Showing papers on "Haptic technology published in 2002"

Humans integrate visual and haptic information in a statistically optimal fashion.

Abstract: When a person looks at an object while exploring it with their hand, vision and touch both provide information for estimating the properties of the object. Vision frequently dominates the integrated visual-haptic percept, for example when judging size, shape or position, but in some circumstances the percept is clearly affected by haptics. Here we propose that a general principle, which minimizes variance in the final estimate, determines the degree to which vision or haptics dominates. This principle is realized by using maximum-likelihood estimation to combine the inputs. To investigate cue combination quantitatively, we first measured the variances associated with visual and haptic estimation of height. We then used these measurements to construct a maximum-likelihood integrator. This model behaved very similarly to humans in a visual-haptic task. Thus, the nervous system seems to combine visual and haptic information in a fashion that is similar to a maximum-likelihood integrator. Visual dominance occurs when the variance associated with visual estimation is lower than that associated with haptic estimation.

Haptic interface for laptop computers and other portable devices

Abstract: A haptic feedback touch control used to provide input to a computer. A touch input device includes a planar touch surface that provides position information to a computer based on a location of user contact. The computer can position a cursor in a displayed graphical environment based at least in part on the position information, or perform a different function. At least one actuator is also coupled to the touch input device and outputs a force to provide a haptic sensation to the user. The actuator can move the touchpad laterally, or a separate surface member can be actuated. A flat E-core actuator, piezoelectric actuator, or other types of actuators can be used to provide forces. The touch input device can include multiple different regions to control different computer functions.

The Rutgers Master II-new design force-feedback glove

Abstract: The Rutgers Master II-ND glove is a haptic interface designed for dextrous interactions with virtual environments. The glove provides force feedback up to 16 N each to the thumb, index, middle, and ring fingertips. It uses custom pneumatic actuators arranged in a direct-drive configuration in the palm. Unlike commercial haptic gloves, the direct-drive actuators make unnecessary cables and pulleys, resulting in a more compact and lighter structure. The force-feedback structure also serves as position measuring exoskeleton, by integrating noncontact Hall-effect and infrared sensors. The glove is connected to a haptic-control interface that reads its sensors and servos its actuators. The interface has pneumatic servovalves, signal conditioning electronics, A/D/A boards, power supply and an imbedded Pentium PC. This distributed computing assures much faster control bandwidth than would otherwise be possible. Communication with the host PC is done over an RS232 line. Comparative data with the CyberGrasp commercial haptic glove is presented.

Haptic guidance: experimental evaluation of a haptic training method for a perceptual motor skill

Abstract: In this paper we investigate a use of haptics for skills training which we call haptic guidance. In the haptic guidance paradigm, the subject is physically guided through the ideal motion by the haptic interface, thus giving the subject a kinesthetic understanding of what is required. Subjects learned a complex 3D motion under three training conditions (haptic, visual, haptic and visual) and were required to manually reproduce the movement under two recall conditions (with vision, without vision). Performance was measured in terms of position, shape, timing, and drift. Findings from this study indicate that haptic guidance is effective in training. While visual training was better for teaching the trajectory shape, temporal aspects of the task were more effectively learned from haptic guidance. This supports a possible role for haptics in the training of perceptual motor skills in virtual environments.

A critical study of the mechanical and electrical properties of the PHANToM haptic interface and improvements for high-performance control

Abstract: This paper presents a critical study of the mechanical and electrical properties of the PHANToM haptic interface and improvements to overcome its limitations for applications requiring high-performance control. Target applications share the common requirements of low-noise/granularity/latency measurements, an accurate system model, high bandwidth, the need for an open architecture, and the ability to operate for long periods without interruption while exerting significant forces. To satisfy these requirements, the kinematics, dynamics, high-frequency dynamic response, and velocity estimation of the PHANToM system are studied. Furthermore, this paper presents the details of how the unknown subsystems of the stock PHANToM can be replaced with known, high-performance systems and how additional measurement electronics can be interfaced to compensate for some of the PHANToM's shortcomings. With these modifications, it is possible to increase the maximum achievable virtual wall stiffness by 35%, active viscous damping by 120%, and teleoperation loop gain by 50% over the original system. With the modified system, it is also possible to maintain higher forces for longer periods without causing motor overheating.

