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Biomedical subjects

Ph A Federspil

Publications and source records attributed to Ph A Federspil.

3 recordsLinked to original sources
PubMed2004

Restoring hearing with active hearing implants.

Due to shortcomings of conventional hearing aid technology, such as unsatisfactory sound quality due to limited frequency range and undesired distortion, occlusion of the outer ear canal, and acoustic feedback with high amplification, but also psychological aspects of stigmatization, a significant of patients in need of hearing aids are actually not wearing them. Active hearing implants can be distinguished in: (1) impedance transformation implants (ITI), (2) cochlear amplifier implants (CAI), (3) cochlear implants (CI), and (4) brain stem implants (BSI). Whereas ITI are designed for patients with middle ear hearing loss, CAI are intended to restore hearing in patients with inner ear hearing loss. Advantages of CAI may be: (1) improved sound fidelity, (2) no occlusion of the outer ear canal, (3) no feedback, and (4) invisibility. However, not all features are true for every device. CI replace inner ear function in deaf or almost deaf patients. This article gives an overview on the range of active hearing implants to restore hearing and outlines the future use of computer and robot aided surgery.

Amplifiers, Electronic↗
PubMed2004

Robotic surgery in otorhinolaryngology.

Otoneurosurgery may greatly benefit from enhanced precision through robotics or from new procedures only made possible with robotic aid. Different implant cavities were milled by a serial robot (Stäubli RX 130) in formaldehyde fixed human skull bones. A variety of sensor data (force, momentum, temperature,...) were measured and evaluated. Ultrasound probes of different frequencies were used to measure skull bone thickness. With a serial robot Stäubli RX 130 it was possible to mill an exact implant cavity for various CI main modules in a human skull specimen. While milling with speed controlled by force feedback, the heat production was tremendously reduced as compared to the non controlled mode. Using coded excitation and a matched-filter technique, a 3D ultrasound scan of the skull bone could be performed in order to plan the drilling task for the robot by means of local navigation. This is the first functional robotic milling procedure for otoneurosurgery with force-based speed control in an experimental setting. Force feedback smoothes the robot's movements and reduces heat damage to surrounding tissues. Ultrasound navigation may replace the need for CT scanning in the future.

Equipment Design↗