BACKGROUND:Inspired Therapeutics is advancing the development of the next generation of the NeoMate mechanical circulatory support (MCS) system for neonate and infant heart failure (HF) populations. The NeoMate system includes a low-cost magnetically-actuated paracorporeal centrifugal pump with an integrated, reusable motor and controller. This design iteration features a compact size (37 mm diameter), small prime volume (10 mL), and redesigned rotor and flow path. We present experimental data from computational fluid dynamics (CFD), mock loops, and acute animals. METHODS:CFD models were used to improve pump design (wall shear stress, hemolysis index) and motor performance (torque, power, efficiency). Static mock loops (3.5 cP) were performed to evaluate hydrodynamics over a range of loads (0-300 mmHg) at 500-5500 rpm (n = 2 pumps tested, 24Fr inflow and 16Fr outflow cannula). A dynamic mock loop (3.5 cP) was tuned to HF, with the pump integrated LV apex-to-aorta and data collected from 0 to 5500 rpm. Two acute sheep studies were performed with each pump implanted paracorporeally: one LV apex-to-aorta (24Fr inflow, 16Fr outflow) and the other via the jugular vein (28Fr dual-lumen cannula). RESULTS:CFD pump and motor performance and hemolysis index metrics were achieved exceeding design criteria (2.5 L/min, 150 mmHg) in static (2.5 L/min flow, 250 mmHg pressure), dynamic (2.8 L/min flow), and animals (3.1 L/min flow, 60 mmHg aortic pressure, plasma free hemoglobin < 20 mg/dL) at 5500 rpm. CONCLUSIONS:The next generation NeoMate pumps demonstrated favorable hydrodynamic, hemodynamic, and blood trauma performance, showing promising progress toward this technology to serve as a versatile therapy for neonates and infants.

Objective: Limb ischemia is a persistent problem in femoral venoarterial extracorporeal membrane oxygenation (VA-ECMO), with clinically significant adverse events and/or poor outcomes occurring in 10% to 70% of patients. The Extracorporeal Life Support Organization recommends the use of a distal perfusion catheter (DPC), but in patients in whom proximal femoral artery access is challenging or no longer viable, a more distal DPC placement may be necessary. Using a dynamic mock flow loop of adult femoral VA-ECMO, we investigated the hemodynamic feasibility of retrograde dorsalis pedis artery DPC placement versus traditional DPC placement. Methods: An adult femoral VA-ECMO dynamic mock flow loop was tuned to heart failure conditions. An ECMO circuit (Affinity pump with Eurosets oxygenator, 15-Fr arterial cannula in the right common femoral artery, 25-Fr contralateral venous cannula, and 6-Fr pediatric arterial cannula as DPC) was integrated into the loop. Two configurations were tested: (1) traditional anterograde DPC (right superficial femoral artery); (2) retrograde DPC of the right dorsalis pedis artery. Hemodynamic data were collected at baseline (ECMO circuit clamped) and with ECMO support at 0-3000 rpm. Results: Retrograde dorsalis pedis perfusion provided distal limb hemodynamics (pressures, flows) comparable with traditional DPC placement. DPC flow (367 mL/min), right-left limb flow balance ratio, and distal limb pulsatility were comparable with both approaches while maintaining equivalent ECMO and central flows (aortic, venous). The dorsalis DPC provided retrograde flow up the right superficial femoral artery to the proximal limb (147 mL/min) and anterograde flow down the tibioperoneal trunk (252 mL/min). Conclusions: Traditional anterograde DPC is not always feasible in patients with hematoma, obesity, infection, severe peripheral vasculopathy, and/or anatomical variation. We demonstrated experimentally that retrograde DPC of the dorsalis pedis artery may be a viable hemodynamic alternative to traditional DPC placement in femoral VA-ECMO to prevent distal limb ischemia.

