title: Tactile sensor using acoustic reflection for lump detection in laparoscopic surgery.
abstract: OBJECTIVE
  Laparoscopic surgery limits a surgeon's tactile sense. A tactile sensor could allow real-time tumor detection in laparoscopic surgery through lump inspection. This study was aimed at developing a simple and biocompatible tactile sensor for laparoscopic surgery. The proposed tactile sensor has a forceps-like shape, has no electrical elements in the tissue contact area, and can be sterilized and cleaned.
  
  
  METHODS
  We developed a tactile sensor using acoustic reflection. It is composed of a handle with a speaker and a microphone, an aluminum tube, and a sensor tip with a deformable elastic cavity. The acoustic wave in the tube is the superposition of the input wave and two waves reflected at the closed edge and the projection generated by deformation due to contact with an object. By measuring the acoustic wave in the tube, information of the deformation is derived.
  
  
  RESULTS
  The sensor is modeled, and the output is analyzed to determine design parameters of the sensor. Then, a prototype of the sensor is assembled. Fundamental experiments show that the sensor output increases with increasing normal deformation. Moreover, experiments using a phantom of the stomach wall with a 0-IIc type tumor (most common early stage gastric cancer) show that large sensor output is obtained for the lump when the sensor is moved across the back surface of the tumor.
  
  
  CONCLUSIONS
  The theoretical and experimental results show that the sensor is sensitive to the deformation due to contact with an object and has the potential to detect a lump in laparoscopic surgery.
authors.affiliation: Department of Engineering Physics, Electronics and Mechanics, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, 466-8555, Japan, tanaka.yoshihiro@nitech.ac.jp.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Fukuda
authors.forename: Michitaka
authors.initials: M
authors.lastname: Fujiwara
authors.forename: Akihito
authors.initials: A
authors.lastname: Sano
mesh_terms: D004867:Equipment Design; D006801:Humans; D010535:Laparoscopy / Q000295:instrumentation* / Q000379:methods; D008962:Models, Theoretical; D025321:Surgery, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D013525:Surgical Instruments; D014110:Touch