WITH PHYSIOLOGICAL MODELING Background

The present disclosure relates generally to interactive education systems for teaching patient care. While it is desirable to train medical personnel in patient care protocols before allowing contact with real patients, textbooks and flash cards lack the important benefits to students that can be attained from hands-on practice. On the other hand, allowing inexperienced students to perform medical procedures on actual patients that would allow for the hands-on practice cannot be considered a viable alternative because of the inherent risk to the patient. Because of these factors patient care education has often been taught using medical instruments to perform patient care activity on a simulator, such as a manikin. Examples of such simulators include those disclosed in U.S. Patent Application No. 1 1 /952,559, U.S. Patent Application No. 1 1 /952,606, U.S. Patent Application No. 1 1 /952,636, U.S. Patent Application No. 1 1 /952,669, U.S. Patent Application No. 1 1 /952,698, U.S. Patent No. 7,1 14,954, U.S. Patent No. 6,758,676, U.S. Patent No. 6,503,087, U.S. Patent No. 6,527,558, U.S. Patent No. 6,443,735, U.S. Patent No. 6,193,519, and U.S. Patent No. 5,853,292, each herein incorporated by reference in its entirety. While these simulators have been adequate in many respects, they have not been adequate in all respects. Therefore, what is needed is an interactive education system for use in conducting patient care training sessions that is even more realistic and/or includes additional simulated features. Summary

The present disclosure provides interactive education systems, apparatus, components, and methods for teaching patient care that include physiological modeling.

In one embodiment, a system for teaching patient care is provided. The system includes a maternal simulator and a fetal simulator. The maternal simulator includes a maternal circulatory model, a maternal cardiac ischemia model, and a maternal respiratory model, while the fetal simulator includes a fetal circulatory model, a fetal cardiac ischemia model, and a fetal central nervous system model. The fetal simulator is in communication with the maternal simulator. Further, a controller is in communication with each of the maternal simulator and the fetal simulator. The controller coordinates parameters of the maternal circulatory model, the maternal cardiac ischemia model, the maternal respiratory model, the fetal circulatory model, the fetal cardiac ischemia model, and the fetal central nervous system model to simulate physiological characteristics of a natural mother and fetus.

In some instances, the maternal circulatory model is a multi-compartment circulatory model that includes a simulated uterus. The maternal circulatory model further includes a simulated right atrium, a simulated right ventricle, a simulated left atrium, and a simulated left ventricle in some embodiments. The maternal circulatory model includes various combinations of the anatomical features of the natural circulatory system. Generally, any combination of the anatomical features of the natural circulatory system may be included in the maternal circulatory model. As described below, in some instances the maternal circulatory model is an 19-compartment circulatory model. In some instances, the maternal ischemia model includes a simulated aorta and a simulated coronary artery. The maternal respiratory model includes a simulated right lung and a simulated left lung, in some embodiments. The respiratory model further includes dead space (e.g., airway and alveoli) in some instances. In some instances, the maternal simulator further includes a maternal cardiac dipole model. In that regard, the maternal cardiac dipole model generates 12-lead ECG waves for four heart chambers of the maternal circulatory model in some instances. The maternal cardiac dipole model further generates a contraction profile that includes timing and contractility of each of the four heart chambers during a contraction, in some embodiments.

In some instances, the fetal circulatory model is a multi-compartment circulatory model that includes a simulated placenta. The fetal circulatory model further includes a simulated right atrium, a simulated right ventricle, a simulated left atrium, and a simulated left ventricle in some embodiments. The maternal circulatory model includes various combinations of the anatomical features of the natural circulatory system. Generally, any combination of the anatomical features of the natural circulatory system may be included in the fetal circulatory model. As described below, in some instances the fetal circulatory model is an 18-compartment circulatory model. In some instances, the fetal ischemia model includes a simulated aorta and a simulated coronary artery. In some instances, the maternal circulatory model and the fetal circulatory model are connected to one another. For example, in some embodiments the maternal circulatory model includes a simulated uterus and the fetal circulatory model includes a simulated placenta such that the simulated placenta is connected to the simulated uterus. Further, in some instances the maternal simulator includes a mechanism configured to translate and rotate the fetal simulator relative to maternal simulator to simulate a birth.

In some embodiments, the controller includes a processor programmed to coordinate parameters of the maternal circulatory model, the maternal cardiac ischemia model, the maternal respiratory model, the fetal circulatory model, the fetal cardiac ischemia model, and the fetal central nervous system model based on a desired physiological scenario. In that regard, the controller is positioned remote from the maternal simulator in some instances. For example, the controller is positioned within a computing device that is in communication with the maternal simulator and/or the fetal simulator in some embodiments. The desired physiological scenario is selectable by a user through a user interface in some instances. The desired physiological scenario is selected from scenarios such as maternal bleeding, maternal uterine rupture, maternal apnea, maternal VFib, maternal VTach, fetal bleeding, fetal cord compression, and/or other physiological scenarios.

In some embodiments, the system further includes a neonatal simulator for use in post birth situations. The neonatal simulator includes a neonatal circulatory model, a neonatal cardiac ischemia model, and a neonatal respiratory model. In some instances, the controller is in communication with the neonatal simulator and configured to coordinate parameters of the neonatal circulatory model, the neonatal cardiac ischemia model, and the neonatal respiratory model to simulate physiological characteristics of a newborn. In that regard, the parameters of the neonatal circulatory model and the neonatal cardiac ischemia model are at least partially based upon the parameters of the fetal circulatory model and the fetal cardiac ischemia model in some instances.

In another embodiment, an apparatus with physiological modeling is provided. In that regard, the apparatus includes a patient simulator having a patient body comprising one or more simulated body portions, including at least a simulated circulatory system and a simulated respiratory system. The apparatus also includes a controller in communication with the patient simulator. The controller is configured to coordinate parameters of the simulated circulatory system and the simulated respiratory system to simulate physiological characteristics associated with a desired physiological scenario. The controller determines the parameters of the simulated circulatory system and the simulated respiratory system for the desired physiological scenario based on a circulatory model and a respiratory model for the patient simulator.

In some instances, the circulatory model is a multi-compartment circulatory model including a simulated right atrium, a simulated right ventricle, a simulated left atrium, and a simulated left ventricle. The circulatory model includes various combinations of the anatomical features of the natural circulatory system. Generally, any combination of the anatomical features of the natural circulatory system may be included in the circulatory model. As described below, in some instances the circulatory model is a 18-compartment circulatory model. In some instances, the patient simulator is a maternal simulator and the circulatory model further includes a simulated uterus. The respiratory model includes a simulated right lung and a simulated left lung. In some instances, the respiratory model further includes dead space. In some embodiments, the controller determines the parameters of the simulated circulatory system for the desired physiological scenario at least partially based on an ischemia model for the patient simulator, where the ischemia model includes a simulated aorta and a simulated coronary artery. In some embodiments, the patient simulator is configured to generate 12-lead ECG waves and contraction profiles for a heart of the simulated circulatory system. In that regard, the controller controls the 12-lead ECG waves and contraction profiles generated by the patient simulator. The controller determines values for the 12-lead ECG waves and the contraction profiles based on a cardiac dipole model in some embodiments.