Objective: Systemic amiodarone is commonly used to treat new-onset postoperative atrial fibrillation (POAF) after cardiac surgery with risk for significant toxicity. This study explored the feasibility and safety of using an extracellular collagen matrix patch (CardiaMend, or the patch), aiming to deliver therapeutically relevant concentrations of amiodarone to atrial tissues whilst mitigating the systemic adverse effects related with intravenous or oral administration of amiodarone. Methods: The patch was saturated with amiodarone hydrochloride solution (50 mg/mL, Fresenius Kabi) and implanted in ovine and rat models for pericardial and epicardial repair for up to 28 days. Amiodarone concentrations were measured in atrial tissue, lungs, liver, and plasma. Histologic analysis assessed tissue response to the patch and amiodarone application. Results: Pharmacologically relevant amiodarone concentrations were detected in atrial and ventricular tissue within 3 to 7 days, correlating with the time window for the highest incidence of POAF. Importantly, during the same time, low or undetectable drug levels were observed in the lungs, liver, and systemic circulation. Histology showed no evidence of tissue damage, fibrosis, or exacerbated inflammation associated with the patch and amiodarone application in either model. Conclusions: These findings indicate that CardiaMend can deliver therapeutically relevant concentrations of amiodarone to atrial tissues while mitigating the systemic adverse effects related with intravenous or oral administration of amiodarone. This approach could present a promising strategy for POAF prevention. Future clinical trials would be valuable to determine whether these findings translate into an effective prophylaxis for reducing the rate of new-onset POAF in cardiac surgery patients.

Objective: There have been many varied approaches to support patients on femoral venoarterial extracorporeal membrane oxygenation (ECMO), yet limb ischemia remains a significant problem. Using a dynamic mock flow loop model, we modified a historically traditional cannulation strategy and circuit (TC) to a proposed “hemodynamically ideal” configuration (HIC) to improve distal limb hemodynamics. Methods: A dynamic mock flow loop model was tuned to simulate heart failure. Two femoral venoarterial ECMO configurations were tested: (1) For TC, 19-Fr arterial cannula (right common femoral artery) with ipsilateral venous cannulation (right femoral vein), and an 8-Fr introducer sheath as the distal perfusion catheter (right superficial femoral artery) with its line T'd from the arterial cannula's Luer port. (2) Proposed HIC: A smaller arterial cannula (15 Fr, right common femoral artery) with contralateral venous cannulation (left femoral vein), and a 10-Fr pediatric arterial cannula as the distal perfusion catheter (right superficial femoral artery) with its line Y'd from the ECMO circuit. Experiments were performed at baseline and with ECMO support at 0, 1000, 2000, and 3000 rpm. Results: The proposed HIC reduced ventricular afterload and provided greater pulsatility and flows to the distal limbs, particularly to the cannulated right superficial femoral artery. The HIC also provided 390% more distal perfusion catheter flow than the TC. Conclusions: The proposed HIC provided more favorable hemodynamics compared with a TC that may offer significant clinical benefits, including less congestion, reduced risk of limb ischemic, and improved patient outcomes, warranting further clinical investigation.

Objectives The HeartMate 3 (HM3) LVAD is an established therapy for advanced heart failure (HF) patients. Warfarin has been the recommended anticoagulant for patients supported by the HM3 LVAD; however, it is accompanied by complications secondary to the lack of time in therapeutic range, dosage related issues, and medical burden. In this study, we present our experience with apixaban as an alternative primary and chronic anticoagulant for patients supported with the HM3 LVAD. Methods We performed a single center retrospective review of patients who were supported with the HeartMate 3 LVAD from January 2018 to October 2025 who were treated with apixaban as the primary and chronic anticoagulant. The INTERMACS database was used to evaluate patient clinical data and adverse events. Patients were assessed for survival and adverse events including bleeding, stroke, pump thrombosis, and hemolysis. Results 113 patients supported with the HM3 LVAD were treated with apixaban as the primary and chronic anticoagulant. Patients had a mean age of 57 and were predominantly male (70%), white (71%), 41% were diagnosed with ischemic cardiomyopathy, 25% with idiopathic cardiomyopathy, and 21% with other cardiomyopathies. By INTERMACS profile patients were classified as: 12% profile 1, 35% 2, 43% 3, 10% 4. There was a total of 272.8 patient years on apixaban with a mean of 2.4 years. There were 23 patients (20%) that experienced a bleeding event. There were 0.158 bleeding events per patient year (EPPY) with only 0.062 severe bleeding EPPY. 12 patients suffered 12 strokes (10%) with 0.022 ischemic stroke EPPY. There was no pump thrombosis or hemolysis events. Survival at 1 year and 5 years was 86% and 51%, respectively. Conclusions Apixaban is a safe and effective primary and chronic therapeutic anticoagulant for patients on a HM3 LVAD.

