Medical simulation system and method

A portable medical simulation system and method employs an artificial patient with a built-in haptic interface device, with up to four carriages for engaging different diameter catheters. A catheter stabilizer between each carriage expands and contracts in an accordion fashion as the carriages move in relation to each other, preventing the catheter from bending and bowing. A contrast display visual effect derived from a particle emitter software tool simulates the release of radiopaque dye within a simulated vasculature system for display on a monitor. A computer software based system is used for generating haptic effects on the catheter through control signals passed to each of the carriage motors controlling translation movement of the catheter and magnetic particle brakes controlling rotational movement of the catheter.

FIELD OF THE INVENTION

This invention relates to the field of simulations for medical training, and more particularly, to an enhanced method and system for training healthcare teams.

BACKGROUND OF THE INVENTION

Healthcare education leaders have seen the need for simulation systems that efficiently train, evaluate, and enhance individual medical practitioner's skills to improve patient outcomes. In a recent survey, 73 of the 124 US medical schools are using some form of computer simulation for student evaluation. The development of simulation and training centers for the cognitive training of healthcare professionals in the practice of interventional medical procedures represents a significant advance in being able to promote the best demonstrated practices in the use of existing and new products and procedures. The introduction rate of new therapeutic devices and procedures is accelerating such that the lifecycle of a new product can be as short as eighteen months. At the same time the American College of Cardiology (“ACC”) reports that 50% of the 10,000 interventional cardiologists do not meet the minimum standards for procedure competency. Current training methodology cannot address these problems. The answer is broad access to cognitive training and education on an industry wide universal platform that the present invention provides.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the Figures, in which like reference numerals and names refer to structurally and/or functionally similar elements thereof,FIG. 1shows a perspective view of an exemplary embodiment of the portable medical simulation system for training healthcare teams of the present invention. Referring now toFIG. 1, Simulation System100provides an industry platform, a standard for technical parameters, skill assessment and measurement, and communications capability. A unique aspect of the invention is the use of Artificial Patient106for cognitive training and decision making. Prior art, such as U.S. Pat. No. 6,074,213, granted to David C. Hon on Jun. 13, 2000, describes a procedural training system that is an event driven state model that utilizes a rule-based expert system that is resident at each workstation. The medical simulation method and system for training healthcare teams of the present invention utilizes Artificial Patient106where the attributes of the simulated patient's anatomy, disease state, and the decisions and selections of the team member interact in both a deliberate and random manor, as in a real patient, to produce unpredictable outcomes. Even though a team member may properly execute a medical procedure, other complications as a result or related to the procedure, anatomy, disease state, medical device, or drug agent could result in an adverse event and a negative outcome. Conversely, if a team member initially experiences an adverse event but recognizes the implications of the event and implements appropriate corrective action, a negative outcome can be avoided. Through the use of Artificial Patient106the team member is trained and evaluated in the proficiency of their cognitive skills for treating the patient, not just their skills in performing medical procedures.

A network of Simulation Systems100located across the country can provide a cost-effective platform for medical device manufacturers, medical societies, hospitals, and educational institutions to distribute their cognitive training products to healthcare industry personnel. A standardized design and layout of each Simulation System100ensures that courseware that is developed at one Simulation System100location can be consistently utilized at other Simulation System100locations, providing the highest quality and most effective education. Universal standards will create a level playing field for all stakeholders. Medical personnel will have access to training on a daily basis if needed. Field sales people can host selected physicians at a local Simulation System100without incurring undue travel cost and time. Product adoption can occur in a matter of months nationally and internationally. Universal standards created for training and skill assessment can be measured and gauged. Each Simulation System100is designed to run courseware developed from a variety of different information sources including, but not limited to, medical device companies, medical societies, accreditation organizations, medical schools, medical centers who advance development of new procedures and therapies, and prominent industry authors. Simulation System100can be utilized to introduce new products, demonstrate difficult procedures, evaluate the effectiveness of new procedures, evaluate the effectiveness of team training, health care professional credentialing, and the effectiveness of hospital training programs.

Simulation System100may be used to establish uniform standards for the development of interactive training courseware and provide comprehensive and objective databases on the performance of medical operators, health care support personnel, and medical institutions. The database may provide feedback on the results of courseware for new health care products and procedures. The uniform standards and database may provide for both general information for all participants and proprietary information to individual participants, such as medical device manufacturers.

Simulation training utilizing Artificial Patient106is not simply an extension of traditional training methodology, but rather is a significant new tool for the medical industry. This tool has the built-in capability to consistently train healthcare professionals in the best-demonstrated practice and in the use of the product to achieve the highest probability of producing a successful outcome. In addition, the system evaluates individuals and teams of healthcare professionals in state-of-the-art medical procedures, knowledge, cognitive skills, and documents their performance of the simulated procedures. Cognitive skills can be gained from real life experience and from good simulation experience. Real life experiences are subject to many risks as opposed to simulation experiences, which have far fewer risks.

The aviation field, with its outstanding safety record, has learned that to provide true cognitive training you must address four key teaching elements: manual dexterity skills, perceptual skills, fund of knowledge, and decision making. Together, these four elements are combined into a dynamic learning process that exposes the participant to a variety of situations that builds depth of experience that cannot be gained in routine practice. Simulation improves decision making on the part of the participant, compared to traditional training methodology, because the consequences resulting from the interaction with the simulation interfaces are fed back to the participant immediately, just as in real life situations, forcing acceptance and/or resolution of problems in real-time. The commercial aviation field now relies on simulation training to the extent that commercially qualified pilots who are trained in simulators are certified to fly aircraft that are transporting revenue-paying passengers upon completion of training in certified simulation training facilities.