Sound data output and manipulation using haptic feedback

Abstract: Sound data output and manipulation with haptic feedback. Haptic sensations are associated with sound data to assist in navigating through and editing the sound data. The sound data is loaded into computer memory and played such that sound is output from an audio device. The sound playing is controlled by user input for navigation through the sound data. Haptic commands are generated based on the sound data and are used to output haptic sensations to the user by a haptic feedback device manipulated by the user. The haptic sensations correspond to one or more characteristics of the sound data to assist the user in discerning features of the sound data during the navigation through and editing of the sound data.

Haptic feedback sensations based on audio output from computer devices

Abstract: Triggering haptic sensations based on sound output from a computer device. A portion of sound data is stored that is output to a user as audio from an application program running on a computer. The portion of sound data is analyzed using intelligent heuristics to extract at least one sound feature from the sound data. The execution of at least one haptic effect is triggered based on the sound feature, where the haptic effect is commanded to the haptic feedback device approximately correlated to the output of the portion of sound to the user as audio. The haptic effect causes a haptic sensation to be output to the user. Different haptic effects can be associated with different sound features, frequency ranges, amplitudes, etc.

Control law design for haptic interfaces to virtual reality

Abstract: The goal of control law design for haptic displays is to provide a safe and stable user interface while maximizing the operator's sense of kinesthetic immersion in a virtual environment. This paper outlines a control design approach which stabilizes a haptic interface when coupled to a broad class of human operators and virtual environments. Two-port absolute stability criteria are used to develop explicit control law design bounds for two different haptic display implementations: the impedance display and admittance display. The strengths and weaknesses of each approach are illustrated through numerical and experimental results for a three degree-of-freedom device. The example highlights the ability of the proposed design procedure to handle some of the more difficult problems in control law synthesis for haptics, including structural flexibility and noncollocation of sensors and actuators.

Textures and other spatial sensations for a relative haptic interface device

Abstract: A low-cost haptic feedback device that provides spatially-based sensations such as textures in correlation with a displayed graphical environment. The device includes a housing, a sensor device, and an actuator for applying a force to the user. A local processor reports relative sensor data to the host processor and receives force information from the host processor. The host force information causes a texture sensation to be output by the actuator, the texture sensation providing forces to the user at least approximately spatially correlated with predefined locations in the graphical environment as determined by a local processor. In some embodiments, the local processor can model a position of the cursor while the cursor interacts with the texture field, where the modeled position is used for determining the force output to the user, and the force information from the host can include a gating command to activate or deactivate the texture sensation when the cursor enters or exits the texture field.

Controlling haptic feedback for enhancing navigation in a graphical environment

Abstract: Method and apparatus for controlling haptic feedback to enhance navigation of a cursor or other controlled displayed object in a graphical environment. An interface device is capable of communicating with a computer running an application program and generating a graphical environment includes an actuator for outputting a haptic effect to a user of the interface device. A modulator modulates the magnitude of the haptic effect in relation to, in various embodiments, a velocity of the cursor or user manipulatable object; a rate of interaction of the cursor with graphical objects; or an amount of time that the cursor engages the graphical object.

Teleoperation of a mobile robot through haptic feedback

Abstract: Teleoperation systems have been developed in order to allow a human operator to perform complex tasks in remote environments. Mobile robots can be considered as a particular example of telemanipulation systems, since they can be operated remotely to perform particular tasks. As an example, the inspection of underwater structures and the removal of mines are performed by mobile platforms controlled by a remote operator, which generally takes advantage only of the visual feedback provided by vision systems. In this sense, the nature and completeness of the data provided to the operator about the state of the remote system are of crucial importance for proper task execution, and it is generally accepted that a more efficient achievement of the task can be obtained by increasing the amount of data feedback and using proper MMI. In this paper, the use of a haptic interface is proposed in order to increase a user's perception of the workspace of a mobile robot. In particular, a virtual interaction force is computed on the basis of obstacles surrounding the mobile vehicle in order to prevent dangerous contacts, so that navigation tasks can be carried out with generally better performances. In addition, passivity of the overall system is taken into account, so that stability of the virtual interaction is guaranteed.

