<p>➀ BodyFriend developed a new optical sensor system using light and slit mechanisms to detect leg length in massage chairs, registering a patent for the technology; </p><p>➁ The method offers higher precision than traditional pressure/mechanical systems, enabling personalized massage experiences by accurately tracking joint positions; </p><p>➂ The technology enhances BodyFriend's RoboWalking Technology, improving massage accuracy and overall user experience.</p>