A BAN System Providing Safety Assistance to People with Visual Disability

- A Wireless Communication System Attached to Sunglasses, Wrist Watch, and Stick -

May 26, 2011

National Institute of Information and Communications Technology (hereinafter called NICT, President: Hideo Miyahara) has succeeded in developing a body area network (BAN) system using the worldwide common high-band of ultra-wideband (UWB) signal.

The BAN system uses UWB to transmit various signals, including video pictures taken by a small camera attached to the frame of sunglasses, data of body temperature, carotid pulse, and oxygen saturation measure by pulse oximetry (SpO2) from a wrist watch type unit, as well as obstacle information detected by an ultrasonic wave sensor attached to a stick, to a belt-attached type hub. In which, the obtained information is processed and a part of the information, like color of traffic signal, etc., is presented in voice for guidance. The media access control (MAC) of the developed system is installed obeying the specifications of IEEE802.15.6, which is an international standard of BAN and which is currently under development.

Background

By combining with various vital sensors (carotid pulse, SpO2, body temperature, etc.), BAN can provide good solutions for prevention of chronic diseases as well as for healthcare for elderly people. Moreover, BAN can also be used for entertainment by providing wireless transmission of voice, video, and data among devices deployed around a human body, such as game controllers and wireless headphones.

The inherent properties of low power consumption and low density of emission power of UWB (see Figure 1) benefit the implementation of BAN. As a result, UWB is specified as one of the PHYs in IEEE 802.15.6, to which NICT has made a lot of contributions. The available frequency bands for UWB contain a low-band and a high-band. Because other wireless systems also seek to use the low band, a number of limitations are addressed by regulations. Therefore, there is a need to develop a BAN system using the worldwide common UWB high-band.

It should be noticed that IEEE802.15.6 is an international standard under development, which defines the specifications of BAN for wireless links among devices deployed on body and in proximity of body.

New Achievements

NICT developed a BAN system using Japanese UWB high-band (7.25-10.25 GHz) in foregoing years. The new developed BAN system uses the worldwide common UWB high-band (7.7376-8.2368 GHz), which has a bandwidth only 1/3 of that of the old system. Moreover, a MAC obeying the specifications of IEEE 802.15.6 is installed to increase both power efficiency and high reliability.

As an application, the new system is developed with functions to assist people with visual disability. Various signals, including video taken by a small camera attached to the frame of sunglasses, data of body temperature, carotid pulse, and SpO2 from a wrist watch type unit, as well as obstacle information detected by an ultrasonic wave sensor attached to a stick, are obtained and transmitted to a belt-attached hub using UWB. At the hub, some of the signals are transformed into vocal guidance for people with visual disability. (see Figure 2）.

The collected vital signals can also be used for general healthcare purposes as that of the old system.
https://www.nict.go.jp/press/2010/05/10-1.html - Japanese

Future Plans

Because of the adoption of the worldwide common high-band, the developed UWB BAN can be used in most countries including USA, EU, and Japan after certification. It can not only be used to provide safety assistance to people with visual disability and for general healthcare purposes, but also be expected to support a large range of applications in entertainment field. It should be noticed, this BAN system will be exhibited at Wireless Technology Park 2011, which will be held at Pacific Yokohama, July 5-6, 2011.
http://www.wt-park.com/eng/index.html

Supplementary Information

Figure 1 Comparison among UWB and traditional narrow band signals．

Compared to traditional narrow band signals like GSM, W-CDMA, etc., UWB lowers its emission power density (below -41.3 dBm/MHz) by spreading its spectrum over an ultra-wide range of frequency (beyond 500 MHz).

Figure 2 Usage model of the developed BAN to assist people with visual disability．

The camera unit takes and sends video pictures to the belt-attached unit.
The wrist watch type unit collects and sends data of carotid pulse, SpO2, and body temperature to the belt-attached unit.
The stick-attached type unit detects the distance of an obstacle and sends the information to the belt-attached unit.
The belt-attached unit is the hub of the BAN. On one hand, it manages channel accesses of all units.
On the other hand, it adds necessary processing to the received signals and provides audio guidance accordingly.