A sub-millimeter size tissue stiffness sensor

The aim of the project is to design and make a micro-fabricated optical sensor that can measure the stiffness of tissue at the tip of a needle. In the Netherlands alone, each year more than 50.000 percutaneous procedures are performed for treatment or removal of tissue from possibly diseased organs. Erroneous needle targeting can have disastrous effects for the patient. For instance, malignant cells may be missed due to inaccurate positioning of the biopsy needle. Since different tissues have a different stiffness a sensitive sensor at the tip of the needle can help the surgeon to guide the needle to the proper location.

Together with experts from different groups you will develop an instrument consisting of a needle tip with an optical fiber interferometric technique to monitor needle advancement through different types of tissue. When the needle encounters the interface between two layers a fiber-top indenter inside the needle is protruded. This can be used to accurately measure the stiffness of the tissue that is about to be perforated. The fiber-top indenter consists of a micromachined membrane, fabricated on top of an optical fiber. Upon contact with the tissue, the membrane experiences a deflection depending on the stiffness of the tissue. By coupling light from the opposite end of the fiber, the cantilever position is assessed. Measurements of cantilever bending and needle motion will be combined to accurately assess tissue stiffness.

Assignment

• Work together with different groups:
  • VU Amsterdam
  • TU Delft - EEMCS/EKL
  • Philips Research
• Perform mechanical simulations / calculations
• Design the sensor
• Get a thorough training in micro-fabrication
• Fabricate the sensor in the DIMES/EKL cleanroom

Contact

Last modified: 2023-01-12