Cities are difficult to navigate (导航) at the best of times, but for people with disabilities they can be like courses with hurdles and bring inconvenience to disabled people.

A UK national travel survey found that adults with mobility difficulties took 39% fewer trips than those with no disability in 2017. Yet that could change as devices and cities grow smarter. Assistive tech is playing a big role in the transformation. The global value of the industry is expected to increase from $14 billion in 2015 to $30.8 billion in 2024, according to Zion Market Research.

One of the things that could transform lives is a smart walking stick designed by engineers from Young Guru Academy (YGA) in Turkey. The WeWalk stick has a sensor that detects hurdles above chest level and uses vibrations (振动) to warn the user. It can be paired with a smartphone to help navigation, and is connected with a voice assistant and Google Maps.

Ceylan, who has been blind since birth, says that connecting the stick to the Internet of Things and smart city solutions makes it user-friendly. “As a blind person, when I am at the Metro station I don’t know which is my exit ... I don’t know which bus is approaching ... which stores are around me. That kind of information can be provided with the WeWalk,” he says.

“The smart walking stick is really an exciting initiative that will make a huge difference to some people,” says Anna Lawson, the director of the Center for Disability Studies at Leeds University in the United Kingdom. “But they are very expensive ... they’re not going to be available to the vast majority of disabled people,” she added.

Bryan Matthews, a lecturer at the Institute for Transport Studies at the University of Leeds, shares the concerns about cost. He says there should also be a focus on inclusive design, and anything that helps people navigate their environment is positive.

Facebook has launched its first pair of smart glasses, which house speakers and cameras, built with eyewear firm Ray-Ban. The glasses, which are available in a range of colours and styles, are priced at £299 and will be available from September 13.

Called Ray-Ban Stories, the glasses feature two five-megapixel cameras to take photos and videos, as well as built-in microphones and speakers enabling users to make calls and listen to audio. The glasses also come with built-in LED lights to let people nearby know when the wearer is taking a photo or video and pair with the new Facebook View app, which enables users to share content from the glasses to their social media accounts.

Announcing the new hardware, Facebook acknowledged that privacy was a key issue it had looked to address when creating the new device. “As with any new device, we have a big responsibility to help people feel comfortable and provide peace of mind, and that goes not only for device owners but the people around them, too,” the social network said in a blog post.

Facebook said it would also offer guidance to users on how to safely use the glasses with regard to others. “We’ve developed guidelines for what is and isn’t an appropriate use of the glasses, some of which are surfaced right in the app during on boarding, and which are available in full online on our dedicated privacy microsite for Ray-Ban Stories.”

“These tips include respecting people’s preferences if they ask you to stop recording or don’t want to be in a photo or video, not capturing photos and videos while driving, and turning off the glasses in private areas like places of worship, a doctor’s office, or locker rooms.”

A new technique to work out a corpse’s time of death

In fiction, forensic (法医的) experts presented with a corpse are able to take a bite of their sandwich and instantly pronounce a time of death. Reality is, of course, a lot messier, and the results — or lack of them — can make or break a case.

Now artificial intelligence is offering a helping hand. By analyzing thousands of deaths and what follows, the technology can offer the best estimates so far of PMI, Post-Mortem Interval (尸体死后间隔).

【小题1】 For decades these specialists have had to rely on intuition, combined with observations of the state of the deceased and clues such as temperature, both of the dead body and the environment. Different bodies decay at different rates, however, and individual circumstances can throw off the most careful PMI calculations. A body found in a ditch in northern England in 2004, for example, was given a wrongly late time of death because the ditch was sheltered from sunlight and the colder-than-expected conditions had helped preserve the corpse.

Forensis-science journals are full of such cases while the potentially useful details of thousands more investigations are buried in case files around the world. 【小题2】. The result is an AI-powered tool, called geoFOR, that could offer the most reliable estimates of PMI so far. Sandwiches are not included.

Developed by a research team led by Katherine Weisensee at Clemson University in South Carolina, the model is based on data pooled from more than 2,500 death investigations, with more added each week. About 1,800 of these are real-world cases involving the discovery of a body. 【小题3】 . Corpses here are left to decay for weeks and months under varied circumstances. With their precise PMI known, photos and descriptions of their various states of decomposition over time, along with information about temperature, humidity, wind, soil type and other conditions, have all helped train the AI model.

The results could be used to check alibis and help solve crimes, but they have other uses too. Madeline Atwell, a forensic anthropologist at Clemson University who works on the project, says the model has already helped close several missing-person cases. 【小题4】 “You match it with missing-person records, and that helps narrow your time frame,” she says.