Toray Industries Inc, Nippon Telegraph and Telephone (NTT) Corp and NTT Docomo Inc co-developed a new functional material that enables to measure heart rate and electrocardiographic (ECG) waveform just by wearing it.
Also, they used the material, "hitoe," to make a T-shirt that can collect biological information as the first application of the material. When the T-shirt is combined with a special wireless communication unit and smartphone, it becomes possible to measure heart rate and ECG waveform in real time.
The most distinguishing feature of the material is that it eliminates the need to attach electrodes to skin. Because the T-shirt collects biological information without hampering daily activities, it becomes possible to collect such information for a long time without feeling uncomfortable.
The T-shirt is expected to be used for measuring the heart rates and ECG waveforms of fitness club members, the heartbeats of those who require nursing care at nursing facilities and home, etc. NTT Docomo plans to launch a new service using the T-shirt and a smartphone within 2014.
The T-shirt is made by attaching rectangular cloths made of the hitoe, which function as electrodes, to the inner side of a T-shirt (areas to be in contact with the right and left sides of the wearer's chest and part below the left side of the chest). A connector for the wireless communication unit is embedded in an area that corresponds to the left shoulder. And a conductive thread whose surface is covered for insulation is woven into the T-shirt to connect the connector and the electrodes.
Though the electrodes contact slightly different parts of the body depending on the body shape of a wearer, the locations and sizes of the electrodes were optimized. The conductive thread is stretchable because of a special weaving method. The hitoe material is also stretchable so that the pressure on the body does not increase too much due to the body shape or movements of the wearer.