VR Central Venous Access Simulation System for NewbornsLizeth Vega-Medina, Byron Perez-Gutierrez, Gerardo Tibamoso

Davinci Research GroupVR Center

Alvaro Uribe-QuevedoIndustrial Engineering

VR CenterNorman Jaimes

Simulation Lab.School of Medicine

Nueva Granada Mil. University∗

ABSTRACT

Central venous access is an invasive medical procedure of highcomplexity used in critically ill patients. Its implementation re-quires great skills and knowledge from a health care specialist. Ad-vances in patient simulators present solutions regarding childrenand adults, however, newborn simulators are scarce.

This paper presents the development of a newborn’s central ve-nous access simulator for training and educational purposes. Thesimulation system is composed of three main subsystems: a pro-cedural simulation, showing how the procedure must be correctlyperformed; a haptic subsystem for increasing realism; and finally anewborn manikin with image projection for guiding the procedure.

Index Terms: J.3 [Computer Applications]: Life and MedicalSciences—Health; H.5.2 [Information Interfaces and Presentation]:User Interfaces—Haptic I/O;

1 INTRODUCTION

Central venous access is an invasive medical procedure of highcomplexity used in critically ill patients requiring the administra-tion of medicaments and nutrients for long periods or when vascu-lar access has been unsuccessful through peripheral lines. Its im-plementation requires great skills and knowledge for reducing theprocedural risks. Initial training simulations are conducted usingboth adult and child sized physical models (manikins).[3].

When newborns present with serious health problems as mal-nutrition and blood loss, the central venous access offers a meansof overcoming the problem, however, for medical students to de-velop the essential skills for performing such a procedure, the onlyavailable scenario involves real patients and the associated risks ifapplied incorrectly.

The research goal is to develop and implement a central venousaccess simulator for newborn patients, combining tissue simulation,haptics and visual-based guidance for obtaining a training tool thatallows for the development of essential skills within a controlledand simulated environment thus reducing the scenarios were thehealthcare professional faces the access without previous practice.The platform training system reduces the risk of failure and compli-cations during the implementation of the actual procedure, as wellas presenting a clear goal, rewards and feedback on user perfor-mance.

Section 2 of this paper describes previous and related works,Section 3 presents proposed methodologies and developed proto-types and Section 4 displays results and future work.

∗Email: {lizvega, byron.perez, gtibamosop, alvaro.j.uribe}@ieee.org,norman.jaimes@unimilitar.edu.coUniversidad Militar Nueva Granada, KR 11 101 80, Bogota D.C., Colombia

a) b) c)

Figure 1: VR Central Venous Access Simulation System. a) Proce-dural, b) Haptic and c) Physical simulator

2 PREVIOUS AND RELATED WORK

There are different central venous access simulators that integratebiomechanical models represented with 3D meshes (skin and bloodvessels) with haptic devices for guiding the procedure[5, 6, 4].These human simulators excel at providing close to reality expe-riences for treating adult, geriatric or pediatric venous accessesfrom different anatomical insertion points. Furthermore, the per-formance information and progress in the ability of the process canbe continuously recorded and stored, allowing for assessment andfeedback that may help improve procedure effectiveness, accuracyand safety. Despite the realism that is generated with these virtualreality systems, staff prefer to practice with physical models as theyprovide a real space, haptics and visual feedback within the possiblescenarios for performing the procedure. [1].

3 CENTRAL VENOUS ACCESS SIMULATION SYSTEM PRO-TOTYPE

The development of the simulator involves four steps: the charac-terization of the procedure, that establish the proper sequence ofthe procedure; the biomechanical characterization and analysis ofthe tissues for implementing the interactive force feedback model;the software development and hardware integration; and finally, thesystem validation through tests.

This simulation system is composed of three main subsystems:the procedural guidelines and simulation, the haptic simulator andthe physical simulator as presented in Figure 1. These systems of-fer complimentary means of training whose goal is to enhance theprocedure practice through different platforms and tools that do notrestrict practice or access to the system. Each component uses 3Dmodels based on a newborn’s average anatomy, resulting in the im-plementation of the heart and subclavian vein, the skeleton and skinwith adjustable parameters for providing information according tothe training. The obtained models are presented in Figure 2.