The parallels between the challenges of training pilots and physicians have been recognized by the medical societies. The American College of Cardiology, the Society for Cardiovascular Angiography and Interventions, the Society for Vascular Medicine and Biology, and the Society for Vascular Surgery have all made firm commitments that simulation training must be incorporated into the physician training process.

The availability of new medical technologies is expanding at an ever-increasing rate. This expanding universe of new technologies has created a formidable task for individual physicians, nurses, and local hospitals to continuously-maintain their proficiency and provide the best possible healthcare consistently across the U.S. and around the world. Recently the Institute of Medicine reported it can take seventeen years for important medical discoveries to become accepted and used by the average doctor. On an annual basis, the United States Food and Drug Administration approves approximately 24 new medical devices for interventional cardiology alone. The daunting problem faced by medical device manufacturers is how to effectively introduce and train 10,000 physicians at 700 key hospitals in a new product every eighteen months. The cost and throughput rate for bringing physicians to formal training centers is so high that medical device manufacturers cannot formally train all of their customers. The industry costs resulting from sub-optimal patient outcomes is estimated to be in the billions of dollars. In the cardiovascular field alone, a one-percent reduction in the need for Cardiac Bypass Graft Surgery (“CABG”) would result in a $250 million reduction in healthcare costs to the American public. As the case experience of the physician increases, the American College of Cardiology has reported a direct correlation between the success associated with increased frequency in procedures and decreased risk of death or risk from a CABG procedure. Simulation System100is designed to enhance the skills of individual physicians and their teams by increasing their frequency and exposure to “real patient” clinical experiences. Simulation System100interactive simulation software is designed to introduce specific learning objectives and levels of complexity, or procedural consequences, into simulation courseware. Essential learning objectives can be indexed to higher levels of complexity as the participant masters the new skill or product as demonstrated by resolving increasingly complex procedural consequences. This unique approach to training, afforded by simulation, controls the balance between overwhelming a physician or nurse with unrecoverable consequences against too little training designed to avoid poor outcomes.

As simulations are performed, metrics are gathered and stored. Metrics are pieces of raw data that indicate competency of the participant. Metrics can be time measurements, amount of substance used measurements, position and force measurements, or test scores from a didactic test. Metrics are quantified and objective, not subjective, measurements of the participant's competency. Key metric parameters include basic skills, fund of knowledge, and decision making or process of care. These metrics can assist in assessing the design of new products or procedures, effectiveness of training programs, and the procedure competency of health care professionals. As this data grows, feedback can be provided to individual participants. For example, a participant may have taken six minutes to perform a particular procedure, whereas the average participant took three minutes. A participant can be shown where he or she falls on the curve of all previous participants and immediately begin corrective measures. Databases of this metric data are extremely valuable. They are very valuable to the individual because the individual will know where he or she will have to work on improving as professionals. The databases are valuable because a hospital will know how well a particular individual's performance compares to others, and how well improvement is progressing where needed. The hospital will be able to assess how well their doctors are doing compared to another hospital, and will be able to compare simulation results to the outcomes on actual patients. Doctors can practice very difficult procedures via Simulation System100as well as the procedures that they may only do one or two times in a lifetime. This practice can be done ahead of time so that the doctor is prepared when a real situation requiring the medical procedure with a real patient arises.

Simulation System100may provide on-demand simulation courseware on new products and procedures, documentation for hospital-based accreditation, Continuing Medical Education (“CME”) courses, and grand round simulations from leading physicians and nurses. Utilizing the metrics gathered over time, services such as health professional accreditation data and documentation management as well as training documentation for hospital accreditation, malpractice and liability insurance assessment can be provided. Simulation System100will enable the rapid distribution of manufacturers' new and existing products using proprietary simulation courseware and provide on-demand market information on utilization of their products by users.

Simulation System100software and training programs besides the real-time in-room simulations are designed for access and review on the World Wide Web. This allows healthcare professionals to access training programs tailored to their training needs around their work schedules. Simulation System100and its associated training programs and website access provides healthcare professionals with a more time-efficient and cost-effective means for maintaining their proficiency. The medical simulation method and system for training healthcare teams of the present invention is a very efficient, effective, and consistent way to provide broad-range, on-demand simulation training and educational products. Worldwide access requires a high level of security. Proprietary courseware as well as general information may be distributed selectively. For example, a medical device manufacturer may limit distribution of new product courseware to approved clinical evaluation facilities only. Similarly, medical societies can limit distribution of new courseware to active members/subscribers.

Simulation System100is portable and can be moved to an appropriately sized room and is preferably set up to resemble an actual medical environment, such as a hospital emergency room, a catheter lab, operating room, etc. Lighting, sounds, medical equipment, and ancillary devices are designed to create the realism of conducting actual interventional procedures. Simulation System100is capable of providing individual operator as well as interactive team training. Simulation Table And Stand102has an upper portion which supports Artificial Patient106and Haptic Interface Device104, which is located within Artificial Patient106, at a convenient height for the team participants. In one embodiment, Artificial Patient106having Haptic Interface Device104is the SIMANTHA® Interventional Tactile-Force-Feel Simulator, an interactive artificial patient device developed by Medical Simulation Corporation. Simulation Table And Stand102has a lower portion with caster wheels which enable Simulation System100to be very portable.

