Power is the scarcest resource for most mobile electronics, and battery technology has improved slowly relative to developments in memory, disk storage, and wireless connection speeds. When creating a mobile device, a rule of thumb is to specify the largest battery the design might tolerate because, unlike most other computing technology, batteries are unlikely to improve during a normal 18-month product design cycle.
In the early 1990s, lead-acid gel cells and nickel-cadmium (NiCd) batteries were often used in mobile consumer electronics. By the late 1990s, lithium-ion (Li-ion) batteries significantly improved stored energy to weight ratios, leading to smaller cellular phones and small MP3 players.
A developing approach to powering mobile consumer electronics is to scavenge energy from the user or the environment. With the growing popularity of cellular phones, several companies produce modern hand-wound generators, a concept similar to pre-World War II pedal-powered radios. Solar chargers have also become popular for campers. Perhaps in the future some on-body sensors will use the effect they are sensing to power themselves?
Squeezing the hand crank on this generator charges a cellular phone or the attached LED flashlight, which stores the energy in a supercapacitor. While supercapacitors have lower energy density than batteries, they are inexpensive and can charge quickly.
RCA ultrasonic TV remote control (in the 1960s, it added 30 percent to the cost of a television)
Solar power is used to charge this USB battery, which in turn can provide extended power for on-body devices or the included LED flashlight.
One of the biggest improvements for small, mobile electronics was in the efficiency of 3 V and 5 V DC-DC power converters in the late 1990s. To be worn on the body, devices must not create too much heat. Yet, inefficient power systems often create significant excess heat.
In 1995, a device that required 10 W of power may have wasted 3 W as heat simply by converting the 12 V from a lead-acid gel cell to the 5 V required for the circuitry. By 2000, much smaller switching 10 W power converters only wasted 0.5 W, leading to longer battery life and smaller devices.
This DC-DC converter can convert 12 V to 5 V at a maximum efficiency of 78 percent. At its peak current, it creates considerable heat.
Modern switching DC-DC converters can achieve over 98 percent efficiency, allowing the design of smaller wearables with cooler running temperatures.
Consumer WiFi (802.11) and digital cellular networks are widespread today, but early wearable computers had to be mostly self-contained. By 1996, Cellular Digital Packet Data (CDPD) radios might have provided effective speeds of 9600 baud. In 1999, universities began to deploy campus-wide WiFi, but otherwise open access points were rare.
IEEE 802.11 Wavelan PCMCIA card (1997, $295)
While power-hungry, WiFi provides wearable computers a high-speed connection to the “cloud.” Free WiFi hotspots started becoming commonplace after the year 2000.
Garmin GPS 35-LVS (2001, $200)
In 2000, Selective Availability was turned off, improving the accuracy of civilian Global Positioning Systems from 100 m to 20 m. Only in the last five years, however, have embedded GPS receiver chips been able to acquire their position quickly and become sensitive enough to connect through cars, wooden houses, and foliage.
Xerox PARC/Olivetti Research Laboratory Active Badge location system (1992, research prototype from the collection of Keith Edwards)
The Active Badge emitted infrared signals that allowed receivers in the infrastructure to detect where a user was in a building. While not commonly thought of as a network, this system was a forerunner of many similar local area systems.
LG Tone Pro headset (2014, $70)
The LG Tone Pro is a pair of Bluetooth wireless stereo earphones. The IEEE 802.15 Wireless Personal Area Network (WPAN) standards can be traced to the IEEE Ad Hoc “Wearables” Standards Committee led by Richard Braley at FedEx in 1997. Bluetooth is described under 802.15.1, and ZigBee uses the 802.15.4 layers. While the basic Bluetooth technology was invented in 1994, it was not until the 2002 1.1 specification that it became stable and popular. A major step forward was the recent introduction of Bluetooth Low Energy wireless technology, which improves many of the power consumption and device speed-of-discovery problems that have limited Bluetooth’s usefulness for wearable devices.
