scholarly journals Effectiveness of diaphragmatic stimulation with single-channel electrodes in rabbits

2013 ◽  
Vol 39 (4) ◽  
pp. 490-494 ◽  
Author(s):  
Rodrigo Guellner Ghedini ◽  
Julio de Oliveira Espinel ◽  
Elaine Aparecida Felix ◽  
Artur de Oliveira Paludo ◽  
Rodrigo Mariano ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Electrical Stimulation ◽  
Experimental Model ◽  
Single Channel ◽  
Neuromuscular Diseases ◽  
Common Causes ◽  
Number Of Individuals ◽  
Different Levels ◽  
Diaphragmatic Stimulation ◽  
Stimulation Of

Every year, a large number of individuals become dependent on mechanical ventilation because of a loss of diaphragm function. The most common causes are cervical spinal trauma and neuromuscular diseases. We have developed an experimental model to evaluate the performance of electrical stimulation of the diaphragm in rabbits using single-channel electrodes implanted directly into the muscle. Various current intensities (10, 16, 20, and 26 mA) produced tidal volumes above the baseline value, showing that this model is effective for the study of diaphragm performance at different levels of electrical stimulation

scholarly journals Development of a new experimental model of intramuscular electrical stimulation of the diaphragm in rabbits

2010 ◽  
Vol 25 (6) ◽  
pp. 475-478 ◽  
Author(s):  
Rodrigo Guellner Ghedini ◽  
Ane Margarites ◽  
Elaine Aparecida Felix ◽  
Rogério Gastal Xavier ◽  
Cristiano Feijó Andrade
Keyword(s):  
Mechanical Ventilation ◽  
Animal Model ◽  
Electrical Stimulation ◽  
Ventilatory Support ◽  
Current Intensity ◽  
Bipolar Electrode ◽  
Minute Interval ◽  
The Relationship ◽  
Diaphragmatic Stimulation ◽  
Stimulation Of

PURPOSE: To develop an animal model of diaphragmatic electrical stimulation able to generate an appropriate ventilatory support through the direct implantation of electrodes in the diaphragm (electroventilation). METHODS: Six New Zealand female rabbits (2-3 kg) were placed on mechanical ventilation. Then, a laparotomy was performed in order to identify the motor points in each hemidiaphragm, followed by the implantation of the electrodes for diaphragmatic stimulation. We tested two types of electrodes according to the conduction of electrical stimulation: unipolar and bipolar. The electrodes were placed on different occasions in the same animals and tested with current intensities of 20, 26 and 32 mA. Each current intensity was repeated three times for 10 respiratory cycles with 1 minute interval between each cycle, and 5 minutes for new current intensity. We recorded the relationship between current intensity and inspiratory volume. RESULTS: The electrodes adequately stimulate the diaphragm and obtain inspired volumes using different intensity currents. The bipolar electrode generated inspiratory volumes as high as 4.5 times of baseline while the unipolar electrode reached up to 3.5 times of baseline. CONCLUSION: This model has proved to be effective for studying the performance of the diaphragm under different electrical stimulations using different set of electrodes.

Efferent-mediated protection from acoustic overexposure: relation to slow effects of olivocochlear stimulation

1995 ◽  
Vol 73 (2) ◽  
pp. 506-514 ◽  
Author(s):  
E. R. Reiter ◽  
M. C. Liberman
Keyword(s):  
Electrical Stimulation ◽  
Inner Ear ◽  
Guinea Pigs ◽  
Threshold Shift ◽  
Exposure Condition ◽  
Protective Effects ◽  
Acoustic Overstimulation ◽  
Different Levels ◽  
Stimulation Of

