Smart pendant in development to help commuters with visual impairment identify arriving buses

SINGAPORE – Commuters with visual impairment could soon be able to use a necklace pendant that can identify and read out bus service numbers, making it easier for them to travel by bus.

Nanyang Technological University (NTU) undergraduate Lee Kiah Hong, 22, and three of his friends are working on a prototype of the pendant that builds on the technology used in an iPhone application called Oculis that they developed.

The iPhone app uses computer vision to identify the bus service number, and then a voice reads it out loud, a feature which comes in especially handy for visually impaired commuters who are travelling alone.

Lee and his friends – full-time national servicemen Ryan Yeo, 21, Sriram Jeyakumar, 21, and Chia Wee Leong, 22 – decided to improve on the iPhone app and create a pendant that can be worn on a necklace.

It will come with specialised cameras and sensors that will help users with visual impairment better navigate the bus system.

The team met while studying applied AI and analytics at Singapore Polytechnic.

They started developing the Oculis iPhone app in July 2025 as part of an accelerator scheme for the Build for Good initiative under Open Government Products – an independent unit of the Government Technology Agency (GovTech).

They received $20,000 in funds and mentoring sessions and successfully carried out tests with members of the visually impaired community, while tracking data and gathering feedback.

The Oculis tech tool taps into real-time bus arrival timings provided by the Land Transport Authority. When the bus they are waiting for is one minute away, the app gives users an alert.

An audio alert provides instructions, and phone vibrations – called haptics – guide users on how best to position the phone in the right direction towards the bus.

When their bus arrives, users will get a voice confirmation.

Lee said the team got feedback from more than 40 users with visual impairment over more than 200 navigation trips, and found that many of them preferred a hands-free option because they needed one hand to hold a cane.

Several of them preferred to keep one hand free, in case they took a tumble and needed to cushion their fall, he added.

Also, the iPhone rolling-shutter camera could not detect and identify bus numbers on the screen displays of older buses quickly and accurately, and ended up showing a “pulsing” image on-screen.

Lee and his team are now in the research and development stage for the wearable pendant, and are still in the midst of making sure it is safe to use as well as user-friendly before running tests with visually impaired users.

Lee said the team is open to experimenting with how the new device looks, and is developing prototypes in the forms of spectacles and necklaces.

The team is also mulling over how the audio announcement will be delivered if the device were in the form of a pendant, with options such as a loudspeaker or Bluetooth connection to earpieces under consideration.

Lee said each wearable device is estimated to cost between $30 and $40 if the team manages to buy materials in bulk and secure a mass production deal.

Lee got the idea for the Oculis app when his uncle lost much of his vision after developing glaucoma in 2021. His uncle felt he needed to rely on others when taking the bus alone, especially when he was at the bus stop and wanted to know if his bus had arrived.

Even going to a nearby market caused him anxiety.

Lee said he hoped the app could help his uncle, who is in his mid-forties, feel more confident when travelling on his own, especially during peak hours when other passengers are in a rush and help is hard to come by.

The team, he added, is working on the project while juggling other commitments, so no firm timeline has been set to produce the devices. These will be among the first such accessibility-focused tech devices in the transportation field in Singapore if they go into production.

Assistant Professor Victor Zhuang, who teaches disability communication at NTU, said it is exciting how artificial intelligence, computer vision and wearable technologies are increasingly able to translate previously inaccessible information into modes like speech or vibration.

However, it is important that accessibility does not become the responsibility of commuters with physical disabilities, who will be required to buy, charge, wear and maintain a special device just to use public transport, he added.

He said: “Apps and wearables should complement accessible infrastructure, information systems, announcements, wayfinding, and trained staff rather than replace them.”

Zhuang added that it is important to get people with disabilities involved not only as testers or users, but also in deciding which problems can be solved by technology, and how these solutions are designed.

A navigation app called Waymap-SG that uses step-by-step audio instructions to guide users through public transport hubs is now available for use at 17 bus interchanges and MRT stations.

Users can be prompted to take photos of their surroundings, and a visual positioning system will determine their starting location.

The app will then guide them along accessible routes, for example, by avoiding stairs where necessary, and providing clear prompts at key points, such as turns, escalators, lifts and exits.