Compression Protocols Research Articles

Prevention of venous thrombosis through intraoperative intermittent pneumatic compression (IPC): a best practice implementation project

IntroductionVenous thromboembolism (VTE), including deep venous thrombosis and pulmonary embolism, is a common and potentially fatal post-surgery complication. Research has shown that 50% of VTE causes are intraoperative, with the risk of occurrence highest during and immediately post-surgery. Therefore, strategies for early assessment and prevention should be established.ObjectiveTo identify optimal equipment selection, compression protocols, and strategies for complication prevention and management during intraoperative intermittent pneumatic compression (IPC), this study aims to synthesize the best available evidence. The objective is to inform accurate risk assessment and facilitate early mechanical prophylaxis against venous thrombosis.MethodsThe Practical Application to Clinical Evidence model proposed by the Joanna Briggs Institute was utilized. Indicators were identified using the available best evidence from January 2023 to October 2023, and a baseline review was conducted. Negative factors were identified based on clinical evidence-based practice. The implementation rates of different indicators before (n = 372) and after (n = 405) evidence-based practice, the incidence rates of intraoperative IPC-related adverse events and VTE, and the risk of venous thrombosis before (n = 50) and after (n = 50) practice were identified and compared. Furthermore, medical staff’s knowledge of best practices for intraoperative IPC was assessed through pre- and post-intervention surveys involving 109 operating room personnel.ResultsAll review indicators significantly improved (P < 0.01) after the evidence-based practice, and 9 reached 100%. Two intraoperative venous thrombosis events occurred before the evidence-based practice, with an incidence rate of 0.53%; no intraoperative venous thrombosis event occurred after the evidence-based practice, with no significant difference (X2 = 2.171, P = 0.141 > 0.05). However, there were significant differences in intraoperative venous blood hemodynamics before and after the practice (P < 0.05). Moreover, 9 IPC-related adverse events, including 4 cases of skin pressure, 3 cases of skin allergy, and 2 cases of lower limb circulation disorders, were reported before the evidence-based practice, with an incidence rate of 2.4%. Notably, no intraoperative IPC-associated adverse events occurred after the evidence-based practice(X2 = 9.913, P < 0.01). Meanwhile, the score of comprehension of the standard utilization of IPC for preventing venous thrombosis by medical staff in the operating room was 93.34 ± 3.64 after the evidence-based practice, which was higher than that (67.55 ± 5.45) before the evidence-based practice. Overall, the clinical practice was significantly improved the evidence-based practice.ConclusionsApplying intraoperative IPC utilization standards based on the best evidence in clinical practice effectively reduces the intraoperative IPC-associated adverse event rate and the risks of intraoperative venous thrombosis. It also improves the execution rates and compliance with mechanical prevention standards in the operating room by medical staff. Future research should prioritize the development and refinement of best clinical practices for intraoperative venous thrombosis prevention, with a particular emphasis on the integration of mechanical prophylaxis strategies.

Modelling and simulation of anisotropic growth in brain tumours through poroelasticity: A study of ventricular compression and therapeutic protocols

Malignant brain tumours represent a significant medical challenge due to their aggressive nature and unpredictable locations. The growth of a brain tumour can result in a mass effect, causing compression and displacement of the surrounding healthy brain tissue and possibly leading to severe neurological complications. In this paper, we propose a multiphase mechanical model for brain tumour growth that quantifies deformations and solid stresses caused by the expanding tumour mass and incorporates anisotropic growth influenced by brain fibres. We employ a sharp interface model to simulate localised, non-invasive solid brain tumours, which are those responsible for substantial mechanical impact on the surrounding healthy tissue. By using patient-specific imaging data, we create realistic three-dimensional brain geometries and accurately represent ventricular shapes, to evaluate how the growing mass may compress and deform the cerebral ventricles. Another relevant feature of our model is the ability to simulate therapeutic protocols, facilitating the evaluation of treatment efficacy and guiding the development of personalized therapies for individual patients. Overall, our model allows to make a step towards a deeper analysis of the complex interactions between brain tumours and their environment, with a particular focus on the impact of a growing cancer on healthy tissue, ventricular compression, and therapeutic treatment.

