Christopher J. Hasser

Force-feedback improves performance for steering and combined steering-targeting tasks

The introduction of a force-feedback mouse, which provides high fidelity tactile cues via force output, may represent a long-awaited technological breakthrough in pointing device designs. However, there have been few studies examining the benefits of force-feedback for the desktop computer human interface. Ten adults performed eighty steering tasks, where the participants moved the cursor through a small tunnel with varying indices of difficulty using a conventional and force-feedback mouse. For the force-feedback condition, the mouse displayed force that pulled the cursor to the center of the tunnel. The tasks required both horizontal and vertical screen movements of the cursor. Movement times were on average 52 percent faster during the force-feedback condition when compared to the conventional mouse. Furthermore, for the conventional mouse vertical movements required more time to complete than horizontal screen movements. Another ten adults completed a combined steering and targeting task, where the participants navigated through a tunnel and then clicked a small box at the end of the tunnel. Again, force-feedback improved times to complete the task. Although movement times were slower than the pure steering task, the steering index of difficulty dominated the steering-targeting relationship. These results further support that human computer interfaces benefit from the additional sensory input of tactile cues to the human user.

Surgical simulator for hysteroscopy: a case study of visualization in surgical training

Computer-based surgical simulation promises to provide a broader scope of clinical training through the introduction of anatomic variation, simulation of untoward events, and collection of performance data. We present a haptically-enabled surgical simulator for the most common techniques in diagnostic and operative hysteroscopy-cervical dilation, endometrial resection and ablation, and lesion excision. Engineering tradeoffs in developing a real-time, haptic-rate simulator are discussed.

Simulated learning environments in anatomy and surgery delivered via the next generation internet.

The Next Generation Internet (NGI) will provide high bandwidth, guaranteed Quality of Service, collaboration and security, features that are not available in todays Internet. Applications that take advantage of these features will need to build them into their pedagogic requirements. We present the Anatomy Workbench and the Surgery Workbench, two applications that require most of these features of the NGI. We used pedagogic need and NGI features to define a set of applications that would be difficult to operate on the current Internet, and that would require the features of the NGI. These applications require rich graphics and visualization, and extensive haptic interaction with biomechanical models that represent bony and soft tissue. We are in the process of implementing these applications, and some examples are presented here. An additional feature that we required was that the applications be scalable such that they could run on either on a low-end desktop device with minimal manipulation tools or on a fully outfitted high-end graphic computer with a realistic set of surgical tools. The Anatomy and Surgery Workbenches will be used to test the features of the NGI, and to show the importance of these new features for innovative educational applications.

Surgical simulator for diagnostic and operative hysteroscopy

Abstract Computer-based surgical simulation promises to provide a broader scope of clinical training through the introduction of anatomic variation, simulation of untoward events, and collection of performance data. We present a haptically enabled surgical simulator for the most common techniques in diagnostic and operative hysteroscopy–cervical dilation, endometrial resection and ablation, and lesion excision. Engineering tradeoffs in developing a real-time, haptic-rate simulator are discussed.