Blood Chamber Research Articles

Modern Medical Practitioners' Theories on Huang Yuan-You's Use of "Pivotal Movements" in Treating Menstrual Disorders

Objective: To explore the academic ideas of the famous Qing dynasty physician Huang Yuan-young's "Four Saints' Heart Source" in identifying and treating menstrual diseases. METHODS: We studied Huang Yuan-yu's works, and analyzed the theory, methods, prescriptions and medicines of Huang Yuan-yu in the treatment of menstrual diseases, taking the Four Sages Heart Source as the main object of study. Results: Huang Yuan-yu's academic thought of "one qi flowing around and pivotal movement" was also reflected in the physiopathology of menstruation. It is believed that Spleen Yang and Kidney Water are the basis for the production of menstrual blood, while Lung Gold and Liver Wood regulate the menstrual cycle. He elaborated on menstrual disorders such as closed knots, menorrhagia, late pre-menstruation, purple and black stasis, abdominal pain during menstruation, and heat entering the blood chamber, and proposed that "the first method to regulate menstruation and nourish blood is to give priority to Chong Yang", and founded the formulas of Gui Zhi Dan Pi Tang, Gui Zhi Jiang Ling Tang, Jiang Ling Ah Gao Tang, Ling Gui Dan Shen Tang, Gui Di Peony Tang, and Chai Hu Di Huang Tang, which provided new ideas for clinical practice. Conclusion: Huang Yuan-you's treatment of menstrual diseases is guided by his academic thought of "one qi flowing around, pivotal movement", and proposes a physiological mechanism for the production and regulation of menstruation, which is different from the traditional mechanism of "kidney - tian-kuei - punching - uterus". It also provides guidance on the etiology of menstrual diseases and the prescriptions and medicines for their treatment, which are of contemporary value in the modern treatment of menstrual diseases.

Extreme membrane position detection and pump output estimation in pulsatile VADs

One of the disadvantages of pulsatile ventricular assist devices (VADs) is the lack of feedback information about the flow and the range of diaphragm movement. This influences the proper selection of control parameters and control automation. Objective: The aim of the present study was to develop algorithms for complete emptying (CE) and complete filling (CF) detection as well as stroke volume estimation. Methods: The developed methods do not require additional measurements, as they are based on the data from the VAD control unit and the modeled value of the flow in the VAD blood chamber Siewnicka and Janiszowski (2018) [1]. The experiments were performed on a measurement stand of a hybrid simulator of the cardiovascular system with a connected POLVAD-MEV device. The algorithms were developed and then tested for a wide range of device operation conditions. Results: The CF detection algorithm had one missed detection out of 39 measurements. The CE algorithm was free of errors for all investigated cases. The pump output algorithm was approximately 90% accurate in relation to the direct measurement. Conclusion and significance: The application of these methods to pulsatile VADs may be very convenient for the medical operators of these devices and could result in a considerable improvement in the field of treatment safety. An abstract of this work was reported in Siewnicka et al., 2017 [2].

An Inexpensive In Vitro Blood-Feeding System for Wild Aedes albopictus (Diptera: Culicidae)

An Inexpensive <i>In Vitro</i> Blood-Feeding System for Wild <i>Aedes albopictus</i> (Diptera: Culicidae)

Haemocompatibility testing allows selective adaption of GA-free SULEEI-preparation strategy for bovine pericardium