Using a micro-device with a deformable ceiling to probe stiffness heterogeneities within 3D cell aggregates

Recent advances in the field of mechanobiology have led to the development of methods to characterise single-cell or monolayer mechanical properties and link them to their functional behaviour. However, there remains a strong need to establish this link for three-dimensional (3D) multicellular aggregates, which better mimic tissue function. Here we present a platform to actuate and observe many such aggregates within one deformable micro-device. The platform consists of a single polydimethylsiloxane piece cast on a 3D-printed mould and bonded to a glass slide or coverslip. It consists of a chamber containing cell spheroids, which is adjacent to air cavities that are fluidically independent. Controlling the air pressure in these air cavities leads to a vertical displacement of the chamber’s ceiling. The device can be used in static or dynamic modes over time scales of seconds to hours, with displacement amplitudes from a few µm to several tens of microns. Further, we show how the compression protocols can be used to obtain measurements of stiffness heterogeneities within individual co-culture spheroids, by comparing image correlations of spheroids at different levels of compression with finite element simulations. The labelling of the cells and their cytoskeleton is combined with image correlation methods to relate the structure of the co-culture spheroid with its mechanical properties at different locations. The device is compatible with various microscopy techniques, including confocal microscopy, which can be used to observe the displacements and rearrangements of single cells and neighbourhoods within the aggregate. The complete experimental and imaging platform can now be used to provide multi-scale measurements that link single-cell behaviour with the global mechanical response of the aggregates.

In-situ experimental investigations to study the impact of mechanical compression on the PEMFC - analysis of the global cell performance

An appropriate clamping pressure is required to ensure the gas-tight operation of a PEMFC assembly and to improve the contacts (i.e. mechanical, thermal, electrical) between its components. However, an excessive mechanical load may also worsen the cell performance, in particular through the reduction in the porosity and mass transport ability of the Gas Diffusion Layers. In this study, the effects of mechanical compression on the global performance of a 225 cm2 PEMFC assembly are investigated by implementing cell voltage monitoring and polarisation curve measurements. The investigations are carried out with gradual increase / decrease and randomised load compression protocols applied using a specially designed mechanical compression unit. 12 levels of mechanical compression are considered, ranging from 0.35 to 2 MPa with steps of 0.15 MPa. The results of the characterisation techniques show that the PEMFC performance is improved at all tested operating conditions for mechanical compression up to 1.55 MPa. This finding is attributed to the dominant reduction of the ohmic drop against the increase of the gas diffusion losses. It is also shown that compressing the PEMFC beyond 1.55 MPa would not lead to any further improvement of the global cell voltage output. This may even worsen the cell electrical characteristics by affecting its mass transport issues.

RECAPITULATING ARTICULATING JOINT MOTION EX VIVO TO BETTER UNDERSTAND CHONDROGENIC DIFFERENTIATION

Articulating cartilage experiences a multitude of biophysical cues. Due to its primary function in distributing load with near frictionless articulation, it is clear that a major stimulus for cartilage homeostasis and regeneration is the mechanical load it experiences on a daily basis. While these effects are considered when performing in vivo studies, in vitro studies are still largely performed under static conditions. Therefore, an increasing complexity of in vitro culture models is required, with the ultimate aim to recreate the articulating joint as accurately as possible. We have for many years utilized a complex multiaxial load bioreactor capable of applying tightly regulated compression and shear loading protocols. Using this bioreactor, we have been able to demonstrate the mechanical induction of human bone marrow stromal cell (BMSC) chondrogenesis in the absence of exogenous growth factors. Building on previous bioreactor studies that demonstrated the mechanical activation of endogenous TGFβ, and subsequent chondrogenesis of human bone marrow derived MSCs, we have been further increasing the complexity of in vitro models. For example, the addition of high molecular weight hyaluronic acid, a component of synovial fluid, culture medium leads to reduced hypertrophy and increased glycosaminoglycan deposition. The ultimate aim of all of these endeavors is to identify promising materials and therapies during in vitro/ ex vivo studies, therefore reducing the numbers or candidates that are finally tested using in vivo studies. This 3R approach can improve the opportunities for success while leading to more ethically acceptable product development pathways.

