• LiTu - A Human-Computer Interface based on Frustrated Internal Reflection of Light

      Edwards, Marc R.; John, Nigel W.; University of Chester (IEEE Conference Publications, 2015-10)
      We have designed LiTu (Laɪ’Tu - Light Tube) as a customisable and low-cost (ca 30 Euros) human-computer interface. It is composed of an acrylic tube, a ball-bearing mirror, six LEDs and a webcam. Touching the tube causes frustrated internal reflection of light due to a change in the critical angle at the acrylic-skin boundary. Scattered light within the tube is reflected off the mirror into the camera at the opposite end for image processing. Illuminated contact regions in the video frames are segmented and processed to generate 2D information such as: pitch and volume, or x and y coordinates of a graphic. We demonstrate the functionality of LiTu both as a musical instrument and as an interactive computer graphics controller. For example, various musical notes can be generated by touching specific regions around the surface of the tube. Volume can be controlled by sliding a finger down the tube and pitch by sliding the finger radially. We demonstrate the adaptable nature of LiTu’s touch interface and discuss our plans to explore future physical modifications of the device.
    • Real-Time Guidance and Anatomical Information by Image Projection onto Patients

      Edwards, Marc R.; Pop, Serban R.; John, Nigel W.; Ritsos, Panagiotis D.; Avis, Nick J.; University of Chester (Eurographics Association, 2016-09)
      The Image Projection onto Patients (IPoP) system is work in progress intended to assist medical practitioners perform procedures such as biopsies, or provide a novel anatomical education tool, by projecting anatomy and other relevant information from the operating room directly onto a patient’s skin. This approach is not currently used widely in hospitals but has the benefit of providing effective procedure guidance without the practitioner having to look away from the patient. Developmental work towards the alpha-phase of IPoP is presented including tracking methods for tools such as biopsy needles, patient tracking, image registration and problems encountered with the multi-mirror effect.