A Collision Response Algorithm for

A Collision Response Algorithm for 3D Virtual Reality Minimally
Invasive Surgery Simulator
Shao-Hua Mi, Zeng-Guang Hou, Fan Yang, Xiao-Liang Xie and Gui-Bin Bian
State Key Laboratory of Management and Control for Complex Systems
Institute of Automation, Chinese Academy of Sciences
Beijing, 100090 China
E-mail: shaohua.mi@ia.ac.cn
Abstract: In recent years, rapid development of minimally invasive surgery has taken place. Virtual reality simulator
enables the trainees to obtain the core catheter/guide wire handling skills and to decrease the error rate of operation prior
to performing them on a real patient. In this paper, we present and evaluate a collision response algorithm and a force
feedback computing method for simulating a catheter/guide wire in the interactive 3D virtual realty simulator based on
a robotic catheter/guide wire operating system. In order to provide a real-time virtual environment, a multi-threading
technology is used to accelerate the medical simulation procedure. Finally, we test the virtual catheter/guide wire with
a complex and realistic 3D vascular model, which is generated from computed tomography angiography (CTA) series
in DICOM datasets captured in a actual patient. The results show that the collision response algorithm in the system is
effective and promising.
KeyWords: Mass-spring model, Catheter/guide wire, Collision response, Force feedback, Multi-threading and Robotic
1 INTRODUCTION
Over the last decade, rapid development of minimally invasive
surgery has taken place. To provide a realistic and realtime
virtual reality simulation environment, a 3D virtual
minimally invasive surgery simulator based on a robotic
catheter/guide wire operating system can be used to handle
the motion of the catheter/guide wire with complex blood
vessel structures, as shown in Fig. 1. The goal of the system
is to assist the trainees to obtain the core catheter/guide
wire handling skills [1], [2].
Two key problems of the 3D virtual minimally invasive
surgery simulator based on a robotic catheter/guide wire
operating system are how to simulate the motion of the
realistic and real-time catheter/guide wire inside the complex
3D vascular model and how to give the trainees accurate
force feedback while interacting with on-screen virtual
catheter/guide wire. In the following, to solve the above
problems, a collision response algorithm and a force feedback
computing method are presented and evaluated.
During the past decades, more and more attention has
been paid to the related research on the development of
catheter/guide wire simulation and force feedback computation.
Several groups have been developing their own virtual
reality simulator for minimally invasive surgery. The
hybird mass-spring model was introduced by Vincent et al.
[3]. In the approach presented by Duriez et al., the finite
This research is supported in part by the National Natural Science
Foundation of China (Grants 61225017, 61175076, 61203342 and
61203318), the Beijing Natural Science Foundation (Grant 4132077), and
the Supervisors Research Fund for the Outstanding Doctoral Thesis of
Beijing (Grant YB20108000103).
element method (FEM) was used to model the guide wire
[4]. Alderliesten et al. presented a different simulation approach
by using energy algorithm [5].
In this paper, a collision response algorithm and a force
feedback computing method for 3D virtual minimally
invasive surgery system are illustrated and evaluated. At
the same time, a multi-threading library is proposed to
accelerate the simulation procedure.
2 PHYSICAL MODEL
2.1 3D Vascular Model
We test the virtual catheter/guide wire with a complex
and realistic 3D vascular model of 25.466 triangles, which
is generated from computed tomography angiography (CTA)
series in DICOM dataset captured in an actual patient.
The graphics rendering engine in the system is based on
OpenSceneGraph library and the physics engine uses Bullet
Physics Library [6], [7]. The rendering model using
OSG is shown in Fig. 2.
2.2 Catheter/guide wire Physics Model
We use the multi-body mass-spring method to model a
catheter/guide wire in the 3D virtual minimally invasive
surgery simulator. The virtual catheter/guide wire is composed
of three parts: tip, link and body. The link is represented
by a rigid body, which is connected by two 6 DOF
constraints nodes. The tip and the body are represented by
mass-spring model, which are formed using different material
properties, as shown in Fig. 3.
Trainees can manipulate a catheter/guide wire by pushing,
pulling and rotating at the proximal end of the
978-1-4799-3708-0/14/$31.00c 2014 IEEE 4594
Figure 1: Anatomy of the aorta
Figure 2: 3D rendering model using OSG
catheter/guide wire. However, these above methods can
not be well used to simulate the motion of a catheter/guide
wire with the complex 3D vasculature model in real-time or
near real-time [7], [8]. In this paper, a new method which
is suitable for the real-time catheter/guide wire simulation
is presented. When a catheter/guide wire is pushed, the external
forces are applied to the two nodes of the link. The
forces applied on the link push the tip at the point tipx(0)
and pull the body at the point bodyx(0) , as shown in Fig. 4.
Figure 3: The multi-body mass-spring model in the graphics
rendering engine based on the Bullet physical library
3 COLLISION DETECTION
How to solve the detection of the collision between a
catheter/guide wire and a 3D blood vessel model is a major
problem of the virtual minimally invasive surgery simulator.
When the trainees steer the virtual catheter/guide wire
by pushing, pulling and rotating at the proximal end of