Tissue fixation by suction increases the accuracy of robotic needle insertion

Needles provide percutaneous access to tissues deep within the body in order to deliver therapy or acquire biological samples for diagnostic purposes. The effectiveness of needle-based access often requires very accurate targeting of the needle tip within tissue. We designed a device that uses suction to fixate tissue during robotic needle insertion and measured its ability to improve targeting accuracy and decrease tissue deformation in artificial and ex vivo tissue. The deformation of the tissue was tracked in ultrasound images to evaluate the device´s performance. The device was particularly effective at fixating ex vivo tissue with an attached skin layer and decreased tissue deformation by up to 96%. When accessing an embedded target within tissue, suction fixation reduced the targeting error by over 1 mm in chicken breast without a membrane and over 2 mm in chicken breast with an attached skin. Suction fixation could be used to improve the accuracy of robotic needle insertion through the skin and into internal organs with capsules.