In some instances, the patient body is sized and shaped to simulate a newborn. In that regard, the parameters of the simulated circulatory system are at least partially based on physiological characteristics of a fetus associated with the newborn in some instances. For example, in some embodiments, the fetus associated with the newborn is the patient simulator prior to a birthing simulation, and the newborn is the patient simulator after the birthing simulation.

In another embodiment, methods of teaching patient care are provided. In one embodiment, the method includes providing a maternal simulator comprising a simulated maternal circulatory system and a simulated maternal respiratory system; providing a fetal simulator for use with the maternal simulator, the fetal simulator comprising a simulated fetal circulatory system; controlling one or more parameters of the simulated maternal circulatory system and simulated maternal respiratory system based on a maternal circulatory model, a maternal cardiac ischemia model, and a maternal respiratory model; and controlling one or more parameters of the simulated fetal circulatory system based on a fetal circulatory model, a fetal cardiac ischemia model, and a fetal central nervous system model. The parameters of the simulated maternal circulatory system, the simulated maternal respiratory system, and the simulated fetal circulatory system are coordinated to simulate physiological characteristics of a natural mother and fetus for a desired physiological scenario. In some instances, the controlling of the one or more parameters of the simulated maternal circulatory system is further based on a maternal cardiac dipole model. The one or more controlled parameters of the simulated maternal circulatory system include one or more of a maternal blood pressure, a maternal heart rate, a maternal cardiac rhythm, and/or other parameters. The one or more controlled parameters of the simulated fetal circulatory system include a fetal heart rate and/or other parameters.

Brief Description of the Drawings

Other features and advantages of the present disclosure will become apparent in the following detailed description of illustrative embodiments with reference to the accompanying of drawings, of which:

Fig. 1 is a diagrammatic schematic view of an arrangement incorporating aspects of the present disclosure.

Fig. 2 is a diagrammatic schematic view of a maternal circulatory model of the arrangement of Fig. 1 according to one embodiment of the present disclosure.

Fig. 3 is a diagrammatic schematic view of a fetal circulatory model of the

arrangement of Fig. 1 according to one embodiment of the present disclosure.

Fig. 4 is a diagrammatic schematic view of a neonatal circulatory model of the arrangement of Fig. 1 according to one embodiment of the present disclosure.

Fig. 5 is a diagrammatic schematic view of a respiratory model of the arrangement of

Fig. 1 according to one embodiment of the present disclosure.

Fig. 6 is a screen shot of a user interface according to another aspect of the present disclosure.

Detailed Description

For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will

nevertheless be understood that no limitation of the scope of the disclosure is intended. Any alterations and further modifications in the described devices, instruments, methods, and any further application of the principles of the disclosure as described herein are contemplated as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and/or steps described with respect to one embodiment may be combined with the features, components, and/or steps described with respect to other embodiments of the present disclosure.

One of the aims of healthcare simulation is to establish a teaching environment that closely mimics key clinical cases in a reproducible manner. The introduction of high fidelity tetherless simulators, such as those available from Gaumard Scientific Company, Inc., over the past few years has proven to be a significant advance in creating realistic teaching environments. The concepts of the present disclosure take the simulators to another level of realism by introducing physiological modeling into the simulators. In particular, the present disclosure provides physiological systems that are modeled on concurrent differential equations to provide

autonomous or semi autonomous control of the simulators' vital signs. In that regard, in many instances the physiological modeling is executed without the need for substantial input or direction from the facilitator or user in control of the simulator. Rather, in many instances, the facilitator or user in control of the simulator need only actuate a particular scenario through a user-interface (e.g., clicking on a simulated button for the particular physiological scenario on a display associated with a computing device) and the physiological models will automatically control the vital signs of the simulators based on the selected scenario and/or the user's interaction with the simulators (e.g., treatments applied to the simulator(s)). In this manner, the present disclosure provides improved medical simulation teaching environments. In some instances, the physiological modeling of the present disclosure is particularly focused on the physiological interaction between a mother and a fetus and, subsequently, the newborn. As the health of the mother, fetus, and newborn are interconnected, a more realistic simulation teaching environment will simulate these interactions in a realistic manner. The present disclosure provides such realistic interaction between the physiological characteristics of the mother and fetus and, in some instances, a corresponding newborn by controlling the physiological

characteristics of each of the simulators based on physiological models relating the physiological characteristics of the simulators to one another.

Referring to Fig. 1 , shown therein is an arrangement 100 illustrating aspects of the present disclosure. In particular, Fig. 1 is a diagrammatic schematic view of the arrangement 100. In that regard, the arrangement 100 includes a pregnancy model 102 that includes a maternal model 104 and a fetal model 106, along with a neonatal model 108. In some instances, aspects of the present disclosure are configured for use with the simulators and the related features disclosed in U.S. Patent Application No. 1 1 /952,559, U.S. Patent Application No. 1 1 /952,606, U.S. Patent Application No. 1 1 /952,636, U.S. Patent Application No. 1 1 /952,669, U.S. Patent Application No. 1 1 /952,698, U.S. Patent No. 7,1 14,954, U.S. Patent No. 6,758,676, U.S. Patent No. 6,503,087, U.S. Patent No. 6,527,558, U.S. Patent No. 6,443,735, U.S. Patent No. 6,193,519, and U.S. Patent No. 5,853,292, each herein incorporated by reference in its entirety. For example, in some instances, one or more of the physiological models of the present disclosure are incorporated into the simulators, controllers, software, and/or user interfaces disclosed in these patents and applications. In that regard, the maternal model 104 is associated with a maternal simulator in some instances. Similarly, the fetal model 106 and/or the neonatal model 108 are associated with a fetal simulator and a neonatal simulator, respectively, in some instances.

As discussed in greater detail below, the maternal model 104, the fetal model 106, and/or the neonatal model 108 are utilized to control the respective simulated physiological characteristics of the simulators in order to simulate the physiological characteristics associated with one or more birthing scenarios. In that regard, the vital signs and physiological characteristics generated by the physiological models are readable or measurable on the simulators using standard medical equipment in some instances. In addition, the vital signs and physiological characteristics are visible on associated monitors and/or a user-interface control program in some embodiments.

