A Coaxial Dual-element Focused Ultrasound Probe for Guidance of Epidural Catheterization.

A Coaxial Dual-element Focused Ultrasound Probe for Guidance of Epidural Catheterization. Ultrason Imaging. 2017 Mar 01;:161734617697740 Authors: Dong GC, Chiu LC, Ting CK, Hsu JR, Huang CC, Chang Y, Chen GS Abstract Ultrasound guidance for epidural block has improved clinical blind-trial problems but the design of present ultrasonic probes poses operating difficulty of ultrasound-guided catheterization, increasing the failure rate. The purpose of this study was to develop a novel ultrasonic probe to avoid needle contact with vertebral bone during epidural catheterization. The probe has a central circular passage for needle insertion. Two focused annular transducers are deployed around the passage for on-axis guidance. A 17-gauge insulated Tuohy needle containing the self-developed fiber-optic-modified stylet was inserted into the back of the anesthetized pig, in the lumbar region under the guidance of our ultrasonic probe. The inner transducer of the probe detected the shallow echo signals of the peak-peak amplitude of 2.8 V over L3 at the depth of 2.4 cm, and the amplitude was decreased to 0.8 V directly over the L3 to L4 interspace. The outer transducer could detect the echoes from the deeper bone at the depth of 4.5 cm, which did not appear for the inner transducer. The operator tilted the probe slightly in left-right and cranial-caudal directions until the echoes at the depth of 4.5 cm disappeared, and the epidural needle was in...
Source: Ultrasonic Imaging - Category: Radiology Tags: Ultrason Imaging Source Type: research