A Step Forward
Desktop interfaces are inappropriate when a user is on-the-go. They require significant manual attention to control a mouse and significant visual attention to track the pointer on the screen. Instead, on-the-go interfaces might use gross gestures and key verbal phrases for input and audio, bold graphics or haptics for feedback. A notable interface problem is text entry. While speech recognition has improved significantly, it is inappropriate in meetings and many other social situations.
Mini-QWERTY keyboards, such as the Blackberry, and virtual keyboards require significant hand-eye coordination. Chording input systems such as the Twiddler and the Chorder shown here are fast and best used without visual attention, but they require training. The Half Keyboard employs a more familiar, flat, desktop QWERTY keyboard layout for touch-typing with one hand, but a user chords with the spacebar to achieve the full alphabet.
Twiddler 1 (1991, $200) & Twiddler 2 (2001, $219)
The Twiddler 1 is a chording input system enabling mobile touch-typing at nearly desktop speeds. The letters A to H have their own buttons, while I to Z are chorded using “shift” buttons. It also includes a tilt sensor-based mouse. The Twiddler 2 uses an isometric joystick for the mouse and offers PS/2 or USB for the interface with the computer. In 2008, the Twiddler 2.1 switched to an eight-way joystick. Coupled with a head-up display (HUD), a user can take detailed notes in the classroom, while having a face-to-face conversation, or while brainstorming during a walk.
Twiddler 3, model and prototypes shown (2014, $199 projected)
The upcoming Twiddler 3 chording input system will connect via Bluetooth or USB. It is smaller and adds separate mouse buttons (previous versions used the A, E, and Space keys modally as mouse buttons). Displayed are 3D printouts of early prototypes of the new device and an SLA model of the final plastics.
Chorder (mid-1990s, handmade by Greg Priest-Dorman)
Five- to seven-button chording keyboards have been a part of computing since the 1960s. Their relative simplicity, typing speed, and usability without visual attention allows them to be incorporated into a wearable system. At Vassar College, Greg Priest-Dorman fashioned this device for fast donning and doffing for use with his Herbert 1 wearable computer.
Matias Half Keyboard (2001, $595)
The Half Keyboard leverages typists’ knowledge of the desktop QWERTY keyboard to quickly teach typing with one hand. When the spacebar is held down, the system mirrors the other side of the full-sized keyboard.
Ring trackball (unknown, $20)
Small trackballs and touchpads can be effective input devices while the user is moving, but tracking a small cursor on the screen requires significant visual attention. Using gross motion and audio feedback in lieu of a mouse pointer to control the interface allows the user to focus on the physical world.
Symbol WSS 1000 Wearable Computing System with RS 1 Ring Scanner (1998, $3500)
Symbol created a ring-based barcode scanner and forearm-mounted wearable computer to help workers more efficiently scan and inventory packages as they moved them. With previous systems, a worker would pick up a package, put it on a table, retrieve a “gun” scanner, scan the package, replace the scanner, and then move the package. With the ring scanner, a worker can scan the package as he reaches to move it. The system is a notable success, with variants still being sold by Motorola (which acquired Symbol) today.
Embroidered Textile Interfaces (2010, research prototypes from Georgia Tech)
Touch-sensitive interfaces use capacitive sensing and are created by embroidering conductive thread or screen-printing conductive ink in desired patterns such as buttons, rocker switches, pleats, menus and jog-wheels. While still not commonplace, e-textiles are beginning to be seen commercially in ski jackets and fashion accessories.
LilyPad Arduino toolkit, designed by Leah Buechley (2007, $25)
These microcontroller boards are designed to be sewn and help makers create interactive accessories and soft textile projects. Input from an accelerometer or light and temperature sensors can generate vibrations, LED lights or sound.
VIRTUAL REALITY (VR) DISPLAYS
A Step Forward
In the late 1980s and early 1990s, the companies VPL Research and Virtual Research sparked popular imagination with virtual reality (VR) helmets. Unlike wearable computing displays that seek to augment the user’s experience in the everyday world, VR displays attempt to remove the user from reality, enclosing the user in high-fidelity, computer-controlled worlds. Beyond introducing the concept of a head-mounted display (HMD) to the public, these systems also helped focus attention on creating small displays and optics suitable for wearing.