Abstract Background/Introduction Bovine pericardium is the main natural source for patches or valve substitutes in cardiac surgery, but still, long-term durability is limited. An alternative, glutaraldehyde (GA)-free preparation combining decellularization, riboflavin/UVA crosslinking, and low-energy electron irradiation (SULEEI) procedure was established to avoid this. Protocol optimization is ongoing to further improve the final material. Haemocompatibility in vitro testing with fresh, human whole blood has advantages for material analysis, as it provides essential information on the activation of the complement system and immune cells therefore substantiating and possibly reducing the amount of animal testing. Purpose The haemocompatibility testing system was applied to reveal advantageous protocol adaptation of GA-free SULEEI preparation of pericardia. Methods Decellularized bovine pericardia were UVA-crosslinked in riboflavin/dextran solution. Protocol SULEEI B adaption includes the addition of trypsin in decellularization buffer and a 10x reduced riboflavin/dextran concentration during prolonged UVA irradiation with reduced intensity. Electron irradiation with 36 kGy was retained. Pericardia were incubated in blood chambers with heparinized human blood (2h, 37°C, GA-fixed/native controls). Inflammation (granulocyte loss and activation [CD11b]), complement activation (C5a) and haemostasis parameters (F1+2, PF4, granulocyte/platelet conjugates, platelet loss) were analyzed via flow cytometry or ELISA. Surface cell adhesion was investigated immunohistologically and via REM-analyses. Nuclear fragments were quantified in HE-stained sections. Results Haemostasis parameters F1+2 and PF4 were significantly higher in SULEEI A-pericardium (133±25 nmol/l and 1507±677 U/ml) vs. GA-fixation (2.9±2.9 nmol/l and 320±160 U/ml). Also, granulocyte/platelet conjugates (76.3±18.8%) and platelet loss (40.4±29.7%) were significantly higher after SULEEI A preparation in comparison to GA-fixation (39.3±9.9% and 20.5±6.4%). SULEEI B treated pericardia did not differ significantly. C5a complement activation was significantly lower in SULEEI A samples but comparable in SULEEI B to GA-fixed material. This is in contrast to a higher rate of nuclear fragments in SULEEI A tissue HE stained sections. Granulocyte activation of SULEEI pericardium (A: 89.8±29.7%; B: 106.2±18.8%) was significantly higher compared to native (46.1±22.6%) and for SULEEI B higher than in GA-fixed samples (67.2±9%). Granulocyte loss was comparable to GA-fixed pericardium after SULEEI B protocol. REM-analyses and histological evaluation visualized a dense blood cell and fibrin covering particular of SULEEI A-pericardium. Conclusions Haemocompatibility testing reveals advantageous properties of SULEEI B-pericardium. The impact of treatment substances such as dextran on high inflammatory response and dense surface covering in SULEEI A protocol is focus in ongoing experiments. Funding Acknowledgement Type of funding sources: Public grant(s) – EU funding. Main funding source(s): EU/EFRE

Defining Patterns and Behaviours of Forward Spatter Gunshot Misting

The purpose of this research was to study forward-spatter misting patterns by shooting a firearm through a chamber of blood encased in ballistic gel to determine if there is a relationship between bloodstain pattern size as a function of distance and orientation. There is a lack of research on forward spatter, blood travelling in the direction of a bullet, as most studies focus on back spatter, blood travelling in the opposite direction of a bullet. A bullet was fired through ballistic gel containing a blood chamber, depositing bloodstains onto a large sheet of butcher paper as the target surface. In total, there were 34 trials. The distances observed were 10, 20, 40, and 80 cm, the angles tested were 30°, 60°, and 90°. The orientation between the ballistic gel and paper target varied. A criterion was established to observe the overall area and symmetry of the bloodstain patterns. Statistical analyses indicated a negative linear relation relationship between the bloodstain pattern size and the paper’s angle and distance (R2 = 0.78) and the vertical symmetry of the bloodstain (R2 = 0.87). The orientation between the ballistic gel and paper target can impact the bloodstain pattern’s symmetry and size.

Automatic left ventricular cavity segmentation via deep spatial sequential network in 4D computed tomography.

