Intraoperative Neuromonitoring

Donohue, Miriam L; Swaminathan, Viswaminathan; Gilbert, Jeremy L.; Fox, Charles W.; Smale, John; Moquin, Ross R.; Calancie, Blair

doi:10.1097/wnp.0b013e3182767aac

Cited by 20 publications

(5 citation statements)

References 32 publications

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“…The extent of this effect on the ability to conduct electrical stimuli has not been extensively addressed in the scientific literature. However, Donohue et al [4] has reported alterations in the time-current and frequency spectrum of the stimulus applied to pedicle screws with different titanium alloys. In the present study, only direct current tests were performed, meaning that future studies should also consider the current step response and the effect of alternating current on pedicle screw impedance.…”

Section: Practical Implicationsmentioning

confidence: 99%

“…While the electrical probing of the pilot hole is recommended [4], since the insertion of the pedicle screw may generate further removal of pedicular and vertebral mass, the stimulation of the pedicle seems to gather more interest. Ideally, this method would enable the verification of the goodness of pedicle screw insertion without the need for imaging confirmation.…”

Section: Introductionmentioning

confidence: 99%

“…Despite all these advantages, TiO 2 is a semiconductor material with a high electrical resistance at room temperature [18]. Indeed, Donohue et al [4] speculated that the differences in conductivity among titanium screws could be related to their oxide layer properties. However, to our knowledge, no study has delved into the effect of different TiO 2 layer thicknesses in pedicle screws and how it may affect their ability to conduct electrical current, thus warranting a need to further research this matter.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Effect of the TiO2 Anodization Layer in Pedicle Screw Conductivity: An Analytical, Numerical, and Experimental Approach

Fonseca,

Goethel,

Vilas-Boas

et al. 2024

Bioengineering

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The electrical stimulation of pedicle screws is a technique used to ensure its correct placement within the vertebrae pedicle. Several authors have studied these screws’ electrical properties with the objective of understanding if they are a potential source of false negatives. As titanium screws are anodized with different thicknesses of a high electrical resistance oxide (TiO2), this study investigated, using analytical, numerical, and experimental methods, how its thickness may affect pedicle screw’s resistance and conductivity. Analytical results have demonstrated that the thickness of the TiO2 layer does result in a significant radial resistance increase (44.21 mΩ/nm, for Ø 4.5 mm), and a decrease of conductivity with layers thicker than 150 nm. The numerical approach denotes that the geometry of the screw further results in a decrease in the pedicle screw conductivity, especially after 125 nm. Additionally, the experimental results demonstrate that there is indeed an effective decrease in conductivity with an increase in the TiO2 layer thickness, which is also reflected in the screw’s total resistance. While the magnitude of the resistance associated with each TiO2 layer thickness may not be enough to compromise the ability to use anodized pedicle screws with a high-voltage electrical stimulator, pedicle screws should be the subject of more frequent electrical characterisation studies.

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Section: Practical Implicationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Effect of the TiO2 Anodization Layer in Pedicle Screw Conductivity: An Analytical, Numerical, and Experimental Approach

Fonseca,

Goethel,

Vilas-Boas

et al. 2024

Bioengineering

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“…Misplacement of these screws can lead to lesion of SC or nerve roots that can impair the patient outcome (paralysis, pain, etc.) [13][14][15][16][17][18][19][20][21][22]. These techniques, with high temporal resolution as compared to MRI, are invasive, sometimes painful, and currently inappropriate in monitoring medullar function in daily living condition, in its actual form.…”

Section: Introductionmentioning

confidence: 99%

“…Thus, there is a real unmet need for methods in order to: 1) monitor the haemodynamic status of the SC during various surgeries [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22], and 2) assess the functional consequences of TSC and, as part of clinical trials, the effect of surgical strategies, pharmacologic, or appropriate rehabilitation [12,[33][34][35][36][37][38][39]. In this project, we aim to contribute to these aspects, proposing a device for continuously measuring various metabolic parameters at the SC level invasively or not, depending on the application context.…”

Section: Introductionmentioning

confidence: 99%

Toward the monitoring of the spinal cord: A feasibility study

Tsiakaka

2019

Microelectronics Journal

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The usual imaging techniques providing only limited information, there is an unmet need for methods, firstly, to monitor in real time the functional status of the Spinal Cord (SC) and, secondly, to assess the functional consequences of the SC Injuries (SCI) and the effect of therapeutic interventions. To meet these needs, our project aims to investigate a new imaging approach, through the realization of a device for measuring the SC activity. This approach will establish locally and specifically the functional state of the SC in real time, which will provide a breakthrough in surgery, as well as in the care and therapeutic trials for SCI. This paper presents the first results of this research project on pig subjects, focusing on the opto-electrical part, based on Near-InfraRed Spectroscopy (NIRS). Firstly, the pig SC optical characterization was performed in different conditions, using a portable spectrophotometer in order to define the wavelengths of interest and their corresponding optical attenuation. In transmission mode, the Optical Density (OD) was evaluated between 3.5 and 6.5 in the [500; 950] nm range. In reflection mode, a figure between 11 % and 33 % is obtained in the same wavelength range. We find that wavelengths between 600 nm and 940 nm are good candidates to monitor the SC functional activity. Secondly, thanks to these results, a specific opto-electrical system has been designed for the transmission mode only, with adapted light sources and custom probes with its front-end to observe the autonomic functions in the SC. 2Results on the measured haemodynamic variations, at rest and under stimulation, show in real time the impact of a global stimulus on a local section of the SC. However, with a low AC-to-DC ratio (around 1 %), the SC PhotoPlethysmoGram (PPG) acquisition isn't simple and the best trade-off between power consumption and Signal-to-Noise Ratio (SNR) must be found in the perspective of the Embedded System (ES) development.This study demonstrates, for the first time, the feasibility of the SC activity monitoring using NIRS in transmission mode in a big animal model, where the perfect alignment of the light emitter and receptor isn't necessary due to the diffusive property of the biological media.It contributes to heading towards the use of the Internet of Things (IoT) for medical applications, through the monitoring of the SC during highly invasive processes, such as the stabilization of the spine, in the form of implants and other surgeries, such as that of the aorta, with the use of specific minimally invasive catheters.

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