Generally, two information pathways connect the maternal model 104, the fetal model 106, and the neonatal model 108. A first information pathway coordinates the interactions between maternal model 104 and the fetal model 106 (e.g., blood flows, gas exchanges, core temperature, etc.), while a second information pathway passes off the model parameters from the fetal model 106 to the neonatal model 108 at the end of a labor scenario. In that regard, the neonatal model 108 corresponds to the fetal model 106 after birth. Accordingly, in some instances the fetal model 106 and the neonatal model 108 are utilized to control the physiological characteristics of a single simulator or manikin. In other instances, the fetal model 106 is utilized to control a fetal simulator/manikin, while the neonatal model 108 is utilized to control the physiological characteristics of a neonatal simulator/manikin that is separate from the fetal simulator/manikin. In such instances, the model parameters of the neonatal model 108 are coordinated with those of the fetal model 106 such that the neonatal simulator/manikin exhibits physiological characteristics consistent with those of the fetal simulator/manikin used in a labor scenario. Accordingly, in some embodiments the neonatal model 108 and associated neonatal simulator/manikin are particularly suited for use in post-birth simulations.

Referring now to Fig. 2, shown therein is a diagrammatic schematic view of a maternal circulatory model 1 10 that makes up at least a portion of the maternal model 104 of the pregnancy model 102 of the arrangement 100 illustrated in Fig. 1 , according to one embodiment of the present disclosure. Generally, the maternal circulatory model 1 10 is a multi-compartment circulatory model that includes simulated anatomical features of the natural circulatory system. In the illustrated embodiment of Fig. 2, the maternal circulatory model is an 19-compartment circulatory model. However, in other instances, the maternal circulatory model 1 10 includes other combinations of the anatomical features of the natural circulatory system. Generally, any combination of the anatomical features of the natural circulatory system may be included in the maternal circulatory model 1 10. The particular combination of anatomical features utilized in the maternal circulatory model 1 10 of Fig. 2 will now be discussed in greater detail.

As shown, the maternal circulatory model 1 10 includes a right atrium 1 12, a right ventricle 1 14, and a pulmonary artery 1 16. The maternal circulatory model 1 10 also includes respiratory features 1 18. In the illustrated embodiment, the respiratory features 1 18 include left and right lungs and a shunt. In some instances, characteristics of the respiratory features 1 18 are at least partially determined by a respiratory model, such as the respiratory model discussed below with respect to Fig. 5. Referring again to Fig. 2, the maternal circulatory model also includes a pulmonary vein 120, a left atrium 122, a left ventricle 124, and an aorta 126. As shown, the aorta 126 is connected to a coronary artery 128 that leads to the right atrium 1 12. In some instances, the aorta 126, the coronary artery 128, and the right atrium 1 12 form a maternal ischemia model. In general, the ischemia model is utilized to calculate characteristics of the components of the maternal circulatory model, including such things as the contractility of the four heart chambers, an ECG output of the maternal model, and/or other ischemia-determinant characteristics of the maternal circulatory model. In some instances, the maternal model includes a maternal cardiac dipole model based on these characteristics that generates 12-lead ECG waves for four heart chambers of the maternal circulatory model and also generates a contraction profile that includes timing and contractility of each of the four heart chambers during a contraction.

The aorta 126 of the maternal circulatory model 1 10 is also connected to a

descending aorta 130 that leads to arterioles 132. The arterioles 132 lead to fat 134, vein-rich tissue 136, muscle 138, and a uterus 140. Generally, the fat 134, vein-rich tissue 136, muscle 138, and uterus 140 represent the tissues and organs of the mother and their corresponding effects on the maternal circulatory system.

However, any combination and/or groupings of tissues and organs of the mother may be utilized in other embodiments to account for the effects of the tissues and organs of the mother on the maternal circulatory system. The fat 134, vein-rich tissue 136, muscle 138, and uterus 140 lead to venules 142. The venules 142 lead to a vena cava 144 that returns back to the right atrium 1 12. Generally, the right atrium 1 12, right ventricle 1 14, pulmonary artery 1 16, respiratory features 1 18, pulmonary vein 120, left atrium 122, left ventricle 124, aorta 126, coronary artery 128, descending aorta 130, arterioles 132, fat 134, vein rich tissue 136, muscle 138, uterus 140, venules 142, and vena cava 144 are interconnected in a manner simulating the interactions of the corresponding anatomical features of the natural circulatory system in order to define the maternal circulatory model 1 10.

As shown, the uterus 140 is connected to a placenta 146 of the fetal model 106. In that regard, the connection between the uterus 140 and the placenta 146 facilitates an exchange 148 between the maternal model 104 and the fetal model 106. The exchange 148 includes a transfer 150 from the uterus 140 to the placenta 146 and a transfer 152 from the placenta 146 back to the uterus 140. Generally, the transfer 150 simulates the sending of oxygen rich blood and nutrients to the fetus through the placenta, while the transfer 152 simulates the sending of blood with increased amounts of carbon dioxide from the fetus back to the mother through the placenta and into the uterus.

Referring now to Fig. 3, shown therein is a diagrammatic schematic view of a fetal circulatory model 160 that makes up at least a portion of the fetal model 106 of the pregnancy model 102 of the arrangement 100 illustrated in Fig. 1 , according to one embodiment of the present disclosure. Generally, the fetal circulatory model 160 is a multi-compartment circulatory model that includes simulated anatomical features of the natural circulatory system of a fetus. In the illustrated embodiment of Fig. 3, the fetal circulatory model 160 is an 18-compartment circulatory model. In that regard, the left and right lungs of the fetal simulator are combined into a single compartment in some instances. However, in other instances, the fetal circulatory model 160 includes other combinations of the anatomical features of the natural circulatory system. Generally, any combination of the anatomical features of the natural circulatory system may be included in the fetal circulatory model 160. The particular combination of anatomical features utilized in the fetal circulatory model 160 of Fig. 3 will now be discussed in greater detail.

As shown, the fetal circulatory model 160 includes a right atrium 162, a right ventricle 164, and a pulmonary artery 166. The fetal circulatory model 160 also includes lungs 168. However, as the fetus is not yet breathing the lungs 168 do not operate according to normal respiratory functions. Accordingly, whereas the respiratory features 1 18 of the maternal circulatory model 1 10, for example, may operate according to a respiratory model, such as the respiratory model described below in conjunction with Fig. 5, the lungs 168 of the fetal circulatory model 160 do not follow such respiratory models based on respiratory features that are being utilized for breathing. In that regard, the lungs 168 do not oxygenize the blood, but rather utilize some of the oxygen in the blood in order to maintain the health of the lungs.

Referring again to Fig. 3, the fetal circulatory model 160 also includes a pulmonary vein 170, a left atrium 172, a left ventricle 174, and an aorta 176. As shown, the aorta 176 is connected to a coronary artery 178 that leads to the right atrium 172. In some instances, the aorta 176, the coronary artery 178, and the right atrium 172 form a fetal ischemia model. In general, the fetal ischemia model is utilized to calculate characteristics of the components of the fetal circulatory model. In some instances, the fetal ischemia model is determines such characteristics as the contractility of the four heart chambers, an ECG output of the fetal model, and/or other ischemia-determinant characteristics of the fetal circulatory model.