Simulation System100as shown inFIG. 1has two Computers108, (the second computer is hidden from view by the first computer and is located next to it on the lower portion of Simulation Table And Stand102). Resident on one or both of Computers108are the various software modules that the medical simulations are built from, including a simulation engine module, a virtual team members module, a data manager module, a metric module, a pre-simulation brief web pages module, a testing module, a database module, and an event handler module. One skilled in the art will recognize that more or fewer computers could be utilized in the present invention depending upon the computing power of the computer(s), type of simulation system (hospital emergency room, a catheterization lab, operating room, etc.) and the particular medical procedure being simulated for training purposes (crash cart, interventional cardiology, interventional radiology, interventional neurology, arthroscopy, endoscopy, laparoscopy, anesthesia, and intensive and critical care nursing). Regardless of the number, the computer(s) and other hardware devices of Simulation System100are interconnected over an Ethernet or other suitable Local Area Network (“LAN”) which may be, but is not limited to, wire, wireless, optical, etc.

Connected between Computers108and Haptic Interface Device104in one embodiment of the invention is Haptic Interface Computer110(more fully described below in relation toFIG. 11). Haptic Interface Computer110is located out of view behind the cabinet doors in the storage area of the lower portion of Simulation Table And Stand102.

In one embodiment Simulation System100incorporates six different monitors to provide visual feedback to team participants and to allow user input through touch screen capability. From Selection Monitor112a user may select which simulation to run and initiate the commands to begin the simulation utilizing touch screen capability built into Selection Monitor112, or the user may select the simulation to run utilizing Keyboard114and/or Mouse116. Keyboard114and/or Mouse116rest on a slide-out tray that can be pushed back in and out of the way during the actual simulation.

Selection Monitor112is also used to make drug selections necessary for the simulation, which replicates the function of drug and/or fluid dispensing apparatus. The touch screen allows for fast and direct user input, and may resemble a real drug dispenser apparatus. The drug dispenser module provides a user interface to requisition drugs and is displayed on Selection Monitor112.

Patient/Mentor Monitor118displays at various times during a simulation an animated person, a virtual person. The animated person may be the patient talking, or a mentor, a doctor, a nurse, or any other individual appropriate for a given medical simulation. The virtual person at the beginning of the simulation may appear on Patient/Mentor Monitor118and through audio output tell the team participant(s)about what he or they are about to do. Patient/Mentor Monitor118may also be touch screen enabled. Pre-recorded messages for delivery by the animated person, which may be audio only, audio and video, or video only, are stored in the database for each different medical simulation. Then, at the appropriate time, the pre-recorded audio, audio/video, or video message is called and output to the participant through Patient/Monitor118.

In another embodiment of the invention, various text files associated with the simulation selected may be retrieved from the database. The text in the files is then synthesized into audio speech, and the virtual person's image is synchronized with the audio speech such that the virtual person's lips move, eyes blink, and other facial movements are coordinated such that the virtual person appears to be talking naturally, just as a real person would talk. Thus, three separate technologies, 3D graphics modeling and rendering, taking text and converting it into actual audio, and then combining the 3D graphics modeling with the audio, provide a very realistic virtual person. This is all done on-the-fly in response to events driven by the participants during the simulation. Simulation System100has complex rules engine that are followed based upon the actions of the participant or team of participants. The animated persons appear on Patient/Mentor Monitor118at various times linked to on-the-fly events. A physician participating in the simulation may make one decision, and the nurse participating in the simulation may make another decision based upon the physician's decision. The animated person needs to say the right thing based upon these two independent decisions, and this has to be done on-the-fly. Since the medical team participants will be doing things on-the-fly, the system has to be able to respond on-the-fly as well, and will retrieve the appropriate text file for conversion to speech. In addition, some of the events are actually random, as opposed to just in response to what one of the participants did. If a participant makes a bad decision then worse events may take place. Even if a participant makes good decisions the random event could result in a bad event happening. The system does have random serious events that happen similar to occurrences in real life. Thus, the system reaches a level of realism as encountered in real life.

Road Map Monitor120displays stored fluoroscopic images of the patient and serves as the guide to the participant(s) for the simulation procedure selected. Simulation System100utilizes a technique called Tri-Reality Simulation. Tri-Reality Simulation is a hybrid combination of actual (real) components, virtual components, and simulated components. A simulated component exists in reality, such as a catheter manipulated by the physician on Artificial Patient106in conjunction with Haptic Interface Device104. Real components may be fluoroscopic, sonographic, MRI, PET, or like images taken from real patients and used in the simulation through display on Road Map Monitor120. Rendered images displayed are the virtual components, such as a rendered image of a contrast injection displayed on Fluoroscopic Monitor122.

A still picture selected by the physician from one of the many diagnostic images presented to the physician at the beginning of a simulation is displayed on Road Map Monitor120throughout the medical procedure simulation. The selection of the diagnostic image by the physician is one of the factors the physician is graded on during the simulation. The better or more optimal the diagnostic view the physician selects, the better grade the physician will receive for selecting the better road map diagnostic image. The graphics module also provides a simulation of fluoroscopic images, sonogram images, MRI, PET, or other images of the like in synchronization with the currently running simulation.

