Flight simulator for training gynaecologists:a mathematical model of the cardiotocogram for use in simulation training

Due to the high complexity and low incidences of emergencies during labor and delivery, gynaecologists often cannot rely on previous experiences during a crisis. Simulation training can provide both experience and skills in a safe environment, such that complications due to emergencies can be reduced as much as possible. Several simulators are available that support a safe learning environment for obstetric emergency training. However, none provides a realistic and physiology-based (simulation of) the cardiotocogram (CTG), which is a continuous and synchronous registration of uterine contractions and fetal heart rate. However, at the labor and delivery ward, the CTG is widely used as main indicator for fetal welfare. The CTG provides information on the fetal stress reaction to uterine contractions, based on oxygen levels in the fetal blood. Since the CTG is widely available and the only non-invasive method for fetal monitoring, medical decisions are often based on deviations in the CTG. The CTG is therefore an essential part of the clinical environment in medical simulation training. In a one-year clinical project as part of a qualified medical engineer training, a start is made with the development of a CTG simulator. The three main deviations in the CTG were studied: early, late and variable decelerations in fetal heart rate, caused by uterine contractions and complications in labor. The mechanism of these three deceleration types were studied, and each step was quantified for early and late decelerations. In this project, early decelerations were implemented in a mathematical model, based on the underlying physiological principles. In future, implementation of late and variable decelerations are planned within a PhD-project. A validation study was performed for the modeled CTG, where a comparison was made between real and computer-generated CTG tracings from our model, based on experts' opinion. The first results show no significant differences between real and computer-generated CTG tracings. However, the number of clinical experts was low, and a larger study has to be performed to confirm these results. Coupling of the modeled CTG to a simulator interface is planned in future. The model can be implemented in different types of simulators: in a screen-based simulator (individual in-depth training to improve insight into and interpretation of the CTG), as part of a full-body delivery simulator, and as part of a serious game (in these two cases the CTG is part of the clinical environment). Future plans include implementation in a screen-based simulator and a full-body delivery simulato

A mathematical model for simulation of fetal heart rate decelerations in labor

Fetal wellbeing during labor and delivery is commonly monitored through the cardiotocogram (CTG), the combined registration of uterus contractions and fetal heart rate (FHR). From the CTG, the fetal oxygen state is estimated as the main indicator of the fetal condition. However, this estimate is difficult to make, due to the complex relation between CTG and oxygen state. Mathematical models can be used to assist in interpretation of the CTG, since they enable quantitative modeling of the flow of events through which uterine contractions affect fetal oxygenation and FHR. This thesis describes the development of a model that can be used to reproduce FHR response to uterine contractions during several clinical scenarios. First, a model was developed that describes the relation between uterine contractions, maternal and fetal hemodynamics, oxygen distribution within the feto-maternal circulation and cardiovascular (reflex) regulation in the fetus in response to deviations in blood- and oxygen pressures. The model is partly based on previously presented models for cardiac function, chemoreceptor control in adults and oxygen distribution in the fetal circulation. These modules are coupled and scaled to meet requirements for the (pregnant) maternal and fetal condition. The model is completed with a module for uterine contractions and a module of the vascular system of both mother and fetus. A first clinical scenario was simulated with the model to test model response to changes in cerebral blood flow during the descent of the fetal head in the birth canal. A validation pilot was performed to investigate the quality of model outcome via expert opinion. Experts were unable to discriminate between real and simulated signals, suggesting that the model can be used for educational training. Second, the model was extended with the baroreceptor reflex. This allowed simulation of a second clinical scenario, where both chemo- and baroreflex pathways lead to a FHR deceleration in response to uterine flow reduction during contractions. Results for the uncompromised fetus show that partial oxygen pressures reduce in relation to the strength and duration of the contraction. Furthermore, decelerations during several scenarios of uteroplacental insufficiency were studied. Results for reduced uterine blood supply or reduced placental diffusion capacity, demonstrated lower baseline FHR and smaller decelarations during contraction. Reduced uteroplacental blood volume was found to lead to deeper decelerations only. The model response in several nerve blocking simulations is similar to experimental findings. Third, the model was used to simulate a third type of decelerations, i.e. variable heart rate decelerations, originating from umbilical cord compression. Different degrees of compression were investigated. An increase in contraction amplitude and duration leads to increased umbilical cord compression grade and thus affects the extent of blood pressure increase, flow redistribution and FHR response. There is a clear relation between fetal oxygenation, blood pressure and the resulting FHR. The extent of umbilical compression and thus FHR deceleration is positively related to increased contraction duration and amplitude, and increased sensitivity of the umbilical resistance to uterine pressure. Fourth, gynaecologists, midwives and residents were asked to rate a set of both model-generated CTGs and real CTGs for the three clinical scenarios. Although real tracings were more likely to be recognized correctly, the suitability for use in simulation training was found to be almost equal for real and computer-generated tracings. Due to limited numbers for early and variable deceleration evaluation, statistical analysis turned out to be valid only for the CTG’s with late decelerations. Additional comments from the respondents revealed that variability and regularity of the simulated signals greatly influence the perception of a tracing. Clinicians agreed that a tracing is suitable for use in simulation training when it is clear and free of physiological incompatibilities, which is the case for all simulated tracings. Fifth, the model was used to test the clinical hypothesis that administration of oxygen to the mother may increase FHR during variable fetal heart rate decelerations. The model was used to test the response of fetal oxygenation and heart rate to maternal oxygen increase following 100% oxygen administration. Model outcome suggests that FHR benefits from oxygen administration as the duration and depth of FHR decelerations and fetal oxygenation improves. However, the beneficial effect of maternal hyperoxygenation on FHR and oxygenation reduces during more severe variable decelerations. In conclusion, a model was developed to simulate the physiologic cascade from uterine contraction to changes in fetal heart rate. Model outcome for various scenarios is in correspondence with findings from animal experiments. The model can be used in an educational setting for the simulation of short-term changes in fetal hemodynamics and oxygenation status in response to uterine contractions to increase insight into the complex physiology. In addition, it can be integrated in a full-body delivery simulator to enhance obstetric team training