Automated segmentation of left ventricular cavity (LVC) in temporal cardiac image sequences (consisting of multiple time-points) is a fundamental requirement for quantitative analysis of cardiac structural and functional changes. Deep learning methods for segmentation are the state-of-the-art in performance; however, these methods are generally formulated to work on a single time-point, and thus disregard the complementary information available from the temporal image sequences that can aid in segmentation accuracy and consistency across the time-points. In particular, single time-point segmentation methods perform poorly in segmenting the end-systole (ES) phase image in the cardiac sequence, where the left ventricle deforms to the smallest irregular shape, and the boundary between the blood chamber and the myocardium becomes inconspicuous and ambiguous. To overcome these limitations in automatically segmenting temporal LVCs, we present a spatial sequential network (SS-Net) to learn the deformation and motion characteristics of the LVCs in an unsupervised manner; these characteristics are then integrated with sequential context information derived from bi-directional learning (BL) where both chronological and reverse-chronological directions of the image sequence are used. Our experimental results on a cardiac computed tomography (CT) dataset demonstrate that our spatial-sequential network with bi-directional learning (SS-BL-Net) outperforms existing methods for spatiotemporal LVC segmentation.

Measurement of swirling flow in a blood chamber by laser Doppler imaging system

We developed a flow visualization system based on laser Doppler velocimetry (LDV) to investigate the relationship between blood flow and blood coagulation in a blood chamber in an extracorporeal circulation circuit. Linear laser intersection was used to implement 32-point simultaneous measurement. The intersection region was traversed along the axial direction to obtain a two-dimensional (2D) velocity distribution as a contour graph. The optical assembly of the flow visualization system is very simple. Furthermore, there is no need to submerge the measurement object in a square water tank to reduce the influence of refraction and reflection. Because LDV has inherently high measurement accuracy, even slight flow velocity changes (less than 1 mm s−1) can be clearly identified in a blood chamber.

A Glance at the Relationship between Blood Chamber and Chong Mai (Penetrating Vessel)

The primary purpose of the meridians is regulation of the flow Qi and the transportation of Blood throughout the body. The term Jing-mai ( in Chinese), accurately referring to two words channel.

Modeling, characterization and test of a pediatric ventricular assist device

This paper presents a 0D model for the pulsatile pediatric Ventricular Assist Device (pVAD), as well as its characterization and test results obtained by using an experimental hydraulic system that provides operational conditions close to the physiological conditions observed in pediatric patients. The measurements of the physical quantities used in characterization of the pVAD have been obtained by using the LabVIEW platform. The air chamber pressure signal is used to model the pneumatic actuation system behaviour, whereas the pressure-volume relationship inside the blood chamber is applied to model the pVAD compliance. The set of test and validation results demonstrated the correctness of the proposed model.

KSZTAŁTOWANIE SZTUCZNEJ KOMORY ORAZ NAPĘDU MIKROPOMPY PULSACYJNEJ DO PRZETACZANIA KRWI

W niniejszym artykule zaprezentowano przykłady laminarnie przepływowych oraz pulsacyjnych urządzeń wspomagających pracę ludzkiego serca oraz całkowicie sztucznych serc. Przykłady tych urządzeń rozpatrywane były pod kątem modelowania kształtu sztucznych komór krwi oraz napędu elektromagnetycznego tych urządzeń. Opisano ogólną zasadę działania oraz wady i zalety wynikające z budowy danej konstrukcji.

Toward the Virtual Benchmarking of Pneumatic Ventricular Assist Devices: Application of a Novel Fluid-Structure Interaction-Based Strategy to the Penn State 12 cc Device.

The pediatric use of pneumatic ventricular assist devices (VADs) as a bridge to heart transplant still suffers for short-term major complications such as bleeding and thromboembolism. Although numerical techniques are increasingly exploited to support the process of device optimization, an effective virtual benchmark is still lacking. Focusing on the 12 cc Penn State pneumatic VAD, we developed a novel fluid-structure interaction (FSI) model able to capture the device functioning, reproducing the mechanical interplay between the diaphragm, the blood chamber, and the pneumatic actuation. The FSI model included the diaphragm mechanical response from uniaxial tensile tests, realistic VAD pressure operative conditions from a dedicated mock loop system, and the behavior of VAD valves. Our FSI-based benchmark effectively captured the complexity of the diaphragm dynamics. During diastole, the initial slow diaphragm retraction in the air chamber was followed by a more rapid phase; asymmetries were noticed in the diaphragm configuration during its systolic inflation in the blood chamber. The FSI model also captured the major features of the device fluid dynamics. In particular, during diastole, a rotational wall washing pattern is promoted by the penetrating inlet jet with a low-velocity region located in the center of the device. Our numerical analysis of the 12 cc Penn State VAD points out the potential of the proposed FSI approach well resembling previous experimental evidences; if further tested and validated, it could be exploited as a virtual benchmark to deepen VAD-related complications and to support the ongoing optimization of pediatric devices.

