Comparison of the O-arm and C-arm guided pedicle screws placement

Background Transpedicular screw placement remains the gold standard technique for destabilization of the lumbar spine. Material and methods This is a retrospective study that analyzes patients that underwent the spinal stabilization surgical procedure. We compared results from two independent neurosurgical centers. At the turn of years 2012-2015, O-arm and StealthStation neuronavigation system was used for implantation of transpedicular screws. In 2018 to 2020 transcutaneous pedicle screw placement procedure was performed using standard C-arm device. Results In 208 procedures performed with the O-arm device, the accuracy of the positioning of the screws was 98.08 %. Screw repositioning was necessary in 1.92 % of all cases. In 30 procedures that were performed using the C-arm, the accuracy of the screws was 86.7% and the screw reposition procedure accounted for 10% (in one case crews were not replaced due to clinical sequelae). Conclusions Our data show that the spinal fusion with the O-arm tool has more accuracy, thus might be more indicated in procedures that require minimally invasive spinal stabilization

Middle ear vibrations with SMA prosthesis. Experimental research

The paper focuses on experimental research of a middle ear prosthesis made of shape memory alloy. The prosthesis provides better adjustment to individual patient than classical prosthesis. The shape memory prosthesis is implemented to a fresh temporal bone and vibrations of the round window are recorded by means of the Laser Doppler Vibrometer. Finally, the results are presented in the form of transfer function and compared to the intact and damaged middle ear

Middle ear vibrations with SMA prosthesis. Experimental research

The paper focuses on experimental research of a middle ear prosthesis made of shape memory alloy. The prosthesis provides better adjustment to individual patient than classical prosthesis. The shape memory prosthesis is implemented to a fresh temporal bone and vibrations of the round window are recorded by means of the Laser Doppler Vibrometer. Finally, the results are presented in the form of transfer function and compared to the intact and damaged middle ear

Dynamics of SMA micro-actuator in biomechanical system

In this paper the polynomial model of shape memory alloy is used to characterise properties of a micro-actuator which is applied as a new middle ear prosthesis. A two degrees of freedom model of the reconstructed middle ear is solve by means of multiple time scales method. The system has various behaviours near the primary resonance depending on ambient temperature. The special case when relative temperature θ = 1.0 characterises untypical resonance curve. Increasing temperature to the normal human body one the resonance curves are typical. Then the system has only one periodic solution if the excitation is not too strong

Dynamics of SMA micro-actuator in biomechanical system

In this paper the polynomial model of shape memory alloy is used to characterise properties of a micro-actuator which is applied as a new middle ear prosthesis. A two degrees of freedom model of the reconstructed middle ear is solve by means of multiple time scales method. The system has various behaviours near the primary resonance depending on ambient temperature. The special case when relative temperature θ = 1.0 characterises untypical resonance curve. Increasing temperature to the normal human body one the resonance curves are typical. Then the system has only one periodic solution if the excitation is not too strong