In typical prior art simulation systems that employ virtual reality, backgrounds for graphic display are being fully volume rendered via software. This full volume rendering increases the computational time and required hardware resources by a factor of ten to fifteen times over the Tri-Reality Simulation method of the present invention. Volume rendering everything being displayed with software necessitates utilizing expensive and high-powered processing hardware to do the necessary mathematical computations. The present invention uses real fluoroscopic, sonogram, MRI, or PET video images in the background (retrieved from the database), and renders only the medical device, such as a catheter, being used by the physician in the simulation in the foreground, and the vascular tree if the simulation has called for radiopaque dye. By doing this, the speed of the system is increased well beyond the capabilities of prior art systems.

Fluoroscopic Monitor122shows simulated live fluoroscopic images of Artificial Patient106in response to the participant who is manipulating the medical device that interacts with Haptic Interface Device104. Hemodynamic Monitor124displays vital statistics of Artificial Patient106such as blood pressure, O2levels, pulse rate, EKG, and other related vital signs or diagnostic outputs.

In one embodiment of the invention, Road Map Monitor120, Fluoroscopic Monitor122, and Hemodynamic Monitor124are attached to a Support Bar126. All three monitors can be raised and lowered by Support Bar126, and can pivot about Support Bar126in order to provide the participants with a better view of the three monitors. In addition, all three monitors can individually be swiveled left and right, and tilted forward and back to aid in positioning each monitor to suit the preference of the participant(s).

Equipment Selection Monitor128allows the participant to select the particular medical device, such as a catheter, that the participant believes is called for in light of the particular simulation selected and the corresponding patient problem. Equipment Selection Monitor128typically has touch screen capability as well. Dual Joy Stick Controller130simulates for the participant control of a C-Arm device and patient table panning.

FIG. 2shows a perspective view of an exemplary embodiment of the portable medical simulation system ofFIG. 1in a collapsed state ready for transport of the present invention. Referring now toFIG. 2, parts of Artificial Patient106are stored in the storage area below the upper portion of Simulation Table And Stand102. All of the monitors have been collapsed down and inward on their support columns. The table extension portion of Simulation Table And Stand102has been folded down and Dual Joy Stick Controller130has been stowed in the storage area. A rigid or flexible top (not shown) can be placed on top of Simulation Table And Stand102and secured thereto for short term storage, or for transportation to a different location, which may be across town or across the country.

FIG. 3shows a perspective view of the haptic interface device in an embodiment of the portable medical simulation system for training healthcare teams of the present invention. Referring now toFIG. 3, the top panel and side panels have been removed to show more clearly the inside portions of Haptic Interface Device104. Haptic Interface Device104has a wedge-shaped Frame326, with a Thick End320located in the lower body and a Thin End322located in the head region of Artificial Patient106. This arrangement allows gravity to assist movement of the Carriages302when engaged with a Catheter328. Haptic Interface Device104is designed to accommodate up to four Carriages302which allows up to four different sized catheters to be utilized in a given simulation. Haptic Interface Device104may be built with only one, two, or three Carriages302instead of the four as shown for a given intended application.

There are two Drive Motors308located at each end of Carriage Bed306, along with two Idler Pulleys310. Each Drive Motor308and each Idler Pulley310are located on the outer edges of Carriage Bed306, with the Rail304extending in between. Each Carriage302is paired with a Drive Motor308located on one end, and an Idler Pulley310located on the opposite end and on the same side of Rail304. A first Drive Belt444is attached at a Fore End440to a first Drive Belt Pinion404on Base402of a first Carriage302(seeFIGS. 4 and 5). The first Drive Belt444is looped around a first Idler Pulley310at Thin End322, then looped around a Fly Wheel324of a first Drive Motor308located at Thick End320and on the same side, and the second end of the first Drive Belt444is attached to a second Drive Belt Pinion404of the first Carriage302. Drive Belt444is attached with enough tension such that when the Drive Motor308turns its Fly Wheel324in either rotational direction, first Carriage302will be translated back and forth along Rail304in the directions indicated by Arrow312. Thus there are two paired Idler Pulleys310and Fly Wheels324of Drive Motors308on each side of Rail304, and each pair are aligned at a different height from Carriage Bed306to allow freedom of movement of each Drive Belt444.

Carriages302slide along Rail304which is affixed to Carriage Bed306. From one up to four Carriages302may be installed, depending upon the scope of use of a particular Simulation System100. Drive Motor308turns its corresponding Fly Wheel324rotationally causing Carriage302to translate back and forth along Rail304. Once a given simulation has been selected, each Carriage302is moved to its starting position. Typically, all Carriages302(one, two, three, or four) are moved to Thick End320and stacked up against each other, with the first Carriage302butted up against Catheter Support Stand314. In this position, the Carriages302are ready to receive Catheter328which is inserted into Catheter Support Tube316.

The Carriage302that is closest to Catheter Support Stand314(the first carriage) is designed to engage the largest diameter catheter that is used in conjunction with Haptic Interface Device104. The next Carriage302in line (the second carriage) is designed to engage the next to largest diameter catheter that is used. Similarly, the next Carriage302in line (the third carriage) is designed to engage a catheter whose diameter is smaller than the second carriage, and the last Carriage302(the fourth carriage) is designed to engage the smallest diameter catheter that is used in conjunction with Haptic Interface Device104. As shown inFIG. 3, Catheter328has passed through the first Carriage302and has engaged the second Carriage302.