Immersive systems feature large field-of-view displays, resulting in heavy headsets that are comfortable only for limited periods of time. These binocular systems sometimes have difficulty creating convincing illusions of 3D environments because only some depth cues can be simulated readily in a headset. Binocular disparity is a strong depth cue, and it may cause considerable conflict with other depth cues such as focus or vergence, leading to fatigue or simulator sickness. Early, heavy CRT technology has yielded to LCDs and recently OLEDs.
Virtual Research Flight Helmet (1991, $6000)
The Flight Helmet has a 100-degree diagonal field of view and a resolution of 240x120 pixels. It weighs 1.67 kg and uses 6.9 cm LCD screens with LEEP Systems' wide angle optics to provide an immersive stereoscopic experience. Subsequent Virtual Research devices employed smaller lenses and a reduced field of view to save weight and cost. By 1994, the LCDs in the VR4 had twice the resolution at half the size. For its era, the Flight Helmet was competitively priced.
Philips Scuba VR Visor head-mounted display (1997, $299)
Weighing 544 g with an active-matrix LCD screen with a resolution of 263x230 pixels and a 50-degree diagonal field of view, the Scuba sold 55,000 units. While this technology was designed originally as a VR helmet for the Atari Jaguar home game system, it was sold and released by other companies without the head tracker, which Atari used only in its Missile Command game.
Oculus Rift Dev Kit 1 VR head-mounted display (2013, $300)
The commoditization of displays and motion sensors from smart phones has significantly improved the quality and reduced the cost for making VR devices. The Oculus Rift Dev Kit 1 has a 110-degree diagonal field of view with a 640x800 pixel resolution per eye, and it weighs 379 g plus a tethered control box. Approximately 60,000 of the first developer kits were sold. Very low latency head tracking and OLED technology are among the improvements featured in the new Dev Kit 2.
Nintendo Virtual Boy video game console (1995, $180)
The Virtual Boy provided an early, portable, 3D experience in an inexpensive package that included the full computing system in the device. As a table-mounted head display, the Virtual Boy has no possibility of head tracking or the freedom of motion available with most VR headsets. It uses Reflection Technology's scanning, mirror-style, monochromatic display in which a column of 224 LEDs is scanned across the eye with an oscillating mirror as the LEDs flash on and off, creating a 384x224 pixel resolution display with persistence of vision. It provides adjustments for focus and inter-eye distance. With over a million devices sold, the Virtual Boy introduced many consumers to immersive gameplay.
Virtual i-O i-glasses! Personal 3D Viewer head-mounted display (1995, $395)
These popular VR goggles with an optional head tracker are relatively inexpensive, lightweight (227 g), have 300x200 pixel resolution, and have a 30-degree field of view. They are also somewhat see-through, allowing the creation of augmented realities in brightly lit environments.
Sony PC Glasstron PLM-S700 head-mounted display (1998, $2900)
This high-end, 3D Glasstron VR system has 800x600 pixel resolution; weighs 120 g without the attached controller box; and has a 38-degree field of view. It features light-blocking LCD shutters that control the opacity of the screen, although the physical world can be seen in bright outdoor light, giving an augmented reality effect. Academic developers favored its adaptability for wearable computing, but it requires up to 11 W of power, often resulting in backpack-sized systems.
MOBILE VIDEO VIEWERS
A Step Forward
What use were mobile head-mounted displays to the average consumer before 2008? Very few digital devices provided a way of feeding an image to an external display. In an attempt to reach consumers, head-mounted display (HMD) manufacturers designed lighter-weight headsets intended primarily for watching videos while stationary, such as during a flight, on a train, or at home.
When Apple’s video iPod was released in 2005, HMD manufacturers had a popular mobile system with which to interface. These systems avoid the eyestrain of 3D viewing by opting instead for a 2D experience. Mobile video viewers used displays originally designed for camcorder viewfinders or video projectors. Wearable computing academics and makers adopted these viewers and often adapted them for their mobile needs by removing the display for one eye. They used messaging, mobile navigation, restaurant reviews, email and web search on their wearables before smart phones became prevalent in 2008. Today, similar video viewers are often self-contained or wireless, using microSD cards to play stored movies or using WiFi to connect to a video player.