The aorta 166 of the fetal circulatory model 160 is also connected to a descending aorta 180 that leads to arterioles 182. The arterioles 182 lead to fat 184, vein-rich tissue 186, muscle 188, and the placenta 146. Generally, the fat 184, vein-rich tissue 186, muscle 188, and placenta 146 represent the tissues and organs of the fetus and their corresponding effects on the fetal circulatory system. However, any combination and/or groupings of tissues and organs of the fetus may be utilized in other embodiments to account for the effects of the tissues and organs of the fetus on the fetal circulatory system. The fat 184, vein-rich tissue 186, muscle 188, and placenta 146 lead to venules 190. The venules 190 lead to a vena cava 192 that returns back to the right atrium 162. The fetal circulatory model 160 further includes a shunt 194 that is in communication with the pulmonary artery 166, as shown. In that regard, the fetal circulatory model 160 also includes a plurality of shunt flows as illustrated by flows 196, 198, and 200. Specifically, flow 196 illustrates the shunt flow between the shunt 194 and a fetal central nervous system model 202. Flow 198 illustrates the shunt flow between the right atrium 162 and the left atrium 172.

Finally, flow 200 illustrates the shunt flow between the placenta 146 and the vena cava 192.

As mentioned above, the fetal circulatory model 160 includes a fetal central nervous system model 202. The connection between the fetal circulatory model 160 and the fetal central nervous system model 202 facilitates an exchange 204 between the circulatory system and the nervous system of the fetus. In particular, the exchange 204 includes a transfer 206 simulating the sending oxygen rich blood from the circulatory system to the central nervous system and a transfer 208 simulating the sending of blood with increased amounts of carbon dioxide from the central nervous system back into the circulatory system. The amount of oxygen utilized by the fetal central nervous system model 202 is influenced by both maternal conditions (e.g., oxygen partial pressure, cardiac output, uterine activity) and fetal conditions (e.g., fetal movement, oxygen level, cord compression, head compression, hemorrhage). Accordingly, the fetal central nervous system model 202 has a direct influence on characteristics of the fetal circulatory model, including fetal heart rate and oxygen level.

Generally, the right atrium 162, right ventricle 164, pulmonary artery 166, lungs 168, pulmonary vein 170, left atrium 172, left ventricle 174, aorta 176, coronary artery 178, descending aorta 180, arterioles 182, fat 184, vein rich tissue 186, muscle 188, placenta 146, venules 190, vena cava 192, shunt 194, and central nervous system 202 are interconnected in a manner simulating the interactions of the corresponding anatomical features of the natural circulatory system in order to define the fetal circulatory model 160.

As noted above, the connection between the uterus 140 and the placenta 146 facilitates the exchange 148 between the maternal model 104 and the fetal model 106. The exchange 148 includes the transfer 150 from the uterus 140 to the placenta 146 and the transfer 152 from the placenta 146 back to the uterus 140. Generally, the transfer 150 simulates the sending of oxygen rich blood and nutrients to the fetus through the placenta, while the transfer 152 simulates the sending of blood with increased amounts of carbon dioxide from the fetus back to the mother through the placenta and into the uterus. Accordingly, the exchange 148 is utilized to link the circulatory models 1 10, 160 of the maternal and fetal models 104, 106 in order to define the overall circulatory model for the pregnancy model 102. Particular interactions and relationships between the maternal model 104 and the fetal model 106, including the circulatory models 1 10, 160, are discussed below with respect to some exemplary physiological scenarios.

Referring now to Fig. 4, shown therein is a diagrammatic schematic view of a neonatal circulatory model 210 that makes up at least a portion of the neonatal model 108 of the arrangement 100 illustrated in Fig. 1 , according to one embodiment of the present disclosure. Generally, the neonatal circulatory model 210 is a multicompartment circulatory model that includes simulated anatomical features of the natural circulatory system. In the illustrated embodiment of Fig. 4, the neonatal circulatory model is a 18-compartment circulatory model. However, in other instances, the neonatal circulatory model 210 includes other combinations of the anatomical features of the natural circulatory system. Generally, any combination of the anatomical features of the natural circulatory system may be included in the neonatal circulatory model 210. The particular combination of anatomical features utilized in the neonatal circulatory model 210 of Fig. 4 will now be discussed in greater detail.

As shown, the neonatal circulatory model 210 includes a right atrium 212, a right ventricle 214, and a pulmonary artery 216. The neonatal circulatory model 210 also includes respiratory features 218. In the illustrated embodiment, the respiratory features 218 include left and right lungs and a shunt. In some instances,

characteristics of the respiratory features 218 are at least partially determined by a respiratory model, such as the respiratory model discussed below with respect to Fig. 5. Referring again to Fig. 4, the neonatal circulatory model 210 also includes a pulmonary vein 220, a left atrium 222, a left ventricle 224, and an aorta 226. As shown, the aorta 226 is connected to a coronary artery 228 that leads to the right atrium 212. In some instances, the aorta 226, the coronary artery 228, and the right atrium 212 form a neonatal ischemia model. In general, the neonatal ischemia model is utilized to calculate characteristics of the components of the neonatal circulatory model, including such things as the contractility of the four heart chambers, an ECG output of the neonatal model, and/or other ischemia-determinant characteristics of the neonatal circulatory model. In some instances, the neonatal model includes a neonatal cardiac dipole model based on these characteristics that generates 12-lead ECG waves for the four heart chambers of the neonatal circulatory model and also generates a contraction profile that includes timing and contractility of each of the four heart chambers during a contraction.

The aorta 226 of the neonatal circulatory model 210 is also connected to a

descending aorta 230 that leads to arterioles 232. The arterioles 232 lead to fat 234, vein-rich tissue 236, and muscle 238. Generally, the fat 234, vein-rich tissue 236, and muscle 238 represent the tissues and organs of the newborn and their corresponding effects on the neonatal circulatory system. However, any

combination and/or groupings of tissues and organs of the newborn may be utilized in other embodiments to account for the effects of the tissues and organs of the newborn on the neonatal circulatory system. The fat 234, vein-rich tissue 236, and muscle 238 lead to venules 242. The venules 242 lead to a vena cava 244 that returns back to the right atrium 212. Generally, the right atrium 212, right ventricle 214, pulmonary artery 216, respiratory features 218, pulmonary vein 220, left atrium 222, left ventricle 224, aorta 226, coronary artery 228, descending aorta 230, arterioles 232, fat 234, vein rich tissue 236, muscle 238, venules 242, and vena cava 244 are interconnected in a manner simulating the interactions of the corresponding anatomical features of the natural circulatory system in order to define the neonatal circulatory model 210.