3.1 Procedural simulator

This part of the simulation system permits a user to interact with thegeometric model and learn the proper steps to perform the centralvenous access in a newborn child as shown in Figure 3. Also theuser can make decisions about the instrumentation and anatomicalissues.

121

IEEE Virtual Reality 201429 March - 2 April, Minneapolis, Minnesota, USA978-1-4799-2871-2/14/$31.00 ©2014 IEEE

Figure 2: Geometric model of the newborn with different trans-parency levels

Figure 3: Procedural simulator

3.2 Haptic simulatorThe system consists of a Phantom Omni haptic device that interactswith the developed models and acts as catheter over the chest ofthe newborn as shown in Figure 4. When the user interacts withthe simulator, the corresponding reaction forces through the hapticdevice when a collision occurs is fed back to the user.

These forces are the response of a computational model whichrepresents the biomechanical behavior of the skin and large bloodvessels using layers of interconnected spheres. The interactionsare implemented using non-linear stress strain relation between twospheres in the same layer, as presented in Equation 1 to 3.

f = k2 ∗ (x− x1) (1)

k2 =E ∗h∗w

L∗

(1− L√

L2 +(x− x1)2

)(2)

x1(n+1) =f +b∗ x1(n)/∆t

k1 +b/∆t(3)

Where x1(0) = 0, f is the applied force, x and x1 the displace-ments, ∆t the sample time, L the distance between two spheres, Ethe Young modulus, h and w are the height and width of the rep-resented tissue, b damping coefficient and k1 stiffness. The coeffi-cients were adapted according to [2].

3.3 Physical simulator with video feedbackAn initial prototype was implemented using a newborn manikinwith a video feedback projected over its chest as shown in Fig-ure 5. The user has the possibility to see the internal anatomy pro-jected as a visual aid for performing the procedure and proceed withthe instrument insertion (catheters and needles) obtaining the cor-responding haptic feedback. The virtual manikin was configured tomatch the physical model. It depicts veins with blood pumping, thenewborn ribs, lungs, muscle and skin, permitting the user to feel theapproximation to the real tissues. A commercial kit for insertion isused to give realism.

Figure 4: Haptic simulator

Figure 5: Physical simulator with video feedback

4 RESULTS AND FUTURE WORK

We have presented the development and implementation of ourCentral Venous Access Simulation System using three complimen-tary systems conformed of procedural, haptic and physical. Theinitial prototypes provide the interaction with the virtual models al-lowing a basic training which can help improve the understandingof the real procedure. As future work, the catheter insertion andmanipulation of all related instruments will be added in order toincrease immersion and interaction.

ACKNOWLEDGEMENTS

This work was supported by the Research Division of the NuevaGranada Mil. University.

REFERENCES

[1] S. A. Engum, P. Jeffries, and L. Fisher. Intravenous catheter trainingsystem: Computer-based education versus traditional learning meth-ods. The American Journal of Surgery, 186(1):67–74, 2003.

[2] Y. Fung. Biomechanics: material properties of living tissues. Springer,1993.

[3] A. J. Macnab and M. Macnab. Teaching pediatric procedures: the van-couver model for instructing seldinger’s technique of central venousaccess via the femoral vein. Pediatrics, 103(1):e8–e8, 1999.

[4] A. Radetzky, A. Nurnberger, and D. P. Pretschner. Elastodynamic shapemodeler: A tool for defining the deformation behavior of virtual tissues.Radiographics, 20(3):865–881, 2000.

[5] S. Ullrich and T. Kuhlen. Haptic palpation for medical simulation in vir-tual environments. Visualization and Computer Graphics, IEEE Trans-actions on, 18(4):617–625, 2012.

[6] M. Ursino, J. L. Tasto, B. H. Nguyen, R. Cunningham, and G. L. Merril.Cathsim: An intravascular catheterization simulator on a pc. Studies inHealth Technology and Informatics, 62:360–366, 1999.

122