Density clustering-based automatic anatomical section recognition in colonoscopy video using deep learning.

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.

A remote-controlled automatic chest compression device capable of moving compression position during CPR: A pilot study in a mannequin and a swine model of cardiac arrest.

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.

Effects of flow rate accuracy in two-day anticancer drug infusion with disposable pumps on plasma drug concentrations.

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.

Suture tie-down forces and cyclic contractile forces after undersized tricuspid annuloplasty using a Tri-Ad Adams tricuspid annuloplasty ring in an ovine model.

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.

Inability to suppress head rotation during the saccade test as a clinical biomarker for cognitive dysfunction in Parkinson's disease.

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.

DNN based reliability evaluation for telemedicine data.

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.

Nasal and temporal curvatures of lamina CRIBROSA in myopic eyes.

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.

Feasibility study of a novel rectal cooling system for hypothermic radical prostatectomy in a swine model.

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 25℃ (±5℃) 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 30℃ within 3 minutes of activation of the rectal balloon. The temperature of the proximal NVB was consistently maintained below 25℃ in all cases. The temperature 1 cm from the bladder neck did not rise above 38℃ 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 10.1℃. 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.

Fat Graft with Allograft Adipose Matrix and Magnesium Hydroxide-Incorporated PLGA Microspheres for Effective Soft Tissue Reconstruction.

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.

Colonoscopic image synthesis with generative adversarial network for enhanced detection of sessile serrated lesions using convolutional neural network.

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.

A unique population of neutrophils generated by air pollutant-induced lung damage exacerbates airway inflammation.

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.

Ideal Nozzle Position During Pressurized Intraperitoneal Aerosol Chemotherapy in an Ex Vivo Model.

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.

3D-Printed Ophthalmic-Retrobulbar-Anesthesia Simulator: Mimicking Anatomical Structures and Providing Tactile Sensations.

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.

Novel Simulation Model That Realizes Arterial and Venous Blood Flow for Ultrasound-Guided Central Venous Catheter Insertion in Children.

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.

Establishment of an Experimental System for Intraperitoneal Chemotherapy in a Rat Model.

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.

Development of rotational intraperitoneal pressurized aerosol chemotherapy to enhance drug delivery into the peritoneum.

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.

Mathematical model of modified hybrid pump mechanism for cardiopulmonary resuscitation.

BACKGROUND AND OBJECTIVE: The "Cardiac pump theory" and "Thoracic pump theory" are representative theories of cardiopulmonary resuscitation (CPR) mechanisms. Based on these theories, many studies on mathematical modeling have been performed to help understand hemodynamics during CPR. However, there are parts that do not yet properly reflect the physiology of CPR. Therefore, this study aims to develop a lumped parameter model of CPR that can more accurately reflect the current CPR physiology. METHODS: By adding compartments of the superior and inferior vena cava of the thoracic cavity to the existing CPR model, and the "Hybrid pump" mechanism was applied to simulate CPR. To compare the hemodynamics of the conventional CPR model and the developed CPR model, various conditions, such as active compression-decompression CPR with an impedance threshold valve device (ACD-CPR+ITV), head-up-tilt (HUT), and head-down-tilt (HDT), were simulated. The coronary perfusion pressure (CPP) was compared by modulating the compression ratio of the atrium and ventricle with the thoracic pump factor. RESULTS: The result for the comparison of coronary blood flow showed that the existing model is predominant in the compression phase, whereas the developed model is dominant in the relaxation phase. ACD-CPR + ITV results showed that the CPP decreased by 5 % in the existing model, and increased by about 46 % in the developed model, revealing a distinct hemodynamic difference between the two models. Likewise, as a result of comparing the hemodynamic differences of the two models according to the changes in tilt angle, the HUT showed similar trends, while the HDT showed slightly different results. The CPP varied accordingly with the ratio of the ventricular and atrial thoracic pump factor. CONCLUSION: Comparison of the hemodynamics with the existing model by simulating various conditions showed that the developed CPR model reflects the CPR physiology better. The model suggests that the hemodynamics may vary depending on the ventricle and atrium compression ratio. This study may provide an important basis for helping understand various situations and patient-specific hemodynamic characteristics during CPR through in-depth research, such as patient-specific model and parameter optimization.

Point-of-care testing of plasma free hemoglobin and hematocrit for mechanical circulatory support.

Hematological analysis is essential for patients who are supported by a mechanical circulatory support (MCS). The laboratory methods used to analyze blood components are conventional and accurate, but they require a mandatory turn-around-time for laboratory results, and because of toxic substances, can also be hazardous to analysis workers. Here, a simple and rapid point-of-care device is developed for the measurement of plasma free hemoglobin (PFHb) and hematocrit (Hct), based on colorimetry. The device consists of camera module, minimized centrifuge system, and the custom software that includes the motor control algorithm for the centrifuge system, and the image processing algorithm for measuring the color components of blood from the images. We show that our device measured PFHb with a detection limit of 0.75 mg/dL in the range of (0-100) mg/dL, and Hct with a detection limit of 2.14% in the range of (20-50)%. Our device had a high correlation with the measurement method generally used in clinical laboratories (PFHb R = 0.999, Hct R = 0.739), and the quantitative analysis resulted in precision of 1.44 mg/dL for PFHb value of 14.5 mg/dL, 1.36 mg/dL for PFHb value of 53 mg/dL, and 1.24% for Hct 30%. Also, the device can be measured without any pre-processing when compared to the clinical laboratory method, so results can be obtained within 5 min (about an 1 h for the clinical laboratory method). Therefore, we conclude that the device can be used for point-of-care measurement of PFHb and Hct for MCS.

Validation of digital tourniquet pressures: An experimental comparison of T-RingTM and conventional surgical glove in human volunteers.

Digital tourniquets are widely used for the management of digital injuries in emergency departments or outpatient clinics. This study is focused on the pressure analysis of digital tourniquets on some points not covered in the existing literature.A total of thirty volunteers were enrolled in this study. Instantaneous surface pressure was measured at the thumbs, index fingers, and little fingers. We investigated the pressure according to the circumference of digits, tourniquet types, and measurement sites (dorsal and mid lateral volar sides) above the digital vessels. Continuous pressure was measured in artificial silicone models to determine the change of pressure over 2 hours.The average pressure measured on the mid lateral volar side of volunteers fingers were 154.3 ± 54.9 mm Hg by T-Ring and 162.6 ±â€Š61.0 mm Hg by surgical glove. The pressure on the dorsal side were 224.7 ±â€Š57.7 mm Hg by T-Ring and 228.8 ±â€Š66.0 mm Hg by surgical glove, each significantly higher than the mid lateral volar side. The circumference of digits did not significantly affect the surface pressure. The pressure pattern did not change significantly over 2 hours in both tourniquet types.The surface pressure of the mid lateral volar side was significantly lower than that of the dorsal side. However, there was no significant pressure difference according to the circumference of digits. Time dependent pressure change were not significantly different between 2 tourniquets.