Referring now to Fig. 5, shown therein is a diagrammatic schematic view of a respiratory model 250 of the arrangement of Fig. 1 according to one embodiment of the present disclosure. In some instances, the respiratory model 250 makes up at least a portion of the maternal model 104 and/or the neonatal model 108 of the arrangement 100. It is understood that the actual parameters of the respiratory model 250 are tailored for the particular model in which the respiratory model is to be used. For example, Table 4 below provides exemplary parameter values for different models representative of patient simulators of varying age, gender, and/or physiological condition.

As shown, the respiratory model 250 includes a right lung 252, a left lung 254, and dead space 256. In the illustrated embodiment the dead space 256 includes a mouth 258, airway 260, and alveolar space 262. An information exchange 264 conveys information relating to the right lung 252 to a corresponding right lung 266 of a circulatory model, in some instances. For example, the information exchange 264 sends information related to the right lung 252 of the respiratory model 250 to the circulatory model 1 10 of the maternal model 104 such that the information related to the right lung 252 is utilized as part of characteristics of the respiratory features 1 18 of the circulatory model 1 10. Similarly, an information exchange 268 conveys information relating to the left lung 254 to a corresponding left lung 270 of a circulatory model, in some instances. For example, the information exchange 268 sends information related to the left lung 254 of the respiratory model 250 to the circulatory model 1 10 of the maternal model 104 such that the information related to the left lung 254 is utilized as part of characteristics of the respiratory features 1 18 of the circulatory model 1 10. The information exchanges 264, 268 are similarly used in conjunction with the respiratory features 218 of the neonatal circulatory model 210 in some embodiments.

As a general matter, the components and/or the values associated with the components of the circulatory models 1 10, 160, 210 and the respiratory model 250 are modifiable in order to simulate patients of varying age, gender, and/or pathologies. In short, the components and associated values of the models can be varied to simulate a seemingly infinite number of patient conditions, each having different baseline physiological characteristics. Accordingly, below are a series of tables identifying baseline physiological characteristics for seven different simulated patients: an average adult male, an average adult female, a pregnant female, a fetus (38 weeks), a newborn (38 weeks), a 1 year old, and a 5 year old. It is understood that the baseline values identified in the tables are exemplary in nature and in no way limit the available values for use with the present disclosure. To the contrary, it is expected that the baseline values set forth in the tables will be modified to define particular physiological characteristics associated with a desired patient scenario. Generally, the baseline values can be modified to correspond to any value necessary to create the desired patient scenario.

Table 1 below sets forth some baseline values for general parameters of the circulatory models of the present disclosure. In particular, Table 1 identifies the corresponding weight (kg), blood volume (ml), metabolism rate (ml/kg/min), heart rate (beats/min), blood pressure (immHg), heart weight (g), baroreflex gain (index), and hematocrit (%) for each patient model.

TABLE 1 Female 1 year- 5 year-

Male Female (Pregnant) Fetus Newborn old old

Weight(kg) 75 55 85 2.5 2.5 10 18.25

Blood

Volume(ml) 5000 4700 6750 225 225 900 1642.5

Metabolism

rate(ml/kg/min) 3 3 3.5 7 1 1 8 5

Heart Rate

(beats/min) 75 75 85 140 140 140 95

Blood

Pressure

(mmHg) 120/81 1 13/74 105/60 53/37 66/48 88/64 99/66

Heart

Weight(g) 300 300 300 25 25 90 180

BaroReflex 2 2 2 0.5 2 2 2 Gain

Hematocrit(%) 44 44 44 47 47 46 45

Table 1. Default Values for General Parameters of the Circulatory Models

Table 2 below sets forth some baseline values for particular compartments of the circulatory models of the present disclosure. In particular, Table 2 identifies the corresponding volume (ml) and elastance (mmHg/ml) for the various compartments and related anatomy of the circulatory models.

TABLE 2 Female

(Pregnant Newbor 1 year- 5 year-

Male Female ) Fetus n old old

LA- unstressed

volume 30 28.2 30 1 .35 1 .35 5.4 9.855

LA-elastance 0.12 0.1 149 0.12 2.1333 1 .3333 0.3667 0.2374

LV- unstressed

volume 30 28.2 30 1 .35 1 .35 5.4 9.855

LV-elastance 0.08 0.0766 0.08 1 .4222 0.8889 0.2444 0.1583

Aorta- unstressed

volume 28 26.32 37.8 1 .26 1 .26 5.04 9.198

Aorta- 69.3333333 43.3333

elastance 3 2.8724 3 3 3 1 1 .9167 7.4201

Intrathoracic

Arteries- unstressed

volume 1 12 105.28 156.8 5.04 5.04 20.16 36.792

Intrathoracic

Arteries- elastance 1 .5 1 .4362 1 .5 34.6667 21 .6667 5.9583 3.71 00

Extrathoracic

Arteries- unstressed

volume 370 347.8 518 16.65 16.65 66.6 121 .545

Extrathoracic

Arteries- 3.97222

elastance 1 0.9574 1 23.1 1 1 1 14.4444 2 2.4734

Muscle- unstressed

volume 35 32.9 49 1 .575 1 .575 6.3 1 1 .4975

Muscle- 21 .6666

elastance 1 .5 1 .43617 1 .5 34.6667 7 5.9583 3.71 00

Vein Rich

Compartment

-unstressed

volume 139 130.66 194.6 6.255 6.255 25.02 45.6615

Vein Rich

Compartment 5.34444 0.915144

-elastance 0.37 0.3543 0.37 8.551 1 4 1 .4697 6

Fat- unstressed 1 1 10.34 15.4 0.495 0.495 1 .98 3.6135 TABLE 2 Female

(Pregnant Newbor 1 year- 5 year-

Male Female ) Fetus n old old volume

Fat-elastance 4.5 4.3085 4.5 104 65 17.875 1 1 .1301

Extrathoracic

Veins- unstressed 974.385 186.584

volume 1036.58 2 1451 .21 19 46.6461 46.6461 4 340.5165

Extrathoracic

Veins- elastance 0.017 0.01 63 0.017 0.3929 0.2456 0.0675 0.0420

Intrathoracic

Veins- unstressed 1216.85 1 143.84 219.033

volume 5 3 1703.5965 54.7585 54.7585 8 399.7367

Intrathoracic

Veins- 0.01723

elastance 0.018 4 0.018 0.41 6 0.26 0.0715 0.0445

RA- unstressed

volume 30 28.2 30 1 .35 1 .35 5.4 9.855

RA-elastance 0.1 0.0957 0.1 1 .7778 1 .1 1 1 1 0.3056 0.1979

Table 2. Default Values for Compartments of the Circulatory Models

Table 3 below sets forth some baseline values for vessel resistance (mmHg ^* sec/ml) of the various compartments and related anatomy of the circulatory models of the circulatory models of the present disclosure.