Subjective and Objective Quality Assessment of Rendered Human Avatar Videos in Virtual Reality.

We study the visual quality judgments of human subjects on digital human avatars (sometimes referred to as "holograms" in the parlance of virtual reality [VR] and augmented reality [AR] systems) that have been subjected to distortions. We also study the ability of video quality models to predict human judgments. As streaming human avatar videos in VR or AR become increasingly common, the need for more advanced human avatar video compression protocols will be required to address the tradeoffs between faithfully transmitting high-quality visual representations while adjusting to changeable bandwidth scenarios. During transmission over the internet, the perceived quality of compressed human avatar videos can be severely impaired by visual artifacts. To optimize trade-offs between perceptual quality and data volume in practical workflows, video quality assessment (VQA) models are essential tools. However, there are very few VQA algorithms developed specifically to analyze human body avatar videos, due, at least in part, to the dearth of appropriate and comprehensive datasets of adequate size. Towards filling this gap, we introduce the LIVE-Meta Rendered Human Avatar VQA Database, which contains 720 human avatar videos processed using 20 different combinations of encoding parameters, labeled by corresponding human perceptual quality judgments that were collected in six degrees of freedom VR headsets. To demonstrate the usefulness of this new and unique video resource, we use it to study and compare the performances of a variety of state-of-the-art Full Reference and No Reference video quality prediction models, including a new model called HoloQA. As a service to the research community, we publicly releases the metadata of the new database at https://live.ece.utexas.edu/research/LIVE-Meta-rendered-human-avatar/index.html.

Co-processed materials testing as excipients to produce Orally Disintegrating Tablets (ODT) using binder jet 3D-printing technology

The use of co-processed materials for Orally Disintegrating Tablets (ODT) preparation by direct compression is well consolidated. However, the evaluation of their potential for ODT preparation by 3D printing technology remains almost unexplored. The present study aimed to estimate the use of commercially available co-processed excipients, conventionally applied in compression protocols, for the preparation of ODTs with binder jetting-3D printing technology. The latter was selected among the 3D printing techniques because the deposition of multiple powder layers allows for obtaining highly porous and easily disintegrating dosage forms. The influence of some process parameters, including layer thickness, type of waveform and spread speed, on the physical and mechanical properties of the prototypes printed were evaluated. Our results suggested that binder jetting-3D printing technology could benefit from the co-processed excipients for the preparation of solid dosage forms. The process optimization conducted with the experiments reported in this work indicated that additional excipients were needed to improve the physical properties of the resulting ODTs.

Arresting dynamics in hardcore spin models

We study the dynamics of hardcore spin models on the square and triangular lattice, constructed by analogy to hard spheres, where the translational degrees of freedom of the spheres are replaced by orientational degrees of freedom of spins on a lattice and the packing fraction as a control parameter is replaced by an exclusion angle. In equilibrium, models on both lattices exhibit a Kosterlitz-Thouless transition at an exclusion angle $\Delta_{\rm KT}$. We devise compression protocols for hardcore spins and find that {\it any} protocol that changes the exclusion angle nonadiabatically, if endowed with only local dynamics, fails to compress random initial states beyond an angle $\Delta_{\rm J}> \Delta_{\rm KT}$. This coincides with a doubly algebraic divergence of the relaxation time of compressed states towards equilibrium. We identify a remarkably simple mechanism underpinning this divergent timescale: topological defects involved in the phase ordering kinetics of the system become incompatible with the hardcore spin constraint, leading to a vanishing defect mobility as $\Delta\rightarrow\Delta_{\rm J}$.

