Comparative Motion Profile Characterization of New Ultrasound Tip to Predecessor Ultrasound Tip
Purpose
To compare the u/s motion and thermal profile of the recently introduced Balanced u/s tip with predecessor Mini-Flared tip to determine the distribution of kinetic energy along the probe length, particularly at the probe distal end and at the incisional region, including models for incision mechanical disturbance and heat generation.
Methods
High speed video recordings were obtained using a conventional system at a frame rate of 10.000 frames per second. Also a microprocessor-controlled stroboscopic image capture system was used to obtain pseudo-slow motion video recordings of the phaco tips operated in torsional mode. Photo-microscopic images were captured in suitable test chambers using either a xenon light source or pulsed high power LEDs. Incisional region tissue motion was observed in a pig cadaver eye model in suitably shaped incisions of 2.2 mm. Comparative thermal image video recordings were performed.
Results
The Balanced tip exhibited a 50% increase in the lateral stroke length of the distal end compared to the Mini-Flared tip for equal ultrasonic power settings. At incisional level the stroke length was reduced in 30% and incision tissue vibration was reduced as observed in the pig eye model. Thermal imaging showed a substantial reduction in heat generation of the Balanced tip compared to the Mini-Flared tip with and without load applied.
Conclusion
The Balanced tip exhibits increased lateral stroke at the tip distal end with simultaneous reduction of the lateral stroke, mechanical disturbance and heat generation at the incision location. The form factor of this tip can allow operation with high efficiency at reduced u/s powers, also reducing vibratory incision disturbance and the risk of incisional thermal injuries.