Design of bilateral teleoperation controllers for haptic exploration and telemanipulation of soft environments

Abstract: In this letter, teleoperation controller design for haptic exploration and telemanipulation of soft environments is studied. First, a new measure for fidelity in teleoperation is introduced which quantifies the teleoperation system's ability to transmit changes in the compliance of the environment. This sensitivity function is appropriate for the application of telesurgery, where the ability to distinguish small changes in tissue compliance is essential for tasks such as detection of embedded vessels. The bilateral teleoperation controller design problem is then formulated in a task-based optimization framework as the optimization of this metric, with constraints on free-space tracking and robust stability of the system under environment and human operator uncertainties. The control design procedure is illustrated with a case study. The analysis is also used to evaluate the effectiveness of using a force sensor in a teleoperation system.

A robotic teacher of Chinese handwriting

Abstract: We introduce a virtual teaching system for Chinese ideograms that guides movements by haptic and visual means. A powerful 6-DOF haptic interface and reflection of the image ensure transparent virtual manipulation with undistorted hand-eye coordination. The guidance mode and assistance levels can be adapted to the user and optimized for learning. The user's performance and progress are quantitatively evaluated. Initial experiments with six subjects showed how the students improve their skills.

SHaDe, a new 3-DOF haptic device

Abstract: This paper presents a new type of haptic device using spherical geometry. The basic idea of haptic devices is to provide users with feedback information on the motion and/or force that he or she generates. Haptic devices have several potential applications such as, for example, fine compliant assembly, VR environment simulation, and high-precision teleoperation, especially in hazardous or hostile areas. The particular architecture of the spherical haptic device developed here will be presented and its advantages will be highlighted. Then, its basic kinematic properties, which shall be used for control and geometric optimization purposes, will be reviewed. The design optimization itself will then highlight some important features of the mechanism. The control scheme and real-time force feedback issues will then be presented. Finally, the results obtained with the prototype will be discussed.

Virtual reality simulators: current status in acquisition and assessment of surgical skills.

Abstract: Medical technology is currently evolving so rapidly that its impact cannot be analysed. Robotics and telesurgery loom on the horizon, and the technology used to drive these advances has serendipitous side-effects for the education and training arena. The graphical and haptic interfaces used to provide remote feedback to the operator - by passing control to a computer - may be used to generate simulations of the operative environment that are useful for training candidates in surgical procedures. One additional advantage is that the metrics calculated inherently in the controlling software in order to run the simulation may be used to provide performance feedback to individual trainees and mentors. New interfaces will be required to undergo evaluation of the simulation fidelity before being deemed acceptable. The potential benefits fall into one of two general categories: those benefits related to skill acquisition, and those related to skill assessment. The educational value of the simulation will require assessment, and comparison to currently available methods of training in any given procedure. It is also necessary to determine - by repeated trials - whether a given simulation actually measures the performance parameters it purports to measure. This trains the spotlight on what constitutes good surgical skill, and how it is to be objectively measured. Early results suggest that virtual reality simulators have an important role to play in this aspect of surgical training.

The Rutgers Master II-ND force feedback glove

Abstract: The Rutgers Master II-ND glove is a follow up on the earlier Rutgers Master II haptic interface. The redesigned glove has all the sensing placed on palm support, avoiding routing wires to the fingertips. It uses custom pneumatic actuators arranged in a direct-drive configuration between the palm and the thumb, index middle and ring fingers. The supporting glove used in the RMII design is eliminated, thus the RMII-ND can better accommodate varying hand sizes. The glove is connected to a haptic control interface that reads its sensors and servos its actuators. The interface pneumatic pulse-width modulated servo-valves have higher bandwidth than those used in the earlier RMII, resulting in better force control. A comparison with the CyberGrasp commercial haptic glove is provided.

