Monday, February 11, 2008

Maintaining Multiple Personas Online

A new site lets users create profiles for the different sides of their personality.

Facing the online world: Moli, a recently launched social-networking site, allows users to make profiles to represent different aspects of their personality. In the image above, a Roman coin depicts Janus, the Roman god of gates and doors, whose two faces, pointed in opposite directions, represent the transition between two times or places.
Credit: Kunsthistorisches Museum, Wien

Online social networks have allowed people to easily stay in touch with large groups of friends, but the flip side has been well publicized. Some users have struggled over what to do when certain people--such as a boss or an ex-boyfriend--ask to be listed as a friend on their profile. Adding someone as a friend gives him access to the user's profile, photos, and daily musings. Worries about privacy were renewed recently when Facebook's Beacon advertising initiative began broadcasting information about users' purchasing habits throughout its networks. (See "Evolving Privacy Concerns.") Now Moli, a recently launched social-networking site, aims to win over concerned users. President and COO Judy Balint says that the site is intended for a more mature audience than the teenagers targeted by many social-networking websites. Directed at users who are trying to balance personal and professional networks, Moli offers multiple profiles--with different privacy settings--within one account.

"As we get a little bit older in our lives, none of us have the time anymore to spend going to 5, 10, or 15 different sites," Balint says. "So what we tried to do was combine the functionality into one account, so that you can go there and do everything that you need."

Users of Moli can set up as many profiles as they want, and they can choose to make them public, private, or hidden. Anyone, whether he has signed up for Moli or not, can search for and view a public profile. A private profile will show up on searches, but to access it, a user must be a member of Moli and must have approval from the profile's owner. A hidden profile is invisible in searches and can only be viewed by people invited by the owner. Balint says that users are free to set up multiple profiles of various types, with the requirement that they must designate at least one public profile.

Balint says that the site is also intended to appeal to small-business owners, who can use it to set up an intranet and extranet for free. For a fee, businesses can run a store through Moli.

Alessandro Acquisti, an assistant professor in information systems and public policy at Carnegie Mellon University, says that, while it's not clear how people will behave on Moli, his research has shown increasing attention to privacy among Facebook users. Studies that he performed on Facebook privacy settings in 2005 and 2006 showed that the vast majority of users left the defaults in place. However, more recent studies have shown that users are now much more likely to adjust those settings than they were in the past. "It's probably because of media attention [to privacy concerns], and more mature people coming into Facebook, and because more time using the technology makes people more sophisticated about data," Acquisti says. However, he notes that, although users may be getting savvier about online privacy, a social network geared toward privacy will still be made or broken by whether it can attract a critical mass of users to the network in the first place.

Michael Zimmer, a fellow at the Information Society Project at Yale Law School, says that he thinks the type of privacy controls offered by Moli will be useful to a certain part of the population. "I'm sort of surprised that it's taken someone this long to let me, through one login, manage multiple identities and personas online," he says. Zimmer notes that it's important for users to feel at ease with privacy controls: he says that he considers some of Facebook's controls, for example, too complex for many users. However, he says, managing who sees what profile information is only "one half of the coin." The other half, as brought out by Beacon, involves what information the site itself has about users, and what the company does with that information. He notes that Moli's strengths in terms of profile management may lead users to trust the site with more personal information than they might otherwise give, and the company would have that information linked to a common e-mail and a common login. Zimmer says that for maximum privacy control, he would like a site to allow him to view what data is being stored about him and to opt in and out.

While Moli does store demographic information about users' activities on the site, Balint says that information is not stored in a personally identifiable way. The site keeps track of how many users of a certain age, for example, access a profile. Users (particularly small-business owners marketing through Moli) can also access this basic demographic data. Balint says that the company developed its own technology to extract demographic data from people visiting profiles without also extracting personally identifiable data. For example, she says, the company keeps statistics on how many females visit a profile, and how many people visit who are in their late twenties, but it does not combine the variables.

Moli recently announced nearly $30 million in new funding from a group of private investors. The company plans to make money through advertising, as well as through small monthly fees paid for premium services, such as the checkout option for small-business owners.

