Introduction: Baseball is a popular sport, and complex sequences of actions and reactions in joints throughout the body are required for players to successfully hit incoming pitches. Despite this, the progressive phases of return-to-sport interval hitting programs (IHPs) have been vastly understudied. Therefore, the present study aimed to examine commonly used performance and ball-flight metrics during progressive phases of an IHP. Methods: Healthy Division I collegiate baseball players ( n = 16, age = 20.5 ± 1.3 yr) participated in the present study. An 18-camera Vicon ® motion capture system and a Rapsodo ® hitting monitor were used to record performance and ball-flight metrics. Each participant performed a standardized version of an IHP, which included five swing types performed at three effort levels for a total of 15 swing conditions. Results: Performance metrics, including bat linear and angular velocity, ball exit velocity, and distance, increased with effort level. Performance metrics were affected by, but did not successively increase with, progressing swing types at a given effort level. Conditions in which ball targeting was present differed considerably from dry swings with the greatest differences on average observed at higher efforts. Some of the highest bat velocities were observed during dry swings with a wiffle bat, particularly at high efforts. Conclusion: Results indicate that swing conditions involving ball targeting at higher efforts differ greatly from dry swings. Results also support the need for caution when performing or prescribing dry swings with any bat, specifically at high effort, in the early phases of rehabilitation. Together, the results demonstrate the value of monitoring performance and ball-flight metrics during IHPs to guide progression. Study results can be utilized by rehabilitation professionals to improve current practices, which may ultimately lead to better athlete outcomes.

Introduction Gastrointestinal bleeding (GIB) is a significant complication affecting up to 40% of left ventricular assist device (LVAD) recipients. It has been hypothesized that LVAD support may cause angiodysplasia, though the underlying mechanism remains unclear. In this study we aim to understand the pathophysiology of GIB in LVAD patients by measuring the serum levels of 15 different angiogenesis factors assays in Continuous Flow-LVAD recipients with and without GIB. Methods In this prospective study, we enrolled 49 LVAD patients (average age 64 ± 14 years 39 males), from whom blood samples were collected to investigate the levels of angiogenesis factors associated with gastrointestinal bleeding, we utilized multiplex assays for 15 key angiogenesis factors in plasma samples. The selected panel comprised EGF, HGF, PDGF-BB, TNF-α, VEGF-A, IL-6, INF-α, TGF-β1, TIE-2, IL-1α, IL-1β, IL-8, VCAM-1, and VEGF-D. We also gathered baseline data for all participants, encompassing demographic details, clinical outcomes, and duration of LVAD support, from electronic medical records. The primary outcome of interest was the occurrence of any bleeding events. The discriminative ability of the predictive factors for bleeding outcomes was evaluated using the area under the receiver operating characteristic (ROC) curve (AUC). Results In our cohort of 49 LVAD patients (36 with HM3 and 13 with HVAD devices), 24 experienced bleeding events. Among the 15 angiogenesis factors analyzed, only 6 yielded measurable results: EGF, HGF, PDGF-BB, TNF-α, VEGF-A, and TGF-β1. The levels of the remaining factors were below the detection threshold. No significant differences were observed in the levels of most of the angiogenesis factors between the bleeders and non-bleeders. However, platelet-derived growth factor (PDGF-BB) levels were significantly elevated in patients who experienced bleeding events [466.3 pg/ml (182.8 to 1038.9)] compared to those who did not [160.0 pg/ml (54.8 to 405.8), p=0.023], indicating PDGF-BB's potential as a predictive marker for bleeding in LVAD patients. ROC analysis indicated an optimal cut-off point of 173.3 for the identification of patients at higher GI bleeding risk (Figure 1). Conclusion Our study identifies PDGF-BB levels as a significant predictive marker for gastrointestinal bleeding in LVAD patients, distinguishing bleeders from non-bleeders. This highlights the potential of targeting angiogenesis pathways in managing and predicting bleeding complications in LVAD patients.

Physical anatomical models constructed from medical images are valuable research tools for evaluating patient-specific clinical circumstances. For example, 3D models replicating a patient's internal anatomy in the cardiovascular system can be used to validate Computational Fluid Dynamics (CFD) models, which can then be used to identify potential hemodynamic consequences of surgical decisions by providing insight into how blood and vascular tissue mechanics may contribute to disease progression and post-operative complications. Patient-specific models have been described in the literature; however, rapid prototyping models that achieve anatomical accuracy, optical transparency, and thin-walled compliance in a cost and time-effective approach have proven challenging. This limits their utility for modeling flows in vessels, e.g., the aorta, where compliance is particularly important. The work described herein is focused on a unique design and fabrication process implemented to produce physical patient-specific models that replicate the original anatomy dimensions and compliance with optical properties consistent with clinical imaging techniques. The patient-specific models are produced for under $150 of easily accessible consumable raw materials within 30 h using a relatively basic approach. • This method can be tuned for anatomies with different shapes and compliance. • This method can produce models to investigate medical device performance in vitro.

