Dr. James Smith, biomechanical engineering researcher, and his team used MapleSim to model a cervix undergoing induction with a Foley catheter.
Modern engineering has a lot to offer the medical world, and tools like MapleSim make it easier and faster to advance projects like these to the point where they can really help people.
Waterloo, Canada (PRWEB) October 05, 2015
Dr. James Andrew Smith specializes in experiential teaching and conducts research in human birth modeling and robotics. He recently used MapleSim to examine how to improve labor induction techniques, as well as how to maximize energy regeneration in rehabilitative devices. Dr. Smith is currently a faculty member in York University's Lassonde School of Engineering.
MapleSim Models Aid in the Development of Training Simulator to Improve Labor Induction Techniques:
Engineering, midwifery and obstetrics researchers at Ryerson University and McMaster University are developing an electro-mechanical model of a cervix during labor. They are interested in this model to demonstrate the changes that occur in the cervix in the process of normal labor. In particular, they are studying the changes in the cervix in an unassisted delivery versus when labor is induced. Their goal is to better understand the process so they can develop a training simulator that can be used by students and researchers to demonstrate normal cervical changes in labor and to practise labor induction techniques and study the effectiveness of different induction methods.
Labor is induced in many pregnant women, often when they are overdue and there is risk to the child if it is not born soon. For example, over 20% of all pregnancies in both the United States and the United Kingdom end in induced labor. One induction tool is the Foley catheter. A small balloon is carefully inserted through the opening of the bottom part of the cervix until it reaches just inside the uterus. Then the balloon is filled with saline in order to increase the downward pressure on the top of the cervix, from inside the uterus, mimicking the pressure from the baby’s head. The downward pressure triggers the body’s natural responses to gradually open the cervix, helping the woman to go into labor.
While this basic technique was first introduced in the 1850s, the precise mechanics are not well quantified. Dr. James Smith decided to use MapleSim to create a model of a cervix undergoing induction with a Foley catheter.
By comparing his MapleSim simulation results with the available experimental data, he was able to tune his model to provide a good match. In particular, his model provides a near constant rate of dilation, which is consistent with observed behaviour.
Next steps in this project include creating an actual electro-mechanical model of a cervix. This physical training simulator will be used to help train medical and midwifery students in inserting the balloon, and will provide a physical method for testing other dilators in a risk-free environment.
“MapleSim is an ideal tool for modeling multidomain systems such as those found in biomedical engineering. Creating models is fast, and the mathematical analysis tools enable me to really understand what it going on in my system, and how to improve it, before building a physical prototype,” said Dr. Smith.
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Maximizing energy regeneration with MapleSim makes improvements to assistive devices possible:
Most research of human, animal and robotic motion has been centered on improving everyday activities such as walking, running, turning, starting, accelerating and decelerating. However, not much attention has been paid to assisting movements such as standing up and sitting down – movements that seem relatively simple but become increasingly difficult with age and reduced health.
Dr. James Andrew Smith, a faculty member in York University's Lassonde School of Engineering, and his research group, have done advanced research on autonomous battery operations in humanoid robots and electrical assistive devices using MapleSim, the system-level modeling and simulation tool from Maplesoft. Smith’s group undertook the task of determining at what point in the transitions between sitting and standing can energy be regenerated in an orthosis or prosthesis, much like how a hybrid vehicle regenerates energy during braking by drawing it from the motor for re-use in the vehicle’s operation.
Determining which of the three joints – the ankle, knee, or hip – is able to regenerate the most energy in the sitting down and standing up movements would prove to be a practical and significant consideration for rehabilitation engineering design. The conclusion could lead to more efficient locomotive devices for those who suffer from diseases or disabilities affecting the muscles around these joints.
In order to successfully determine at which point regenerative power is at its peak, Smith’s group applied biomechanical data from actual human trials to a robotic model created in MapleSim. The robotic model mimics human movements when transitioning between sitting and standing positions. To investigate regeneration at the ankle, knee and hip specifically, MapleSim models of an electromechanical subsystem actuator, a DC-to-DC bridge converter, and a battery were placed at each localized joint.
Simulation of the sitting down and standing up movements began with the model sitting on a virtual chair. As the simulated robot rose from the chair, the state of charge decreased over time as power was drawn from the battery. Once the body was above the foot, the hip began to brake and regenerate energy. This occurred also in the sit-down motion when the body maintained its center of mass over the foot. Very little regeneration occurred overall for the ankle and knee subsystems compared to the hip. Smith’s group also demonstrated that regeneration is more prominent during the sitting down phase than during the standing up phase.
Smith’s group’s findings have a meaningful application for prostheses and orthoses design. Determining the most efficient battery autonomy means the operation time of these devices can be extended, and smaller, lighter batteries can be used, reducing their bulkiness. Ultimately, a more efficient device can reduce the joint loads during standing-to-sitting for users – a critical consideration for people suffering from joint diseases.
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Dr. Smith discussed the above projects in a recent IEEE Spectrum webinar. Other biomechanical research projects were also presented in the webinar. Click here to view the webinar recording.
