K. L. Drake

Bio: K. L. Drake is an academic researcher from University of Michigan. The author has contributed to research in topics: Microelectrode & Microprobe. The author has an hindex of 4, co-authored 7 publications receiving 571 citations.

Performance of planar multisite microprobes in recording extracellular single-unit intracortical activity

Abstract: The microprobes consist of a thin-film electrode array supported by a silicon micromachined substrate and insulated using deposited dielectrics. Microprobes with multiple recording sites spaced from 30 mu m to 200 mu m apart are used to record spontaneous single-unit activity from rat cerebral cortex. Additionally, a theoretical model is used to establish a basis for interpreting the multisite single-unit data. The results suggest that the microprobes (1) couple tightly to the neural tissue with relatively little disturbance to the neural system, (2) facilitate the identification of single units in multiunit records through the use of spatially-separate recording sites, and (3) can be used to detect the cell position in tissue and observe events such as the propagation of electrical activity from the soma to the dendritic tree. >

Solid-State Electrodes for Multichannel Multiplexed Intracortical Neuronal Recording

Abstract: Thin-film arrays of extracellular recording electrodes have been developed for use in studies of information processing in neural structures and eventual use in closed-loop control of neural prostheses. These probes consist of a silicon substrate which supports an array of thin-film conductors. The conductors are insulated above and below with deposited dielectrics. The electrode sites are defined by openings in the upper dielectric layer and are inlaid with gold to form low-impedance recording surfaces. The probes are typically 15 pim in thickness with shank widths as narrow as 20 ?m. The probe fabrication process is compatible with the inclusion of signal processing circuitry directly on the probe substrate. A 12 channel on-chip signal processor design with per-channel gain of 100, bandwidth of 100 Hz-6 kHz, multiplexed output, and recording-site impedance check capability is described. The probes have adequate strength to penetrate the gerbil pia-arachnoid layer and have recorded single neuron activity of over 500 ?V peak-to-peak from tip, side, and mid-carrier sites. Signal-to-noise ratios as high as 10:1 have been achieved. An equivalent circuit model for the conducting leads, the recording site, and the electrode-electrolyte interface is described. Development of biocompatible insulation and encapsulation materials for long-term implantation of active probes is underway.

Venovenous Extracorporeal Membrane Oxygenation (ECMO) Using a Double-Lumen Cannula

Abstract: Extracorporeal membrane oxygenation (ECMO) can support neonates with severe respiratory failure. Currently, the most common application of ECMO requires venoarterial access. Venovenous (VV) ECMO is desirable to avoid common carotid artery ligation. However, the best technique of venous access for VV ECMO is not established. Using a single cannula with a double-lumen (DLC) in the right atrium for simultaneous drainage and infusion of blood, VV ECMO provided total respiratory support for six apneic puppies for 3 h each. Mean systemic arterial oxygenation was lower with DLC VV (50 torr) compared to VA ECMO (247 torr), but a physiologic pH (mean 7.34) was maintained on DLC VV bypass. Higher mean bypass flow was required on DLC VV (124 ml/kg/min) compared to VA flow (101 ml/kg/min) because of recirculation of oxygenated blood. The position of the DLC in the right atrium needed to be closely monitored. Hemorrhage was noted in the myocardium after use of DLC VV ECMO.

Accuracy of Tetrode Spike Separation as Determined by Simultaneous Intracellular and Extracellular Measurements

Abstract: Simultaneous recording from large numbers of neurons is a prerequisite for understanding their cooperative behavior. Various recording techniques and spike separation methods are being used toward ...

Intracellular Features Predicted by Extracellular Recordings in the Hippocampus In Vivo

Abstract: Multichannel tetrode array recording in awake behaving animals provides a powerful method to record the activity of large numbers of neurons. The power of this method could be extended if further i...