The original publication is available at http://www.ifc.cnr.it/lecce In: Minimally Invasive Technologies and Nanosystems for Diagnosis and Therapies. Casciaro, S. & Samset, E. (Eds.): Lupiensis Biomedical Publications, Lecce Italy, Chapter 20, p. 177-186, ISBN 978-88-902880-2-9 1/9 20. SURGICAL NAVIGATION DURING MINIMALLY INVASIVE PROCEDURES Thomas Stüdeli Delft University of Technology, Faculty Industrial Design Engineering Landbergstraat 15, 2628 CE Delft, the Netherlands Email: T.P.Studeli@tudelft.nl Abstract: Surgical navigation is a term often used in the field of biomedical engineering in connection with computer assisted surgery and minimally invasive surgery. New technological solutions such as computer systems, visualization techniques, and robotic technology aim to enable or support the surgeons in his essential actions during these procedures. The aim of this chapter is to give an introduction to navigation with as special focus on surgical navigation during minimally invasive procedures. The roots of the term navigation are described as well as cognitive models of orientation, navigation and wayfinding to highlight the different aspects of navigation. Diversity in interpretation of the term “navigation” in the medical field and the importance of surgical navigation performance for successful image guided procedures are pointed out. Selected aspects of surgical navigation during minimally invasive procedures as well as medical mixed reality systems are discussed. The chapter concludes with an exploration on design aspects for the development of navigational aids. 1. Introduction Surgical navigation is a term often used in the field of biomedical engineering in connection with computer assisted surgery and minimally invasive surgery, e.g. the CARS conference session on “Surgical Navigation” [1, 2]. New technological solutions, such as computer systems, visualization techniques, and robotic technology aim to enable or support surgical actions during these procedures. Navigation is obviously one of these essential actions. Although surgical navigation is often used in the literature of the medical and the biomedical fields, the term has not generally been well defined and therefore has been used inconsistently. It’s essential for communication in between multidisciplinary teams to be aware of those different foci and usages of key words. This chapter aims to introduce the navigational process with a special focus on surgical navigation during minimally invasive procedures. It starts with a general introduction of three important terms: navigation, orientation and wayfinding. In a second step selected aspects are put in connection with surgical work environments as well as surgical orientation, navigation and wayfinding strategies during minimally invasive procedures. 2. Navigation The word navigation has its linguistic roots and is therefore first of all linked to ships and marine transport. The word navigate is derived from the Latin roots navis meaning "ship" and agere meaning "to move" or "to direct". Nathaniel Bowditch who is often credited as the founder of modern maritime navigation describes navigation in his book The New American Practical Navigator, first published in 1802, as “the process of planning, recording, and controlling the movement of a craft or vehicle from one place to another” [3, p.815]. Traditional fields of navigation are e.g. navigation of water crafts (marine navigation), navigation of aircrafts (air navigation), and navigation of vehicles across land (land navigation). An aviator or aircraft pilot is someone who controls an aircraft; a maritime pilot is someone who guides ships through the waters near a harbour or dangerous coastal waters. In the traditional fields of navigation different navigational techniques have evolved over the ages in different cultures. Bednarik e.g. reports about he first known sea travel by humans 885’000 years ago [4]. At this moment I do not want to elaborate more on these different techniques, let’s just take as a fact that despite of all cultural and individual differences, all those techniques involve locating one's position compared to known locations or patterns as a mutual basis. We’ll later see that these common aspects among different