TABLE 3 Female 1 year-

Male Female (Pregnant) Fetus Newborn old 5 year-old

LA-LV 0.0072 0.0069 0.0065 0.1287 0.0804 0.0221 0.0143

LV-Aorta 0.0172 0.01 65 0.01 65 0.3065 0.1916 0.0527 0.0341

Aorta-

IntraAtery 0.0261 0.0250 0.0209 0.464 0.29 0.0798 0.0516

Intra Artery- Extra Artery 0.0486 0.0052 0.0048 0.1248 0.078 0.0215 0.0139

Extra Artery- Muscle 4.1 3.9255 3.28 72.8889 45.5556 12.5278 8.1 126

Extra Arte ry- VeinRich

Comp 1 .14 1 .0915 0.912 20.2667 12.6667 3.4833 2.2557

Extra Artery- Fat 12.8 12.2553 10.24 227.5556 142.2222 39.1 1 1 1 25.3272

Muscle-

ExtraVein 0.5 0.4787 0.4 8.8889 5.5556 1 .5278 0.9893

VeinRich

Comp- ExtraVein 0.14 0.1340 0.1 12 2.4889 1 .5556 0.4278 0.2770

Fat-

ExtraVein 1 .55 1 .4840 1 .24 27.5556 17.2222 4.7361 3.0670

ExtraVein-

IntraVein 0.09 0.0862 0.072 1 .6 1 0.275 0.1781

IntraVein-RA 0.003 0.0029 0.003 0.0533 0.0333 0.0092 0.0059

RA-RV 0.003 0.0029 0.003 0.0533 0.0333 0.0092 0.0059

RV-PA 0.003 0.0029 0.003 0.0533 0.0333 0.0092 0.0059 TABLE 3 Female 1 year-

Male Female (Pregnant) Fetus Newborn old 5 year-old

PA-

Rlung/Llung 0.205 0.1963 0.1435 3.6444 2.2778 0.6264 0.4056

PA-Shunt

flow 4 3.8298 2.8 35.5556 44.4444 12.2222 7.9148

Rlung/Llung- PV 0.06 0.0574 0.042 1 .0667 0.6667 0.1833 0.1 1 87

Shunt flow-

PV 2.5 2.3936 1 .75 NA 27.7778 7.6389 4.9467

PV-LA 0.003 0.0029 0.003 0.0533 0.0333 0.0092 0.0059

ExtraA-Ut NA NA 3.45 NA NA NA NA

UT-ExtraV NA NA 1 .85 NA NA NA NA

RA-LA NA NA NA 0.1 NA NA NA

Extra Arte ry- Pla NA NA NA 2 NA NA NA

Pla-lntraV NA NA NA 1 .6 NA NA NA

Shunt-lntraA NA NA NA 35 NA NA NA

Table 3. Default Values for Vessel Resistance of the Circulatory Models

Table 4 below sets forth some baseline values for general parameters of the respiratory models of the present disclosure. In particular, Table 4 identifies the corresponding residual volume (L), expiratory residual capacity (L), tidal volume (L), airway resistance (normal, slightly high, and high), anatomical dead space (L), and alveolar dead space (L) for each patient model. In some instances, airway resistance is measured on a scale from 1 -5, where 5 is normal airway resistance and smaller values are indicative of increased airway resistance (e.g., 3 is indicative of slightly high airway resistance, 2 is indicative of high airway resistance, and 1 is indicative of extremely high airway resistance). Other airway resistance scales are utilized in other embodiments.

Table 4. Default Values for Parameters of the Respiratory Models In use, the physiological models of the present disclosure are utilized to control the physiological characteristics of patient simulators in order to provide more realistic medical training environments. For example, in some instances, the pregnancy model 102 is utilized to simulate one or more birthing scenarios where the

physiological characteristics of the maternal model 104 and the fetal model 106 are configured to emulate the natural physiological characteristics associated with the one or more birthing scenarios. In that regard, the maternal model 104 is utilized to control aspects of a maternal simulator and the fetal model 106 is utilized to control aspects of a fetal simulator associated with the maternal simulator. In some instances, the maternal model 104 includes one or more of a circulatory model, a respiratory model, an ischemia model, and a cardiac dipole model, while the fetal model includes one or more of a circulatory model, an ischemia model, and a central nervous system model.

In some embodiments, a controller coordinates parameters of the maternal model 104 and the fetal model 106 based on a desired physiological birthing scenario. In some instances, the desired physiological birthing scenario is selectable by a user or instructor through a user interface associated with the simulators. The desired physiological birthing scenario is selected from a plurality of scenarios, including maternal bleeding (varying amounts), maternal uterine rupture (varying sizes), maternal apnea, maternal VFib, maternal VTach, fetal bleeding (varying amounts), fetal cord compression, normal labor, shoulder dystocia, breech presentation, cord prolapse, peripartum hemorrhage, amniotic fluid embolism, preterm labor, and/or other physiological birthing scenarios.

Aspects of some of these scenarios are discussed in greater detail below. In that regard, the effects of the physiological birthing scenarios on various vital signs will generally be discussed in relation to exemplary starting values for vital signs of the maternal and fetal models. For example, Table 5 below provides examples of such starting values. The values in Table 5 generally represent a starting point where both the mother and fetus are healthy. For sake of simplicity, these healthy starting values will be used to discuss the birthing scenarios below. However, it is understood that the maternal model and/or the fetal model may have other starting values (including values representative of various pathologies). Further, the birthing scenarios discussed generally only include a single variable or condition. However, it is understood that the individual birthing scenarios discussed below may be combined, either concurrently or consecutively, with one or more other birthing scenarios such that multiple variables or conditions are presented simultaneously or in series.

Table 5. Exemplary Starting Values for Birthing Scenarios

Table 6 below describes the variations in the vital signs of the maternal and fetal models associated with maternal bleeding. The maternal bleeding of Table 6 is intended to represent bleeding out of local tissue. For example, in the context of the maternal circulatory model 1 10 described above, bleeding would be out of one or more of the fat 134, vein-rich tissue 136, and muscle 138. The rate of bleeding can be varied to simulate different levels of trauma. In that regard, Table 7 below provides the corresponding values for the vital signs of the maternal and fetal models for a low rate of bleeding, while Table 8 below provides the corresponding values for a high rate of bleeding.