1. The present study attempts to resolve discrepancies in the reported role of olivocochlear (OC) efferent activation in protecting the inner ear from acoustic overstimulation: in previous studies, activating the OC system in guinea pigs reduced the threshold shift caused by 1 min monaural exposure to a 10-kHz tone; whereas unilateral OC activation in cats had no effect on threshold shifts following binaural exposure to a 10 min 6-kHz tone. 2. In this study, anesthetized and curarized guinea pigs were exposed either monaurally or binaurally to tones of different duration (1-5 min), frequency (6 to 10 kHz) and intensity (105-118 dB SPL). For each exposure condition, threshold shifts were compared among ears with different levels of OC activation: in some cases, the OC bundle (OCB) was electrically stimulated during (and/or before) the acoustic overexposure; in others, the OCB was cut before the exposure; in control cases, the OCB was neither cut nor electrically stimulated. 3. Electrical stimulation of the OCB delivered simultaneously with acoustic overstimulation produced significant reductions in threshold shift only for acoustic exposures at higher frequencies (8 and 10 kHz) and shorter durations (1 and 2 min). The protective effects on 1-min exposures could be extinguished by prior stimulation of the OCB, i.e., if the OC stimulation was turned on 4 min before the acoustic overexposure.(ABSTRACT TRUNCATED AT 250 WORDS)

An experimental model of stress-induced immunosuppression produced by electrical stimulation of the brain in the rat

2001 ◽  
Vol 114 (1-2) ◽  
pp. 35-39 ◽  
Author(s):  
Marı́a Martha Villaseñor-Garcı́a ◽  
Xavier Lozoya ◽  
Ana Marı́a Puebla-Pérez
Keyword(s):  
Electrical Stimulation ◽  
Experimental Model ◽  
The Brain ◽  
Stimulation Of

Cutaneous and muscle vascular responses to electrical stimulation of lumbar sympathetic trunk in the dog

1960 ◽  
Vol 199 (1) ◽  
pp. 112-116 ◽  
Author(s):  
Robert O. Rawson ◽  
Walter C. Randall
Keyword(s):  
Electrical Stimulation ◽  
Intravenous Administration ◽  
Gastrocnemius Muscle ◽  
Sympathetic Trunk ◽  
Vascular Response ◽  
Vertebral Level ◽  
Vascular Responses ◽  
Changing Patterns ◽  
Different Levels ◽  
Stimulation Of

Simultaneous vascular responses in three cutaneous (thigh, calf, footpad) and one muscle (gastrocnemius) bed of the dog's hind leg were recorded during stimulation of the ipsilateral lumbar sympathetic trunk, and correlated with the vertebral level of stimulation. Changing patterns of vascular response with successively lower stimulations was interpreted to indicate the levels of preganglionic entry of vasomotor fibers into the sympathetic trunk. Significant variations in the anatomic patterns of vasomotor pathways were found. In a few animals vasoconstrictor fibers innervating only the proximal portions of the extremity were found in the more rostral portions (L2-L3) of the trunk. In others, however, these same segments of the trunk carried rich innervation to the most distal regions of the extremity. In a majority of animals, the most effective cutaneous vasomotor innervation entered the trunk between L3 and L5. There were notable instances of entry as low as the L6–L7 interganglionic segment. Both vasoconstrictor and vasodilator responses were elicited in the gastrocnemius muscle, frequently by stimulation at different levels of the trunk in a given animal. The dilator responses were readily abolished by intravenous administration of atropine, leaving constrictor reactions relatively unaffected.

Present Status and Future Development of the Cochlear Prosthesis

1975 ◽  
Vol 84 (4) ◽  
pp. 494-498 ◽  
Author(s):  
Robin P. Michelson ◽  
Michael M. Merzenich ◽  
Robert A. Schindler ◽  
David N. Schindler
Keyword(s):  
Electrical Stimulation ◽  
Communication Skills ◽  
Auditory Nerve ◽  
Single Channel ◽  
Speech Discrimination ◽  
Cochlear Prosthesis ◽  
Aural Rehabilitation ◽  
Complex Sounds ◽  
Place Pitch ◽  
Stimulation Of

Presently devised single channel devices generate relatively primitive sensation of hearing. They provide some enhancement of communication skills for the totally deaf. Definite psychological advantages for the totally deaf have been observed. Pitch discrimination is by the mechanism of “periodicity pitch.” No “place” pitch encoding is possible. The recognition of complex sounds is not possible. Multiple segments of auditory nerve must be stimulated in a manner which will simulate the complex patterns of neural activity necessary for speech discrimination. Electrodes can be optimized and the pathophysiological consequences of electrical stimulation can be determined in experimental animals. The perceptual consequences of electrical stimulation, however, can best be determined in man himself. How much we will have to rely on known and future methods of aural rehabilitation will depend upon how well perceptual speech patterns can be generated by electrical stimulation of the auditory nerve.

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