Abstract Background Biomedtrix BFX® cementless total hip replacement (THR) requires the use of femoral broaches to prepare a press-fit envelope within the femur for subsequent stem insertion. Current broaches contain teeth that crush and remove cancellous bone; however, they are not particularly well-suited for broaching sclerotic (corticalized) cancellous bone. In this study, three tooth designs [Control, TG1 (additional V-grooves), TG2 (diamond tooth pattern)] were evaluated with a quasi-static testing protocol and polyurethane test blocks simulating normal and sclerotic bone. To mimic clinical broaching, a series of five sequential broach insertions were used to determine cumulative broaching energy (J) and peak loads during broach insertion. To determine the effect of broach tooth design on THR stem insertion, a BFX® stem was inserted into prepared test blocks and insertion and subsidence energy and peak loads were determined. Results Broach tooth design led to significant differences in broaching energy and peak broaching loads in test blocks of both densities. In low density test blocks, TG1 required the lowest cumulative broaching energy (10.76 ±0.29 J), followed by Control (12.18 ±1.20 J) and TG2 (16.66 ±0.78 J) broaches. In high density test blocks, TG1 required the lowest cumulative broaching energy (32.60 ±2.54 J) as compared to Control (33.25 ±2.16 J) and TG2 (59.97 ±3.07 J). During stem insertion and subsidence testing, stem insertion energy for high density test blocks prepared with Control broaches was 14.53 ± 0.81 J, which was significantly lower than blocks prepared with TG1 (22.53 ± 1.04 J) or TG2 (19.38 ± 3.00 J) broaches. For stem subsidence testing in high density blocks, TG1 prepared blocks required the highest amount of energy to undergo subsidence (14.49 ± 0.49 J), which was significantly greater than test blocks prepared with Control (11.09 ±0.09 J) or TG2 (12.57 ± 0.81 J) broaches. Conclusions The additional V-grooves in TG1 broaches demonstrated improved broaching performance while also generating press-fit envelopes that were more resistant to stem insertion and subsidence. TG1 broaches may prove useful in the clinical setting; however additional studies that more closely simulate clinical broach impaction are necessary prior to making widespread changes to THR broaches.

Since the very beginning of space exploration, NASA has been building actual size replicas of spaceships and rovers to help them troubleshoot issues when the vehicles are out in outer space. Furthermore, real-time data captured and processed during spaceship launches has helped with timely maneuvering decisions. Similar concepts are currently utilized in various industrial processes such as manufacturing, oil and gas industry, and supply chain to name a few. A good example of the use of Digital twin technology is the GPS-based navigation system where maps are overlaid with location coordinates and real-time traffic data to make decisions on the best available routes. In this chapter we describe the use of digital twin technology in various industries such as manufacturing (including drug and vaccine development), pharmaceutical, healthcare and the practice of medicine. We further describe the rapid development of computation technologies and better structuring of electronic health records which in turn has ushered the emergence of digital health in medicine. Lastly, we provide examples of the use of digital twin technology in the areas of personalized medicine (immunology, dementia, and oncology), biomarker development (Multiple sclerosis, Chron's and Cardiovascular diseases), and clinical trials (Alzheimer's and breast cancer).

Heart failure remains a significant cause of mortality in the United States and around the world. While organ transplantation is acknowledged as the gold standard treatment for end stage heart failure, supply is limited, and many patients are treated with left ventricular assist devices (LVADs). LVADs extend and improve patients' lives, but they are not without their own complications, particularly the hemocompatibility related adverse events (HRAE) including stroke, bleeding and pump thrombosis. Mainstream imaging techniques currently in use to assess appropriate device function and troubleshoot complications, such as echocardiography and cardiac computed tomography, provide some insight but do not provide a holistic understanding of pump induced flow alterations that leads to HRAEs. In contrast, there are technologies restricted to the benchtop-such as computational fluid dynamics and mock circulatory loops paired with methods like particle image velocimetry-that can assess flow metrics but have not been optimized for clinical care. In this review, we outline the potential role and current limitations of converging available technologies to produce novel imaging techniques, and the potential utility in evaluating hemodynamic flow to determine whether LVAD patients may be at higher risk of HRAEs. This addition to diagnostic and monitoring capabilities could improve prevention and treatment of LVAD-induced complications in heart failure patients.