Each Carriage302has a Flex Circuit330(only one is shown inFIG. 3for simplicity) attached to Carriage Printed Circuit Board434at either Junction708(seeFIG. 7). Flex Circuit330extends and folds over on itself along Carriage Bed306as Carriage302is moved back and forth along Rail304. The second end of Flex Circuit330is fixed to Carriage Bed306and from there connected to the Haptic Printed Circuit Board318located under Carriage Bed306, which is electrically connected to Haptic Interface Computer110. Positioned between each Carriage302and between the first Carriage302and Catheter Support Stand314, but not shown inFIG. 3, is a Catheter Stabilizer804(seeFIG. 8).

FIG. 4shows a front perspective view,FIG. 5shows a rear perspective view, andFIG. 6shows a side view/hidden view of a carriage within the haptic interface device in an embodiment of the portable medical simulation system for training healthcare teams of the present invention. Referring now toFIGS. 4,5, and6, Carriage302has Base402which bolts onto a Block (not visible) that slidably engages with Rail304. Drive Belt444attaches to Drive Belt Pinions404. Brake Bracket406attaches to Base402towards Fore End440and secures Magnetic Particle Brake408thereto. Optical Encoder436is attached to Shaft438of Magnetic Particle Brake408. Two Flex Beams410also attach perpendicularly to Base402, one at Fore End440and one at Aft End442, and are connected transversely at the top by Cross Member412. Each Flex Beam410has two legs with a lower and upper Thinned Sections414. Flex Beams410are typically made of titanium, and Thinned Sections414allow slight bending when Spring Loaded Collet416of Carriage302comes into contact with Catheter Support Stand314or other Carriages302. In another embodiment, Flex Beams410may only have one leg each, with a lower and upper Thinned Sections414.

Spring Loaded Collet416is secured between the tops of Flex Beams410and below Cross Member412. As shown inFIG. 6, Spring418is fully extended, forcing Circumferential Clamp420to engage with the larger Outward Tapered End454of Collet422, all located within the outer housing of Spring Loaded Collet416. This is the closed position for Spring Loaded Collet416at the beginning of a simulation. The inside diameter of Lumen452of Collet422is sized to cooperate with one of the up to four catheter sizes compatible with a specific Simulation System100. Opening424receives the tip of a catheter, and if the catheter diameter is smaller than the diameter of Lumen452of Collet422, the catheter will pass right through Lumen452of Collet422and out Opening425and proceed to the next Carriage302.

If the catheter is the size that is designed to cooperate with this Collet422in Carriage302, then upon entering part way through Lumen452, the tip of the catheter will engage the restricted walls of Lumen452. This exerts a force on Spring Loaded Collet416which is transferred throughout the structure of Carriage302. The sensors, electronics, and software controls built into Simulation System100recognizes this force as an engage catheter state, and the Simulation System100responds by sending signals to Drive Motor308controlling Carriage302to force Carriage302to move against Catheter Support Stand314, or an adjacent stationary Carriage302as the case may be, in order to compress Spring418, allowing Collet422to open up, allowing the catheter to move farther through Lumen452of Collet422. Then, the motion is reversed, causing Spring418to decompress, forcing Circumferential Clamp420to move along Outward Tapered End454of Collet422, reducing the inside diameter of Lumen452, which exerts a clamping force on the tip of Catheter328, thus securing Catheter328to Carriage302.

In a typical simulation, a small diameter Catheter328, called a guide wire, may be inserted into Artificial Patient106through Catheter Support Tube316. Depending upon the simulation, this small diameter Catheter328may pass right through the first, second, and third Carriages302before engaging the fourth Carriage302. The guide wire is simulated and displayed on Fluoroscopic Monitor122as the participant continues to push and/or rotate the guide wire. Next, a larger diameter Catheter328may be inserted into Artificial Patient106over the guide wire such that the guide wire is within a lumen of the larger diameter Catheter328. This larger diameter Catheter328will engage the Carriage302that is designed to cooperate with the size Collet422in its Carriage302. As the participant pushes and/or rotates Catheter328, it is simulated and displayed on Fluoroscopic Monitor122. The user may now want to withdraw the smaller diameter guide wire, and does so by first pulling on the smaller diameter guide wire, which exerts a force on the Spring Loaded Collet416it is engaged with, which is transferred throughout the structure of that Carriage302. The sensors, electronics, and software controls built into Simulation System100recognizes this force as a catheter exchange state, and the Simulation System100responds by sending signals to Drive Motor308controlling that Carriage302to force Carriage302to move against Catheter Support Stand314, or the Carriage302next to it as the case may be, in order to compress Spring418, allowing Collet422to open up, allowing the smaller diameter catheter to be released from Collet422. The user can now easily remove the smaller diameter catheter from Artificial Patient106. This removal is also simulated and displayed on Fluoroscopic Monitor122. Thus, by analyzing the forces exerted by the user on the Catheters328engaging with each Collet422in a Carriage302, the various stages of the simulation are tracked by Simulation System100.

Magnetic Particle Brake408is used to provide feedback to the user for rotational movement of the Catheter328engaged with Collet422. Magnetic Particle Brake408has Gear426and Spring Loaded Collet416has Pulley428. Timing Belt446(shown in cut-away view inFIG. 6) wraps around both. Current is applied to Magnetic Particle Brake408to increase resistance to rotation.

