Patient monitoring equipment, probe for use therewith, and method of measuring anesthesia based on oesophagal contractions

Apparatus for controlling the amount of an anaesthetic administered to a patient comprising sensor means for providing signals indicative of contractions in the oesophagus of a patient, means for deriving from said signals an output indicative of the depth of anaesthesia of a patient, and means for automatically controlling the amount of an anaesthetic administered to a patient in response to variation in the output indicative of the depth of anaesthesia.

Apparatus for monitoring the depth of anaesthesia of a patient, which apparatus comprises means for stimulating contractions in the oesophagus of the patient, a sensor for providing signals indicative of the oesophageal contractions, discriminating means for accepting only signals of more than a preset threshold magnitude to eliminate signals arising from non-aesophageal activities, and means for deriving from the signals an output indicative of the rate of occurrence of signals having a magnitude greater than said preset threshold magnitude.

A method of monitoring the depth of anaesthesia in a patient, which method comprises the steps of (a) deriving signals indicative of contraction in the oesophagus of the patient, and (b) deriving from the said signals an output indicative of the depth of anaesthesia of the patient.

A method of controlling the depth of anaesthesia of a patient, which method comprises the steps of (a) deriving signals indicative of contractions in the oesophagus of the patient, (b) deriving from the signals an output indicative of the depth of anaesthesia of the patient, and (c) controlling the administration of anaesthetic or sedative drugs to the patient in response to the said output.

A method as claimed 21, wherein step (b) further includes the step of deriving the output only from signals having a magnitude greater than a desired threshold value.

An elongate probe for measuring oesophogeal contractions, having a distal end adapted to pass downwardly through the oesophagus of the patient, and a proximal end adapted in use to lie externally of the mouth of the patient, the probe including stimulating means adapted in use to lie within the oesophagus of a patient and operable by means external to the patient for stimulating the oesophagus, to cause contractions therein, pressure sensing means adapted in use to lie within the oesophagus of the patient for enabling the measurement of pressure within the oesophagus, thereby to sense contractions of the oesophagus.

A probe for measuring oesophogeal contractions, comprising an elongate body portion for insertion into the oesophagus and having at least first and second lumens sealed with respect to each other, the first lumen being in communication at its distal end with a sensing balloon for sensing oesophageal pressure, and being provided at its proximal end with means for connection to a pressure measuring device, and the second lumen being adapted to receive a fluid under pressure to stimulate the oesophagus to cause contractions therein.

Patient monitoring apparatus, which comprises means for assigning a score value to each of a plurality of different bodily functions of a patient, the said score values being indicative of a depth of anaesthesia or sedation, means for summing the score values, and means for producing an output from the summed score values indicative of the amount of anaesthetic to be fed to the patient.

A method of monitoring the depth of anaesthesia of a patient, which method comprises assigning a score value to each of a plurality of different bodily functions, the said score values being indicative of a depth of anaesthesia, and summing the score values to obtain a total score indicative of the depth of anaesthesia of the patient.