Air-Cushion Tactile Sensor for Medical Applications

Student thesis: Doctoral ThesisDoctor of Philosophy


In the surgical field, the trend tends increasingly towards performing minimally invasive procedures as they offer improved aesthetics, a reduction in blood loss, tissue trauma and post operative complications. However, the limited accessibility of the surgical site due to the use of small incisions does generate a few drawbacks. One of the main concerns is that surgeons cannot manually palpate the tissue they are operating on as they would in traditional open surgery. Manual palpation of the surgical site is performed to feel any tissue abnormalities such as tumours that may be present. This inability to feel the organs through minimally invasive surgery (MIS) is known as a lack of haptic feedback. Over the last decade, there has been an extensive amount of research in tactile and force sensing for MIS in an effort to overcome this limitation. The air cushion sensor for MIS is one of those. This novel sensing concept employs a spherical component that is surrounded by a cushion of air, to roll over the surface under inspection. The proposed sensing concept employs optical sensing when it is rolled to determine the areas of increased stiffness in a tissue. Using this concept, three sensors were designed and built. Their ability to detect tissue abnormalities in ex vivo tissues was assessed and so was their capability at estimating the force distribution over that area. The results show that all of the sensors were capable of detecting the tissue abnormalities and that one sensor was able to generate a force distribution map of the area under investigation.
Date of Award2012
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorKaspar Althoefer (Supervisor) & Prokar Dasgupta (Supervisor)

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