Anvils430are attached to a top portion of each Flex Beam410. Force Sensors432are attached to either side of an upper portion of Brake Bracket406. When Spring Loaded Collet416moves into Catheter Support Stand314or another Carriage302, Flex Beams410will bend at Thinned Sections414. When viewed from a direction perpendicular to the direction indicated by Arrow312, the upper portions of each Flex Beam410connected by Cross Member412and above the upper Thinned Sections414, and the lower portion of each Flex Beam410connected to Base402and below the lower Thinned Sections414, remain vertical. The middle portion of each Flex Beam410located between the Thinned Sections414, will skew to the left or the right from vertical depending upon which side of Spring Loaded Collet416is being engaged with an adjacent structure, due to the flexible nature of each upper and lower Thinned Sections414. Thus, one or the other Anvil430will be driven into one or the other Force Sensor432. Force Sensors432are electrically connected to Carriage Printed Circuit Board434which is attached to Brake Bracket406. Flex Circuit330, Magnetic Particle Brake408, and Optical Encoder436are also electrically connected to Carriage Printed Circuit Board434.

In order to protect the Carriages302from damage due to severe collisions with each other, a Collision Sensor448is mounted on Carriage Printed Circuit Board434. Collision Arm450extends from each Carriage302and is aligned in the direction indicated by Arrow312. A Collision Arm450also extends from Catheter Support Stand314to detect impending collisions with the first Carriage302. A Collision Sensor448is also mounted on Thin End322of Frame326(not shown) to detect collisions with a collision arm of the fourth (or last) carriage. The tip of Collision Arm450will engage Collision Sensor448if the Carriages302get too close to each other. Collision Sensor448sends a signal that translates to control signals to stop one or the other of the Drive Motors308to prevent the Carriages302from damaging each other.

FIG. 7shows a top plan view of the carriage printed circuit board ofFIGS. 4,5, and6in an embodiment of the portable medical simulation system for training healthcare teams of the present invention. Referring now toFIG. 7, Junction702provides power to Magnetic Particle Brake408. Junctions704are for the two Force Sensors432. Junction706is for Optical Encoder436. One or the other of Junction708is for Flex Circuit330, depending upon the location of the particular Carriage302in relation to the other Carriages302. Junction710is for the translation gain, and Junction712is for the translation offset. Junction714is for Collision Sensor448.

FIGS. 8A,8B,8C, and8D show various views of an embodiment of the catheter stabilizer within the haptic interface device in an embodiment of the portable medical simulation system for training healthcare teams of the present invention. Referring now toFIGS. 8A,8B,8C, and8D, for very flexible catheters used in the medical simulation, a support means must be supplied to keep the catheter from bending and bowing in traversing distances between Carriages302. Telescoping tubes have been used in the past as a means of stabilizing the catheter within a haptic device. The present invention utilizes Catheter Stabilizer804in one embodiment of the invention to stabilize flexible catheters between Carriages302.

InFIG. 8C, Catheter Stabilizer804is shown in a top view in a contracted state typical of when two Carriages302are very close together. InFIG. 8D, Catheter Stabilizer804is shown in a top view in an expanded state typical of when two Carriages302are very far apart. The first Catheter Stabilizer804is attached on a First End818to Catheter Support Stand314and attached at its Second End820to Aft End442of a first Carriage302. The second Catheter Stabilizer804is attached on First End818to Fore End440of the first Carriage302and attached at its Second End820to an Aft End442of a second Carriage302. Thus, as each Carriage302moves in relationship to each other, Catheter Stabilizers804will expand and contract between them as shown.

Catheter Stabilizer804is made from two different sized links that are alternately adhered together at their middle portions to form an expandable linked structure. Primary Link802is shown in a front view inFIG. 8B, and Secondary Link800is shown in a front view inFIG. 8A. Primary Link802and Secondary Link800are made from a flat piece of material that is folded twice along Fold Edges805,806and seamed, typically through an overlap between the two ends. The seam may be accomplished by an adhesive, or through heat welding. In another embodiment, the two ends could be butted up against each other and an adhesive strip applied over the abutted ends. In one embodiment of the invention, Primary Link802and Secondary Link800are made from a 0.003 inch thick Kapton film.

Bottom Edge808slides against the top surface of Rail304. Notches814engage with Support Rails822located on either side of Rail304(seeFIGS. 8C and 8D). Thus, Catheter Stabilizer804is prevented from moving up and down by Notches814, Support Rails822, and Rail304as it translates back and forth in the direction indicated by Arrow824.

Catheter Holes810and812line up with Catheter Support Tube316and Openings424,425in Spring Loaded Collets416. Thus, a catheter inserted in Catheter Support Tube316will pass through each alternating Catheter Holes810and812of Catheter Stabilizer804before reaching Opening424and Lumen452in a Spring Loaded Collet416of a Carriage302. After exiting the Carriage302through Opening425, the catheter will pass through each alternating Catheter Holes810and812of a next Catheter Stabilizer804before reaching Opening424and Lumen452in a Spring Loaded Collet416of a next Carriage302. Catheter Holes810and812are sized large enough to not impinge on a catheter inserted there through when Catheter Stabilizer804is in an expanded state. An oval shaped or oblong shaped hole may be used instead of a circular hole to help achieve this end. On either side of Catheter Hole812are Collision Arm Holes816which allow the Collision Arm450on a Carriage302to pass through in order to engage Collision Sensor448on the next Carriage302. Since Secondary Links800are narrower in width, Collision Arm Holes816are not needed for Secondary Links800.

