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Last Updated 8/15/06
VAM Instructor Area Content Login to VAM

Coming soon - a new section in the instructor area on the Physics of Anesthesia

Configurable transparent reality simulation of anesthesia machines (Modulus II, Aestiva, etc.)

CVVH/Dialysis Simulation

Stochastic visualization of a 1-compartment pharmacokinetic model

Hydraulic analog simulation of a 1-compartment pharmacokinetic model (Deterministic)

Stochastic visualization of a 2-compartment pharmacokinetic model

Hydraulic analog simulation of a 2-compartment pharmacokinetic model (Deterministic)

Stand alone, configurable simulation of high pressure systems of anesthesia machines

Stand alone, configurable simulation of low pressure systems of anesthesia machines

Stand alone, configurable simulation of scavenging systems for anesthesia machines

Black box simulation of the Aestiva anesthesia machine

Black box simulation of the Modulus II anesthesia machine

Instructor Version of VAM

Instructor's manual for teaching with instructor VAM

How to Obtain Access to the VAM Instructor Area

Why is the Access Model Being Tweaked for the VAM Instructor Area?

Configurable VAM

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Dialysis Simulation

This simulation is a VAM-like version of a dialysis machine, specifically a CVVH (Continuous Veno Veno Hemodialysis) machine. It is modeled after BBraun's Diapact CRRT. Development was funded entirely by the University of Florida (UF) in an unsucccessful effort to develop a collaborative educational simulation in partnership with BBraun. UF is currently seeking industry partners to continue development of the CVVH/dialysis simulations. The simulation is targeted primarily towards ICU nurses, who may need to interface with the dialysis machine when dialysis technicians are unavailable.

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Stochastic Visualization of a One-Compartment PK Model

Knowledge of first-order systems and the characteristics of exponential functions is necessary to understand basic pharmacokinetics. This interactive simulation is designed to illustrate the exponential nature of a first order system to a learner without a background in mathematics or physics.

Particles move randomly about a table with a hole. The more particles there are on the table, the more drop through the hole. A plot of the number of particles remaining on the table is an exponential. The particles are analogous to drug molecules, the table is analogous to a compartment, and the hole is analogous to drug clearance in the circulation.

Plots from two consecutive runs with identical settings will be slightly different because of the stochastic nature of the simulation, but it is useful for visualization purposes, especially for the lay person. A version with two compartments that displays second order behavior is also available below.

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One-Compartment Hydraulic Analog Simulation (Deterministic)

Based on deterministic equations, this simulation of a hydraulic analog of a single compartment pharmacokinetic model facilitates visualization of the response to a bolus injection. The height of the meniscus, the cross-sectional area and the size of the drain hole are user adjustable and correspond to the drug concentration, the volume of distribution and the clearance rate respectively.

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Stochastic Visualization of a Two-Compartment PK Model

This simulation is mainly for visualization purposes and is similar in design to the first order stochastic visualization described above. It illustrates the nature of a second order system without resorting to mathematics.

Particles representing drug molecules move randomly between two areas (depicting two compartments, such as plasma and tissue) through two individually adjustable directional transfer paths (K12 and K21). One area has a hole analogous to drug clearance in the circulation (Kel).

Because of the stochastic nature of the simulation, plots from two consecutive runs with identical user-adjustable settings will be slightly different, as opposed to repeatable outputs with a similar deterministic simulation. The plots driven by the stochastic simulation display exponential behavior but are rough, especially when the number of particles is small. Real second-order pharmacokinetic systems have trillions of particles.

 

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Two-Compartment Hydraulic Analog Simulation

Based on deterministic equations, this simulation of a hydraulic analog of a two compartment pharmacokinetic model facilitates visualization of the response to a bolus injection, infusion and oral administration. The drug concentration in both compartments is plotted.

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High Pressure Systems (User-configurable)

In this simulation, the ventilator drive gas may be configured to come from either the oxygen or air manifold; an Aeetiva or Modulus II high pressure system is user-selectable and allows users to appreciate the subtle differences between the 2 designs such as different oxygen failsafe valves and cylinder pressure gauge behaviors when the cylinders are removed. Cylinders may be disconnected and drained to see how the systems respond to inadequate pressures. The operation of the ball-in-tube auxiliary O2 flowmeter is simulated.

 

 

 

 

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Low Pressure Systems

This simulation may be configured to reflect different anesthesia machine designs. Options include an air flowmeter, a second vaporizer, a common gas outlet, a common gas outlet checkvalve, and a selectable auxiliary common gas outlet.

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Scavenging Systems

There is a wide variation in scavenging systems around the world. This simulation models the active open (common in Europe), active bag (common in US), passive bag, and the passive activated charcoal scavenging systems. All simulations may be configured to scavenge ventilator drive gas.

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Aestiva Simulation

A blackbox simulation of the Aestiva anesthesia machine, with no visible gas flows.

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Modulus II Simulation

A blackbox simulation of the Modulus II anesthesia machine, with no visible gas flows.

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Instructor Version of VAM


The unique features of Instructor VAM relative to the free basic VAM version are listed below.

Spontaneous breathing

Fourteen anesthesia machine faults and a randomized mystery fault.

A tutorial on how to use instructor VAM and how the faults may be used for instruction

Ability to pause/resume the simulation

Ability to hide/show the gas molecule icons, depending on teaching style or to make some faults less obvious

Ability to select and track a single gas molecule as it flows through the machine

Adjustable Ventilator Settings

I:E ratio
Tidal volume
Frequency
Inspiratory pause
Inspiratory pressure limit

Monitoring

SpO2 including tones and alarms
FiO2 including alarm
Capnogram including normal and abnormal capnograms
NIBP
HR
Airway pressure trace
Exhaled VT measurement
Minute ventilation measurement
Audible alarm and silence button

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How to Obtain Access to the VAM Instructor Area
To obtain free access to the VAM instructor area, ask representatives of drug and anesthesia equipment companies to sponsor access to the VAM instructor area (US$100 per year per instructor). Alternatively, you or your hospital, University or institution can purchase access to the VAM Instructor area by sending US$100 by credit card or check/money order for an annual fee. Click here for details for sponsoring/obtaining access to the VAM instructor area. Continued free access to the simulations in the free Member's Area is supported, in part, by the fees for accessing the VAM Instructor area.

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Why is the Access Model Being Tweaked for the VAM Instructor Area?
The VAM project, beyond being an exploration of model-driven, interactive web simulation, is also an experiment in sustainable web philanthropy. The VAM team, with the financial support of the chair of the UF Department of Anesthesiology, made the decision right from the start in 1999 to make the VAM simulation available free of charge over the Web so that financial means would not be a barrier to access to essential patient safety materials. Our strategy was to obtain funding via corporate sponsorship and donations to eventually (within 5 years) meet the VAM team's payroll and make the VAM project self-sustaining.

Five years into this funding experiment, we had to admit that VAM's philanthropic access model as originally conceived has failed and will not work without tweaking. From 1999 to 2004, we received $22,500 in corporate sponsorship and $510 in donations, accounting for less than 5% of the total VAM team payroll. Lampotang et al, Anesthesiology 99: A1319, 2003

It is important to note that the simulations in the Member's Area remain free. Access to the VAM instructor area is also "free" to you if one of your industry contacts sponsors you.

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