BACKGROUND:Hemocompatibility-related adverse events (HRAE) occur commonly in patients with left ventricular assist devices (LVADs) and add to morbidity and mortality. It is unclear whether the outflow graft orientation can impact flow conditions leading to HRAE. This study presents a simulation-based approach using exact patient anatomy from medical images to investigate the influence of outflow cannula orientation in modulating flow conditions leading to HRAEs.METHODS:A 3D model of a proximal aorta and outflow graft was reconstructed from a computed tomography (CT) scan of an LVAD patient and virtually modified to model multiple cannula orientations (n = 10) by varying polar (cranio-caudal) (n = 5) and off-set (anterior-posterior) (n = 2) angles. Time-dependent computational flow simulations were then performed for each anatomical orientation. Qualitative and quantitative hemodynamics metrics of thrombogenicity including time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), endothelial cell platelet activation potential (ECAP), particle residence time (PRT), and platelet activation potential (PLAP) were analyzed.RESULTS:Within the simulations performed, endothelial cell activation potential (ECAP) and particle residence time (PRT) were found to be lowest with a polar angle of 85°, regardless of offset angle. However, polar angles that produced parameters at levels least associated with thrombosis varied when the offset angle was changed from 0° to 12°. For offset angles of 0° and 12° respectively, flow shear was lowest at 65° and 75°, time averaged wall shear stress (TAWSS) was highest at 85° and 35°, and platelet activation potential (PLAP) was lowest at 65° and 45°.CONCLUSION:This study suggests that computational fluid dynamic modeling based on patient-specific anatomy can be a powerful analytical tool when identifying optimal positioning of an LVAD. Contrary to previous work, our findings suggest that there may be an "ideal" outflow cannula for each individual patient based on a CFD-based hemocompatibility profile.

The goal of this work was to experimentally validate a computational model for TKRs to improve implant alignment accuracy and assess potential implant misalignment during preoperative planning. Initial validation of the model was achieved by comparing ligament strain energies between the computational model and a physical knee model comprised of bone and ligament analogues. Experimental validation would be considered met when the computational model strain energies were within 10% of the measured values for all six physical knees. Physical and computational knee models were created with six variations of implant alignment to test the robustness of the computational model. Strain energy errors were well within the 10% threshold across knee range of motion.

Bone fragments embedded in a rib of a mastodon ( Mammut americanum ) from the Manis site, Washington, were digitally excavated and refit to reconstruct an object that is thin and broad, has smooth, shaped faces that converge to sharp lateral edges, and has a plano-convex cross section. These characteristics are consistent with the object being a human-made projectile point. The 13,900-year-old Manis projectile point is morphologically different from later cylindrical osseous points of the 13,000-year-old Clovis complex. The Manis point, which is made of mastodon bone, shows that people predating Clovis made and used osseous weapons to hunt megafauna in the Pacific Northwest during the Bølling-Allerød.