Lighting Ballasts That Direct Patients

An innovative navigation system uses optical signals from hospital lights to guide patients with traumatic brain injuries around hospitals.

Indoor location: An optical receiver sewn onto the left shoulder of a vest (bottom) picks up unique modulation signals from fluorescent lights such as that held by MIT engineer Steven Leeb (top). The optical signal is sent to a PDA in the vest’s pocket. The PDA uses mapping software to generate audio directions for patients in rehab because of head trauma.
Credit: Donna Coveney (top)

Researchers are developing a high-resolution tracking system that uses PDAs and audio directions to guide patients around hospital wards. The system also helps rehabilitate those with traumatic brain injuries. The system, which is made by Boston startup Talking Lights, uses light fixtures as beacons to send information to a PDA via an optical receiver. The PDA is also loaded with mapping software, information about the building, and user-specific data such as appointment schedules.

Traumatic brain injuries, which might result from car accidents or the detonation of an improvised explosive device, among other possible causes, can lead to cognitive problems that include trouble with abstract thinking, memory, and spatial orientation. The Talking Lights guidance system is "a tremendous asset for someone with traumatic brain injury," says Heechin Chae, medical director of the brain injury center at Spaulding Rehabilitation Hospital, in Boston. The system has been tested at the hospital over the past two years and is currently used by about 20 patients. It not only helps patients navigate the rehab center, but it also appears to help them relearn how to process visual cues and navigate unfamiliar environments, Chae says.

Installing the indoor guidance system in a building is a simple and fairly cheap process, says Neil Lupton, president of Talking Lights. The light fixtures don't need to be replaced. All that needs to be switched out is the ballast, an electrical component that's normally replaced every few years in all fluorescent lights. The ballast regulates the amount of electricity that goes into the bulb to maintain the light level and keep the bulb from exploding.

Steven Leeb, a professor of electrical engineering and computer science at MIT, designed a ballast that modulates the light coming out of the bulb in a set pattern to give each bulb a unique optical signature. No flickering is visible to the naked eye, but off-the-shelf optical receivers can detect these patterns.

Patients at Spaulding Hospital who are participating in the project wear a vest with an optical receiver sewn on the shoulder. The receiver is connected to a PDA that is stored in the vest's pocket. A database containing maps for the building is stored on the device, outlining all the lights and their signatures. Software on the PDA rapidly computes the user's position based on which light she's nearest to. Then, based on the particular patient's location and a unique preloaded schedule, the PDA plays recorded directions. A typical sequence, read in a firm voice, goes, "Katie, go to the gym. Go through the double doors." If the user goes through the wrong double doors, the device provides a correction: "You are going in the wrong direction. Pass the photocopier. Turn to your right." Information about what's near each light at each particular location can be put into a global database in about a day's time, says Daniel Taub, an engineer with Talking Lights.

The system can be customized to particular users. Depending on their stage of recovery, some brain-trauma patients might need more or less frequent instructions, or they might need to start out with a reminder to put on a helmet or check their shoelaces. Family members can make the audio recordings so that patients can hear a trusted voice, and the recordings can be in any language. User data is recorded during use and analyzed afterward to assess each patient's progress--how many reminders he needed, how much time it took him to reach his destination--and the system is adjusted accordingly.

"The brain is a dynamic organ," says Chae. "The whole basis of rehab is repetition of voice commands and tasks." He believes that the system helps patients learn to adapt to unfamiliar places, and so ultimately, it could benefit the patient outside the hospital, too, by retraining his or her brain.

Leeb and Lupton say that their system processes users' locations more quickly and accurately than do other systems that rely on GPS, radio frequencies, or Wi-Fi triangulation. GPS doesn't work well in buildings, and it only has a resolution of about 30 feet, so it isn't ideal for guiding patients around a hospital. Systems that calculate location based on the local strength of Wi-Fi signals from transmitters in multiple locations require more time-consuming calculations than the lightbulb system does, and this could slow people down and drain the PDA's battery. Conversely, the resolution of Leeb and Lupton's system is limited only by the spacing of the light fixtures. (Signals from the Talking Lights system don't interfere with hospital equipment, much of which is shielded.)