Impact of radial compression protocols on radial artery occlusion and hemostasis time in coronary angiography

Protocols for hemostasis after trans-radial approach (TRA) vary depending on the institute as there is no established evidence-based protocol. This study aimed to investigate the clinical implications of radial compression protocols. Consecutive patients who underwent outpatient invasive catheter angiography before and after April 2018 were treated with traditional and new protocols, respectively. Using the same hemostasis band, in the conventional protocol, fixed amount of air was removed soon after the procedure, 2 h later, and 3 h later, whereas the air was removed as much as possible every 30 min in the new protocol. A total of 1842 patients (71 ± 10 years old, 77% male) were included. Compared with the traditional protocol group (n = 1001), the new protocol group (n = 841) had a significantly lower rate of dual antiplatelet therapy (35% and 24% in the traditional and new groups, respectively, p < 0.001). The time required for complete hemostasis was approximately one-third with the new protocol (190 ± 16 and 66 ± 32 min, p < 0.001) with no clinically relevant bleeding. The incidence of radial artery occlusion (RAO) was 9.8% and 0.9% in the traditional and new protocol groups, respectively (p < 0.001). After adjusting for covariates, the new protocol was associated with a reduced risk of RAO (odds ratio 0.10, p < 0.001) and a shorter hemostasis time (odds ratio 0.01, p < 0.001). The new protocol for hemostasis after TRA was strongly associated with a shorter hemostasis time and a lower rate of RAO.

Performance of mycelium composites of Lentinus crinitus under two compression protocols

Considering the current environmental problems that has been generated by the excessive production of synthetic plastics, more sustainable alternatives have been proposed. One of these recently studied materials are the mycelium composites, a product obtained with lignocellulosic particles agglomerated together by the myceliar growth of a filamentous fungus. This novel type of materials could represent an option to replace non-biodegradable materials. In this work, mycelium composites with characteristics comparable to expanded polystyrene (EPS) and potentially suitable for fabrication of insulation panels were developed using a Lentinus crinitus strain previously selected after mycelial phases tests. Mechanical variables in bending, compression strength and stiffness were measured following ASTM D143 standard. Two protocols for composite fabrication were followed using different compression loads. Flexural strength reached 0.48 MPa and compression strength 0.235 MPa. Results obtained were compared with data of balsa wood (Ochroma pyramidale) for the similarity of possible applications, expanded polystyrene as its possible substitute and early published data on mycelium composites. Mechanical performance in flexural and compressive strength of the obtained materials revealed their potential use as biodegradable alternatives to some applications of synthetic plastics as insulation panels and packing materials.

Physical activity and quality of cardiopulmonary resuscitation: A secondary analysis of the MANI-CPR trial.

The association between the level of physical activity and quality of cardio-pulmonary resuscitation (CPR) performed by laypeople is unclear. The aim of this study was to evaluate the associations between physical activity level and laypeople performance during an eight-minute scenario of CPR. This study was a secondary analysis of the MANI-CPR Trial. The entire cohort of participants was grouped based on the level of physical activity assessed using the International Physical Activity Questionnaire (IPAQ) into a "low-moderate" level group and a "high" level group. Descriptive statistics were used for unadjusted analysis and multivariate logistic and linear regression models were also performed. A total of 492 participants who reached the score of "Advanced CPR performer" at the 1-min final test monitored by Laerdal Resusci Anne QCPR were included in this analysis; 224 with a low-moderate level and 268 with a high level of physical activity. A statistically significant difference was found for the outcome of percentage of compressions with adequate depth (low-moderate group: 87.8% [41·4%-99·3%], high group: 97% [63·2%-100%]; P=0·003). No associations remained significant after controlling for biometric characteristics of the participants, compression protocols and sex. Adequate quality CPR may not need high baseline level of physical activity to be performed by a lay rescuer.

Characterizing the Material Properties of the Kidney and Liver in Unconfined Compression and Probing Protocols with Special Reference to Varying Strain Rate

The liver and kidneys are the most commonly injured organs due to traumatic impact forces applied to the abdomen and pose a challenge to physicians due to a hard-to-diagnose risk of internal bleeding. A better understanding of the mechanism of injury will improve diagnosis, treatment, forensics, and other fields. Finite element modelling is a tool that can aid in this understanding, but accurate material properties are required including the strain rate dependency and the feasibility of using animal tissue properties instead of human. The elastic modulus in a probing protocol and the elastic modulus, failure stress, and failure strain in a compression protocol were found for both liver and kidney tissue from human and porcine specimens at varying strain rates. Increases in the elastic modulus were seen for both the human kidney and liver, but only for the porcine kidney, when comparing the unconfined compression and probing protocols. A strain rate dependency was found for both the liver and kidney properties and was observed to have a larger saturation effect at higher rates for the failure stress than for the elastic modulus. Overall, the material properties of intact liver and kidney were characterized, and the strain rate dependency was numerically modelled. The study findings suggest that some kidney and liver material properties vary from human to porcine tissue. Therefore, it is not always appropriate to use material properties of porcine tissue in computational or physical models of the human liver and kidney.