On application of virtual fixtures as an aid for telemanipulation and training

Abstract: This paper presents a study on the application of virtual fixtures as a control aid for performing telemanipulation or in the training environment. The implementation features both manual and supervisory control modes. It also studies approaches for using virtual fixtures in generating visual and force clues and/or for restricting the motion of the slave using the definition of virtual fixtures. In this preliminary study it was found that the virtual fixtures could: improve the speed and precision of the operator, and reduce the operator's workload and the duration of the training phase for the novice operator.

Haptic control of a mobile robot: a user study

Abstract: We address the problem of teleoperating a mobile robot using shared autonomy: an on-board controller performs obstacle avoidance while the operator uses the manipulandum of a haptic probe to designate the desired speed and rate of turn. Sensors on the robot are used to measure obstacle range information. We describe a strategy to convert such range information into forces, which are reflected to the operator's hand, via the haptic probe. This haptic information provides feedback to the operator in addition to imagery from a front-facing camera mounted on the mobile robot. Extensive experiments with a user population show that the added haptic feedback significantly improves operator performance in several ways (reduced collisions, increased minimum distance between the robot and obstacles) without a significant increase in navigation time.

Feeling is Believing: Using a Force‐Feedback Joystick to Teach Dynamic Systems

Abstract: As an innovative approach to providing physical demonstrations in the engineering classroom, we present the haptic paddle: a low-cost, single-axis force-feedback joystick. Using the paddle in the laboratory component of an undergraduate course on dynamic systems, students not only learned to model and analyze dynamic systems, but they also felt the effects of phenomena such as viscous damping, stiffness, and inertia. By interacting with virtual environments using their sense of touch, students improved their understanding of dynamic systems, modeling and control. In addition, the paddles added entertainment and excitement to the course. In this paper, we describe the purpose and design of the haptic paddle, show examples of how the paddle was integrated into the course, and present the results of preliminary student evaluations.

Analysis of Suture Manipulation Forces for Teleoperation with Force Feedback

Abstract: Despite many successes with teleoperated robotic surgical systems, some surgeons feel that the lack of haptic (force or tactile) feedback is detrimental in applications requiring fine suture manipulation. In this paper, we study the difference between applied suture forces in three knot tying exercises: hand ties, instrument ties (using needle drivers), and robot ties (using the da Vinci? Surgical System from Intuitive Surgical, Inc.). Both instrument and robot-assisted ties differ from hand ties in accuracy of applied force. However, only the robot ties differ from hand ties in repeatability of applied force. Furthermore, comparison between attendings and residents revealed statistically significant differences in the forces used during hand ties, although attendings and residents perform similarly when comparing instrument and robot ties to hand ties. These results indicate that resolved force feedback would improve robot-assisted performance during complex surgical tasks such as knot tying with fine suture.

Improving realism of a surgery simulator: linear anisotropic elasticity, complex interactions and force extrapolation

Abstract: In this article, we describe the latest developments of the minimally invasive hepatic surgery simulator prototype developed at INRIA. The goal of this simulator is to provide a realistic training test bed to perform laparoscopic procedures. Therefore, its main functionality is to simulate the action of virtual laparoscopic surgical instruments for deforming and cutting tridimensional anatomical models. Throughout this paper, we present the general features of this simulator including the implementation of several biomechanical models and the integration of two force-feedback devices in the simulation platform. More precisely, we describe three new important developments that improve the overall realism of our simulator. First, we have developed biomechanical models, based on linear elasticity and finite element theory, that include the notion of anisotropic deformation. Indeed, we have generalized the linear elastic behaviour of anatomical models to 'transversally isotropic' materials, i.e. materials having a different behaviour in a given direction. We have also added to the volumetric model an external elastic membrane representing the 'liver capsule', a rather stiff skin surrounding the liver, which creates a kind of 'surface anisotropy'. Second, we have developed new contact models between surgical instruments and soft tissue models. For instance, after detecting a contact with an instrument, we define specific boundary constraints on deformable models to represent various forms of interactions with a surgical tool, such as sliding, gripping, cutting or burning. In addition, we compute the reaction forces that should be felt by the user manipulating the force-feedback devices. The last improvement is related to the problem of haptic rendering. Currently, we are able to achieve a simulation frequency of 25 Hz (visual real time) with anatomical models of complex geometry and behaviour. But to achieve a good haptic feedback requires a frequency update of applied forces typically above 300 Hz (haptic real time). Thus, we propose a force extrapolation algorithm in order to reach haptic real time.

