A high fidelity ungrounded torque feedback device: The iTorqU 2.0

This paper discusses the design and operation of the iTorqU 2.0, an ungrounded, handheld torque feedback device for haptic applications. Based upon the gyroscopic effect, the iTorqU 2.0 uses a metal flywheel inside of a two-axis actuated gimbal to create directional torques that are applied to the user\u27s hand. The coupling of angular velocity and angular momentum creates a torque that is orthogonal to the two input angular velocities, giving the user the impression that their hand is being twisted in free air. Following a review of prior work in the field of ungrounded torque feedback devices, we first present our preliminary prototype, the iTorqU 1.0. Building on empirical observations and user feedback from a public demonstration, we revised and augmented this design to create the iTorqU 2.0. This paper covers the major mechanical, electrical, and controls design considerations that went into creating the iTorqU 2.0, along with an analysis of its torque output capabilities

VerroTouch: High-Frequency Acceleration Feedback for Telerobotic Surgery

The Intuitive da Vinci system enables surgeons to see and manipulate structures deep within the body via tiny incisions. Though the robotic tools mimic one\u27s hand motions, surgeons cannot feel what the tools are touching, a striking contrast to non-robotic techniques. We have developed a new method for partially restoring this lost sense of touch. Our VerroTouch system measures the vibrations caused by tool contact and immediately recreates them on the master handles for the surgeon to feel. This augmentation enables the surgeon to feel the texture of rough surfaces, the start and end of contact with manipulated objects, and other important tactile events. While it does not provide low frequency forces, we believe vibrotactile feedback will be highly useful for surgical task execution, a hypothesis we we will test in future work

In vivo efficacy of platelet-delivered, high specific activity factor VIII variants

Ectopically expressed, human B-domainless (hB) factor 8 (F8) in platelets improves hemostasis in hemophilia A mice in several injury models. However, in both a cuticular bleeding model and a cremaster laser arteriole/venule injury model, there were limitations to platelet-derived (p) hBF8 efficacy, including increased clot embolization. We now address whether variants of F8 with enhanced activity, inactivation resistant F8 (IR8) and canine (c) BF8, would improve clotting efficacy. In both transgenic and lentiviral murine model approaches, pIR8 expressed at comparable levels to phBF8, but pcBF8 expressed at only approximately 30%. Both variants were more effective than hBF8 in cuticular bleeding and FeCl3 carotid artery models. However, in the cremaster injury model, only pcBF8 was more effective, markedly decreasing clot embolization. Because inhibitors of F8 are stored in platelet granules and IR8 is not protected by binding to von Willebrand factor, we also tested whether pIR8 was effective in the face of inhibitors and found that pIR8 is protected from the inhibitors. In summary, pF8 variants with high specific activity are more effective in controlling bleeding, but this improved efficacy was inconsistent between bleeding models, perhaps reflecting the underlying mechanism(s) for the increased specific activity of the studied F8 variants