject(s)
Magnesium Hydroxide , Tissue Scaffolds , Adipose Tissue , Allografts , Animals , Biocompatible Materials , Mice , MicrospheresABSTRACT
Computer-aided detection (CADe) systems have been actively researched for polyp detection in colonoscopy. To be an effective system, it is important to detect additional polyps that may be easily missed by endoscopists. Sessile serrated lesions (SSLs) are a precursor to colorectal cancer with a relatively higher miss rate, owing to their flat and subtle morphology. Colonoscopy CADe systems could help endoscopists; however, the current systems exhibit a very low performance for detecting SSLs. We propose a polyp detection system that reflects the morphological characteristics of SSLs to detect unrecognized or easily missed polyps. To develop a well-trained system with imbalanced polyp data, a generative adversarial network (GAN) was used to synthesize high-resolution whole endoscopic images, including SSL. Quantitative and qualitative evaluations on GAN-synthesized images ensure that synthetic images are realistic and include SSL endoscopic features. Moreover, traditional augmentation methods were used to compare the efficacy of the GAN augmentation method. The CADe system augmented with GAN synthesized images showed a 17.5% improvement in sensitivity on SSLs. Consequently, we verified the potential of the GAN to synthesize high-resolution images with endoscopic features and the proposed system was found to be effective in detecting easily missed polyps during a colonoscopy.
Subject(s)
Colonic Polyps/pathology , Colonoscopy , Colorectal Neoplasms/pathology , Early Detection of Cancer , Image Interpretation, Computer-Assisted , Neural Networks, Computer , Databases, Factual , Humans , Predictive Value of Tests , Prospective Studies , Reproducibility of Results , Retrospective StudiesABSTRACT
BACKGROUND: Diesel exhaust particles (DEPs) are the main component of traffic-related air pollution and have been implicated in the pathogenesis and exacerbation of asthma. However, the mechanism by which DEP exposure aggravates asthma symptoms remains unclear. OBJECTIVE: This study aimed to identify a key cellular player of air pollutant-induced asthma exacerbation and development. METHODS: We examined the distribution of innate immune cells in the murine models of asthma induced by house dust mite and DEP. Changes in immune cell profiles caused by DEP exposure were confirmed by flow cytometry and RNA-Seq analysis. The roles of sialic acid-binding, Ig-like lectin F (SiglecF)-positive neutrophils were further evaluated by adoptive transfer experiment and in vitro functional studies. RESULTS: DEP exposure induced a unique population of lung granulocytes that coexpressed Ly6G and SiglecF. These cells differed phenotypically, morphologically, functionally, and transcriptionally from other SiglecF-expressing cells in the lungs. Our findings with murine models suggest that intratracheal challenge with DEPs induces the local release of adenosine triphosphate, which is a damage-associated molecular pattern signal. Adenosine triphosphate promotes the expression of SiglecF on neutrophils, and these SiglecF+ neutrophils worsen type 2 and 3 airway inflammation by producing high levels of cysteinyl leukotrienes and neutrophil extracellular traps. We also found Siglec8- (which corresponds to murine SiglecF) expressing neutrophils, and we found it in patients with asthma-chronic obstructive pulmonary disease overlap. CONCLUSION: The SiglecF+ neutrophil is a novel and critical player in airway inflammation and targeting this population could reverse or ameliorate asthma.
Subject(s)
Air Pollutants , Asthma , Adenosine Triphosphate/metabolism , Air Pollutants/toxicity , Animals , Humans , Inflammation/metabolism , Lung , Mice , Neutrophils/pathology , Vehicle Emissions/toxicityABSTRACT
BACKGROUND/AIM: Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is known to show uneven distribution and penetration of agents based on the nozzle position. Thus, this study aimed to investigate the ideal nozzle position for maximizing drug delivery during PIPAC. MATERIALS AND METHODS: We created 2 cm-, 4 cm- and 8 cm-ex vivo models according to the distance from the bottom to the nozzle using 21×15×16 cm-sized sealable plastic boxes. After each set of eight normal peritoneal tissues from swine were placed at eight different points (A to H), we performed PIPAC, compared the methylene blue staining areas to investigate the distribution, and estimated the depth of concentrated diffusion (DCD) and the depth of maximal diffusion (DMD) of doxorubicin. RESULTS: In terms of distribution, the 4 cm- and 8 cm-ex vivo models showed more stained faces than the 2 cm-ex vivo model. Regarding the penetration depth, the 4 cm- ex vivo model showed the highest DCD (mean; 244.1 µm, C; 105.1 µm, D; 80.9 µm, E; 250.2 µm, G; 250.2 µm, H) and DMD (mean; 174.8 µm, D; 162.7 µm, E; 511.7 µm, F; 522.2 µm, G; 528.1 µm, H) in the most points corresponding to 62.5%. CONCLUSION: The ideal nozzle position during PIPAC might be halfway between the nozzle inlet and the bottom in the ex vivo model.