Distal Transradial Artery Access for Neuroangiography and Neurointerventions : Pitfalls and Exploring the Boundaries.

IntroductionThe distal transradial approach (dTRA) is progressively gaining more clinical use in the fields of cardiology and other vascular interventions, as it offers a number of advantages compared to conventional radial approach (TRA). These include lower rates of vascular occlusion which permits preservation of the proximal radial artery for future procedures in the event of a distal occlusion.AimTo share the experience in the use of dTRA for neurointerventions, showing its advantages, pitfalls as well as sharing our optimized puncture and hemostatic ultrarapid compression protocols to improve the use of this vascular access.MethodsA retrospective analysis of our experience of diagnostic and interventional procedures performed via dTRA using an optimized protocol for puncture and postpuncture compression of the dTRA was performed.The rate of complications (hematoma and arterial dissection at puncture site) femoral crossover, and assessment of postprocedural stenosis/occlusion with the ultrarapid compression protocol were also assessed.ResultsFrom March 2019 to July 2020 a total of 100 distal radial procedures were carried out and 53 diagnostic angiograms (53%) and 47 interventional procedures (47%) were included in the analysis. We achieved a 96% technical success, with a femoral crossover requirement in 3 cases (3%), and one conventional TRA crossover due to puncture failure.Of the patients 3 presented puncture site hematomas (3%) with no intervention required, 61 patients (61%) underwent the ultrarapid hemostasis protocol in association with a hemostatic pad. Ultrasound follow-up was performed in 20 patients (20%) at 1–2 months with 1 case of occlusion (5%) and 2 of radial stenosis (10%). In all 3 cases proximal radial artery remained patent.ConclusionThe dTRA is a safe and feasible access route for angiography and neurointerventions. Using vasodilators prepuncture, we attained a variable increase in the vascular diameter facilitating puncture and reducing the risk of occlusion and vascular spasm.A rapid deflation protocol for postpuncture hemostasis does not significantly increase the hematoma rate.

Evolution of Meniscal Biomechanical Properties with Growth: An Experimental and Numerical Study.

The menisci of the knee are complex fibro-cartilaginous tissues that play important roles in load bearing, shock absorption, joint lubrication, and stabilization. The objective of this study was to evaluate the interaction between the different meniscal tissue components (i.e., the solid matrix constituents and the fluid phase) and the mechanical response according to the developmental stage of the tissue. Menisci derived from partially and fully developed pigs were analyzed. We carried out biochemical analyses to quantify glycosaminoglycan (GAG) and DNA content according to the developmental stage. These values were related to tissue mechanical properties that were measured in vitro by performing compression and tension tests on meniscal specimens. Both compression and tension protocols consisted of multi-ramp stress–relaxation tests comprised of increasing strains followed by stress–relaxation to equilibrium. To better understand the mechanical response to different directions of mechanical stimulus and to relate it to the tissue structural composition and development, we performed numerical simulations that implemented different constitutive models (poro-elasticity, viscoelasticity, transversal isotropy, or combinations of the above) using the commercial software COMSOL Multiphysics. The numerical models also allowed us to determine several mechanical parameters that cannot be directly measured by experimental tests. The results of our investigation showed that the meniscus is a non-linear, anisotropic, non-homogeneous material: mechanical parameters increase with strain, depend on the direction of load, and vary among regions (anterior, central, and posterior). Preliminary numerical results showed the predominant role of the different tissue components depending on the mechanical stimulus. The outcomes of biochemical analyses related to mechanical properties confirmed the findings of the numerical models, suggesting a specific response of meniscal cells to the regional mechanical stimuli in the knee joint. During maturation, the increase in compressive moduli could be explained by cell differentiation from fibroblasts to metabolically active chondrocytes, as indicated by the found increase in GAG/DNA ratio. The changes of tensile mechanical response during development could be related to collagen II accumulation during growth. This study provides new information on the changes of tissue structural components during maturation and the relationship between tissue composition and mechanical response.