Evaluation of the effectiveness of manual and automated dialyzers reprocessing after multiple reuses

A cross-sectional study was conducted to evaluate the effectiveness of manual and automated dialyzer reprocessing. Dialyzers were filled with fluid thioglycollate medium from blood and dialysate chambers after being reprocessed and chemically sterilized with 0.2% peracetic acid. They were incubated for 14 days at 35°C ± 2°C, and microbiologic analysis was performed. Microorganisms were identified in 3 of the 11 samples (27.3%) from the blood chambers: Sphingomonas paucimobilis (2/3) and Penicillium spp (1/3) and in 11 of the 11 samples (100%) from the dialysate chambers: S paucimobilis (7/11), Stenotrophomonas maltophilia (4/11), Pseudomonas aeruginosa (3/11), Candida spp (1/11), and Acinetobacter baumannii (1/11). Of the 4 manually reprocessed dialyzers, gram-positive bacillus were identified in 1 sample (25%) from the blood chamber, and Bacillus spp and Burkholderia spp were identified in 1 sample (25%) from the dialysate chamber. The dialyzers reprocessing can pose risks safety because of exposure patient to microorganisms.

Accuracy of a prototype dark blood late gadolinium enhancement technique for the detection and quantification of myocardial infarction

Background Conventional inversion recovery (IR) techniques for the detection of late gadolinium enhancement (LGE) in the myocardium are bright blood methods in which the signal in the blood chamber is often similar to the signal in hyperenhanced irreversibly damaged myocardial areas. Due to the low contrast to noise ratio (CNR) between blood and the hyperenhanced myocardium at the tissue-blood interface, the discrimination of subendocardial LGE from blood is often challenging with this approach. The aim of our study was to evaluate the accuracy of a prototype dark blood LGE technique for the detection and quantification of myocardial LGE in patients with myocardial infarction (MI) when compared to conventional IR LGE technique.

Online Hemoglobin and Oxygen Saturation Sensing During Continuous Renal Replacement Therapy with Regional Citrate Anticoagulation

Optical hemoglobin and oxygen saturation sensor (OHOS) monitor when used in combination with other hemodynamic tools may be useful for continuous hemodynamic monitoring during ultrafiltration. The stand-alone OHOS monitor can easily be deployed predialyzer into the extracorporeal circuit of continuous renal replacement therapy (CRRT) systems. To maximize the accuracy of the OHOS in 24 hr CRRT systems, clotting in the optical blood chamber and the presensor dilution incurred by replacement fluid should be minimized. Sustained low-efficiency dialysis (SLED) with regional citrate anticoagulation is a therapy that incorporates an OHOS and maintains the overall reliability of hemoglobin (Hb) and saturation sensing. The system operates at a blood flow rate of 60 ml/min and a fixed acid citrate infusion rate of 150 ml/hr. The presensor dilution incurred by concentrated citrate infusion would result in a minimal Hb dilution (<0.7 g/dl) while minimizing optical blood chamber clotting during 24 hr SLED.

Computational fluid dynamics analysis and PIV validation of a bionic vortex flow pulsatile LVAD.

