Bringing CT Scanners to the Skies: Design of a CT Scanner for an Air Mobile Stroke Unit

Abstract

Stroke is the second most common cause of death and remains a persistent health challenge globally. Due to its highly time-sensitive nature, earlier stroke treatments should be enforced for improved patient outcome. The mobile stroke unit (MSU) was conceptualized and implemented to deliver the diagnosis and treatment to a stroke patient in the ultra-early time window (<1 h) in the pre-hospital setting and has shown to be clinically effective. However, due to geographical challenges, most rural communities are still unable to receive timely stroke intervention, as access to specialized stroke facilities for optimal stroke treatment poses a challenge. Therefore, the aircraft counterpart (Air-MSU) of the conventional road MSU offers a plausible solution to this shortcoming by expanding the catchment area for regional locations in Australia. The implementation of Air-MSU is currently hindered by several technical limitations, where current commercially available CT scanners are still oversized and too heavy to be integrated into a conventional helicopter emergency medical service (HEMS). In collaboration with the Australian Stroke Alliance and Melbourne Brain Centre, this article aims to explore the possibilities and methodologies in reducing the weight and, effectively, the size of an existing CT scanner, such that it can be retrofitted into the proposed search and rescue helicopter—Agusta Westland AW189. The result will be Australia’s first-ever customized CT scanner structure designed to fit in a search-and-rescue helicopter used for Air-MSU.

A scenario based approach to optimizing cost-effectiveness of physician-staffed Helicopter Emergency Medical Services compared to ground-based Emergency Medical Services in Finland

“…However, due to the absence of validated instruments or supporting data, this study adopts a more conservative estimate. A significant advancement in this direction could be the development of CT imaging technology compact enough for helicopter use [ 54 ]. This innovation could transform stroke care by enabling the initiation of thrombolysis treatment directly at the patient location, dramatically reducing the time to treatment for stroke patients and potentially improving outcomes.…”

Pre-Hospital Stroke Care beyond the MSU

“…It is unclear whether and how these advances can or need to be translated into a broader scale given the associated costs of development and the existing evidence for the utility of CT-equipped MSUs, even though certain scenarios might exist, in which an MRI-based approach could be useful (wake-up-stroke, stroke-mimics). Similar approaches trying to further miniaturize mobile CT scanners to reach geographically more challenging areas by land or air are already conceptualized [55,56] and could complement existing concepts in this field [57].…”

Can We Miniaturize CT Technology for a Successful Mobile Stroke Unit Roll-Out?

“…A digital twin was first developed of the commercial CT scanner. As reported in Kwok et al [4], the digital twin provided a virtual representation of the physical CT scanner and provided a bidirectional connection of data to re-design and improve the performance of the CT scanner using computational modelling and simulations. The design process for modifying and retrofitting a CT scanner can be classified into three steps: (1) default structure reduction, (2) support structure design, and (3) integration onto a mobile stroke unit interior.…”

“…As can be seen with the addition of the standard Ambulance Victoria stretcher (Stryker MX-Pro, US) it is not possible to accommodate the full CT scanning set up as such a larger AW189 aircraft is required to fit the CT scanner and stretcher. The current road-MSU uses a modified Mercedes Sprinter 519 box van (L 3,272 mm -4,707 mm, H 1,719 mm -2,009 mm, W 1,555 mm)[4], however as seen in Figure7the LiteCT scanner in the cabin of a Mercedes Sprinter 419 (L 3,272mm -4,307 mm, H 1,719 mm -2,009 mm, W 1,555 mm), the standard vehicle used by Ambulance Victoria, providing an alternative solution to the 519 without the need for modifications.…”