Haptic

{ExpPsy}}
 * This article is about haptic technology. For the study of touching behaviour in humans, see Haptics. For the biology of sensory receptors, see Somatosensory system.

Haptic, from the Greek αφή (Haphe), means pertaining to the sense of touch (or possibly from the Greek word haptesthai meaning “contact” or “touch”).

Haptic technology refers to technology which interfaces the user via the sense of touch by applying forces, vibrations and/or motions to the user. This mechanical stimulation is used to create haptic virtual objects. Watch an animated demo of these basic haptic technology concepts here. This emerging technology promises to have wide reaching applications. Although haptic devices are capable of measuring bulk or reactive forces that are applied by the user it should not to be confused with touch or tactile sensors that measure the pressure or force exerted by the user to the interface.

History
One of the earliest forms of haptic devices is used in large modern aircraft that use servo systems to operate control systems. Such systems tend to be "one-way" in that forces applied aerodynamically to the control surfaces are not perceived at the controls, with the missing normal forces simulated with springs and weights. In earlier, lighter aircraft without servo systems, as the aircraft approached a stall the aerodynamic buffeting was felt in the pilot's controls, a useful warning to the pilot of a dangerous flight condition. This control shake is not felt when servo control systems are used. To replace this missing clue, the angle of attack is measured, and when it approaches the critical stall point a "stick shaker" (an unbalanced rotating mass) is engaged, simulating the effects of a simpler control system. This is known as haptic feedback or force feedback.

Teleoperators and simulators
Teleoperators are remote controlled robotic tools, and when contact forces are reproduced to the operator, it is called "haptic teleoperation". The first electrically actuated teleoperators were built in the 1950's at the Argonne National Lab, USA, by Dr. Raymond C. Goertz, to remotely handle radioactive substances. Since then, the use of "force feedback" has become more widespread in all kinds of teleoperators such as underwater exploration devices controlled from a remote location.

When such devices are simulated using a computer (as they are in operator training devices) it is useful to provide the force feedback that would be felt in actual operations. Since the objects being manipulated do not exist in a physical sense, the forces are generated using haptic (force generating) operator controls. Data representing touch sensations may be saved or played back using such haptic technologies.

Haptic simulators are currently used in medical simulators and flight simulators for pilot training (2004).

Games
Some low-end haptic devices are already common. Some joysticks and game controllers provide haptic feedback. The simplest form is the Rumble Pak, which is simply an attachment which vibrates upon command from the software. This is often incorrectly referred to as force feedback. True force feedback involves the feedback of a resisting force to the user. This feature is available in some simulated automobile steering wheels which provide the road "feel" for race car simulations. The ability to change the temperature of a controlling device could also be used. However, the technology may be cost prohibitive in terms of how much power it would need to operate properly.

Novint Technologies recently announced their development of a high-fidelity consumer haptic (3D touch) controller which they plan to introduce in the video game market in 2007. The device, which is called the Novint Falcon, lets users feel weight, shape, texture, dimension, and force effects when playing touch-enabled games. The device, which is designed to retail for under $250 in mass market quantities, performs comparably to commercial devices that cost thousands of dollars, making the technology practical for consumer applications for the first time. Users hold the interchangeable handle, or end effector of the Novint Falcon as shown in this image.

Haptics in virtual reality
Haptics is gaining widespread acceptance as a key part of Virtual Reality systems, adding the sense of touch to previously visual-only solutions such as 'The Wedge' and more recently in laptop-based VR solutions such as the '3D-Mobile Immersive Workstation'. Most of these solutions use stylus-based haptic rendering, where the user interfaces to the virtual world via a tool or stylus, giving a form of interaction that is computationally realistic on today's hardware

Research
Some research has been done into simulating the different kinds of tactition by means of high-speed vibrations or other stimuli. One device of this type uses a pad array of pins, where the pins vibrate to simulate a surface being touched. While this does not have a realistic feel, it does provide useful feedback, allowing discrimination between various shapes, textures, and resiliencies.

Medicine
Various haptic interfaces for medical simulation may prove especially useful for training of minimally invasive procedures (laparoscopy/interventional radiology) and remote surgery using teleoperators. In the future, expert surgeons may work from a central workstation, performing operations in various locations, with machine setup and patient preparation performed by local nursing staff. Rather than traveling to an operating room, the surgeon instead becomes a telepresence. A particular advantage of this type of work is that the surgeon can perform many more operations of a similar type, and with less fatigue. It is well documented that a surgeon who performs more procedures of a given kind will have statistically better outcomes for his patients.

In ophthalmology, "haptic" refers to a supporting spring, two of which hold an artificial lens within the lens capsule (after surgical removal of cataracts).

A 'Virtual Haptic Back' (VHB) is being successfully integrated in the curriculum of students at the Ohio University College of Osteopathic Medicine. Research indicates that VHB is a significant teaching aid in palpatory diagnosis (detection of medical problems via touch). The VHB simulates the contour and compliance (reciprocal of stiffness) properties of human backs, which are palpated with two haptic interfaces (SensAble Technologies, PHANToM 3.0). This research is being conducted at the 'Interdisciplinary Institute for Neuromusculoskeletal Research (IINR)'

Literature
The use of haptic devices in entertainment appeared in the 1932 futurist fiction book Brave New World by Aldous Huxley. The author described a future entertainment theater where the arm rests of the seats had positions for the hands to rest that gave haptic stimulation. Rather than "the movies" these theaters and shows were called "the feelies". The programs exhibited were of an erotic nature. Haptic devices, including self-propelled haptics, feature prominently in Vernor Vinge's 2006 novel Rainbows End.