MyVu Personal Viewer (2006, $270)
The MyVu Personal Viewer (320x240 pixel resolution) and later MyVu Crystal (640x480) were sold on apple.com, in stores such as Brookstone, and even from airport vending machines. Popular with makers for its quality and durability, some combined the out-of-production Crystal with a Raspberry Pi to create a low-cost wearable computer. Prior to MyVu's focus on the consumer market, the company was called MicroOptical and targeted the professional market.
Sony Glasstron PLM-A35 (2000, $499)
The low-end Glasstron, Sony PLM-A35, is a two-eyed, opaque system designed for connecting to a home video game system or DVD player. It weighs 150 g without the attached controller box and has a 38-degree field of view.
Vuzix Wrap 230 (2010, $170)
This 320x240 pixel resolution video viewer has a 22-degree diagonal field of view and an adjustable focus. It weighs less than 85 g and is one of a long series of video viewers produced by Vuzix (formerly called Icuiti).
Vuzix iWear (2008, $250)
The iWear was designed for use with the custom iPod connector and re-branded for Brookstone and Sharper Image. Vuzix video viewers are some of the most commonly available head-mounted displays, and their line of Video Eyewear continues today.
Eyetop Centra DVD bundle (2004, $599)
Intended to be portable and including a satchel, one-eyed video viewers such as the Eyetop could be easily adapted for wearable computers. However, the device's bulkiness, head weight, power requirements and dependence on composite video input limited its appeal.
Epson Moverio BT-100 (2012; $700)
The Moverio BT-100 is a self-contained, Android-based wearable computer with an attached control pendant that contains the computer and trackpad. The display weighs 220 g and has both 2D and 3D viewing modes. It is two-eyed and up to 70 percent see-through with 960x540 pixel resolution and a 23-degree field of view. With WiFi and a full computer, this device straddles the gap between personal everyday use, video viewing, and industrial use.
INDUSTRIAL, MILITARY & MEDICAL SYSTEMS
A Step Forward
Instead of immersing the user, one-eyed HUDs designed for industrial, military, and medical purposes often provide brief, intermittent assistance while the user is performing another primary task. For example, an anesthesiologist in the operating room may use a HUD to glance at the patient’s vital signs while looking at his face for signs of hypoxia (lack of oxygen). A soldier may refer to a display to determine his location on a map, or a worker in a warehouse may view a diagram showing which part to pick next for an order.
These “microinteractions” last a few seconds and require a device that is faster to access than a smartphone, which averages about 20 seconds simply to unlock and navigate. Like the dashboard of a car, a user glances at it and is quickly back to the task at hand. What tasks would consumers desire if they had similarly fast access to a computer?
Reflection Technology Private Eye display (1989, $795)
The Private Eye uses persistence of vision to create a 720x280 pixel monochrome screen. A vibrating mirror scans a column of 280 LEDs across the user’s eye, and the LEDs turn on and off rapidly to form each pixel of the screen. The display is surprisingly sharp, and it may be focused at different distances, relieving eyestrain. It is low power (0.5 W), provides a 22-degree field of view, and weighs 71 g without the head mount. While an opaque display might cover one eye, the user has the illusion that the display is see-through because the human visual system combines and shares the images received from both eyes.
These displays were integrated into many early wearable computers, including those of some academics in MIT's Wearble Computing Project, Park Engineering's CompCap (1991, $5000), and Carnegie Mellon University's VuMan
series of devices.
Triplett VisualEYEzer 3250 multimeter (2000, $500)
The VisualEYEzer multimeter is an example of a special-purpose head-up display (HUD). A worker can use a hand for each of the two probes while touching them to a circuit and glance up at the segmented LED display for a reading.
Georgia Tech Multimeter Watch (2014, class project courtesy of Chad Ramey)
This operational multimeter uses Bluetooth to transmit readings to Google Glass for display.
