Ultrasound can provide useful guidance for needle insertion in epidural anesthesia, but image interpretation can be challenging. The aim of this work is to determine the feasibility of a new ultrasound-based system (ProjectAlign) capable of identifying the spinal midline directly at the puncture site. ProjectAlign’s main benefit is that it requires no operator interpretation of ultrasound images. Instead, the operator is guided by automatic real-time estimates of spinal midline position projected onto the skin. A simple cross-correlation routine generates increasingly accurate estimates of midline location as the transducer is centred over the spine. A clinical feasibility study was performed to assess the performance of ProjectAlign in identifying the midline in the L2 to L4 lumbar region of 12 subjects. We hypothesized that (i) ProjectAlign can identify the spinal midline within a 5 mm lateral distance of a sonographer’s manual marking, and (ii) ProjectAlign is more laterally accurate than palpation in identifying the spinal midline. Both hypotheses were validated by the data. Midline measurement with ProjectAlign generated an RMS error of 2.0 mm, with a maximum error of 5.0 mm. The results of this study support further investigation into the use of ProjectAlign, in particular for obese patients where palpation is most difficult.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.