A force-sensing microsurgical instrument that detects forces below human tactile sensation

Area of Science:

• Ophthalmology
• Microsurgery
• Surgical Instrumentation

Background:

• Microsurgical maneuvers often involve forces below the threshold of tactile sensation.
• Current microsurgical instruments lack the sensitivity to detect these subtle forces, potentially leading to complications.

Purpose of the Study:

• To evaluate the sensitivity and reproducibility of a 25-gauge force-sensing micropick.
• To determine if the device can differentiate forces during normal surgical actions versus those causing complications.

Main Methods:

• Force measurements were taken using the micropick during membrane peeling in ex vivo models (raw egg, chick chorioallantoic membrane).
• In vivo testing involved posterior hyaloid detachment and simulated retinal tear creation during rabbit vitrectomy.

Main Results:

• The device detected forces as low as 0.5 ± 0.4 mN during membrane peeling.
• Forces generated during simulated retinal tears (7.3 ± 0.5 mN) were significantly higher than those during normal peeling.
• The rate of force generation differed significantly between posterior hyaloid detachment and retinal tear creation.

Conclusions:

• Force-sensing microsurgical instruments are capable of detecting forces below tactile sensation.
• This technology can reliably distinguish forces associated with routine maneuvers from those leading to surgical complications, improving safety.