Catheter for spinal epidural injection of drugs and measurement of evoked potentials

Claim 1

A method for determining the effect of epidurally administered drugs on the spinal cord electrical activity of an animal, comprising the steps of: (1) insertion of a catheter into the epidural space of the spinal cord, said catheter having at least two electrodes and a means for injecting drugs; (2) administration of a drug through said catheter into the epidural space; (3) administering an electrical stimulus to the animal; (4) detecting the evoked response at the electrodes of said catheter; and (5) comparing said detected response with the response detected in the same animal when drugs have not been inserted into the epidural space.

Claim 2

A method for determining the effect of epidurally administered drugs on the spinal cord electrical activity of an animal, comprising the steps of: (1) insertion of a catheter into the epidural space of the spinal cord, said catheter having at least two electrodes and a means for injecting drugs; (2) administration of a drug through said catheter into the epidural space; (3) administering an electrical stimulus to the animal; (4) detecting the evoked response at the electrodes of said catheter; and (5) comparing said detected response with the response detected in the same animal when drugs have not been inserted into the epidural space.

Claim 4

A device for epidurally administering a drug to the spine of an animal and measuring spinal cord electrical activity, comprising: a catheter sized and dimensioned for insertion into the spinal epidural space and having a distal tip and a proximal end, said catheter having drug passage means for passage of a drug through the catheter and including an outlet opening for allowing the drug to exit the catheter into the epidural space when the catheter is in use, and said catheter further having first electrode means and second electrode means, both being connectable by means of separate electrical connections within the catheter to an external electrical transmission or reception device, wherein said first electrode means is disposed at or near the distal tip of the catheter and distal to said outlet opening, and said second electrode means is disposed proximal to said outlet opening.

Claim 5

A device for epidurally administering a drug to the spine of an animal and measuring spinal cord electrical activity, comprising: a catheter sized and dimensioned for insertion into the spinal epidural space and having a distal tip and a proximal end, said catheter having drug passage means for passage of a drug through the catheter and including an outlet opening for allowing the drug to exit the catheter into the epidural space when the catheter is in use, and said catheter further having first electrode means and second electrode means, both being connectable by means of separate electrical connections within the catheter to an external electrical transmission or reception device, wherein said first electrode means is disposed at or near the distal tip of the catheter and distal to said outlet opening, and said second electrode means is disposed proximal to said outlet opening.

Claim 12

A method for monitoring the effect of spinal epidural anaesthesia using a device for epidurally administering a drug to the spine of an animal and measuring spinal cord electrical activity, comprising: a catheter sized and dimensioned for insertion into the spinal epidural space and having a distal tip and a proximal end, said catheter having drug passage means for passage of a drug through the catheter and including an outlet opening for allowing the drug to exit the catheter into the epidural space when the catheter is in use, and said catheter further having first electrode means and second electrode means, both being connectable by means of separate electrical connections within the catheter to an external electrical transmission or reception device, wherein said first electrode means is disposed at or near the distal tip of the catheter and distal to said outlet opening, and said second electrode means is disposed proximal to said outlet opening, said method comprising: inserting the catheter into the spinal epidural space of the animal to be anesthetized until the drug passage means outlet opening is at the desired location; administering anaesthetic via said drug passage means, through said outlet opening, into the epidural space; applying triggered electrical stimuli by means of one of said first and second electrode means; measuring the evoked potential at the other of said first and second electrode means; and adjusting the amount of anaesthetic being administered dependent on the nature of the measured evoked potential to assure that sufficient anaesthetic is being administered for the desired anaesthetic effect without overloading the animal with anaesthesia.

Claim 13

A method for monitoring the effect of spinal epidural anaesthesia using a device for epidurally administering a drug to the spine of an animal and measuring spinal cord electrical activity, comprising: a catheter sized and dimensioned for insertion into the spinal epidural space and having a distal tip and a proximal end, said catheter having drug passage means for passage of a drug through the catheter and including an outlet opening for allowing the drug to exit the catheter into the epidural space when the catheter is in use, and said catheter further having first electrode means and second electrode means, both being connectable by means of separate electrical connections within the catheter to an external electrical transmission or reception device, wherein said first electrode means is disposed at or near the distal tip of the catheter and distal to said outlet opening, and said second electrode means is disposed proximal to said outlet opening, said method comprising: inserting the catheter into the spinal epidural space of the animal to be anesthetized until the drug passage means outlet opening is at the desired location; administering anaesthetic via said drug passage means, through said outlet opening, into the epidural space; applying triggered electrical stimuli by means of one of said first and second electrode means; measuring the evoked potential at the other of said first and second electrode means; and adjusting the amount of anaesthetic being administered dependent on the nature of the measured evoked potential to assure that sufficient anaesthetic is being administered for the desired anaesthetic effect without overloading the animal with anaesthesia.

Claim 17

A method for monitoring the effect on an animal of spinal epidural anaesthesia using a device comprising a catheter sized and dimensioned for insertion into the spinal epidural space of the animal to be anesthetized, said catheter having drug passage means for passage of a drug through the catheter and including an outlet opening for allowing the drug to exit the catheter into the epidural space when the catheter is in use, and said catheter further having first electrode means disposed at or near the distal tip of the catheter, said first electrode means being connectable by means of an electrical connection within the catheter to an external electrical transmission or reception device, the method comprising: inserting the catheter into the spinal epidural space of the animal to be anesthetized until the drug passage means outlet opening is at the desired location; administering anaesthetic via said drug passage means, through said outlet opening, into the epidural space; applying triggered electrical or mechanical stimuli to the animal; measuring the evoked potential at said electrode means; and adjusting the amount of anaesthetic being administered dependent on the nature of the measured evoked potential to assure that sufficient anaesthetic is being administered for the desired anaesthetic effect without overloading the animal with anaesthesia.

Claim 18

A method for monitoring the effect on an animal of spinal epidural anaesthesia using a device comprising a catheter sized and dimensioned for insertion into the spinal epidural space of the animal to be anesthetized, said catheter having drug passage means for passage of a drug through the catheter and including an outlet opening for allowing the drug to exit the catheter into the epidural space when the catheter is in use, and said catheter further having first electrode means disposed at or near the distal tip of the catheter, said first electrode means being connectable by means of an electrical connection within the catheter to an external electrical transmission or reception device, the method comprising: inserting the catheter into the spinal epidural space of the animal to be anesthetized until the drug passage means outlet opening is at the desired location; administering anaesthetic via said drug passage means, through said outlet opening, into the epidural space; applying triggered electrical or mechanical stimuli to the animal; measuring the evoked potential at said electrode means; and adjusting the amount of anaesthetic being administered dependent on the nature of the measured evoked potential to assure that sufficient anaesthetic is being administered for the desired anaesthetic effect without overloading the animal with anaesthesia.