First steps towards mutually-immersive mobile telepresence

Abstract: Mutually-Immersive Mobile Telepresence uses a teleoperated robotic surrogate to visit remote locations as a substitute for physical travel. Our goal is to recreate to the greatest extent possible, both for the user and the people at the remote location, the sensory experience relevant for business interactions of the user actually being in the remote location. The system includes multi-channel bidirectional video and audio on a mobile platform as well as haptic feedback. This paper describes our first system prototypes and initial experiences using them.

Haptic remote control for toys

Abstract: A haptic feedback remote control device provides control signals to a toy device. The remote control device includes: a housing (24), a layer of compliant foam (62), a rechargeable battery (60), and an actuator assembly (50). The layer of compliant foam (62) reduces the inertial contribution of the battery (60) to the system and allows a user to feel stronger tactile sensations with the actuator assembly (50).

Method of using tactile feedback to deliver silent status information to a user of an electronic device

Abstract: Embodiments of the present invention use haptic feedback (110) to deliver status information to users in environments and situations where sight and/or sound is too overt from a privacy perspective. In one embodiment, localized haptic sensations can be delivered to a user through a tactile element (120) that is positioned on a region of a housing (102) of the electronic device that is engaged by a user.

Real-time haptic and visual simulation of bone dissection

Abstract: Bone dissection is an important component of many surgical procedures. In this paper, we discuss a haptic and visual implementation of a bone-cutting burr that is being developed as a component of a training system for temporal bone surgery. We use a physically motivated model to describe the burr-bone interaction, which includes haptic force evaluation, the bone erosion process and the resulting debris. The current implementation, directly operating on a voxel discretization of patient-specific 3D CT and MRI data, is efficient enough to provide real-time feedback on a low-end multiprocessing PC platform.

Haptic feedback stylus and other devices

Abstract: A force feedback interface and method including an actuator in a non-primary axis or degree of freedom. The force feedback interface device is connected to a host computer that implements a host application program or graphical environment. The interface device includes a user manipulatable object, a sensor for detecting movement of the user object, and an actuator to apply output forces to the user object. The actuator outputs a linear force on the user object in non-primary linear axis or degree of freedom that is not used to control a graphical object or entity implemented by the host computer, and movement in the non-primary degree of freedom is preferably not sensed by sensors. The axis extends through the user object, and there are preferably no other actuators in the device, thus allowing the force feedback device to be very cost effective. Force sensations such as a jolt, vibration, a constant force, and a texture force can be output on the user object with the actuator. The force sensations can be output in a direction perpendicular to a planar degree of freedom, radial to spherical degree of freedom, and/or along a lengthwise axis of the user object.

Virtual Temporal Bone Dissection: An Interactive Surgical Simulator

Abstract: OBJECTIVE: Our goal was to integrate current and emerging technology in virtual systems to provide a temporal bone dissection simulator that allows the user interactivity and realism similar to the cadaver laboratory.STUDY DESIGN: Iterative design and validation of a virtual environment for simulating temporal bone dissection.SETTING: University otolaryngology training program with interdisciplinary interaction in a high-performance computer facility.RESULTS: The system provides visual, force feedback (haptic), and aural interfaces. Unlike previous “fly through” virtual systems, this environment provides a richer emulation of surgical experience.CONCLUSION: The system provides a high level of functional utility and, through initial evaluations, demonstrates promise in adding to traditional training methods.SIGNIFICANCE: The system provides an environment to learn temporal bone surgery in a way similar to the experience with cadaver material where the subject is able to interact with the data without const...