Robot assisted stapedotomy ex vivo with an active handheld instrument

Micron is a fully handheld active micromanipulator that helps to improve position accuracy and precision in microsurgery by cancelling hand tremor. This work describes adaptation, tuning, and testing of the Micron system for stapedotomy, a microsurgical procedure performed in the middle ear to restore hearing that requires accurate manipulation in narrow spaces. Two end-effectors, a handle, and a brace (or rest) were designed and prototyped. The control system was adapted for the new hardware. The system was tested ex vivo in stapedotomy procedure comparing manually-performed and Micron-assisted surgical tasks. Tremor amplitude was found to be reduced significantly. Further testing is needed in order to obtain statistically significant results regarding other parameters dealing with regularity of the fenestra shap

マイクロマシン技術を応用した術中使用可能な耳小骨可動性測定装置の開発

平成11年度-平成12年度科学研究費補助金(基盤研究(B)(2))研究成果報告書,課題番号.1155712

Towards Automated Ear Surgery: Improved Calibration and Registration Procedures

A micro-electro-mechanical system (MEMS) based hydrophone inserted into the cochlea may be utilized to study acoustic pressure distribution. The objective of this project, performed through collaboration between WPI and UniversitätsSpital Zürich, was to develop an improved procedure for experiments at the UniversitätsSpital Zürich that would increase the insertion accuracy. This is necessary due to the small scale, complex anatomy, and delicate nature of the inner ear. This was done by calibrating tools and completing registration and insertion processes. The goal was to achieve an overall accuracy of 250 microns, which was met with a final accuracy below 200 microns, suggestive that the devised procedure can provide an accurate roadmap for future experiments

Thermal constraints on in vivo optogenetic manipulations.

A key assumption of optogenetics is that light only affects opsin-expressing neurons. However, illumination invariably heats tissue, and many physiological processes are temperature-sensitive. Commonly used illumination protocols increased the temperature by 0.2-2 °C and suppressed spiking in multiple brain regions. In the striatum, light delivery activated an inwardly rectifying potassium conductance and biased rotational behavior. Thus, careful consideration of light-delivery parameters is required, as even modest intracranial heating can confound interpretation of optogenetic experiments

Endoscopic and Robotic Stapes Surgery: Review with Emphasis on Recent Surgical Refinements

Purpose of Review Stapes surgery has been established as the gold standard for surgical treatment of conductive hearing loss in otosclerosis. Excellent outcomes with very low complication rate are reported for this surgery. Recent advances to improve surgical outcome have modified the surgical technique with endoscopes, and recent studies report development of robotical assistance. This article reviews the use of endoscopes and robotical assistance for stapes surgery. Recent Findings While different robotic models have been developed, 2 models for stapes surgery have been used in the clinical setting. These can be used concomitant to an endoscope or microscope. Endoscopes are used on a regular base regarding stapes surgery with similar outcomes as microscopes. Endoscopic stapes surgery shows similar audiological results to microscopic technique with an advantage of less postoperative dysgeusia and pain. Its utility in cases of revision surgery or malformation is emphasized. Summary Endoscopic stapes surgery is used on a regular basis with excellent outcomes similar to the microscopic approach, while reducing surgical morbidity. Robotic technology is increasingly being developed in the experimental setting, and first applications are reported in its clinical use

Pressure and Temperature Changes in In Vitro Applications with the Laser and Their Implications for Middle Ear Surgery

Background. The purpose of this study was to evaluate the thermal and pressure effects using a Titan Sapphire chirped-pulse amplifier system configured to deliver ultrashort pulses of 180 femtoseconds (fs) in an inner ear model. Materials and Methods. Temperature increases and heat exchange processes in the fluid (physiological saline) were examined in a calorically and physiologically approximated cochlea model for applying laser parameters effective in the creation of footplate perforations. Results. In the effective energy density range, the highest temperature increases achieved with the Carbon dioxide (CO2) laser were about 11 degrees C. The lowest temperature maxima were 6 degrees C with the Er:YAG laser (Yttrium-Aluminum-Oxide doted with Erbium3+-ions) and <5 degrees C with the femtosecond laser. Comparison of the laser-induced pressure with the limit graph published by Pfander indicated that the use of the fs laser is unobjectionable for fluences <1 J/cm2. Conclusions. Our investigations demonstrated that the application of the fs laser in middle ear surgery presents a new and promising addition to the range of ultrashort wavelength lasers used for this purpose

Electrophysiologic Consequences of Flexible Electrode Insertions in Gerbils With Noise-Induced Hearing Loss

Hypothesis—Flexible electrode interaction with intracochlear structures in a noise-damaged region of the cochlea can lead to measureable electrophysiologic changes. Background—An emerging goal in cochlear implantation is preservation of residual hearing subsequently allowing for combined electric and acoustic stimulation (EAS). However, residual hearing is at least partially lost in most patients as a result of electrode insertion. A gerbil model was used to examine changes to acoustically evoked cochlear potentials during simulated cochlear implantation. Methods—Gerbils were partially deafened by noise exposure to mimic residual hearing in human cochlear implant candidates. After one month, round window (RW) and intracochlear recordings during flexible electrode insertion were made in response to 1 kHz tone burst stimuli at 80 dB SPL. After the insertion the cochleas were histologically examined for hair cell loss due to the noise exposure and trauma due to the electrode insertion. Results—Anatomical damage from the flexible electrode was not observable in most cases. However, insertions caused response declines that were on average greater than the controls, although some losses were similar to the controls. The CM was more sensitive than the CAP for detecting cochlear disturbance. Conclusions—Because response reductions occurred in the absence of anatomical damage, disturbances in the fluid at the base appear to affect responses from the apex. The losses were less than in previous experiments where the basilar membrane was penetrated