Development of a Clinical Simulation Protocol for the Transfer of a Premature Fetal Manikin to the Perinatal-Life-Support System

Introduction:At present, Perinatal-Life-Support (PLS) research is progressing to offer extreme premature infants an extracorporeal environment for extended growth that mimics the natural womb closely. During the early phase development of this novel life-support technology, validation and training could be facilitated by the use of a medical simulation. By doing so, the need for animal testing can be greatly reduced. Within this abstract, the development to realize a wellorchestrated clinical simulation protocol is described, tailored to the specific needs of novel procedure(s) regarding the transfer of a premature fetus from the maternal uterus to the PLS system.Materials & Methods:Throughout protocol development an iterative approach is used, initiated with a literature analysis and a review of existing obstetrics guidelines for premature births. Next, co-creation sessions and interviews with medical and engineering experts led to a holistic understanding of fetal physiology, patient and specialist needs, current procedures, task divisions, hospital resources and drug specifications. Expert feedback on drafts, checklists and an explanatory step-by-step video, led to multiple re-designs as unforeseen procedural difficulties arose. Verified with available data from literature, multiple perspectives and options were analyzed and weighed to ensure the advancement of a safe, hygienic, effective, and user-friendly simulation protocol.Results:We describe the development process of a simulation protocol and showcase an overview of the current protocol design through an infographic, outlining the different phases and tasks during a transfer procedure and the planning of involved medical experts within the operating theatre. We demonstrate that an iterative approach to protocol development for an unprecedented procedure allows for a comprehensive understanding of the challenges that a transfer to the PLS-system could bring.Conclusions:Using medical simulation during the early phase development process of the PLS-system allows us to train and validate novel practices, in particular the transfer procedure. With the demonstrated approach we aim to establish a thorough simulation protocol by providing a step-by-step plan, informed by literature and expert consultation. We expect to offer a realistic simulation training whilst also informing requirements for the future development of PLS-related devices and their validation

The effect of briefing videos in medical simulation-based education:a randomised controlled trial

The aim of this study is to compare the effects of an affective briefing video with a textual briefing on cognitive appraisal (threat or challenge response). It is hypothesized that briefing videos will cause a threat response, which is associated with increase in cortisol and memory consolidation

Clinical aspects of umbilical cord cannulation during transfer from the uterus to a liquid-based perinatal life support system for extremely premature infants:A qualitative generic study

A liquid-based perinatal life support system (PLS) for extremely premature infants (born before 28 week of gestational age) envisions a connection between the infant’s native umbilical cord and an artificial placenta system through cannulation. This system mimics a natural mothers’ womb to achieve better organ maturations. The objective of this study is to gain insight into the clinical focus points of umbilical cord cannulation and how cannulation should be addressed in extremely premature infants during the transfer from the uterus to an in-utero simulating liquid-based PLS system. We performed an explorative qualitative study. Twelve medical specialists with knowledge of vessel cannulation participated. We collected data through twelve interviews and two focus group discussions. Data were analyzed using inductive content and constant comparison analysis via open and axial coding. Results were derived on the following topics: (1) cannulation technique, (2) cannula fixation, (3) local and systemic anticoagulation, and (4) vasospasm. A side-entry technique is preferred as this may decrease wall damage, stabilizes the vessel better and ensures continuous blood flow. Sutures, especially via an automatic microsurgery instrument, are favored above glue, stents, or balloons as these may be firmer and faster. Medication possibilities for both vasospasm and anticoagulation should function locally since there were uncertainties regarding the systemic effects. According to the findings of this research, the needed umbilical cord cannulation method should include minimal wall damage, improved vascular stability, blood flow maintenance, a strong fixation connection, and local anticoagulation effect