The company is currently developing a system that connects to a robust Wi-Fi mesh network to deliver information about patients' locations to hospital staff. Nurses monitoring people with dementia in an assisted-living facility, for example, could be quickly alerted when a patient wanders into an area that poses a fall risk. Talking Lights will demonstrate this monitoring capability in an Alzheimer's facility in a few months, says Leeb. The company has also installed a system for the blind in Stanford University's department of psychology.

In the coming years, Talking Lights plans to develop software that can run on smart phones and hardware for a Bluetooth headset with an optical receiver. The headset would pick up the optical signals, send them to the phone, and then play back directions to the wearer.

Preventing Concussions

A new football helmet could help players avoid brain injuries.

Head protection: A new football helmet developed by Xenith is lined with 18 thermoplastic airflow shock absorbers embedded in a flexible cap to better protect athletes from concussions. The helmet’s design adapts to the force of an impact and dissipates the energy to decrease the acceleration of the head and prevent the jarring that causes concussions. A transparent inside view of the helmet is shown at top, while the complete helmet is shown at bottom.
Credit: Xenith

, a startup company based in Lowell, MA, has developed a new football helmet to better protect athletes from concussions. The helmet is lined with a thermoplastic material that can adapt to the force of impact. On a routine hit to the head, the discs cushion the head, while following a harder, more forceful blow, the material remains stiff and prevents the sudden jarring of the head that causes concussions.

"The idea is that we have something that is more intelligent and responds uniquely to what is happening to it," says Vincent Ferrara, the founder and CEO of Xenith. Testing has also shown that the discs can withstand hundreds of impacts without notable degradation in performance. The Xenith helmet will be available this spring for approximately $350, which is considerably more expensive than helmets already on the market.

The protective material in football helmets has evolved over time from traditional foam padding to gel-filled and inflatable padding. But Joseph Maroon, a neurosurgeon at the University of Pittsburgh Sports Medicine Center, says that none of the designs for football helmets are ideal, and concussions remain a common problem in the sport. "It is estimated that 10 to 25 percent of football players in the United States sustain a concussion each year, and the effects can be catastrophic," says Maroon, the team physician for the NFL's Pittsburgh Steelers. "There is a need for a new type of helmet technology."

To address this need, Xenith has embedded 18 shock absorbers into a flexible cap that lines the inside of a helmet. The shock absorbers are made out of a plastic that is elastic and flexible, thus it can accept a wide range of forces and return to its original shape instantaneously. The shock absorbers are hollow discs featuring a tiny hole to allow air to flow in and out. Upon impact, the walls of the discs collapse to absorb and dissipate the energy.

"When you force air or any fluid to flow through a small hole, you get an adaptive response: the harder [the disc] is hit, the stiffer it behaves, because you are generating more resistance inside the disc," says Ferrara. "You want a system to behave softly under low energy, but under high energy, you want it to get progressively stiffer so that it does not collapse down to nothing."

The inside lining of the Xenith helmet shown here is a flexible cap embedded with shock absorbers, or black discs, intended to dissipate the energy of a hit and lessen the sudden movement of the head that causes concussions.
Credit: Xenith

Conventional helmets are lined with different types of absorbency materials, such as foam or fluid-filled pads, intended to conform to the shape of the head and dissipate energy. Upon impact, the pads deform. However, the material lacks resiliency and thus degrades over time. Gel- and air-filled pads have to be refilled and monitored for leaks. What's more, these materials can't adjust to the amount of force.

A cable runs around the flexible cap from the back of the helmet toward the front, and through the helmet's chin straps. When a player pulls on the chin straps, the chin piece pulls the cable downward. This secures the back and sides of the helmet around a person's head, so the inside of the helmet is literally adapting to the person's head size and shape, says Ferrara.

The Xenith helmet is one more step in a football-helmet design that seems to be effective in absorbing energy and dispersing the impact so that it's not all going to the head, says Laurence Young, a professor of aeronautics and astronautics at MIT. Young is also working on a helmet design, still in the research phases, based on a similar concept.

The Xenith helmet will be available in one size this spring, and a full range of sizes will be released in 2009. Ferrara also plans to use the helmet technology in other sports helmets, as well as in military helmets.