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Right ventricular (RV) failure remains a significant clinical burden particularly during the perioperative period surrounding major cardiac surgeries, such as implantation of left ventricular assist devices (LVADs), bypass procedures or valvular surgeries. Device solutions designed to support the function of the RV do not keep up with the pace of development of left-sided solutions, leaving the RV vulnerable to acute failure in the challenging hemodynamic environments of the perioperative setting. This work describes the design of a biomimetic, soft, conformable sleeve that can be prophylactically implanted on the pulmonary artery to support RV ventricular function during major cardiac surgeries, through afterload reduction and augmentation of flow. Leveraging electrohydraulic principles, a technology is proposed that is non-blood contacting and obviates the necessity for drivelines by virtue of being electrically powered. In addition, the integration of an adjacent is demonstrate, continuous pressure sensing module to support physiologically adaptive control schemes based on a real-time biological signal. In vitro experiments conducted in a pulsatile flow-loop replicating physiological flow and pressure conditions show a reduction of mean pulmonary arterial pressure of 8 mmHg (25% reduction), a reduction in peak systolic arterial pressure of up to 10 mmHg (20% reduction), and a concomitant 19% increase in diastolic pulmonary flow. Computational simulations further predict substantial augmentation of cardiac output as a result of reduced RV ventricular stress and RV dilatation., QC 20230614

Haptic interfaces, that apply forces to the fingertips of a human operator, can be classified as grounded or ungrounded. Grounded devices, such as SensAble Devices' Phantom or Immersion's Impulse Engine, are attached to a stationary object such as a desk. When the operator touches a virtual wall, a contact force is applied through the interface, inhibiting further motion. For ungrounded devices a contact force is felt but there is no impediment to motion of the arm. Little prior research has been done on the perceptual effects of displaying contacts with virtual objects using an ungrounded haptic interface. Experiments were conducted at Stanford to compare how accurately subjects could identify contacts with virtual walls using ungrounded versus grounded feedback. Two haptic interfaces were constructed and operated in three modes: with grounded force feedback applied to the wrist, with ungrounded forces applied to the fingertips, and with grounded wrist forces in addition to fingertip forces. Tests were conducted to see how quickly subjects could arrest motion upon sensing contact (measured as virtual boundary penetration) and how accurately they could distinguish among objects of different size.

We present a scheme by which a manipulator can identify when it is about to lose hold of a grasped object so that it can take preventive measures to maintain the grasp before slipping occurs. By detecting localized slips which precede gross slip between the gripping surface and a grasped object, a controller can reliably modify the grasp force and prevent the object from slipping. The motivation behind our sensor design comes from current physiological research which reveals the importance of a textured gripping surface in detecting these localized, or incipient, slips and provides us with insight into human grasping and manipulation strategies. By using our sensor as an active gripping surface on a simple manipulator and modeling our control strategy after humans, we are able to dynamically control the amount of force used to grasp objects, while preventing them from slipping. Our results show that the sensor is no greatly affected by variations in the material properties of the grasped object and indicate that the force control strategy is adequately immune to mechanical vibrations in the manipulator., Presented at the Japan-USA Symposium on Flexible Automation held in San Francisco, CA on 13-15 Jul 1992.