Clinical aspects of umbilical cord cannulation during transfer from the uterus to a liquid-based perinatal life support system for extremely premature infants:A qualitative generic study

A liquid-based perinatal life support system (PLS) for extremely premature infants (born before 28 week of gestational age) envisions a connection between the infant’s native umbilical cord and an artificial placenta system through cannulation. This system mimics a natural mothers’ womb to achieve better organ maturations. The objective of this study is to gain insight into the clinical focus points of umbilical cord cannulation and how cannulation should be addressed in extremely premature infants during the transfer from the uterus to an in-utero simulating liquid-based PLS system. We performed an explorative qualitative study. Twelve medical specialists with knowledge of vessel cannulation participated. We collected data through twelve interviews and two focus group discussions. Data were analyzed using inductive content and constant comparison analysis via open and axial coding. Results were derived on the following topics: (1) cannulation technique, (2) cannula fixation, (3) local and systemic anticoagulation, and (4) vasospasm. A side-entry technique is preferred as this may decrease wall damage, stabilizes the vessel better and ensures continuous blood flow. Sutures, especially via an automatic microsurgery instrument, are favored above glue, stents, or balloons as these may be firmer and faster. Medication possibilities for both vasospasm and anticoagulation should function locally since there were uncertainties regarding the systemic effects. According to the findings of this research, the needed umbilical cord cannulation method should include minimal wall damage, improved vascular stability, blood flow maintenance, a strong fixation connection, and local anticoagulation effect

Transfer Of A Preterm Baby From A Natural Womb

The present invention relates to a transfer assembly for transferring a preterm baby from a natural womb of a pregnant mammal to a transfer bag. The present invention further relates to a kit-of-parts for assembling a transfer assembly. Also the present invention relates to a transfer device and/or a birth canal retractor for use in a transfer assembly of the present invention. An alternative transfer device is provided as well. Further, the present invention relates to a method for transferring a preterm baby from a natural womb of a pregnant mammal to a transfer bag

Simulation-based development: shaping clinical procedures for extra-uterine life support technology

Background Research into Artificial Placenta and Artifcial Womb (APAW) technology for extremely premature infants (born < 28 weeks of gestation) is currently being conducted in animal studies and shows promising results. Because of the unprecedented nature of a potential treatment and the high-risk and low incidence of occurrence, translation to the human condition is a complex task. Consequently, the obstetric procedure, the act of transferring the infant from the pregnant woman to the APAW system, has not yet been established for human patients. The use of simulation-based user-centered development allows for a safe environment in which protocols and devices can be conceptualized and tested. Our aim is to use participatory design principles in a simulation context, to gain and inte‑ grate the user perspectives in the early design phase of a protocol for this novel procedure.Methods Simulation protocols and prototypes were developed using an iterative participatory design approach; usability testing, including general and task specifc feedback, was obtained from participants with clinical expertise from a range of disciplines. The procedure made use of fetal and maternal manikins and included animations and protocol task cards.Results Physical simulation with the active participation of clinicians led to the difusion of tacit knowledge and an iteratively formed shared understanding of the requirements and values that needed to be implemented in the procedure. At each sequel, participant input was translated into simulation protocols and design adjustments.Conclusion This work demonstrates that simulation-based participatory design can aid in shaping the future of clinical procedure and product development and rehearsing future implementation with healthcare professional

Simulation-based development: shaping clinical procedures for extra-uterine life support technology

Background Research into Artificial Placenta and Artifcial Womb (APAW) technology for extremely premature infants (born < 28 weeks of gestation) is currently being conducted in animal studies and shows promising results. Because of the unprecedented nature of a potential treatment and the high-risk and low incidence of occurrence, translation to the human condition is a complex task. Consequently, the obstetric procedure, the act of transferring the infant from the pregnant woman to the APAW system, has not yet been established for human patients. The use of simulation-based user-centered development allows for a safe environment in which protocols and devices can be conceptualized and tested. Our aim is to use participatory design principles in a simulation context, to gain and inte‑ grate the user perspectives in the early design phase of a protocol for this novel procedure.Methods Simulation protocols and prototypes were developed using an iterative participatory design approach; usability testing, including general and task specifc feedback, was obtained from participants with clinical expertise from a range of disciplines. The procedure made use of fetal and maternal manikins and included animations and protocol task cards.Results Physical simulation with the active participation of clinicians led to the difusion of tacit knowledge and an iteratively formed shared understanding of the requirements and values that needed to be implemented in the procedure. At each sequel, participant input was translated into simulation protocols and design adjustments.Conclusion This work demonstrates that simulation-based participatory design can aid in shaping the future of clinical procedure and product development and rehearsing future implementation with healthcare professional