BACKGROUND:Magvad LLC is developing an innovative total artificial heart (TAH) based on a single nutating (nonrotating, "wobbling") disc pump design to provide up to 8 L/min pulsatile flow at 100 mmHg pressure in children and adults with end-stage heart failure (HF). We present an early-stage in vitro study to demonstrate proof-of-concept of a nutating disc mechanism for future cardiovascular applications. METHODS:A commercially available single nutating disc water meter (Recordall, Badger Meter 25-3/4″) was modified and connected to a motor via a shaft coupler and controlled via software to regulate disc "wobbles" per minute. The nutating disc pump was integrated into static and HF-tuned dynamic mock loops and operated at shaft rotational speeds of 25-225 rpm. RESULTS:Pressure-flow (H-Q) curves demonstrated the pump generated 7 L/min flow at 100 mmHg (225 rpm). Pump flow, motor work, hemodynamic work, and pump efficiency increased with increasing wobble speed. The pump restored hemodynamics in the dynamic HF mock loop by increasing mean arterial flow and pressure, augmenting pulsatility, and decreasing venous pressure with increasing wobble speed. CONCLUSIONS:These results demonstrate proof-of-concept and very early-stage feasibility of a single nutating disc to function as a novel low-speed volume displacement pulsatile flow mechanism for future cardiovascular applications including the development of an innovative TAH.

Objective:Patients on venoarterial extracorporeal membrane oxygenation undergoing ipsilateral cannulation may develop distal limb ischemia. We postulate 2 clinical questions: (1) Would contralateral cannulation have a lower distal limb ischemia rate than ipsilateral? (2) Do larger diameter arterial and venous cannulae increase the risk of distal limb ischemia independent of cannulation approach? A dynamic mock loop study investigating the potential hemodynamic benefits and risks of ipsilateral versus contralateral cannulation and cannulae size is presented. Methods:The hemodynamics of ipsilateral versus contralateral cannulation with arterial (15F, 17F) and venous (23F, 25F) cannulae combinations over pump speeds (0-3000 rpm) delivering 0 to 3.5 L/min extracorporeal membrane oxygenation flow was evaluated in an adult heart failure dynamic mock loop. Results:In the dynamic mock loop, contralateral cannulation was more effective than ipsilateral at increasing flow and decreasing pressure in both limbs. Increasing arterial cannula size from 15F to 17F enabled higher extracorporeal membrane oxygenation flows but at the expense of greater intravascular obstruction. Venous cannula size (23F, 25F) had no effect on limb hemodynamics. Conclusions:Our dynamic mock loop findings are consistent with reported Extracorporeal Life Support Organization Registry data and others, while also suggesting added hemodynamic benefits of venoarterial extracorporeal membrane oxygenation using a contralateral approach with the potential for better clinical outcomes.

There are conflicting clinical data on whether the use of a distal perfusion catheter (DPC) is beneficial for reducing the risk of limb ischemia in peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO) patients. We investigated the hemodynamic effects of arterial cannula size, use of and size of a DPC, and ECMO flow (pump speed) on femoral artery hemodynamics in an adult peripheral VA-ECMO dynamic mock loop. The mock loop was tuned to heart failure conditions (cardiac output 3 L/min, arterial pressure 50 mm Hg, venous pressure 20 mm Hg). Three arterial cannulae (15Fr, 17Fr, 19Fr; right iliac) were each integrated into the loop with/without DPC (none, 5Fr, 8Fr; right superficial femoral artery [RSFA]), creating nine configurations tested. Hemodynamic pressures and flows were recorded over a range of pump speeds generating 0–3.5 L/min ECMO flow. The right femoral arteries demonstrated reduced flow, pressure, and pulsatility compared with the left across all cannula configurations and which worsened with increasing arterial cannula size and ECMO flow. Impaired right femoral hemodynamics were not improved with the use or size of DPC, suggesting that the increased resistance created by the presence of the arterial cannula and the DPC may be too great to overcome, thereby offsetting any potential flow benefits provided by the DPC.