Hemocompatibility is highly affected by the flow field in Left Ventricular Assistant Devices (LVAD). An asymmetric inflow and outflow channel arrangement with a 45° intersection angle with respect to the blood chamber is proposed to approximate the vascular structure of the aorta and left atrium on the left ventricle. The structure is expected to develop uninterruptible vortex flow state which is similar to the flow state in human left ventricle. The Computational Fluid Dynamics (CFD) asymmetric model is simulated using ANSYS workbench. To validate the velocity field calculated by CFD, a Particle Image Velocimetry (PIV) experiment is conducted. The CFD results show that the proposed blood chamber could generate a shifting vortex flow that would be redirected to the aorta during ejection to form a persistent recirculating flow state, which is similar to the echocardiographic flow state in left ventricle. Both the PIV and the CFD results show the development of a persistent vortex during the pulsatile period. Comparison of the qualitative flow pattern and quantitative probed velocity histories in a pulsatile period shows a good agreement between the CFD and PIV data. The goal of developing persistent quasi intra-ventricle vortex flow state in LVAD is realized.

Numerical And Experimental Analysis Of Fracture Of Athrombogenic Coatings Deposited On Ventricular Assist Device In Micro-Shear Test

Abstract The Polish left ventricular assist device (LVAD – RELIGA_EXT) will be made of thermoplastic polycarbonate-urethane (Bionate II) with deposited athrombogenic nano-coatings: gold (Au) and titanium nitride (TiN). Referring to the physical model, the two-scale model of LVAD developed in the previous works in the authors’ finite element code is composed of a macro-model of blood chamber and a micro-model of wall: TiN, Au and Bionate II. The numerical analysis of stress and strain states confirmed the possibility of fracture based on localization of zones of the biggest values of triaxiality factor. The introduction of Au interlayer between TiN and polymer improved the toughness of the connection, and increased the compressive residual stress in the coating what resulted in reduction of stress and strain close to the boundary between substrate and coating. However, the proper design of multilayer wall of the medical device requires the introduction of the real stress and strain states in the deposited coatings. The characteristics of TiN nano-coating such as residual stress, material model and fracture model were determined in the previously completed studies such as experimental and numercial nanoindentation tests, profilometry studies and in situ SEM’s micro-tension tests. The experimental in situ SEM’s micro-shear test was performed in the present paper and the corresponding numerical model of the test was also developed, and then, interpreted. The critical strains taken from experiment and considered as the effective strains in the model of test are the values which are the function of triaxiality factors for the tested samples. The developed in the authors’ FE code model of multilayer wall of VAD enriched with critical strain determined in the present paper enables prediction of fracture.

Multi-objective optimization of pulsatile ventricular assist device hemocompatibility based on neural networks and a genetic algorithm.

Given the benefit of pulsatile blood flow for perfusion of coronary arteries and end organs, pulsatile ventricular assist devices (VADs) are still widely used as paracorporeal mechanical circulatory support devices in clinical applications. However, poor hemocompatibility limits the service period of the VADs. Most previous improvements on VAD hemocompatibility were conducted by trial-and-error CFD analysis, which does not easily arrive at the best solution. In this paper, a multi-objective optimization method integrating neural networks and NSGA-II (Non-dominated Sorted Genetic Algorithm-II) based on FSI simulation was developed and applied to a pulsatile VAD to optimize its hemocompatibility. First, the VAD blood chamber was parameterized with the principal geometrical parameters. Three hemocompatibility indices including hemolysis, platelet activation, and platelet deposition were chosen as goal functions. The neural networks were built to fit the nonlinear relationship between goal functions and geometrical parameters. Next, a multi-objective optimization algorithm (NSGA-II) was used to search out the Pareto optimal solutions in the built neural networks. Finally, the best compromise solution was selected from the Pareto optimal solutions by a fuzzy membership approach and validated by FSI simulation. The best compromise solution simultaneously possesses an acceptable hemolysis index, platelet activation index, and platelet deposition index, and the corresponding relative errors between the indices predicted by optimization algorithm and the one calculated by FSI simulations are all less than 5%. The results suggest that the proposed multi-objective optimization method has the potential for application in optimizing pulsatile VAD hemocompatibility, and may also be applied to other blood-wetted devices.