Background: Recent evidence indicates that combined upper extremity blood flow restriction (BFR, applied distally to the shoulder) and low-load resistance exercise (LIX) augments clinically meaningful responses in shoulder region tissues proximal to the occlusion site. The purpose of this investigation was to determine the efficacy of BFR-LIX for the shoulder when added to standard offseason training in Division IA collegiate baseball pitchers. We hypothesized that BFR-LIX would augment training-induced increases in shoulder-region lean mass, rotator cuff strength, and endurance. As secondary outcomes, we sought to explore the impact of BFR- LIX rotator cuff training on pitching mechanics.Methods: Twenty-eight collegiate baseball pitchers were randomized into 2 groups (BFRN=15 and non-BFR [NOBFR]N=13) that, in conjunction with offseason training, performed 8 weeks of shoulder LIX (Throwing arm only; 2/week, 4 sets [30/15/15/fatigue], 20% isometric max) using 4 exercises (cable external and internal rotation [ER/IR], dumbbell scaption, and side-lying dumbbell ER). The BFR group also trained with an automated tourniquet on the proximal arm (50% occlusion). Regional lean mass (dual-energy x-ray absorptiometry), rotator cuff strength (dynamometry: IR 0 & 90, degrees ER 0 & 90, degrees Scaption, Flexion), and fastball biomechanics were assessed pre and post-training. Achievable workload (sets x reps x resistance) was also recorded. An ANCOVA (covaried on baseline measures) repeated on training timepoint was used to detect within-group and between-group differences in outcome measures (a=0.05). For significant pairwise comparisons, effect size (ES) was calculated using a Cohen's d statistic and interpreted as: 0-0.1, negligible; 0.1-0.3, small; 0.3-0.5, moderate; 0.5-0.7, large; >0.7, and very large (VL). Results: Following training, the BFR group experienced greater increases in shoulder-region lean mass (BFR: T 227 + 60g, NOBFR: T 75 + 37g, P=.018, ES=1.0 VL) and isometric strength for IR 90 degrees (T 2.4 + 2.3 kg, P=.041, ES=0.9VL). The NOBFR group experienced decreased shoulder flexion [ 1.6 + 0.8 kg, P=.007, ES=1.4VL) and IR at 0 degrees [ 2.9 + 1.5 kg, P=.004, ES=1.1VL). The BFR group had a greater increase in achievable workload for the scaption exercise (BFR: T 190 + 3.2 kg, NOBFR: T 90 + 3.3 kg,P=.005, ES=0.8VL). Only the NOBFR group was observed to experience changes in pitching mechanics following training with increased shoulder external rotation at lead foot contact ([ 9.0 degrees +/- 7.9, P=.028, ES=0.8VL) as well as reduced forward 13.6 degrees +/- 2.1, P=.001, ES=1.2VL) and lateral 14.6 degrees +/- 3.4, P=.007, ES=1.0VL) trunk tilt at ball release.Conclusion: BFR-LIX rotator cuff training performed in conjunction with a collegiate offseason program augments increases in shoul- der lean mass as well as muscular endurance while maintaining rotator cuff strength and possibly pitching mechanics in a manner that may contribute to favorable outcomes and injury prevention in baseball pitching athletes.Level of Evidence: Level I; Randomized Controlled Trial; Treatment Study (c) 2023 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.

PurposeRight ventricular failure (RVF) occurs in up to 35 % of patients who undergo left ventricular assist devices (LVAD) implantation. Our aim is to assess the relationship of inflow cannula (IFC) and outflow cannula (OFC) position with RVF outcome in centrifugal flow LVAD.MethodsInflow cannula is a complex structure best assessed in a three-dimensional x-y-z plane. In this single-center retrospective study, we identified patients with centrifugal flow pumps implanted with optimal cardiac CT imaging and performed a novel point-based 3D measurement of IFC angle relative to the mitral valve as well as OFC angle and inflow depth. Baseline demographic data, pre and post-implant hemodynamics, Euromacs score and outcome data were collected for all patients. The main outcome was RVF as defined by mechanical circulatory support academic research consortium (MCS-ARC).ResultsOverall, 43 patients with 3D measurements were included where 27 subjects had HM III and 16 were on HVAD support. The median age was 64 (IQR [51-71]) with 67% patients being male. The IFC angle was higher in the RVF group versus the no RVF group 27 [19-31]vs 23 [15-29] but the result was not statistically significant (p=0.42). Hemodynamic analysis showed that right atrial pressure (RAP) was the most important predictor of RVF post LVAD. The relative change in RAP from in the RVF group was 3.2 mm Hg [1.11-5.35] higher than the no RVF group. The median Euromacs score of patients with early acute RVF was likely to be higher than those without RVF 7.3 [7.0, 7.5] vs 4.0 [2.0, 4.0]. However, the difference was not significant (p=0.13).ConclusionIn our small cohort, RAP remains the most significant predictor of RVF post-LVAD. Although, IFC was not statistically significant, but there was a signal towards more angulated IFC relative to mitral valve in patients with RVF. Further studies with larger sample size may elucidate the role of an optimal cannula position in mitigating the risk of RVF. Right ventricular failure (RVF) occurs in up to 35 % of patients who undergo left ventricular assist devices (LVAD) implantation. Our aim is to assess the relationship of inflow cannula (IFC) and outflow cannula (OFC) position with RVF outcome in centrifugal flow LVAD. Inflow cannula is a complex structure best assessed in a three-dimensional x-y-z plane. In this single-center retrospective study, we identified patients with centrifugal flow pumps implanted with optimal cardiac CT imaging and performed a novel point-based 3D measurement of IFC angle relative to the mitral valve as well as OFC angle and inflow depth. Baseline demographic data, pre and post-implant hemodynamics, Euromacs score and outcome data were collected for all patients. The main outcome was RVF as defined by mechanical circulatory support academic research consortium (MCS-ARC). Overall, 43 patients with 3D measurements were included where 27 subjects had HM III and 16 were on HVAD support. The median age was 64 (IQR [51-71]) with 67% patients being male. The IFC angle was higher in the RVF group versus the no RVF group 27 [19-31]vs 23 [15-29] but the result was not statistically significant (p=0.42). Hemodynamic analysis showed that right atrial pressure (RAP) was the most important predictor of RVF post LVAD. The relative change in RAP from in the RVF group was 3.2 mm Hg [1.11-5.35] higher than the no RVF group. The median Euromacs score of patients with early acute RVF was likely to be higher than those without RVF 7.3 [7.0, 7.5] vs 4.0 [2.0, 4.0]. However, the difference was not significant (p=0.13). In our small cohort, RAP remains the most significant predictor of RVF post-LVAD. Although, IFC was not statistically significant, but there was a signal towards more angulated IFC relative to mitral valve in patients with RVF. Further studies with larger sample size may elucidate the role of an optimal cannula position in mitigating the risk of RVF.

