Infrared neural stimulation in the cochlea.

The application of photonics to manipulate and stimulate neurons and to study neural networks has gained momentum over the last decade. Two general methods have been used: the genetic expression of light or temperature sensitive ion channels in the plasma membrane of neurons (Optogenetics and Thermogenetics) and the direct stimulation of neurons using infrared radiation (Infrared Neural Stimulation, INS). Both approaches have their strengths and challenges, which are well understood with a profound understanding of the light tissue interaction(s).

Optical cochlear implants: evaluation of surgical approach and laser parameters in cats.

Previous research has shown that neural stimulation with infrared radiation (IR) is spatially selective and illustrated the potential of IR in stimulating auditory neurons. The present work demonstrates the application of a miniaturized pulsed IR stimulator for chronic implantation in cats, quantifies its efficacy, and short-term safety in stimulating auditory neurons. IR stimulation of the neurons was achieved using an optical fiber inserted through a cochleostomy drilled in the basal turn of the cat cochlea and was characterized by measuring compound action potentials (CAPs).

Laser stimulation of auditory neurons: effect of shorter pulse duration and penetration depth.

We have pioneered what we believe is a novel method of stimulating cochlear neurons, using pulsed infrared radiation, based on the hypothesis that optical radiation can provide more spatially selective stimulation of the cochlea than electric current. Very little of the available optical parameter space has been used for optical stimulation of neurons. Here, we use a pulsed diode laser (1.

Optical parameter variability in laser nerve stimulation: a study of pulse duration, repetition rate, and wavelength.

Pulsed lasers can evoke neural activity from motor as well as sensory neurons in vivo. Lasers allow more selective spatial resolution of stimulation than the conventional electrical stimulation. To date, few studies have examined pulsed, mid-infrared laser stimulation of nerves and very little of the available optical parameter space has been studied.

Malignant pericardial tamponade.

We studied the clinical course and management of 27 patients with malignant pericardial tamponade seen in a single Medical Center over a 10 year period. Patients treated with repeat pericardial tap as their only mode of therapy had a high rate of recurrent tamponade (6 of 13 subjects) whereas most patients treated with drainage (either surgical or percutaneous) had sustained control of their pericardial effusion (achieved in 10/13 subjects). Intra-pericardial instillation of tetracycline or cyclophosphamide did not clearly improve the good results obtained with drainage alone.