Impact of radial compression protocols on the compression time and radial artery occlusion

Abstract Background Trans-radial access (TRA) has been established as a safe and established approach for invasive coronary catheter procedures. However, protocols for post-procedural hemostasis varies depending on institutes and an evidence-based protocol is lacking. Purpose The objective of this study was to investigate the clinical implications of procedural hemostasis. Methods Consecutive patients who were referred to outpatient catheter examination before and after April 2018 were treated with an old and a new protocol, respectively. In both protocols, we used the same commercially available hemostasis band with injecting an air of 16 ml for hemostasis. In the old protocol, the amount and timing of deflation were fixed, whereas the air was removed as much as possible for every 30 minutes in the new protocol. Time to complete hemostasis, the rate of major bleeding, and the rate of radial artery occlusion (RAO) at 6 months after the catheter examination were compared between the protocols. Results Total of 1,843 (71±10 years old, 77% male) patients was included in the study. Between patients in the old and the new protocol group (n=1,000 and 843, respectively), there was no significant difference in age, gender, body size, or systolic blood pressure. The new group had significantly higher prevalence of diabetes (47% vs 39%, p=0.002), slightly larger sheath size (4.1±0.3 vs 4.0±0.2 Fr, p&amp;lt;0.001), and lower rate of dual antiplatelet therapy (DAPT: 24% vs. 35%, p&amp;lt;0.001). Time for complete hemostasis was about one-third with the new protocol compared with the old protocol (65±32 vs. 190±16 min, p&amp;lt;0.001) and there was no major bleeding in either group. The rate of radial artery occlusion was 0.7% and 9.8% in the old and the new group (p&amp;lt;0.001). Multivariate analysis showed that the significant predictor of prolonged hemostasis time were the old protocol (odds ratio: OR 80.5, p&amp;lt;0.001) and the prescription of DAPT (OR 2.9, p&amp;lt;0.001), while the factors associated with higher risk of radial occlusion were the old protocol (OR 13.9, p&amp;lt;0.001), the number of previous TRA (OR 1.1, p&amp;lt;0.001), and smaller body size (OR 0.127 per 1 m2 increase p=0.005). Conclusions Our new protocol for hemostasis after TRA was strongly associated with shorter hemostasis time and a lower rate of radial artery occlusion. This approach will decrease the post-procedural hospital time with even fewer complication rates. Study outline Funding Acknowledgement Type of funding source: None

On the Entanglement Cost of One-Shot Compression

We revisit the task of visible compression of an ensemble of quantum states with entanglement assistance in the one-shot setting. The protocols achieving the best compression use many more qubits of shared entanglement than the number of qubits in the states in the ensemble. Other compression protocols, with potentially larger communication cost, have entanglement cost bounded by the number of qubits in the given states. This motivates the question as to whether entanglement is truly necessary for compression, and if so, how much of it is needed. Motivated by questions in communication complexity, we lift certain restrictions that are placed on compression protocols in tasks such as state-splitting and channel simulation. We show that an ensemble of the form designed by Jain, Radhakrishnan, and Sen (ICALP'03) saturates the known bounds on the sum of communication and entanglement costs, even with the relaxed compression protocols we study. The ensemble and the associated one-way communication protocol have several remarkable properties. The ensemble is incompressible by more than a constant number of qubits without shared entanglement, even when constant error is allowed. Moreover, in the presence of shared entanglement, the communication cost of compression can be arbitrarily smaller than the entanglement cost. The quantum information cost of the protocol can thus be arbitrarily smaller than the cost of compression without shared entanglement. The ensemble can also be used to show the impossibility of reducing, via compression, the shared entanglement used in two-party protocols for computing Boolean functions.

