Publications by authors named "David Neustadter"

Article Synopsis
  • - The study explores a new transcatheter device called the Vsling, designed to reshape the dilated left ventricle in patients with systolic heart failure, offering a potentially better alternative to current treatments.
  • - Trials showed that the Vsling was successfully implanted in a series of tests, including chronic animal models and a human cadaver, with positive feedback from interventional cardiologists regarding its usability.
  • - Results indicated that the device had good safety, showing minimal inflammation and no serious adverse reactions over 90 days, leading to plans for human trials starting in summer 2022.
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Objective: Easy and safe methods of fascia closure are needed in order to reduce the risk for trocar site hernias without affecting procedure time significantly. Here we present a method for port site closure using heat induced collagen denaturation.

Material And Methods: Controlled heat-induced collagen denaturation was applied to laparoscopic trocar sites in living porcine animal models.

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Grasping soft, irregular material is challenging both for animals and robots. The feeding systems of many animals have adapted to this challenge. In particular, the feeding system of the marine mollusk , a generalist herbivore, allows it to grasp and ingest seaweeds of varying shape, texture and toughness.

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Purpose: To evaluate the performance and safety of a radiation therapy positioning system (RealEye) based on tracking a radioactive marker (Tracer) implanted in patients with localized prostate cancer.

Methods And Materials: We performed a single-arm multi-institutional trial in 20 patients. The iridium-192 ((192)Ir)-containing Tracer was implanted in the patient together with 4 standard gold seed fiducials.

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Purpose: In radiation therapy there is a need to accurately know the location of the target in real time. A novel radioactive tracking technology has been developed to answer this need. The technology consists of a radioactive implanted fiducial marker designed to minimize migration and a linac mounted tracking device.

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Purpose: A fiducial tracking system based on a novel radioactive tracking technology is being developed for real-time target tracking in radiation therapy. In this study, the authors calculate the radiation dose to the patient, the spouse/caretaker, and the medical staff that would result from a 100 microCi Ir192 radioactive fiducial marker permanently implanted in the prostate of a radiation therapy patient.

Methods: Local tissue dose was calculated by Monte Carlo simulation.

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Purpose: To analyze the stability, visibility, and histology of a novel implantable soft-tissue marker (nonradioactive and radioactive) implanted in dog prostate and rabbit liver.

Methods And Materials: A total of 34 nonradioactive and 35 radioactive markers were implanted in 1 dog and 16 rabbits. Stability was assessed by measuring intermarker distance (IMD) variation relative to IMDs at implantation.

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What are the mechanisms of multifunctionality, i.e. the use of the same peripheral structures for multiple behaviors? We studied this question using the multifunctional feeding apparatus of the marine mollusk Aplysia californica, in which the same muscles mediate biting (an attempt to grasp food) and swallowing (ingestion of food).

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Muscular hydrostats, such as tongues, trunks or tentacles, have fewer constraints on their degrees of freedom than musculoskeletal systems, so changes in a structure's shape may alter the positions and lengths of other components (i.e., induce mechanical reconfiguration).

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How does neural control reflect changes in mechanical advantage and muscle function? In the Aplysia feeding system a protractor muscle's mechanical advantage decreases as it moves the structure that grasps food (the radula/odontophore) in an anterior direction. In contrast, as the radula/odontophore is moved forward, the jaw musculature's mechanical advantage shifts so that it may act to assist forward movement of the radula/odontophore instead of pushing it posteriorly. To test whether the jaw musculature's context-dependent function can compensate for the falling mechanical advantage of the protractor muscle, we created a kinetic model of Aplysia's feeding apparatus.

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Magnetic resonance imaging has shown increasing clinical utility for the diagnosis of abnormalities in fetal development. MRI is not yet as effective for fetal imaging as ultrasound because of the difficulty of imaging freely moving subjects. We describe a design approach to overcome this difficulty.

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A kinematic model of the buccal mass of Aplysia californica during swallowing has been developed that incorporates the kinematics of the odontophore, the muscular structure that underlies the pincer-like grasping structure, the radula. The model is based on real-time magnetic resonance images (MRIs) of the mid-sagittal cross section of the buccal mass during swallowing. Using kinematic relationships derived from isolated odontophores induced to perform feeding-like movements, the model generates predictions about movement of the buccal mass in the medio-lateral dimension during the feeding cycle that are well-matched to corresponding coronal MRIs of the buccal mass during swallowing.

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Two kinematic models of the radula/odontophore of the marine mollusc Aplysia californica were created to characterize the movement of structures inside the buccal mass during the feeding cycle in vivo. Both models produce a continuous range of three-dimensional shape changes in the radula/odontophore, but they are fundamentally different in construction. The radulacentric model treats the radular halves as rigid bodies that can pitch, yaw and roll relative to a fixed radular stalk, thus creating a three-dimensional shape.

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A novel magnetic resonance imaging interface has been developed that makes it possible to image movements in intact, freely moving subjects. We have used this interface to image the internal structures of the feeding apparatus (i.e.

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