Method of further developing the measuring of a neuro-muscular junction

• US 4,595,018 A
• Filed: 06/06/1984
• Issued: 06/17/1986
• Est. Priority Date: 06/10/1983
• Status: Expired due to Fees

• Current Assignee: Instrumentarium Dental Incorporated (Envista Holdings Corporation)
• Original Assignee: Instrumentarium Dental Incorporated (Envista Holdings Corporation)
• Inventors: Rantala, Borje
• Primary Examiner(s): Coven, Edward M.
• Application Number:
  US06/617,936
• Time in Patent Office: 741 Days
• Field of Search: 128/733, 128/741, 128/783
• US Class Current: 600/546
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/395 Details of stimulation, e.g. nerve stimulation to elicit EMG response
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker

Abstract

The invention relates to a method of further developing the measuring of so-called neuromuscular transmission (or NMT), said measuring being effected by stimulating with electric pulses a given muscular nerve, e.g. the ulnar nerve in the arm of a patient, and by measuring a corresponding muscular block by means of EMG. In the prior art NMT-measurings, a stimulus artefact, caused by stimulation and induced directly electrically and independently of a stimulus passing through said muscular nerve, may often distort measuring results. According to the invention, this artefact is not tried to be eliminated by various gate solutions but, instead, it is measured by first effecting a measurement prior to the actual neuromuscular block measurements e.g. in connection with the calibration of the control or reference value of a muscular block and by recording or storing this first value of a stimulus artefact. This is followed by monitoring the changes of stimulus artefact values by measuring said stimulus artefact during the measurements of a neuromuscular junction and by comparing the thus obtained stimulus artefact values with said first value, not only for securing the reliability of measuring information but also preferably for controlling the state variations and condition of NMT-measuring instruments. By digitizing the collected information, the measuring errors can be preferably eliminated mathematically by utilizing data processing.

Claims

1. A method of enhancing the accuracy and reliability of neuromuscular block monitoring, comprising the steps of stimulating with electric pulses a given muscular nerve of a patient, measuring a corresponding muscular block by EMG, measuring a stimulus artefact caused by stimulation induced directly electrically and independently of a stimulus passing through said muscular nerve prior to the actual neuromuscular block, recording the value of stimulus artefact, monitoring changes of stimulus artefact values by measuring said stimulus artefact during measurements of a neuromuscular junction, and comparing the latter obtained stimulus artefact values with said first stimulus artefact values to control the state variations of NMT-measuring instruments and improve the reliability of measuring information.

2. A method as set forth in cliam 1, characterized in that, when a stimulus artefact and a muscular block appear partially simultaneously, the portion of stimulus artefact overlapping with a muscular block is determined and this portion is subtracted from the measured values of a muscular block.