Acoustic System of Determining the Instantaneous Volume of the Blood Part of the Ventricular Assist Device POLVAD-EXT

Abstract The paper presents the results of investigations concerning the noninvasive method of estimating the actual volume of the blood chamber of the POLVAD-EXT type ventricular assist device (VAD) during its operation. The proposed method is based on the principle of Helmholtz's acoustic resonance. Both the theory, main stages of the development of the measurement method as well as the practical implementation of the proposed method in the physical model of the POLVAD-EXT device are dealt with. The paper contains the results of static measurements by means of the proposed method (conducted at the Department of Optoelectronics, Silesian University of Technology) as well as the dynamic measurements taken at the Foundation of Cardiac Surgery Development (Zabrze, Poland) with the professional model of the human cardiovascular system. The results of these measurements prove that the proposed method allows to estimate the actual blood chamber volume with uncertainties below 10%.

Vascular repair utilising immobilised heparin conjugate for protection against early activation of inflammation and coagulation.

Ischaemia-reperfusion injury (IRI) poses a major challenge in many thrombotic conditions and in whole organ transplantation. Activation of the endothelial cells and shedding of the protective vascular glycocalyx during IRI increase the risk of innate immune activation, cell infiltration and severe thrombus formation, promoting damage to the tissue. Here, we present a novel one-step strategy to protect the vasculature by immobilisation of a unique multi-arm heparin conjugate to the endothelium. Applying a new in vitro blood endothelial cell chamber model, the heparin conjugate was found to bind not only to primary human endothelial cells but also directly to the collagen to which the cells adhered. Incubation of hypoxic endothelial cells with freshly drawn human blood in the blood chambers elicited coagulation activation reflected by thrombin anti-thrombin formation and binding of platelets and neutrophils. Immobilisation of the heparin conjugate to the hypoxic endothelial cells created a protective coating, leading to a significant reduction of the recruitment of blood cells and coagulation activation compared to untreated hypoxic endothelial cells. This novel approach of immobilising multi-arm heparin conjugates on the endothelial cells and collagen of the basement membrane ensures to protect the endothelium against IRI in thrombotic disorders and in transplantation.

Hemodiafiltration using pre-dilutional on-line citrate dialysate: A new technique for regional citrate anticoagulation: A feasibility study.

A prospective, observational, feasibility study was carried out on four patients with end-stage renal failure undergoing bicarbonate hemodialysis to study the feasibility of an on-line hemodiafiltration technique using a citrate dialysate with pre-dilutional infusion of citrate as a technique for regional citrate anticoagulation. All patients had contraindication to systemic heparin anticoagulation. The dialysis technique consisted of an on-line hemodiafiltration with a citrate dialysate without calcium using a Fresenius 4008S dialysis machine and Fresenius Polysulfone F60 dialyzers. The infusion solution was procured directly from the dialysate and was infused into the arterial line. To avoid the risk of hypocalcemia, calcium gluconate was infused to the venous return line. The study was carried out in two stages. During the first stage, the citrate infusion rate was 80 mL/min and the calcium infusion rate was 9 mmol/h. At the second stage, the rates were 100 mL/min and 11 mmol/h, respectively. The primary endpoint of this study was the incidence of thrombosis in the extracorporeal blood circuit and/or the dialyzer. A total of 78 sessions were conducted. All the sessions were well tolerated clinically and there were no major incidents in any of the four patients. At the first stage of the study, there were five incidences of small clots in the venous blood chamber, an incidence of extracorporeal blood circuit thrombosis of 12.5%. At the second stage of the study, no cases of extracorporeal blood circuit or dialyzer thrombosis were noted. Hemodiafiltration with on-line citrate dialysate infusion to the arterial line is safe and allows an effective regional anticoagulation of the extracorporeal blood circuit without the need for systemic anticoagulation.