Could toy hearts possibly work as well as a real heart? To find out, we purchased six toy hearts, ranging from a spooky Halloween beating heart to a colorful plush heart. Our guess was that toy hearts would not work as well as a real human heart! We tested the toys in our laboratory using the exact same tools and methods we use for testing real hearts and mechanical blood pumps. We looked at flow, pressure, volume, and how well the toy heart pumped water. We also asked three heart surgeons to judge each toy heart based on how real they looked and what features they liked. As expected, the toy hearts were not realistic and could not pump as well as a real heart. This article combines human health and engineering as a fun and silly scientific question. Our hope is that readers will find it educational and entertaining!

Innovation is a critically important concept, overlooked in traditional didactic lecture-based medical school curricula. We developed a fun and novel experiential role-play program, “Inventor, Investor, Surgeon” (IIS), as a vehicle for medical student immersive learning of biomedical innovation. Medical students were guided through the device design and development process by faculty mentors and were divided into teams of three; each team member adopted a role: the Inventor selected a device and presented their design/rationale to the Investor; the Investor used entrepreneurial skills to determine whether to fund/champion the device to the Surgeon; the Surgeon weighed device/clinical efficacy and risk-benefits for their patients. Students then implanted devices (ex. valves) in porcine hearts under the mentorship of cardiothoracic surgeons and industry representatives. Students completed programmatic evaluations (1 = poor; 5 = excellent). Sixty-seven first- and second-year medical students participated in our IIS program, embracing the unique role-play and hands-on activities and engaging in highly animated discussions. 100

Objective We test the hypothesis that pediatric arterial (“peds art”) cannulae as distal perfusion catheters (DPCs) for venoarterial extracorporeal membrane oxygenation provide more favorable distal limb hemodynamics than introducer sheaths. Methods Introducer sheaths (Teleflex 5, 6, 8 Fr) and peds art cannulae (Medtronic 6, 8, 10 Fr) were tested as DPCs in static and dynamic mock loops. Flow through each and flow loss caused by their intravascular obstructiveness was measured to calculate pressure gradient versus flow, intravascular obstruction flow, and resistances. Results All 3 peds art cannulae tested delivered greater flows than the 3 introducer sheaths. The 10-Fr peds art cannula provided the most flow (0.97 L/min, 1500 rpm), whereas all 3 introducer sheaths provided much lower and nearly identical flows (only 0.18-0.20 L/min, 1500 rpm) despite their different diameters. The 10-Fr peds art cannula provided the most flow at equivalent head pressures despite being the most obstructive (least amount of flow around it, 2.0 L/min) relative to no DPC (2.5 L/min), resulting in the highest cumulative flow distally. Conclusions The 10-Fr peds art cannula was the most beneficial DPC tested. All peds art cannulae tested possessed a better tradeoff of flow delivery versus intravascular obstructiveness compared to introducer sheaths, resulting in more favorable distal limb hemodynamics. The integrated stopcock with small holes (0.061′′ = 4.65 Fr) on the introducer sheath's sidearm and at the 90° sidearm's attachment to the sheath's hub increase resistance. These chokepoints of introducer sheaths prevent sufficient flow to support distal limb perfusion as DPC.

We characterize the anatomy and function of never before studied total artificial hearts (TAHs) using established methods for testing mechanical circulatory support (MCS) devices. A historical review of TAHs is also presented to aid in benchmarking performance metrics. Six TAHs, ranging from spooky Halloween beating hearts to a cute colorful plush heart, were imaged, instrumented (mock flow loops) to measure their pressure, volume, and flow, and qualitatively evaluated by 3rd party cardiac surgeons for anatomical accuracy and surgical considerations. Imaging of Claw, Beating, and Frankenstein TAHs revealed internal motors, circuit boards, and speakers. Gummy TAH was ranked favorite TAH for tactile realism, while Frankenstein TAH had the most favorable audible/visual indicators, including an illuminated Jacob’s Ladder. Beating TAH demonstrated superior pulsatile hemodynamic performance compared to Claw TAH (16mL vs 1.3mL stroke volume). Light Up TAH and Gummy TAH functioned only as passive compliance chambers. Cute TAH rapidly exsanguinated due to its porosity (-3.0 L/min flow). These TAHs demonstrated a wide range of anatomical accuracy, surgeon appeal, unique features, and hemodynamic performance. While Claw TAH and Beating TAH successfully generated a modicum of pulsatility, we recommend the clinical community continue to support pre-clinical development of emerging or use of clinically-approved TAHs.