Carnegie Mellon University VuMan 3 (1994, manufactured by CMU, from the collection of Dan Siewiorek)
CMU created an extensive series of wearable computers designed for industrial, military, and medical applications starting in the 1990s. VuMan 3 had a large rotary dial that enabled input when moving and in awkward positions. A 1997 CMU study on Army tank inspection using the VuMan 3 showed 70 percent time savings while requiring only half the personnel for the same task.
Liteye Systems Liteye-300 display (1999, $3995)
This 48-degree field of view amber monitor has 800x600 pixel resolution and can produce images that are so bright that they are easily readable in daylight. The display weighs 43 g without eyeglasses or the control box. The field of view is so large that it blocks a significant amount of the user’s vision when mounted directly in front of the eye. However, it can be mounted in a soldier’s helmet, up and away from his normal line of sight.
Vuzix Tac-Eye LT head-up display (2010, $3000)
The Vuzix Tac-Eye is sold as a rugged HUD for the military. It has 800x600 pixel resolution, weighs 51 g without eyeglasses or the control box, and has a 30-degree field of view. It requires less than 1 W when hooked to a VGA source and has a relatively small control box, making it attractive for many applications.
MicroOptical CO-3 display (2001, $2000)
MicroOptical displays have some of the best eyeboxes (the 3D region of space in which the eye can rest and still see all four corners of the screen), which is very beneficial because mobile displays slip and move during normal work. They created small, VGA-compatible displays with high optical quality from the mid-1990s to the mid-2000s. They were used by Charmed, ViA's FlexiPC, and a variety of other wearable computer manufacturers for tasks in industry, medicine, military and academia. The CO-3 is 24-bit color, has 320x240 pixel resolution, and is power-hungry, requiring 3.5 W of power.
MicroOptical SV-6 display (2003, $1995)
The SV-6 is an 18-bit color, 640x480 pixel resolution display with a 20-degree field of view. The display head weighs 35 g, and the system consumes 2 W of power. Its VGA converter box is much smaller than for the CO-3.
MicroOptical DV-1 display (2003, not sold commercially)
In an effort to remove MicroOptical’s tether to the computer, several wireless Bluetooth-controlled prototype displays were created that acted as text terminals or graphics thin clients. Most were 320x240 pixel resolution to minimize size and weight.
Second Sight M1100 display and driver (2003, $2000)
Second Sight created a CompactFlash driver for a MicroOptical headset that requires significantly less power, and thus less battery weight, than the normal VGA converter box.
Xybernaut MA-IV computer (1999, $7500)
In the mid-1990s and early 2000s, Xybernaut (formerly CPSI) sold a series of body-worn computers focusing on industrial applications. Most wearable computing system companies created high-end, laptop-class machines because they perceived that Microsoft Windows and local speech recognition were required. Often they struggled with the limitations of using a desktop-based graphical user interface. The Mobile Assistant IV featured up to a 233 MHz Pentium MMX processor, 128 MB of RAM, a 4.3 GB hard drive, and a 640x480 pixel display with a unique mirror design.
Xybernaut MA-V computer (2001, $5000)
This next iteration of the Xybernaut industrial wearable continued to emulate high-end laptops featuring Windows XP, a 500 MHz Intel Celeron processor, 5 GB of disk space, and 256 MB of RAM. The display was an Olympus Monocular Eye-Trek with 800x600 pixel resolution.
Xybernaut/Hitachi VII/POMA/WIA computer (2002, $1500)
Switching to a 32-bit RISC architecture and Windows CE (which was much lighter-weight than Windows and focused on the embedded market) enabled Xybernaut to employ a smaller form factor for its devices. The 640x480 pixel resolution headset weighed 85 g, and the system itself weighed 280 g. The interface still centered around normal windowing metaphors, but the mouse hardware was smaller and more agile, similar to an optical mouse inverted so the user could swipe his finger over it for control.
InoTrack Firefighter Boot (2008, Universität Bremen, member of the wearIT@work consortium)
Equipped with a dead reckoning sensor and a processing module, this boot provides information on a firefighter's path through a building to a remote commander. If the firefighter needs help or loses consciousness, reinforcements can be sent to his location quickly.
