AREA: an augmented reality system for epidural anaesthesia.
OBJECTIVE
Spinal needle injection procedures are used for anesthesia and analgesia, such as lumbar epidurals. These procedures require careful placement of a needle, both to ensure effective therapy delivery and to avoid damaging sensitive tissue such as the spinal cord. An important step in such procedures is the accurate identification of the vertebral levels, which is currently performed using manual palpation with a reported 30% success rate for correct identification.


METHODS
An augmented reality system was developed to help identify the lumbar vertebral levels. The system consists of an ultrasound transducer tracked in real time by a trinocular camera system, an automatic ultrasound panorama generation module that provides an extended view of the lumbar vertebrae, an image processing technique that automatically identifies the vertebral levels in the panorama image, and a graphical interface that overlays the identified levels on a live camera view of the patient's back.


RESULTS
Validation was performed on ultrasound data obtained from 10 subjects with different spine arching. The average success rate for segmentation of the vertebrae was 85%. The automatic level identification had an average accuracy of 6.6 mm.


CONCLUSIONS
The prototype system demonstrates better accuracy for identifying the vertebrae than traditional manual methods.
Electrical and Computer Engineering Department, University of British Columbia, Vancouver, BC, Canada.
Hussam Al-Deen
HA
Ashab
Victoria A
VA
Lessoway
Siavash
S
Khallaghi
Alexis
A
Cheng
Robert
R
Rohling
Purang
P
Abolmaesumi
D000767:Anesthesia, Epidural / Q000379:methods*; D000775:Anesthesia, Spinal / Q000379:methods*; D003952:Diagnostic Imaging / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008159:Lumbar Vertebrae