FlexDex, Enhanced Dexterity Laparoscopic Tool

A significant effort in our group has been on the development of enhanced dexterity laparoscopic tool technology for minimally invasive surgery. Traditional laparoscopic tools either lack the necessary dexterity for complex procedures that are becoming increasingly common in minimally invasive surgery (MIS), or are unintuitive to operate resulting in limited functionality and significant surgeon training times. On the other hand, robotic tools generally provide exceptional dexterity and controllability, but lack haptic feedback and are very expensive. We have collaborated with Dr. James Geiger from Pediatric Surgery (UMHS) to overcome this affordability versus functionality tradeoff via a novel minimally invasive surgical (MIS) tool technology platform – FlexDex.

Developed in the Precision Systems Design Lab (PSDL), the FlexDex technology employs a novel forearm mounted tool configuration and an associated parallel-kinematic virtual center mechanism that makes the tool input joint coincident with the surgeon's wrist. This enables a highly natural control of the two wrist-like rotations of the end-effector, along with the translations and roll rotation. The resulting intuitive mapping between the surgeon's hand motions and the end-effector motions makes the tool a natural extension of the surgeon's hand inside the patient's body. While such motion transmission, in surgery as well as other applications, has long been possible via robotics, we have created comparable functionality via a simple, low-cost, mechanical design without using sensors, actuators, or computers.

This technology has led to the creation of a start-up company FlexDex LLC that is focusing on product development, regulatory approval, and commercialization. Ongoing work in PSDL in this area includes development of cable based articulated motion transmission systems and miniaturized parallel kinematic mechanisms capable of multi-DoF motion capability.





Robotically Controlled Endo-Illumator

PSDL has collaborated with Dr. Thiran Jayasundera in the Department of Ophthalmology (Kellogg Eye Institute, UMHS) on the development of a robotically controlled endo-illumator system that automatically tracks the active surgical instrument being used by the surgeon during a vitreo-retinal surgery. This eliminates the need for the surgeon to hold and manually maneuver the endo-illuminator, thus freeing up the surgeon's secondary hand for bi-manual surgery. The superiority of bi-manual surgery is evident in virtually all surgical fields and is ideal for implementation in vitreoretinal surgery. Benefits include reduced surgery times, lower risks of complications, and faster learning curves for training surgeons. Additionally, bi-manual techniques in vitreoretinal surgery allow the surgeon to externally depress the eye without the need of a trained assistant.

The traditional illumination options include a rigid endo-iluminator that provides localized but focused lighting, or a chandelier that provides wide-field but diffused lighting. We are developing a novel endo-illuminator "automatically" track the surgical instrument during operation to maintain the lighting location and focus. As opposed to other extra-ocular robotic solutions that take up valuable space around the patient, we have proposed an intraocular actuation approach that results in a compact, and low cost system.



Minimally Invasive Skin Tissue Biopsy Device

In Winter 2012, Prof. Awtar and an ME450 team developed a novel, low-cost, minimally invasive skin tissue biopsy device that can extract a piece of skin with minimum pain and store it for research and disease diagnosis. The device developed in this project contains an outer housing, two latch components, inner needle, and an outer needle, arranged in unique manner to provide an easy, single-trigger operation. Skin tissue biopsies are commonly used to extract skin from a person's body to either study for research or for clinical diagnostic purposes. These include tests for any markers for diseases such as osteoporosis, skin cancers or other skin diseases.


1.  Awtar, S., Trutna, T.T., Nielsen, J.M., Abani, R., and Geiger, J.D., 2010, "FlexDex: A Minimally Invasive Surgical Tool with Enhanced Dexterity and Intuitive Control", ASME Journal of Medical Devices, 4 (3)
2.  Awtar, S., Trutna, T., Nielsen, J., Mansfield, A., and Abani, R., 2009, "Flex-Dex: A Minimally Invasive Surgical Tool with Enhanced Dexterity and Intuitive Actuation", Proc. ASME IDETC/CIE 2009, San Diego, CA, Paper No. 87824
3.  Awtar, S., et al., Minimally Invasive Surgical Tool, Provisional Filed: 04/08, PCT filed: 04/09, US patent Granted: 2014
4.  Pinon, R., Ke, C., Sachachar, I., Jayasundera, T., and Awtar, S., 2014, "Automatic Instrument Tracking Endo-illuminator for Intraocular Surgeries", ASME Design of Medical Devices Conference, under review
5.  Endo-illuminator and Apparatus and Systems for use Therewith, Provisional Filed: 05/2013, US Serial No. 61/829,758
6.  Skin Tissue Biopsy Device, Provisional Filed: 04/12, PCT filed: 04/13, PCT/US2013/036136


1.  College of Engineering:
2.  The University Record:
3.  The FlexDex invention was showcased at the annual Celebrate Invention event organized by the Technology Transfer Office as one out of six inventions short-selected from approximately 350 filed with the university, for holding the greatest potential impact and commercialization.
4.  A team of graduate students from PSDL won the first place in ASME Student Mechanism Design Competition for the FlexDex design at the 34th Mechanisms and Robotics Conference, in the 2010 ASME International Design and Engineering Technical Conferences.
5.  The FlexDex paper that appeared in the ASME Journal of Medical Devices was in the "Top 10 Most Downloaded Articles" list of that journal for three months in a row – #1 most downloaded in Sep 2010, #2 in Oct 2010, and #5 in Nov 2010.
6.  Prof. Awtar received the Leonardo da Vinci Award for the FlexDex invention, to recognize eminent achievement and important advances in the field of machine design, American Society of Mechanical Engineers, 2011.