A predetermined number of alternating Primary Links802and Secondary Links800are adhered together so as to be able to span, in an expanded state, the maximum distance anticipated between any pair of Carriages302or between a Carriage302and Catheter Support Stand314and stabilize the catheter across the separation distance. The reason Secondary Links800are narrower than Primary Links802is to allow an offset area for the Fold Edges805to lie when in the contracted state. If Secondary Links800and Primary Links802are the same width, then in the compressed state the Fold Edges805,806all line up and tend to fan out due to their thickness and not allow for a tightly compressed structure.

FIGS. 9A,9B,9C, and9D show various views of an alternative embodiment of the catheter stabilizer within the haptic interface device in an embodiment of the portable medical simulation system for training healthcare teams of the present invention. Referring now toFIGS. 9A,9B,9C, and9D, inFIG. 9C, Catheter Stabilizer904is shown in a top view in a contracted state typical of when two Carriages302are very close together. InFIG. 9D, Catheter Stabilizer904is shown in a top view in an expanded state typical of when two Carriages302are very far apart. Catheter Stabilizers904are attached to Catheter Support Stand314and to Carriages302as described above. Thus, as each Carriage302moves in relationship to each other, Catheter Stabilizers904will expand and contract between them as shown.

Catheter Stabilizer904is made from two fairly identical strips of material, Top Strip900shown in plan view inFIG. 9A, and Bottom Strip902shown in plan view inFIG. 9B, the difference being the location of Slits919,920. A series of Slits919are cut half way through Top Strip900from the Bottom Edge907upward. A series of Slits920are cut half way through Bottom Strip902from the Top Edge918downwards. The offset distances between each pair of Slits919,920and Fold Lines905,906are one of two different distances, and they alternate with each other along the length of each strip Top Strip900and Bottom Strip902, smaller, larger, smaller, etc. Top Strip900and Bottom Strip902are folded along Fold Lines905,906accordion style, with the first fold of Top Strip900folded opposite to the first fold in Bottom Strip902. The two strips are then mated along corresponding Slits919,920and inserted together, seating each Slit919,920at its end location to form an expandable linked structure, and forming the criss-cross shape as seen inFIGS. 9C and 9D. An adhesive tape may be applied to Top Edges918to add stability to the structure. In one embodiment of the invention, Top Strip900and Bottom Strip902are made from a 0.003 inch thick Kapton film.

Bottom Edges907,908slide against the top surface of Rail304. Notches913,914engage with Support Rails822located on either side of Rail304. Thus, Catheter Stabilizer904is prevented from moving up and down by Notches914, Support Rails822, and Rail304as it translates back and forth in the direction indicated by Arrow924.

Catheter Holes910and912line up with Catheter Support Tube316and Openings424in Spring Loaded Collets416as described above. Catheter Holes910and912are sized large enough to not impinge on a catheter inserted there through when Catheter Stabilizer904is in an expanded state. An oval shaped or oblong shaped hole may be used instead of a circular hole to help achieve this end. Collision Arm Holes915,916allow the Collision Arm450on a Carriage302to pass through in order to engage Collision Sensor448on the next Carriage302.

A predetermined length of Top Strip900and Bottom Strip902are inserted together so as to be able to span, in an expanded state, the maximum distance anticipated between any pair of Carriages302or between a Carriage302and Catheter Support Stand314and stabilize the catheter across the separation distance. The reason for the difference in width between the Fold Lines905,906and the Slits919,920is to allow an offset area for the alternating Fold Lines905,906to lie in the compressed state as discussed above.

FIG. 10shows a schematic electrical diagram of the printed circuit board of the haptic interface device in an embodiment of the portable medical simulation system for training healthcare teams of the present invention. Referring now toFIG. 10, all of the components of the Haptic Interface Device104tie into the Schematic Electrical Diagram1000.

FIG. 11shows a block diagram of the relationship between the hardware components in an embodiment of the portable medical simulation system for training healthcare teams of the present invention. Referring now toFIG. 11, once a medical simulation has been selected to run, the one or more Computers108send signals of Desired Behavior Data1102to the Haptic Interface Computer110. Haptic Interface Computer110sends Position and Rotation Data1104to Computer(s)108, and sends Motor and Brake Commands1106to Haptic Interface Device104. Haptic Interface Device104sends Position, Force, Rotation, and Collision Data1108to Haptic Interface Computer110.

Within Haptic Interface Computer110, Haptic Effects Generator1110processes Desired Behavior Data1102and sends Desired Force Data1112to Force Controller1114. Force Controller1114processes the Desired Force Data1112and generates Motor and Brake Commands1106which are sent to Haptic Interface Device104.

The exception to this process occurs when a catheter exchange event is detected, in which case a Haptic Effects Off Signal1116activates Catheter Exchange1118, which in turn sends Catheter Exchange Data1120to Force Controller1114. Force Controller1114processes the Catheter Exchange Data1120and generates Motor and Brake Commands1106for the catheter exchange which are sent to Haptic Interface Device104.