Table 7. ime Lapse of Values for Maternal Bleeding (Low Rate)

TABLE 8

Parameter 30s 1 min 2 min 3 min 4 min 5 min 6 min

RR 22 22 23 38 45 0

Osat 96 97 94 86 80 78

EtC02 31 30 37 34 33 0

Car. Rhy. Sinus Sinus Sinus Sinus Sinus Vfib

HR 1 10 133 135 137 135 0

BP 86/62 74/61 75/61 75/63 74/62 0/0

Temp 37.4 38 39 39.8 40.4 40.3

Baseline 135 135 140 125 1 1 1 91 71

Var mod mod minimal minimal minimal absent absent non- late late

Spont. Ch reactive reactive reactive reactive reactive decels decels

Periodic Ch none none none none none none none

Var. Ch none none none none none none none

Table 8. Time Lapse of Values for Maternal Bleeding (High Rate)

Table 9 below describes the variations in the vital signs of the maternal and fetal models associated with a uterine rupture. The uterine rupture of Table 9 is intended to represent bleeding out of the uterus of the maternal simulator. For example, in the context of the maternal circulatory model 1 10 described above, bleeding would be out of the uterus 140. The rate of bleeding can be varied to simulate different levels of trauma. In that regard, Table 10 below provides the corresponding values for the vital signs of the maternal and fetal models for a low rate of bleeding. There will be less latency of fetal deterioration relative the maternal bleeding of local tissue discussed above due to direct loss of uterine blood, which is the oxygen source for the fetus.

Table 9. Variations in Values for Uterine Rupture

TABLE 10

Parameter 30s 1 min 2 min 3 min 4 min 5 min 6 min

Resp. Rate 22 22 21 21 21 21 23

Osat 96 96 96 96 95 96 95

EtC02 32 31 31 31 31 34 32

Car. Rhy. Sinus Sinus Sinus Sinus Sinus Sinus Sinus

HR 83 101 109 106 107 109 108

BP 1 10/64 100/65 94/66 94/66 91 /66 93/64 90/66

Temp 37 37 37 37 37 37.3 37.3 Baseline

HR 125 135 135 135 135 135 135

Var minimal mod mod mod mod mod mod

Spont. Ch reactive reactive reactive reactive reactive reactive reactive

Periodic Ch none none none none none none none

Var. Ch none none none none none none none

Parameter 7 min 8 min 10 min 12 min 14 min 16 min 18 min

Resp. Rate 24 23 26 35 45 45 0

Osat 95 95 93 88 83 75 0

EtC02 30 31 30 30 28 30 0

Car. Rhy. Sinus Sinus Sinus Sinus Sinus Sinus Vfib

HR 1 19 1 15 125 136 135 138 0

BP 86/65 91 /66 81 /64 77/64 77/64 78/65 0

Temp 37.3 37.5 37.6 39.1 39.1 40.3 39.9

Baseline

HR 135 135 131 85 65 0 0

Var mod mod minimal absent absent subtle none

Spont. Ch reactive reactive reactive none none none none

late late

Periodic Ch none none none decels decels none none

Var. Ch none none none none none none none

Table 10. Time Lapse of Values for Uterine Rupture (Low Rate)

Table 1 1 below describes the variations in the vital signs of the maternal and fetal models associated with maternal apnea. Table 12 below provides the corresponding values for the vital signs of the maternal and fetal models for an exemplary

embodiment of maternal apnea. Note that the "??" values for Osat in Table 12 are representative of a Osat less than 60%.

Table 11. Variations in Values for Maternal Apnea

TABLE 12

Parameter 30s 1 min 2 min 3 min 4 min 5 min 6 min 7 min 8 min

RR 0 0 0 0 0 0 0 0 0 Osat 97 88 ?? ?? ?? ?? ?? ?? ??

EtC02 0 0 0 0 0 0 0 0 0

Car. Rhy. Sinus Sinus Sinus Sinus Sinus Sinus Sinus Sinus VFib

HR 85 85 85 85 85 85 85 85 0

BP 100/62 96/59 94/57 94/56 95/58 91 /59 88/58 68/45 0

Temp 37 37 37 37 37 37 37 37 37

Baseline 135 135 135 120 95 80 65 60 0

Var mod mod minimal minimal absent absent absent absent none non

Spont. Ch reactive reactive reactive reactive none none none none none late late late

Periodic Ch none none none none none decels decels decels none

Var. Ch none none none none none none none none none

Table 12. Time Lapse of Values for Maternal Apnea

Table 13 below describes the variations in the vital signs of the maternal and fetal models associated with maternal ventricular fibrillation (VFib). Table 14 below

provides the corresponding values for the vital signs of the maternal and fetal models for an exemplary embodiment of maternal VFib. Notably, compared to maternal apnea scenario discussed above, in the maternal VFib scenario, the maternal

simulator stops using oxygen. Accordingly, there's more oxygen supply for fetus and, therefore, the fetus is able to maintain good condition for longer (8 minutes in the illustrated embodiment).

Table 13. Variations in Values for Maternal VFib

TABLE 14

Parameter 30s 1 min 2 min 3 min 4 min 5 min 6 min 7 min

RR 0 0 0 0 0 0 0 0

Osat ?? ?? ?? ?? ?? ?? ?? ??

EtC02 0 0 0 0 0 0 0 0

Table 14. Time Lapse of Values for Maternal VFib Table 15 below describes the variations in the vital signs of the maternal and fetal models associated with maternal ventricular tachycardia (VTach). Table 16 below provides the corresponding values for the vital signs of the maternal and fetal models for an exemplary embodiment of maternal VFib. The slight deterioration in fetal condition is due to decreased maternal cardiac output which leads to decreased blood flow to uterus.

Table 15 Maternal Model Properties

Resp. Rate Small variation (normal)

Osat Small variation (normal)

EtCO2 Small variation (normal)

ECG Vtach

HR 120

BP 60/45 + Small variation (normal)

Temperature No change

Fetal Model Properties

Baseline HR Decrease at 1 1 ^th min -> maintain at 120 bpm

Variability Mod -> minimal

Episodic Ch. Reactive -> non reactive

Periodic Ch. None

Variables None (no cord compression) Table 15. Variations in Values for Maternal VTach

Table 16. Time Lapse of Values for Maternal VTach

Table 17 below describes the variations in the vital signs of the fetal model associated with fetal bleeding. The rate of bleeding can be varied to simulate different levels of trauma. In that regard, Table 18 below provides the corresponding values for the vital signs of the maternal and fetal models for a low rate of bleeding, while Table 19 below provides the corresponding values for a high rate of bleeding.

s

Baseline 120 131 135 135 140 135 120 80 60 0

Var sinusoidal

Spont. Ch none

Periodic Ch none

Var. Ch none

Tal ble 18. Time Lapse of Values 'or Fetal Bleeding (Low Rate)

At the end of a delivery or labor scenario, the parameters of the fetal model are transferred to the neonatal model. In some instances, the fetal model and the neonatal model are controlled by the same controller or processor and, therefore, the transfer of parameters is performed by the controller. In other instances, the fetal 0 model and the neonatal model are controlled by separate controllers or processors such that the parameters of the fetal model must be communicated to the controller or processor for the neonatal model. Generally, the communication of the parameters may occur over any suitable communication protocol including both wired and wireless connections. In some instances, the parameters are 5 communicated utilizing TCP/IP communication. In this manner, the final fetal parameters are the initial parameters of the neonate model. Additionally, in some instances the term (i.e., gestational age) of the fetus determines the lung maturity of the neonate. Accordingly, the respiratory model of the neonatal model is adjusted to match the development of the fetus. Further, the fetal central nervous system 0 model's final oxygen level at least partially determines the neural activity of the neonatal model in some instances. These and other parameters of the fetal model affect the resulting characteristics of the neonatal model. In turn, the characteristics of the neonatal model directly affect how the neonatal simulator responds to resuscitation efforts in post-birth simulations (e.g., the rate at which the neonatal simulator responds to various resuscitation techniques).