Doctor's Wristband (2007, Universität Bremen, member of the wearIT@work consortium)
While doing rounds at a hospital, a doctor wearing the Doctor's Wristband can browse a patient's file on a bedside terminal using gestures. It is intended to provide an interface that is less obstructive to the patient-doctor rapport.
wearIT@work was an Integrated IST Project (IP) funded by the European Union under the 6th Framework Programme for Research and Technological Development. The five-year project, a collaboration among 36 partners in 15 countries, began in 2004 and is probably the largest publicly funded research project on wearable computing to date. It focused on the use of wearable computers in industrial environments. The project's efforts produced many forward-looking prototypes in the fields of industrial maintenance and production, emergency rescue, and healthcare.
FIDO (2013, academic prototype, Georgia Tech)
Facilitating Interactions for Dogs with Occupations examines wearable computing tropes from a canine’s perspective. Using on-body sensors and actuators, FIDO systems help canines communicate with their handlers. Applications for assistance, military, and search and rescue dogs are being researched.
MAKER & ACADEMIC SYSTEMS FOR EVERYDAY USE
A Step Forward
A handful of makers and academics began designing wearable computers to be used as part of their everyday lives in the early- to mid-1990s. Instead of focused, work-related duties, these devices were used for more personal tasks: email, messaging, music, note-taking, photography, and scheduling. The MIT Wearable Computing Project established a “living lab” where advocates explored a wearable computing lifestyle in a community of users. Collaboration with designers led to wearable computing fashion shows, where the importance of fashion for devices on the body became clear. A community led by Carnegie Mellon University, Georgia Tech, and MIT established wearable computing as its own academic field and encouraged makers to participate.
Herbert 1(1994, designed by Greg Priest-Dorman)
Herbert 1 was a primarily audio-based wearable computer used by Greg Priest-Dorman in his everyday life at Vassar College from 1994 to 1998. Through Emacspeak and a Linux platform, it could be used for general computing functions, reading email, or books. It used a seven-button chording keyboard for input and was often used while walking. The system was based on a Gateway Handbook and a DECtalk Express.
Herbert 3 (1998, designed by Greg Priest-Dorman)
In 1998 Greg Priest-Dorman created a new machine, adding a Liquid Image M1 display and incorporating the device into a vest. The output was still primarily voice, and input was chorded text using the Chorder displayed in the Mobile Input section of this exhibit, but the display enabled the more rapid navigation of information in conjunction with the audio interface. It was built around modular PC/104 embedded computing boards, which allowed some adaptability in design.
Lizzy 2 (1995, designed by Thad Starner, MIT Wearable Computing Project)
The Lizzy 2 was an open-hardware reference platform for the MIT Wearable Computing Project. Based on modular PC/104 boards and often equipped with a Twiddler
keyboard, Reflection Technology Private Eye
display, and Sierra Wireless CDPD modem (1996), the Lizzy 2 was the most common design worn on a daily basis by members of the project. Displayed here is a variant of the Lizzy 2 made in collaboration with the design firm Fitch. The original Lizzy (1993) was based on a CompCap industrial wearable computer heavily modified by Doug Platt and Thad Starner.
CharmIT (2000, $3000)
Reminiscent of the Apple 1, Charmed Technology, Inc. sold the CharmIT and CharmIT Pro to makers, academics, and early-stage developers. The case, peripherals, clothing, and display show many of the characteristics of the Herbert and Lizzy designs, and it was primarily advertised as a Linux-based machine. Much of the hardware was open source, encouraging makers and academics to improve upon the design.
MicroOptical embedded prescription display (1997, approximately $5000)
Mark Spitzer made these prescription eyeglasses for Thad Starner as an experiment in everyday use. The monochrome display has a nine-degree field of view and 320x240 pixel resolution. The LCD panel is in the earpiece, and the image is reflected through the lens to a concave mirror and beam splitter to reach the wearer’s eye. Google Glass uses a similar optical configuration.
