MINT: Minimally INvasive Tensiometry

A novel method to assess laparoscopic herniorrhaphy

Master thesis (2021)

Authors

E.F. van Koten Mechanical Engineering

Contributors

J.J. van den Dobbelsteen Medical Instruments & Bio-Inspired Technology - Mechanical, Maritime and Materials Engineering (supervisor 1)
M. van der Elst Support Biomechanical Engineering (supervisor 2)
Bob Bloemendaal Reinier de Graaf Gasthuis (coach)
Faculty
Mechanical Engineering
Copyright: © 2021 Eveline van Koten
More Info
expand_more

Published Date

06-07-2021

Language

English

Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Faculty

Mechanical Engineering

Abstract

In up to 30% of hernia patients revision surgery is needed due to infection, pain and defect recurrence. The role that abdominal wall tension plays in this is incontrovertible: most repair techniques in herniorrhaphy aim to reduce tension at the aponeurotic edge, as excess tension is directly related with local ischemia and recurrence of the hernia. Currently, fascial tension is subjectively observed by the surgeon and rarely quantified intra­-operatively. The choice of procedure is based on pre­operative characteristics of the defect, surgeon experience and preference, which can be highly variable. Research shows that an objective assessment of fascial tension can be a feasible adjunct to surgical decision making. Therefore, this thesis provides a proof of principle for MINT: minimally invasive tensiometry. MINT is an add­on tool for existing laparoscopic instruments, which enables an objective assessment of abdominal wall tension by the use of a linear spring. Universal applicability has been evaluated and confirmed in this research. MINT is fabricated using carbon fibre reinforced PA­12 (”Onyx”) at the TU Delft. The device’s safety and effectivity have been validated using several experiments and sterilisation test runs. MINT provides accurate and consistent results in Newton without further calibration. Forces up to 60N can be quantified, with an accuracy of 5.5+/­2%, expressed in Mean Absolute Percentage Error (MAPE). Results show that ”Onyx” and the silicon used can be sterilised using an autoclave at least five times. Moreover, its ease of use and functionality have been assessed in a clinical setting using an embalmed cadaver. Further testing will have to be done to substantiate the results from this research through a larger study. In addition, redesign will have to take place to decrease part count and further improve assembly of the device. The findings of this thesis provide a first step in the implementation of fascial tension measurements for intra­-operative decision making during laparoscopic surgery.