Biomechanical study of the mobilization of trauma patients with inertial sensors

2 September, 2019

Recently, DyCare participated in several biomechanical analyses on the mobilization of polytraumatic patients in which Lynx inertial sensors were used to assess the movement of the cervical spine throughout the removal or transfer process. The results of the complete pilot study were presented last June at the 31st National SEMES Congress , a benchmark event in the emergency medicine sector organized by the Spanish Society of Emergency Medicine, which this year brought together more than 3,400 professionals.

Currently, there are several techniques for picking up or removing a trauma patient and transferring him or her from the ground to a device. However, these recommendations are based on expert consensus and not on evidence from experimental studies. For this reason, experts from the Falck VL Health Services together with professors from the Master’s in Prehospital and Urgent Hospital Care at the Institute for Continuing Education (IL3) of the University of Barcelona and the DyCare team, wanted to carry out several pilot studies: a biomechanical comparison of lateral vehicle extraction with and without the Ferno – XT® immobilization device, a biomechanical analysis during the placement of the cervical collar and a study of the mobilization of the traumatic patient in supine position.

Placement of an immobilizer for trauma patients in an accident vehicle

In recent years, thanks to the implementation of inertial biomechanical sensors, measurements can be made that were previously very expensive and difficult. In order to know the time needed and the movements that occur in the patient’s spine after an accident, a study was launched with healthy volunteers, health personnel and a rollover simulator.

Eight patient extractions were performed by teams of professionals made up of nurses and health emergency technicians: 4 with the Ferno – XT® (FXT) immobilization device and 4 without.

Four DyCare Lynx® inertial sensors were placed on the volunteers to accurately measure cervical spine movement throughout the process. Two independent evaluators measured FXT placement time and subsequent vehicle removal time.

Analysis of movement during collar placement with inertial sensors

Cervical collars are now widely used in initial trauma care, but there is controversy about their use. For this procedure and from a biomechanical point of view, there are no studies evaluating the time of placement and the movements that occur. In order to draw conclusions, a simulation was carried out with two groups of volunteers, one seated at 90 degrees inside the vehicle and the other in supine position on a flat surface, meaning, lying face up.

Again, four inertial sensors were placed on the volunteer: the first two sensors measured the movement of the cervical segment and the other two measured the movement of the thoracic spine. The values of flexion, extension, rotation and lateralization were recorded. In addition, two independent evaluators measured the placement time of the collar.

An analysis was also performed to evaluate the degree of movement of the cervical spine with different models of rigid cervical collars.

Evaluation of collection maneuvers of traumatic patient in supine position

For this procedure, three types of mobilizations were carried out from the supine position: log-roll on a spinal board, modified bridges on a spinal board and retrieval with a scoop stretcher.

Lynx inertial sensors record the movements of each volunteer in each of the positions until the volunteer was correctly centered on the pick-up device. regarding its placement inside the vehicle.

Conclusions of the experimental pilot study of patient extraction and transfer

At the end of the complete study it was concluded that the FXT immobilization system requires a little more than 3 minutes for its placement and the movements for its placement were less than those generated in the extraction without its use.

On the other hand, the positioning time of the collar was faster in the supine position with respect to its placement inside the vehicle. In both cases it was less than 31 seconds. During placement, the movement recorded was very small, insufficient to cause an injury or aggravate a pre-existing injury when performed by trained health personnel. Therefore, by means of this study it could be affirmed that the technique of the collar is safe and needs few resources of personnel and time.

In relation to the mobilizations from supine decubitus, all of them are safe from the biomechanical point of view and the average time of accomplishment of the maneuvers is of less than 1 minute. The movements recorded with Lynx sensors are less than 10º in the two segments of the column: the pickup with a scoop stretcher is the one that moves the column the least but is it the slowest mobilization.

In addition, the experts observed that the use of sensors is useful for the design of decision algorithms and does not require complex equipment. Likewise, the data collected are reliable, safe and very accurate and therefore fully valid for experimental studies of this type. However, it would be necessary to extend the trial in future studies to determine whether the differences found are significant and extrapolated to the population.

Finally, it is worth mentioning the great work of the professionals of the Falck Group, consisting of doctors, nurses and Health Emergency Technicians who attend to and transport thousands of patients daily in more than 20 countries around the world. DyCare would like to thank you for your collaboration as your work is of vital importance to improve the situation of people who have suffered a trauma and are in a serious condition.

Research Team:
Joan Sánchez Montaña, forensic specialist. Professor MAPHU
Javier Colina Torralva. Nurse. Director MAPHU.
Xavier Bernárdez. Nurse. MAPHU Coordinator.
Fisher Paz Rubio. Nurse. MAPHU Coordinator.
Pere Sánchez Valero. Nurse. Professor MAPHU.
Norma Pomares Steiner. Nurse. Professor MAPHU.
Laura Salvadó Vilà. Nurse. Professor MAPHU.
Alfonso Muñoz de León. TES. Professor MAPHU.
Eduard Montero Viñuales. Development Director Falck VL
Ricardo Jauregui, CTO and Co-Founder DyCare

Thanks for the impulse to Guillem Íñiguez Papell; General Director IL3 and Francisco Pérez Lozano; Academic Director IL3 and Sergi Vicente Mañez; General Director Falck VL.