A Novel Endoscopic Surgical Device for Real-Time Measurement of Hernia Defects and Other Anatomic Geometries

Gyusung Lee, PhD, Ivan M George, Adrian Park, MD. University of Maryland

Objective of the technology or device.
At the University of Maryland we are developing a novel device (US patent pending) that will allow surgeons to measure the size and shape of a hernia defect so that mesh size and potentially shape can be more accurately estimated than currently possible. This device acquires a probe’s tip location as it makes contact with points of interest. This instrument is designed as well to provide measurement and visualization of two-dimensional or three-dimensional geometries. The device also is designed to perform various calculations applicable in other clinical applications, such as moving beyond the methodology of location to the outcome of determining points of fixation.

Description of the technology and method of its use or application.
This system consists of four essential components: probe, tracking sensor unit, control unit, and measurement and post-processing unit. The probe–a long, rigid object to which the tracking sensor is attached–is partially introduced into the human body for measurement and visualization. As the probe’s distal tip gently touches specific anatomical landmarks of interest, our system permits identification of the tip’s location in space. The user holds the probe by a proximally located handle. The tracking sensor unit may be composed of a single sensor or array of markers. A variety of existing motion tracking systems can be used to calculate the location information of the tip. The control unit is an actuation device that regulates power to the tracking sensor and/or the measurement and post-processing unit. The measurement and post-processing unit is composed of an array of devices such as computers, monitors, data delivery and processing hardware and software. This unit measures the tracking sensor location, calculates the probe tip location in addition to various kinds of distance and geometries from the probe tip’s movement trajectories, visualizes the probe tip movement trajectories, and performs post processing of probe tip movement data, providing additional information including the circumference area of an anatomical object and the size of the hernia defect.

Preliminary results available.
The feasibility of this device has been initially confirmed. Using an optical motion tracking system as well as an active miniature magnetic tracking system, we measured and visualized several geometries placed within a laparoscopic trainer box. We introduced the tracking probe through a port in the trainer box to 1) measure distances between two points when presented with an array of pairs, 2) permit 2D shape tracking from a variety of patterns (circle, oval, star) printed on a paper, and 3) allow 3D visualization of a triangle block and a mannequin’s hand.

Conclusions/Future directions.
Preliminary investigation of our novel endoscopic surgical device demonstrated its unique use as a supplier of accurate measurements and visualization. Future research regarding this device is planned with goals including testing this technology in simulated and real environments for the purpose of ensuring its capability of for capturing accurate, confident measurement of hernia defects and other anatomic structures.