While many ultrasound machines are large, bulky, and difficult to operate by anyone but a trained ultrasonographer, newer portable devices have been developed that are easier to use. The objective of this experiment was to test a portable ultrasound device during a simulated medical event in the space flight analog provided by NEEMO.
At an undesignated time during the mission, one crewmember was green-carded with symptoms indicative of a medical condition. At that point, a trained crewmember, following the instructions of the crew surgeon in the Exploration Planning and Operations Control (ExPOC), attempted to manipulate the ultrasound probe in such a manner that allowed the surgeon to diagnose the condition. Standard ultrasound gel (Aquasonic or similar) was used to maintain acoustical contact of the probe with the subject’s skin.
All activities were video taped by a third crewmember. The resulting video was used to evaluate the quality of training received, the ease-of-use of the ultrasound device and its procedures, and the ability to communicate successfully with the crew surgeon from the remote environment.
One data session was planned and completed. Additional data was captured during the session by using two different operators to capture the images. Although some visible degradation of the images was noticeable, the pixel resolution, grayscale resolution, and frame rate were all acceptable for both remote guidance and real-time focused diagnostic assessment. There was some fluctuation in the bandwidth available for video conferencing, which caused slower frame rate of the video for short (2-5 seconds) periods of time. The remote guidance expert waited until the connection improved and continued the guidance. Although not ideal this was tolerable and expected. No other hardware anomalies were encountered.
Data Analysis and Findings
Subjective perception of the data quality was such that gross pathology would not be overlooked. Fine detail (such as minute non-obstructing calculi (stones) in the renal collecting system) could potentially be overlooked, and in case of suspicion would be ruled out through post-event image transfers. The approach to quality, in the opinion of the investigators, should be conservative, and in the absence of scientifically proven metrics, the interpretation of data should consist of phases.
1. Preliminary Real-Time Imaging Interpretation : most conservative and preliminary, focusing on the imaging representation of anatomical and functional situation in the patient's organism potentially causing signs and symptoms or threatening safety or life. This preliminary real-time assessment (in the process of the imaging session)
2. Preliminary Post-Imaging Interpretation : takes place in less demanding conditions, after the remote guidance session is completed, and has some additional features
3. Final Imaging Report : includes results of the above phases of interpretation, and any new information derived from additional data reviews, lossless downloaded still image or cine-loop files, takes into account technical image quality analysis.
Clinical Outcome and Contribution of Imaging
During this simulation, ultrasound allowed ruling out major urinary obstruction. Thus, it contributed objective data for diagnosis and management. The Crew Surgeon accepted the results in both real-time and immediate post-imaging phases, and prescribed monitoring instead of considering emergency evacuation. While the diagnosis of kidney stones, urolithiasis, in this simulated patient remained unchanged, the following evidence:
This allowed medical personnel to postpone the consideration of immediate medical evacuation, and distribute the available treatment resources (including the limited amount of analgesics and antibiotics) according to best available prognosis of the further course and outcome.
|Mission||Launch/Start Date||Landing/End Date||Duration|
|NEEMO 5||06/16/2003||06/29/2003||14 days|