Respiratory muscle pacing with chronically implanted intramuscular Permaloc electrodes: A feasibility study

Abstract

Abstract-We tested the feasibility of stimulating upperintercostal and abdominal muscles plus the diaphragm by using chronically implanted intramuscular electrodes. During two survival surgeries with six dogs, intramuscular electrodes were implanted bilaterally in the three respiratory muscles. Standard stimulation of the diaphragm was conducted. The dorsolateral and ventrolateral abdominal wall areas were stimulated with a 25 mA current. The second to fourth intercostal spaces were stimulated to elicit the largest tidal volume associated with the least coactivation of the serratus and latissimus muscles. Lone diaphragm and upper-intercostal muscle pacing produced inhaled tidal volumes (mean +/-standard error of the mean) of 293 +/-36 mL and 59 +/-17 mL, respectively. Lone abdominal muscle pacing produced an exhaled volume of 55 +/-17 mL. Combined pacing of diaphragm and intercostal muscles increased the inhaled volume to 389 +/-39 mL. The addition of abdominal pacing following the combined stimulation of diaphragm and intercostals increased the exhaled volume to 472 +/-54 mL. During autopsy, dislodgement of the electrodes overlying the ribs was a concern and probably resulted from loose animal jackets. Chronic intramuscular Permaloc electrodes can be implanted in several respiratory muscles and increase tidal volumes more than diaphragm stimulation alone.

Respiratory responses to stimulation of abdominal and upper-thorax intercostal muscles using multiple Permaloc®electrodes

“…Respiratory responses in our prior studies were limited because of the use of too few electrodes, stimulating currents that were too low, and less than optimal electrode implant locations [19][20][21][22]. In the current study, improved methods to address each of these concerns were conducted and corresponding increases in respiratory responses were obtained.…”

“…Esophageal pressure was monitored with a small balloon-tipped tube made from a surgical glove finger that was sealed at the end of the tube with glue and thread. The balloon and tube were filled with water and advanced orally to the esophagus to a location just rostral to the diaphragm [21][22]. The same type of balloontipped tube was used for abdominal pressure recording, and the balloon was introduced anally and advanced 23 cm into the colon to lie caudal to the diaphragm [21][22].…”

“…The balloon and tube were filled with water and advanced orally to the esophagus to a location just rostral to the diaphragm [21][22]. The same type of balloontipped tube was used for abdominal pressure recording, and the balloon was introduced anally and advanced 23 cm into the colon to lie caudal to the diaphragm [21][22]. A respiratory pneumobelt was used to record chest wall movement and was placed around the chest at the inferior edge of the sternum near the xiphoid process.…”

A 12-channel neuroprosthetic platform for SCI: Applications in the urinary, respiratory and muscle atrophy areas

“…Further work is needed to study effects of stimulation on muscle fatigue and metabolic responses. In one long term study we identified a problem with securing Permaloc ® electrodes in extradiaphragmatic muscles [8]. To address this concern we plan to test opening the polypropylene securing barb and snaking the electrode lead away from the muscle exit site and using multiple sutures.…”

“…For urinary applications, we are investigating Permaloc ® Intramuscular Electrodes for direct bladder wall stimulation and voiding as well as bilateral pudendal nerve stimulation for neuromodulation and bladder inhibition [3,[8][9][10][11]. Successful clinical methods of Magasi and Simon [12] for direct bladder wall stimulation and Possover et al [13] for pudendal nerve stimulation and neuromodulation are being followed.…”