Computer(s)108throughout the above processes send Display Signals1122to the various Monitors, and receives User Input Signals1124from the Monitors which are touch screen enabled.

FIGS. 12-20show representations of a contrast display visual effect derived from a particle emitter software tool that simulates the release of radiopaque dye within a simulated vasculature system for display on a display device in an embodiment of the portable medical simulation system for training healthcare teams of the present invention. The particle based contrast software allows for a more realistic visual display of medically simulated contrast. In the past contrast was simulated by solid shading of the vessel tree in the location of the contrast (dye) injection. The particle based contrast approach allows for physics based particles to be “injected” into a confined vessel space and react to the vessel walls as it would with actual contrast fluid (dye) in an actual surgical procedure.

The particle based contrast software utilizes a node based hierarchy interaction where each node in the tree inherits attributes from its parent node. An emitter node contains all of the physics attributes as well as the trajectory and velocity attributes that it will apply to its particle node children. An emitter node dynamically creates as many particle nodes as is necessary for the given simulation. As a particle node ages it is deactivated and re-used later as needed.

Each node in the particle system can have the following attributes:Whether the node is actively being processed;The Fuse or countdown to when this node becomes active;The current age of the node (how long this node has been active);The position of the node;The size (Scale) of the node;The Color of the node;The Velocity of the node;The Mass of the node;The Display Object associated with this node (if any); andModifiers that modify children of this node, including:Scale Modifier—changes the size of the particle;Color Modifier—changes the red, green, blue, and alpha (“RGBA”) color of the particle;Path Modifier—the path that each particle must travel; andPhysics modifier—described below.

The emitter node physics modifiers contain the following information:Max age—the maximum age for each particle;Age variance—the randomness of the starting age of the particle;Flow direction—the direction of particle flow;Flow angle variance—randomness in the flow direction;Start speed—the starting speed of the particle;Start speed variance—randomness in the start speed;Mass—the mass of the particle;Mass variance—randomness in the mass;Mass growth—rate of change in mass;Gravity—current gravity;Drag—current drag; andNumber To Spawn—how many particles to create at each trigger time.

As a particle is emitted into the vessel tree the emitter physics has its strongest control over the position and direction of a particle. The particle is still restrained to the confines of the vessel wall but otherwise may move freely within it. As the calculated blood flow changes in the vessel the particle begins to move in the direction of blood flow and homogenously distributes itself within the vessel wall. Fading down the opacity of the particle and opacifying the vessel wall creates the homogenous distribution effect. This effect allows for the perception of movement from the particles as well as the dissolving effect of the contrast liquid distributing itself inside the vessel wall. As the particle ends its cycle it fades and is deactivated.

The particle based contrast software effect also utilizes the stencil buffer on the display device to allow the particles to pass slightly over the edge of the vessel wall and create a “hard edge” as it reaches the wall. As a particle approaches a branch in the vessel tree the particle calculates its probability of entering that branch and enters it if the odds allow. Otherwise it continues down the vessel path.

Referring now toFIG. 12, the angle variance from an Emitter Node1202is defined by the Angle θ. Arrow1204represents the direction of flow in the vessel.

Referring now toFIG. 13, the number of Particles1302to spawn per trigger are released from Emitter Node1202in directions that vary within the confines of Angle θ in the direction of flow (Arrow1204).

Referring now toFIG. 14, each Particle1302calculates its current position based on its current velocity represented by Arrow1406, its acceleration in the direction represented by Arrow1406, its mass, the drag in the direction represented by Arrow1404, and gravity in the direction represented by Arrow1402.

Referring now toFIG. 15, each particle interpolates its list of modifiers over its specified amount of time after its Fuse Time1514has elapsed. For each Particle Lifespan1502, an Initial Scale1504lasts for a specified period of time, and then a Next Scale1506is established for another specified period of time, and so on until the end of Particle Lifespan1502. Likewise, an Initial Color1508lasts for a specified period of time, and then a Next Color1510is established over another specified period of time, and a Next Color1512, and so on until the end of Particle Lifespan1502.

Referring now toFIG. 16, emitted Particles1602are collision detected and restrained to stay inside the established walls of Vessel1606and move within the direction of flow indicated by Arrow1604.

Referring now toFIG. 17, once Particle1702is emitted from the end of Catheter1708, Particle1702reacts to the changing flow properties of the environment within Vessel1704. Interpolating in the flow of the vessel, represented by Arrow1706, slowly takes over the physics of the Particle1702until it is moving in the same direction as the flow indicated by Arrow1706.

Referring now toFIG. 18, as particle opacity decreases, vessel opacity increases to give the appearance of contrast dispersion. Then, as further time passes, both fade to zero opacity.

Referring now toFIG. 19, flow direction and position for newly emitted particles are updated by the position and direction of Catheter1708,1708′.

Referring now toFIG. 20, during cannulation, Vessel Back Flow2002is simulated by reversing the flow direction of the node emitter. Smaller branches receive darker vessel shading and particles are still sent down the Vessel2004in the direction of blood flow indicated by Arrow2008. Based on the vessel size and the simulated volume of contrast injection fluid, the particles and vessel shading will be lighter to simulate the contrast dispersion. The particles of Vessel Back Flow2002move in the direction of blood flow indicated by Arrow2006.

Having described the present invention, it will be understood by those skilled in the art that many changes in construction and circuitry and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the present invention.