Heartwheels! STEM Mobile Outreach is a scientist-led collaborative, innovative, and reproducible experiential educational program and mobile lab developed to engage people young and old in the cardiovascular sciences, improve health literacy and awareness of heart-healthy living, and spark curiosity in the science, technology, engineering, and mathematics (STEM) fields. Applied hands-on interactive activities at Heartwheels! events include heart dissection, cardiovascular physiology, and mock flow loops (science); medical devices (technology); instrumentation and sensors (engineering); and calibration and validation methods and models (math). These modules are complementary to school activities and are particularly successful from an educational standpoint because they are fun, interactive, engaging, voluntary, open-ended, and not graded or assessed and can lead participants and their families to develop STEM-positive identities. Primary learning objectives include a broad understanding of cardiovascular anatomy and physiology, advanced technologies and emerging medical devices, and the benefits of a heart-healthy lifestyle and stimulating interest, building self-confidence, and helping participants envision themselves participating in and making potentially significant contributions to STEM fields. To date, 11,229 attendees of all ages and backgrounds have participated in 55 Heartwheels! events. Excellent programmatic ratings (1-5 scale: 1 = poor, 5 = excellent), including 94.5% of participants self-reporting that it was a fun educational experience and 96.6% reporting that they learned new things, with complimentary verbal and open-ended written feedback, demonstrate the significant impact and value that Heartwheels! and hands-on experiential educational events contribute to diverse, resource-limited, and underserved communities.NEW & NOTEWORTHY Heartwheels! STEM Mobile Outreach is an innovative, portable, scaled-down version of the authors' research laboratory that they take out into the schools and communities to engage and connect with people young and old in the cardiovascular sciences, improve health literacy and awareness of heart-healthy living, and spark curiosity in the science, technology, engineering, and mathematics (STEM) fields through fun, hands-on, experiential educational activities.

CoRISMA MCS Systems Inc (Hamden CT) is developing an innovative mechanical circulatory support system (CMCS) as a durable therapeutic option for heart failure (HF) patients. The CMCS system is comprised of an axial flow pump, non-contacting hydrodynamic bearings, and integrated DC motor designed to be fully implantable in a left atrial (LA) to aortic (Ao) configuration; this unloading strategy may be particularly beneficial for HF patients with preserved ejection fraction (HFpEF). The small (5.5 cm3), lightweight (20 g), and low power (5–7 W) device design should allow for a less invasive off-pump implant. We present early-stage engineering development and testing of the prototype CoRISMA pumps. Computational fluid dynamics (CFD) modeling was performed to evaluate flow and shear in two impeller (3 blades, 0.5 mm thickness, 8.9 mm diameter, 0.15 mm gap, polished titanium) and diffusor (5 blades, polished titanium) candidate designs. Test apparatuses were custom built to expedite development of the impeller/diffuser designs and iteratively refine the CFD models. Two candidate impeller/diffusor designs were fabricated and tested in each of the two test apparatuses (n = 4 impeller/diffuser + test fixture configurations) in static mock flow loops (hydrodynamic H-Q curves, 3.5 cP glycerol solution at 37 °C), and in dynamic mock flow loops (hemodynamics, 3.5 cP glycerol solution at 37 °C) tuned to HF conditions (mean aortic pressure 50 mmHg, central venous pressure 15 mmHg, aortic flow 3.0 L/min, and heart rate 80 bpm). CFD predicted flows of 4.56 L/min and 4.82 L/min at 100 mmHg for impellers/diffusers 1 and 2, respectively. Impeller 2 required less torque to generate a 6

