Pediatric hospital works with CSIA member to develop unique test chamber

By Darren Jones

Ann & Robert H. Lurie Children’s Hospital of Chicago approached system integrator DMC, a certified member of the Control System Integrators Association, with a very special need. They wanted to develop the world’s only thermoregulatory chamber designed and built from the ground up specifically for children. The system integrator (SI) partnered with the hospital clinicians, researchers, architects, construction crews, and patients to deliver this one-of-a-kind solution.

The thermoregulatory test chamber is used for diagnosing sweat abnormalities in children. The test chamber controls the temperature of the patient’s body to evaluate its ability to self-regulate. In this case, the chamber closes a temperature control loop to very slightly raise the core and skin temperature of the patient to test sweat response as a critical part of human body temperature regulation.

“When your child has symptoms that nobody can explain, it’s scary and frustrating, and the chamber has allowed us to comfort parents,” said Dr. Debra E. Weese-Mayer, chief of the Center for Autonomic Medicine in Pediatrics and professor of pediatrics for Northwestern University’s Feinberg School of Medicine.

The SI met with the team at the Lurie Children’s Hospital to identify the unique needs of the test facility for research and clinical work. The hospital was moving to a new location in downtown Chicago and had a fixed time frame to design and build the new facility. The SI worked along with the clinicians and researchers to determine software and test requirements, which continued to evolve over the year of project development. This included system integration coordination with the building architects to ensure the facility was built in a way that best integrated the test chamber for patient comfort, test operability, and nurse and doctor involvement.

Because the patients are children, comfort was an important design consideration. Some heat lamps heat up very gently, and some heat up very rapidly. The team looked for solutions that would be as noninvasive as possible. Ultimately, they selected National Instruments compactRIO as the brains of the system, because it met the necessary requirements for performance, safety, tolerance, and accuracy.

Standard off-the-shelf system software spans three layers: the Windows user-interface software package configured for the application, the chamber control and data collection in real time, and the safety controls and low-level operation configured for a field-programmable gate array in the controller.

Alongside the system’s distinctive control requirements were requirements for data collection, storage, and reporting. Continuous acquisition of patient temperature data is performed by the real-time hardware and streamed to the PC during testing. Any interruption of the PC to the real-time connection is handled with a data stream buffer, such that it can catch up when the connection is restored, ensuring no critical patient data is lost. Raw data is then stored in a data format called technical data management streaming (TDMS), which is an efficient and open standard for test and measurement data. The raw data is always available to be read by a number of publicly available TDMS readers, as well as by a custom application that the system integrator developed specifically for the hospital’s needs. The physicians and hospital staff can peruse this data for significant physiological responses and add information about diagnosis and analysis. The information all comes together in customized report generation that can be shared.

The system hardware uses infrared heating elements to generate heat energy and temperature probes to monitor and record the patient’s skin and core body temperature. This temperature control loop is performed on the controller device. Multiple safety mechanisms are in place to ensure patient safety and comfort.

The system integrator worked with the construction team and electrical contractors to deliver an electrical panel and field wiring instructions. The SI collaborated with the crews on site in downtown Chicago to ensure smooth installation and testing. Post-installation, the SI also met with real patients in a clinical test environment. The SI team forged a deep relationship with the hospital staff, and they continue to work together to pioneer test methods and tools for autonomic medicine in pediatrics.

“By having this wonderful teamwork between an engineering team and a translational medicine team, we were able to produce a product that gives us what we need to answer medical questions and improve healthcare,” said Weese-Mayer.

The test chamber has given the hospital the ability to diagnose and research autonomic disorders in children, improve patient safety and comfort, and enhance data integrity with automatic storage of test data and generation of test reports. The hospital is testing patients monthly and has made numerous useful diagnoses for the betterment of pediatric health worldwide.

About the Author

Darren Jones (Darren.Jones@dmcinfo.com) is a project director at Chicago-based DMC Inc., a certified member of the Control System Integrators Association. To learn more about DMC, visit www.dmcinfo.com. To learn more about CSIA, visit www.controlsys.org. To see a video about the project, visit YouTube.

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