Remote sexual relations
One envisioned use of haptics is for "teledildonics". Recent developments such as the 'CyberGlove' indicate that this may be plausible and not just an interesting idea. Some sex toys are now available which can be computer controlled; normally this comes in the form of an online movie or Web site which sends commands to the toy at scripted moments.

Robotics
The Shadow Dextrous Robot Hand uses the sense of touch, pressure, and position to reproduce the human grip in all its strength, delicacy, and complexity. The SDRH was first developed by Richard Greenhill and his team of engineers in Islington, London, as part of The Shadow Project, (now known as the Shadow Robot Company) an ongoing research and development program whose goal is to complete the first convincing humanoid. An early prototype can be seen in NASA's collection of humanoid robots, or robonauts (http://robonaut.jsc.nasa.gov/robonaut.html). The Dextrous Hand has haptic sensors embedded in every joint and in every finger pad which relay information to a central computer for processing and analysis. Carnegie Mellon University in Pennsylvania and Bielefeld University in Germany in particular have found The Dextrous Hand is an invaluable tool in progressing our understanding of haptic awareness and are currently involved (2006) in research with wide ranging implications.

Arts
Touching is not limited to a feeling, but it allows interactivity in real-time with virtual objects. Thus haptics are commonly used in virtual arts, such as sound synthesis or graphic design/animation. The haptic device allows the artist to have direct contact with a virtual instrument which is able to produce real-time sound or images. We can quote the physical modelling synthesis which is an efficient modelling theory to implement cross-play interaction between sound, image, and physical objects. For instance, the simulation of a violin string produces real-time vibrations of this string under the pressure and expressivity of the bow (haptic device) held by the artist.

Haptics communities

 * 
 * The Haptics Community Website Resources for haptics researchers
 * The International Society for Haptics
 * Haptics-L: The electronic mailing list for the international haptics community
 * 

Open source and other software

 * Haptik Library An open-source component-based library for uniform access to haptic devices
 * Chai3D Free, open-source library for haptic and graphic rendering
 * H3D Free, open-source API for haptics and 3D visualisation programming
 * The International Society for Haptics' Software Archive

Companies

 * Immersion Corp.Immersion develops touch feedback technologies that engage the sense of touch in the digital world for communicating, driving, designing, training, or just for fun
 * Force Dimension Provider of high-end haptic devices and solutions for medical, industrial and research applications
 * Handshake VR Inc. provider of a haptic and telehaptic development toolkit to empower application developers with little or no haptic experience
 * Novint Technologies, Inc. develops, markets, and licenses haptic technology for commercial and consumer applications
 * Quanser Inc. manufacturer of high-transparency and robust Haptic systems for education, research, and industrial integration. All of Quanser’s Haptic systems are open-architecture and are currently implemented in the heavy equipment, medical, robotic, and didactic industries.
 * Haption. Haption provides haptic devices and software solutions for Virtual Reality.
 * SensAble Technologies, Inc. provider of 3D touch-enabled digital solutions for commercial software development, academic and commercial research, product design, and digital content creation.
 * Reachin Technologies AB provider of high-fidelity 2D and 3D touch-enabled solutions for software development within manufacturing, design, R&D, meditech and entertainment.
 * SenseGraphics provides display systems for integrated haptics and graphics. Develops the X3D based open source API, H3D API, used for development of haptic applications. Also provides consulting for development of haptic applications.
 * Ergos-Technologies develops n-DOF modular haptic devices for multisensory real-time interaction. Ergos also provides consulting and physical modelling synthesis software for high-bandwidth-loop haptic/sound/image simulations.
 * MPB Technologies Inc. manufactures the Freedom 6S force-feedback hand controller. It features high-accuracy 16-bit sensors, and is capable of rendering precision forces and torques in 6 degrees of freedom.

Haptics research and media

 * 'Haptics and Applications in Medicine' at Johns Hopkins
 * 'Haptics-e: The Electronic Journal of Haptics Research' - Scholarly papers on haptics
 * Haptics-L Literature Update The latest papers on haptics and touch research, by Gabriel Robles-De-La-Torre
 * Haptics-L Newslog The latest news and views on haptics, by Gabriel Robles-De-La-Torre
 * Haptics Bibliography List of haptics papers, made by researcher Margaret Minsky (not updated since 1999)
 * Haptics Links List of haptics links, made by researcher Margaret Minsky (not updated since 1999)
 * Haptic Spaces Exploration of haptic technologies and touch culture, made by philosopher Mark Paterson
 * Haptics: An award-winning humorous and ironic animated film in a future where reality is blurred by the science of Haptics
 * The Cutting Edge of Haptics An article in MIT's Technology review by Duncan Graham-Rowe.
 * Realistic Multi-Finger Haptics Haptics Research at the University of Reading, UK.
 * Design Based Medical Training Learning medical procedural skills through haptics, University College Cork and University of Limerick, Ireland.
 * Computer haptics An animated demo explaining basic haptic technology concepts.
 * How Touching. An article on haptics in The Economist's Technology Quarterly. Subscription and free versions are online.
 * Touch, technology, digital arts and philosophy
 * The International Society for Haptics
 * The Cutting Edge of Haptics An article in MIT's Technology review by Duncan Graham-Rowe.