Design of a Dynamic Force Measurement System for Training and Evaluation of Suture Surgical Skills.

The aim of this study is to present the SurgeForce system, a tissue handling training device for analysis of dynamic force applied to the tissue and objective assessment of basic surgical skills during the suture process. The SurgeForce system consists of a mechanical base formed by two platforms joint with three stainless steel springs and a three axial digital accelerometer attached to the upper platform, which detects the dynamic force caused by a surgeon when performing a suture task over a synthetic tissue pad. Accelerometer data is sent to a control unit where preprocessing to transform the raw data into a force signal is done, and then, the force signal is sent to a computer application, which register the force exerted over the synthetic tissue pad. For validation, 17 participants (6 surgeons and 11 medical students) performed three simple interrupted sutures with knot tying using the SurgeForce system. Ten force-based metrics were proposed to evaluate their performance during the suturing task. Results of the validation showed statistical differences in 8 of 10 force-based parameters for assessment of basic surgical skills during the suture task. The SurgeForce system demonstrated its capacity to differentiate force-based performance of surgeons and medical students. The SurgeForce system has been successfully validated. This system was able to distinguish force performance between experts and novices, showing its potential to distinguish surgeons with basic suture skills from those who are not yet prepared.

Orthogonal cameras system for tracking of laparoscopic instruments in training environments.

INTRODUCTION: Motion analysis is a valuable tool for assessment of psychomotor skills in laparoscopy. Nonetheless, it requires technologies for tracking the activity of the laparoscopic instruments during training. This paper presents a sensor-free system to track the movements of laparoscopic instruments based on an orthogonal camera system and video image processing. METHODS: The movements of the laparoscopic instruments are tracked with two webcams placed in an orthogonal configuration. The position and orientation in the three-dimensional workspace are obtained using color markers placed on the tip of the instruments. RESULTS: Accuracy tests show a resolution of 0.14 mm for displacement, with 1694 cm3 of total workspace, and 0.54° in the angular movements. Mean relative errors of the tracking system were <1%. The orthogonal cameras show high precision, linearity, and repeatability of motion recording of the laparoscopic instruments. CONCLUSION: The proposed system offers unconstrained manipulation of the instruments and a low-cost alternative for traditional tracking technologies.

INTRODUCCIÓN: El análisis del movimiento es una valiosa herramienta para la evaluación de las habilidades psicomotrices en la laparoscopia. Sin embargo, requiere tecnologías para el seguimiento de la actividad de los instrumentos laparoscópicos durante el entrenamiento. En este artículo presentamos una técnica sin sensores para realizar el seguimiento de los movimientos de los instrumentos laparoscópicos basado en un sistema de cámara ortogonal y procesamiento de imágenes de video. MÉTODO: Los movimientos de los instrumentos laparoscópicos son capturados con dos cámaras web colocadas en configuración ortogonal. La posición y la orientación en el espacio de trabajo tridimensional se obtienen utilizando marcadores de color colocados en la punta de los instrumentos. RESULTADOS: Las pruebas de precisión mostraron una resolución de 0.14 mm para el desplazamiento, con 1694 cm3 de espacio de trabajo total y 0.54° en los movimientos angulares. Los errores relativos medios del sistema de seguimiento fueron <1%. Las cámaras ortogonales demostraron alta precisión, linealidad y repetibilidad de la captura de movimiento de los instrumentos laparoscópicos. CONCLUSIONES: El sistema propuesto ofrece una manipulación sin restricciones de los instrumentos laparoscópicos y una alternativa de bajo costo para las tecnologías tradicionales de captura de movimiento.