Subject(s)
Antibiotics, Antineoplastic/administration & dosage , Antineoplastic Agents/administration & dosage , Doxorubicin/administration & dosage , Drug Delivery Systems/instrumentation , Peritoneal Neoplasms/drug therapy , Peritoneum/metabolism , Aerosols , Animals , Antibiotics, Antineoplastic/metabolism , Antineoplastic Agents/metabolism , Diffusion , Doxorubicin/metabolism , Equipment Design , Pressure , Sus scrofa , Tissue DistributionABSTRACT
OBJECTIVE: We developed and validated a realistic simulation model for ultrasound-guided central venous catheter insertion in children that is easy to build and inexpensive and can automatically reproduce arterial and venous blood flow. METHODS: The simulation model was constructed with a chicken breast, two DWP-385 water pumps, two types of tubes and a controller. An elastic rubber tourniquet and a silicone tube were connected to each water pump, which generated different continuous flows mimicking those of the pediatric internal carotid artery and internal jugular vein, respectively. Both tubes were inserted into a piece of chicken breast and connected to the controller. Then, we provided a simulation program of ultrasound-guided central venous catheter insertion using our novel model to resident emergency medicine physicians. We also collected data on their knowledge and confidence levels regarding the procedure before and after the simulation via questionnaires utilizing a 5-point Likert scale. RESULTS: The flow patterns of the artery and vein were well demonstrated with our model. A total of 11 resident physicians were enrolled. The knowledge and confidence regarding the discrimination of arteries and veins were significantly improved after training with our simulation model (p-value < 0.01). The subjective similarity and usefulness of our model also scored high on the questionnaire (median: 4; interquartile range in both categories: 4-5). CONCLUSION: Our novel simulation model is useful and realistic for ultrasound-guided central venous catheter insertion training. Clinical impact: This controlled motor system can be applied to many simulation models of artery and vein circulation.
Subject(s)
Catheterization, Central Venous , Central Venous Catheters , Arteries/diagnostic imaging , Child , Humans , Jugular Veins/diagnostic imaging , Ultrasonography, InterventionalABSTRACT
AIM: To establish an experimental system for comparing different methods of intraperitoneal chemotherapy in a rat model. MATERIALS AND METHODS: We used six-week-old Sprague-Dawley rats, and created an early postoperative intraperitoneal chemotherapy (EPIC) system using 18-gauge syringes and evacuators, and a hyperthermic intraperitoneal chemotherapy (HIPEC) system using two peristaltic pumps which controlled the flow rate and temperature. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) was achieved using a nozzle for dispersing aerosols at a flow rate up to 41.5 ml/min. The distribution and intensity of 0.2% trypan blue dye was compared among three methods. RESULTS: The distribution was limited and the intensity was weak after EPIC, and the dye stained moderately in gravity-dependent regions after HIPEC. On the other hand, the distribution was the most comprehensive, and the intensity was the greatest after PIPAC. CONCLUSION: This experimental system in a rat model may reflect the comparative effect among EPIC, HIPEC and PIPAC in humans.
Subject(s)
Hyperthermic Intraperitoneal Chemotherapy , Aerosols , Animals , Rats , Rats, Sprague-DawleyABSTRACT
Objective: A simulator for retrobulbar anesthesia administration mimicking the orbital anatomy and providing tactile sensation is proposed. Methods: The production process involves 3D modeling of anatomical structures on the basis of computerized tomography (CT) images, printing the models using a 3D printer, and casting the silicone. Twenty ophthalmologists administered retrobulbar anesthesia using the simulator with four different ocular axial lengths (including extreme myopes); the position of the needle tip was evaluated. The effectiveness of this simulator for training was also surveyed. Results: The proportions of the final location of the needle tip were 59.25%, 36.25%, and 4.5% for the retrobulbar space, peribulbar space, and intraocular space, respectively. Experienced ophthalmologists showed lower complication rates than residents (0.5% vs 8.5%, [Formula: see text]) and agreed that this simulator will help young ophthalmologists advance their anesthesia-administering skills. Discussion/Conclusion: The 3D-printered simulator for retrobulbar anesthesia was produced and performance was verified. The technology could be used to simulate critical orbital anatomic features and could be used as a training tool for resident ophthalmologists.
Subject(s)
Anesthesia , Printing, Three-Dimensional , Eye , Orbit/diagnostic imaging , SensationABSTRACT
This study aims to evaluate the drug distribution, tissue concentrations, penetration depth, pharmacokinetic properties, and toxicities after rotational intraperitoneal pressurized aerosol chemotherapy (RIPAC) in pigs. Because relevant medical devices have not been introduced, we developed our prototype of pressurized intraperitoneal aerosol chemotherapy (PIPAC) and RIPAC by adding a conical pendulum motion device for rotating the nozzle. RIPAC and PIPAC were conducted using 150 ml of 1% methylene blue to evaluate the drug distribution and 3.5 mg of doxorubicin in 50 ml of 0.9% NaCl to evaluate the tissue concentrations and penetration depth, pharmacokinetic properties, and toxicities. All agents were sprayed as aerosols via the nozzle, DreamPen® (Dalim Biotech, Gangwon, South Korea), with a velocity of 5 km/h at a flow rate of 30 ml/min under a pressure of 7 bars, and capnoperitoneum of 12 mmHg was maintained for 30 min. As a result, RIPAC showed a wider distribution and stronger intensity than PIPAC. Compared with PIPAC, RIPAC demonstrated high values of the tissue concentration in the central, right upper, epigastrium, left upper, left lower, right lower, and right flank regions (median, 375.5-2124.9 vs. 161.7-1240 ng/ml; p ≤ .05), and higher values of the depth of concentrated diffusion and depth of maximal diffusion (median, 232.5-392.7 vs. 116.9-240.1 µm; 291.2-551.2 vs. 250.5-362.4 µm; p ≤ .05) in all regions except for bowels. In RIPAC, the pharmacokinetic properties reflected hemodynamic changes during capnoperitoneum, and there were no related toxicities. Conclusively, RIPAC may have the potential to enhance drug delivery into the peritoneum compared to PIPAC.