MIThril (2000, designed by Rich DeVaul, MIT Wearable Computing Project)
Eschewing the monolithic design of the Lizzy 2, MIThril distributed the components of the wearable computer over a vest. The system avoided the x86 processor family and drove a 320x240 MicroOptical display directly, thus saving significant power. Its Anduin window manager focused on quick access and low-attention interfaces. It did not include a mouse pointer because “in many situations, using a pointer while engaged in other tasks is impractical.”
CONSUMER ELECTRONIC SYSTEMS FOR EVERYDAY USE
A Step Forward
Wearable computers have been mainstream since the late 1990s; digital music players, wireless earphones, fitness and sports devices, wristwatches, and body-mountable cameras have been commonly available for many years. However, with reliable digital networks, cloud services, low-power processors, plastic optics, and miniaturization, general purpose HUD-based wearables can be designed as fashionable packages and marketed to the general consumer. The popularity of smart phones has helped create a market by acquainting the consumer with desirable mobile services as well driving innovation in small, low-power components.
FitSense FS-1 (2000, $200)
FitSense wirelessly couples a shoe pod and heart strap to a wristwatch to help users track pace, distance, calories burned, and heart rate.
Fitbit One (2012, $100)
The Fitbit One tracks steps, energy expenditure, and sleep time using a small sensor and computer package that can be worn on the belt or bra or carried in a pocket.
4iiii Innovations Sportiiiis (2012, $150)
This simple head-up display and wireless, chest-mounted heart rate monitor uses audio and a series of lights on a boom to indicate heart rate, cadence, power, speed, and pace during a workout.
Recon Instruments MOD (2011, $400)
The MOD uses a 428X240 pixel resolution display with a 10-degree diagonal field of view to show speed, GPS location, altitude, temperature, jump height and other stats while a user is skiing. It is designed to fit in compatible ski goggles, runs Android, and weighs 65 g.
Audible MobilePlayer (1997, $200)
While big-name companies were avoiding making flash-based music players because of piracy fears, Audible skirted the issue by focusing on audio-based books.
Texas Instruments EZ-430 Chronos wristwatch (2009; $49)
This wristwatch is a reference platform for developers interested in creating smartwatch applications. It includes an accelerometer, pressure sensor, temperature sensor, and battery voltage sensor.
Sony Ericsson LiveView MN800 wristwatch (2010, $180)
This Android-based smartwatch features a touchpad and can control music, incoming calls, social network feeds, and downloadable apps.
Glass prototypes: Pack headset (December 2010)
Glass prototypes: Ant (March 2011)
Glass prototypes: Cat (May 2011)
The Google Glass project started in 2010. By December, several team members were wearing the “Pack,” a backpack with a laptop, GPS, and mobile keyboard attached to the headset shown here, with a TacEye display, webcam, IMU, multi-touch touchpad, and earbuds. It was the first operational version of Glass. Ant, Bat (not shown), and Cat were three operational prototypes designed by repurposing Nexus One phones. Cat was the first of the series to use the current Glass optics design.
Glass prototypes: Lennon (April 2011)
Glass prototypes: Dog plastic (June 2011) / Glass prototypes: Dog metal (June 2011)
Glass prototypes: Emu (September 2011)
Glass prototypes: Fly (October 2011)
Lennon was an effort parallel to the animal-family line to determine how light a wearable computer could be made and still be useful. It was the first device that could be worn reasonably all day. Meanwhile, Dog was the first system to incorporate Glass’s high-end computer board. Emu demonstrated the attempt to enclose all the electronics and tested the concept of a bone-conduction speaker. Fly was the first attempt at creating a sleekly designed, functional prototype.
Glass prototypes: Gnu (December 2011), Hog (February 2012), Ibex (May 2012), Koala (October 2012)
Google refined the Glass prototype over time based on users’ experiences. In April 2012, the project was announced so that the team could wear Glass publicly. This “living lab” approach, through which a community of users discovers the benefits and challenges of a technology worn openly in their everyday lives, was expanded to the public in April 2013 through the Glass Explorer program.
Google Glass Explorer Edition
Other current lightweight wearable computers such as the Vuzix M100 and Epson Moverio
focus on industry applications. However, Glass is designed for the consumer. Through “microinteractions,” Glass strives to provide the most functionality with the least amount of user attention.