In this work, virtual fields method (VFM) is applied to extract the constitutive parameter of silicone elastomers under equi-biaxial and general biaxial tests; the influence of missing deformation data near specimen edges and noise introduced by digital image correlation (DIC) on parameter identification using VFM is investigated. The results indicate that the negative impact of the missing data and noise can be mitigated by scaling the load applied to the specimen boundary properly and extracting parameters based on the deformation fields of all loading steps through the least square method.

Atrial fibrillation induced stroke accounts for up to 15% of all strokes. These strokes are caused approximately 90% of the time by clot formation in the left atrial appendage (LAA). To prevent these clots, the most common approach is to administer blood thinners. However, contraindications prevent some people from being able to have blood thinners. Devices have been developed to seal the LAA to prevent clot formation in these patients. Current devices, such as the LARIAT® tie off the LAA theoretically preventing blood from entering the LAA. These have had limited clinical success mainly due to failure to completely close the LAA leaving holes and orifices for thrombi to form. To overcome this lack of complete closure, many surgeons use off-label approaches, classically filling the LAA filamentous coils, to cover these holes. Although this usually helps largely cover the holes, placement is challenging, the coils can migrate, the holes are not fully closed as there is space within and around the coils that don't fully mold to the LAA geometry. Furthermore, the coils can develop device related thrombi defeating their purpose. Therefore, these are not fully sufficient to complement the closure techniques in closing the LAA. To address limitation of the closure devices and coil sealing of remaining holes, we developed a thermally responsive hydrogel (Thermogel) that solidifies once injected into the LAA to uniformly and fully close off the LAA thus preventing clot formation and device related thrombi. This Thermogel consists of three portions: 1) a structural component composed of thiolated Pluronic F127 for gel to solid transition following injection, 2) Heparin for anticoagulation, and 3) Dopamine for adhesion to the surrounding endothelium in the turbulent flow encountered in cardiovascular applications. Here we have demonstrated that Thermogel, in conjunction with the LARIAT®, is capable of filling the defects in small and large animals through catheter injection. Thermogel was biocompatible and led to atrophy of the LAA at 5 weeks in a large animal model. Given the advantages of this Thermogel for sealing this defect and ability to be delivered through an endovascular approach, Thermogel presents a viable adjuvant to current occlusion-based treatments for sealing cardiovascular defects.

Information DisplayVolume 38, Issue 6 p. 1-40 Complete IssueFree Access Complete Issue First published: 14 November 2022 https://doi.org/10.1002/msid.1358AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Volume38, Issue6November/December 2022Pages 1-40 RelatedInformation

LVADs have been in clinical use for a half-century and have advanced through at least 3 generations resulting in compact, durable, and powerful pumps that can deliver blood flow that exceeds the needs of the body at rest. In so doing, these devices have become the best alternative to transplant for patients with end-stage heart failure. That said, the blood contacting interface of these pumps is likely the cause of complications and contraindications that persist with successive generations. Patients with elevated risk for side effects or patients with biventricular failure and other conditions represent the 25% of patients that are not candidates for LVAD therapy. Such patients represent the clinical need for non-blood contacting mechanical circulatory support. The clinical use of direct cardiac compression devices is limited, and there are no devices available for human use. Technological challenges remain, yet these devices continue to be developed and tested in animal models of heart failure.