How new technology makes mobile stroke units safer
Frazer, builder of the nation’s first mobile stroke unit, adds new levels of protection for medics and patients in crash conditions
The following is paid content sponsored by Frazer Ltd.
By Nathan Stanaway, BS, NRP, for EMS1 BrandFocus
Medical professionals agree that stroke care and treatment is extremely time-sensitive. Billions of synapses and millions of neurons die during every minute of the average large vessel occlusion stroke. For every hour a stroke is left untreated, the brain loses as many neurons as it does in almost four years of normal aging (Jeffrey L. Saver, 2006).
Time truly is brain. Stroke care networks in the United States are still evolving, and many people live in areas where transport decisions can mean the difference between life, death, or debilitating injury. In 2014, Frazer Ltd. produced the country’s first mobile stroke unit, developed in partnership with stroke specialists at the Texas Medical Center, to help fill those gaps.
What is a mobile stroke unit?
When a 911 call is placed to the dispatch center and triaged as a possible stroke, the mobile stroke unit, along with other EMS resources, is dispatched. Stroke patients can be immediately evaluated in the unit and treated with tPA if appropriate.
These units have proven their value in reducing time to treatment, with one study showing an average time to treatment savings of 25 minutes. When a patient is losing millions of neurons every second, 25 minutes is a very long time.
In addition to being able to begin stroke treatment in the field, the CT angiogram capabilities of the MSU allow for more accurate destination triaging because prehospital providers are able to determine the exact type of stroke occurring. Not all stroke centers have the same capabilities, so choosing the appropriate destination facility is critical. In many cases patients need the capabilities of a comprehensive stroke facility with resources like neurointerventionalists, interventional radiology and mechanical retrievers.
Mobile scan technology
The Frazer MSUs feature a Samsung NeuroLogica CereTom CT scanner, which can be used to perform multislice CT scanning with and without contrast, CT angiography with bolus tracking, CT perfusion with auto-start and CT topograms.
Significantly smaller than a traditional scanner, the CereTom weighs 966 pounds and can be operated by a single technician. It is designed for portable diagnostic scanning of the head and neck via a 32-centimeter opening (Z. Rumboldt, W. Huda and J.W. All, 2009). The patient is secured in the cot, and a special cot adapter made of carbon fiber that does not affect the image quality supports the patient’s head.
A typical axial scan takes 45 seconds, with a max helical scan time of 60 seconds and real-time image reconstruction. Data is transmitted wirelessly or via gigabit ethernet.
The scanner moves along tracks on the floor during the scan. Precision-leveled flooring is critical to the accuracy of the CT scanner, and the flooring in Frazer’s MSU ambulances is laser calibrated for optimum performance. UTHealth, Frazer’s first MSU customer, has not needed to calibrate the mobile scanner at all since its delivery in 2014, said Scott Harrell, Frazer’s marketing supervisor.
Safety is critical, and Frazer’s mobile stroke units are built to withstand rigorous everyday use. The company has developed several key safety features in the two years since the first MSU.
To secure the scanner during transit, Frazer has developed a CT scanner mounting and retention system or "cage" that wraps around the scanner. This cage is bolted to the vehicle's chassis and also features cargo netting, which helps protect passengers from possible projectiles in the event of a crash.
The safety cage and retention system are rigorously tested to meet new Society of Automotive Engineers ambulance safety standards. In fact, the system has been certified through destructive testing by an independent lab to meet SAE J3043, which in part specifies that mounted equipment must remain in place when subjected to a 26 g-force collision. Frazer’s units exceed that requirement, and the company has successfully tested the scanner mounting and retention system to 150 percent of the required g-force.
“Whether or not there are standards that say that we have to contain the CT scanner in place, this is something that we absolutely want to be doing,” said David Tracy, Frazer’s engineering manager and a Houston-area volunteer firefighter and EMT.
Another safety feature standard on all Frazer mobile stroke units is Stryker's Power-PRO and Performance-LOAD cot system, which is compliant with SAE J3027. Older antler/bar systems are only designed to withstand forces up to 2,200 pounds – nowhere near adequate in the event of a crash. Put simply, these newer standards get rid of the antler/bar system and require that a system remain intact in the event of a crash with forces up to 22g in a front impact and up to 26g in a side impact.
In addition, Frazer EMS vehicles contain no wood for additional durability and safety in case of a crash. The base frames are constructed using welded, dual structural aluminum tubes on all sides and top for maximum strength.
EMTs and paramedics are taught from day one that our safety is always the primary concern. “Scene safe” is a mantra ingrained from the very first day of training. Patient and provider safety are paramount, but usability and ergonomics are also important. Frazer continues to improve the interior space of the unit based on input from clinicians in hopes of developing best practices for mobile diagnosis and treatment.
The newest MSU models provide an optimized working environment for the medics on board, with easy access to electrical systems and supplies from a seated position, as well as 4 extra inches of headroom for additional provider comfort.
“We have heard a lot of positive response to the MSU. Customers agree that the Frazer MSU is the clear choice, considering safety and durability are of top priority. They have already seen how the MSU changes the way they treat patients to get improved outcomes,” said Harrell. “In addition, the standard Frazer platform already meets the large power requirements for this kind of application.”
For more information on mobile stroke units, contact Frazer.
About the author
Nathan Stanaway, BS, NRP, has over 10 years of experience in a variety of healthcare organizations. He has participated in research projects and frequently consults for EMS and other health care organizations, typically focusing on process improvement and marketing. Currently, Nathan resides with his family in upstate South Carolina. One of Nathan's greatest passions is improving the EMS profession by promoting education, engagement, marketing and strong positive leadership. Nathan is always open for a new challenge and can be reached on LinkedIn.