As noted above, the relationship(s) between the various models and/or

compartments within the models are based on concurrent differential equations in some embodiments. Below specific examples of equations used to define the physiological relationships of the present disclosure. It is understood that these equations are exemplary in nature and in no way limit the specific relationships and/or equations that can be utilized in the context of the physiological models the present disclosure.

With respect to the circulatory models, in some instances the following relationships are utilized:

Pressure = (Volume - Unstressed Volume) * Elastance

Flow Rate = (Pressure _up fi ₀ w - Pressuredowntiow) / Resistance With respect to the respiratory models, in some instances the following relationships are utilized for inspiration aspects of the respiratory models:

Normal/Asthma:

Vttiidal

r-j D 44- trespiration

rtranspulmonary = - I max ft ,

L lnsp

P Alveolar = P pleural - Ptranspulmonary

fair = - P Alveolar I P Emphysema: 5/46

Pleural— - / ^" max 1- e

Fpiaral = - Rm # _Λ 1- _ _3flnp - Fmmr

e

1- e ^"" "

Ptu sr = flo al - Panqxl ray

fair = - PfiJveolarl Fi

Fibrosis:

-| Q

Rranspulmonary

P ^j wolar = Floral - RranpJmonary

fair = - PAIveolar/ P

With respect to the respiratory models, in some instances the following relationships are utilized for expiration aspects of the respiratory models:

Normal:

J ^

Ppleural = /"max # ^ _3f&p - nin - /"max

-j

Ptranspulmonary = / ^" max # - /~min - Pm

Plwclar = Pplexsi - Prarep rrrrery

fair = - PAIveolar / P

Emphysema: 1 - e ^p

J

ranspul monary — ~ na ^ . † _Ex

1 - e

Reived ar = ffd ral ~ RrargxJ 'monary

fair = - ΡλΙνωΙειτΙ Fi

In the above equations related to the respiratory models, R = Resistance; P _ma x = Max Plueral Pressure; ti _nsp = Inspiration Time; V^ai = Intake Tidal Volume; P _p i _eur ai = Pleural Pressure; P _m in = Min; Ptranspuimonary = Transpulmonary Pressure; P _A i _ve oiar = Alveolar Pressure; and fair = air flow rate.

With respect to the gas exchanges utilized within the circulatory and respiratory models, in some instances the relationships discussed below are utilized. As a general matter, for the respiratory models the equations are based on dividing the airways into at least two segments, where one of the segments is dead space.

Oxygen (02) and carbon dioxide (CO2) are exchanged between the adjacent segments and then with the pulmonary capillaries (which are the right lung and left lung compartments of the circulatory model, in some instances). The fractions of oxygen and carbon dioxide are calculated and converted to partial pressures, such that the amount of gas exchanged with the capillaries is defined by the following general equation: V _exC riange = a (Partial Pressure in Lungs - Partial Pressure in Capillaries), where "a" is a constant. In some instances, for exchanges at the

Alveoli-capillary interface it is assumed that Con ₀ 2ca _P = Con ₀ 2ai _ve oii and Con _C o2ca _P = Con _C o2aiv _e oii- That is, it is assumed that 02 concentration in capillaries is equal to the 02 concentration in alveoli and, similarly, the CO2 concentration in capillaries is equal to the CO2 concentration in alveoli. Similar equations are utilized for gas exchanges at other locations. For example, for gas exchanges at the placenta-uterus interface the following equations are utilized in some instances:

ν ₉₃ ίηθ2 (ml/sec) = 0.00315 ^* (P _ut0 2 - Ppla0 ₂ )

V| _0S tco2 (ml/sec) = 0.00255 ^* (P _p i _a co2 - P _u tco ₂ )

In that regard, P _ut o2 = Uterus 02 Pressure; P _p i _a o2 = Placenta 02 Pressure; P _ut co2 = Uterus CO2 Pressure; and P _p i _a co2 = Placenta CO2 Pressure.

Referring now to Fig. 6, shown therein is a screen shot of user interface 300 illustrating aspects of another embodiment of the present disclosure. In particular, the user interface 300 is an exemplary embodiment of a user interface that facilitates control of one or more of the physiological models described above. In that regard, the user interface 300 is shown as being suitable for controlling at least the maternal and fetal models 104, 106 of the pregnancy model 102 described above. As a general matter, the user interface 300 allows a user to control aspects of the physiological model(s) manually, if desired, or simply allow the models to run automatically. For example, the user can choose to operate FHR tracings in Manual, Auto or Birth mode. In that regard, Birth mode is understood to represent a particular birthing scenario selected or created by the user. Further, the user has the freedom to have parameters like "Baseline", "Varability", "Accel/Decel Intensity", "Fetal Movement", "Fetal 02 Level", and/or other parameters of the models to be automatically controlled by the model or manually controlled by the user.

As a general matter, when in manual mode the user is able to select or define the values for the various parameters. For example, in some instances the user selects a particular value from a drop down menu, selection of buttons, or other visual display. Examples of such available selections include but are not limited to: Fetal Movement: Auto, None, 0-1 , 2-3, 4-5, >5; Fetal 02 Level: Auto, Normal, Poor, Very Poor; Cord Compression: none, slight, severe; Placenta Previa: None, Marginal, Partial, Total; and Abruptio Grade: 0, 1 , 2, 3. In some instances, the user defines a particular value by inputting a numerical value or other parameter defining term into an input field. It is understood that a user will have some parameters running in auto mode while others are in manual mode in some instances. In other instances, the user will have the models running in either full auto mode or full manual mode.

Although illustrative embodiments have been shown and described, a wide range of modification, change, and substitution is contemplated in the foregoing disclosure and in some instances, some features of the present disclosure may be employed without a corresponding use of the other features. It is understood that such variations may be made in the foregoing without departing from the scope of the embodiment. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the present disclosure.