To address the clinical need for totally implantable mechanical circulatory support devices, Bionet Sonar is developing a novel Ultrasonic Transcutaneous Energy Transmission (UTET) system that is designed to eliminate external power and/or data communication drivelines. UTET systems were designed, fabricated, and pre-clinically tested using a non-clinical HeartWare HVAD in static and dynamic mock flow loop and acute animal models over a range of pump speeds (1800, 2400, 3000 RPM) and tissue analogue thicknesses (5, 10, 15 mm). The prototypes demonstrated feasibility as evidenced by meeting/exceeding function, operation, and performance metrics with no system failures, including achieving receiver (harvested) power exceeding HVAD power requirements and data communication rates of 10kB/s and pump speed control (> 95

RT Cardiac Systems (RTCS, Raleigh, NC) is developing an intravascular percutaneous mechanical circulatory support (pMCS) device drive system for use during high-risk percutaneous coronary intervention and emergent cardiogenic shock. The proprietary pMCS device (US patent 10,780,206) consists of a miniaturized axial flow pump with an integrated motor connected via a short flexible drive system. This novel flexible drive system creates a flexible pump that is advantageous for percutaneous placement and conforming to anatomy. This design also has the benefit of not requiring a continuous external lubrication source. In this article, we present engineering development and feasibility testing of the prototype pMCS system. Computational fluid dynamics (CFD) modeling was performed to evaluate candidate blade set designs (impeller leading and trailing edges, diffuser) and predict hydrodynamic performance and hemolysis risk. Bench testing of candidate lip seal designs (radial interference, durometer, and seal angle) was evaluated for leak rate. Two 16Fr prototype devices were then fabricated and tested in a static mock flow loop. Experimental testing demonstrated 3 L/min flow against 110 mmHg and 4 L/min flow against 80 mmHg, which matched the CFD-predicted hydrodynamic performance. These results demonstrate feasibility of the engineering design and performance of the prototype devices.

Inspired Therapeutics (Merritt Island, FL) is developing a mechanical circulatory support (MCS) system designed as a single driver with interchangeable, extracorporeal, magnetically levitated pumps. The NeoMate system design features an integrated centrifugal rotary pump, motor, and controller that will be housed in a single compact unit. Conceptually, the primary innovation of this technology will be the combination of disposable, low-cost pumps for use with a single, multi-functional, universal controller to support multiple pediatric cardiopulmonary indications. In response to the paucity of clinically available pediatric devices, Inspired Therapeutics is specifically targeting the underserved neonate and infant heart failure (HF) patient population first. In this article, we present the development of the prototype Inspired Therapeutics NeoMate System for pediatric left ventricular assist device (LVAD) support, and feasibility testing in static mock flow loops (H-Q curves), dynamic mock flow loops (hemodynamics), and in an acute healthy ovine model (hemodynamics and clinical applicability). The resultant hydrodynamic and hemodynamic data demonstrated the ability of this prototype pediatric LVAD and universal controller to function over a range of rotary pump speeds (500-6000 RPM), to provide pump flow rates of up to 2.6 L/min, and to volume unload the left ventricle in acute animals. Key engineering challenges observed and proposed solutions for the next design iteration are also presented.

The youngest species of Amphoracrinus, A. tenax new species, is described from the Muldraugh Member of the Borden Formation (early Visean) of north-central Kentucky. With this new occurrence, both the oldest and youngest named species of Amphoracrinus are from North America. Numerous Tournaisian and Visean crinoid faunas are documented in the United States, but only four are known to contain Amphoracrinus. Morphological analysis indicates that A. tenax is more closely aligned with species from China than with species from Western Europe or other species from North America, where Amphoracrinus was most diverse and abundant, which has implications for understanding paleogeographic dispersal. The holotype of A. tenax was partially disarticulated on the seafloor before burial, and final burial occurred early during disarticulation. The relative state of disarticulation from pinnules to columnals suggests that plates bound only with ligaments disarticulated as a function of surface area of ligaments binding an articulation. UUID: http//zoobank.org/c7faf06e-bdd1-43a2-8c10-1364a0aeae0d

Evolutionary and taphonomic implications