Lossless Event Compression of Discrete Event Systems

This article investigates the lossless event compression problem of discrete event systems which is, given a discrete event system and a source string generated by it, to find a minimal recoverable compressed string by removing as many events as possible. In order for the problem to be well post, two compression protocols are introduced. One requires that the last event is always kept. The other requires that, for any loop substring, at least one event is kept. We say a compressed string is recoverable if we can uniquely determine the source string based on the knowledge of the given discrete event system. We first construct an automaton to present all the possible source strings for a given compressed string. Based on the automaton, an algorithm is proposed to check whether the given compressed string is recoverable or not. We then propose an algorithm to calculate a minimal recoverable compressed string for a source string. The compressed string satisfies monotonicity which can significantly reduce the computational complexity of the algorithm. Finally, we use a practical example to illustrate these results.

The differences in measured prostate material properties between probing and unconfined compression testing methods

Characterization of the mechanical properties of organs is important for determining their behavior under load and understanding and predicting their response. In order to appropriately understand behavior, including developing predictive models, the method used to measure the properties should match the application as different testing techniques can yield different results. One of the organs where little mechanical testing has been performed is the prostate. Therefore, the goal of this paper is to expand the knowledge of prostate gland mechanical behavior by using two different compressive testing methods under various loading rates. No differences were found between the elastic modulus measured using the compression and probing protocols for both human and porcine specimens. The elastic modulus ranged from 0.08 MPa at 1%/s to 0.24 MPa at 25%/s for human specimens and from 0.2 MPa at 1%/s to 0.4 MPa at 25%/s for porcine specimens. A strain rate dependency of the elastic modulus was observed for both testing methods. The dependency on strain rate started to saturate at higher rates and a material model was created to quantify this dependence as well as the stress-strain behavior. No strain rate dependency was observed for failure stress or failure strain. Overall, similar values of elastic modulus were found for both probing and compression protocols and the relationship developed between elastic modulus and strain rate could be implemented in models of the prostate gland to aid in understanding the response to dynamic loads.

TR BAND® “LIGHT” PROTOCOL WITH REDUCED COMPRESSION AND DURATION TO REDUCE RADIAL ARTERY OCCLUSION

Radial artery occlusion (RAO) rates of 7 - 8% occur early after transradial access (TRA) using standard compression protocols with a mechanical compression device, i.e. TR band® (Terumo, Japan). Factors associated with increased rates of RAO include longer compression times, higher compression

Impact of point-of-care ultrasound on the hospital length of stay for internal medicine inpatients with cardiopulmonary diagnosis at admission: study protocol of a randomized controlled trial\u2014the IMFCU-1 (Internal Medicine Focused Clinical Ultrasound) study

BackgroundPoint-of-care ultrasound (POCUS) is emerging as a reliable and valid clinical tool that impacts diagnosis and clinical decision-making as well as timely intervention for optimal patient management. This makes its utility in patients admitted to internal medicine wards attractive. However, there is still an evidence gap in all the medical setting of how its use affects clinical variables such as length of stay, morbidity, and mortality.Methods/designA prospective randomized controlled trial assessing the effect of a surface POCUS of the heart, lungs, and femoral and popliteal veins performed by an internal medicine physician during the first 24 h of patient admission to the unit with a presumptive cardiopulmonary diagnosis. The University of Melbourne iHeartScan, iLungScan, and two-point venous compression protocols are followed to identify left and right ventricular function, significant valvular heart disease, pericardial and pleural effusion, consolidation, pulmonary edema, pneumothorax, and proximal deep venous thrombosis. Patient management is not commanded by the protocol and is at the discretion of the treating team. A total of 250 patients will be recruited at one tertiary hospital. Participants are randomized to receive POCUS or no POCUS. The primary outcome measured will be hospital length of stay. Secondary outcomes include the change in diagnosis and management, 30-day hospital readmission, and healthcare costs.DiscussionThis study will evaluate the clinical impact of multi-organ POCUS in internal medicine patients admitted with cardiopulmonary diagnosis on the hospital length of stay. Recruitment of participants commenced in September 2018 and is estimated to be completed by March 2020.Trial registrationAustralian and New Zealand Clinical Trial Registry, ACTRN12618001442291. Registered on 28 August 2018.