Improving standing balance is critical for preventing falls and ensuring the well-being of older adults. In this paper, we present Invisible Light Touch (ILT), a mid-air haptic feedback application designed to improve standing balance by utilizing the light touch effect, a well-documented phenomenon in medical research. The light touch effect refers to improved balance when a person lightly touches a surface, such as a wall or handrail, with a force of 1 N or less. We replicate this effect utilizing focused ultrasound to create a tactile point in mid-air. When users interact with this invisible tactile point, they experience the light touch effect, which subsequently improves their balance. We conducted a pilot study with 29 participants and a user study with 25 older adults, evaluating the balance improvement by measuring the center of pressure trajectory. The results confirmed that standing balance improved significantly when using the ILT.
https://dl.acm.org/doi/10.1145/3706598.3713396
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