Mindray 3-directional NMT Module (a new generation “Tri-axial” neuromuscular monitor) versus the Relaxometer mechanomyograph and versus the TOF-Watch SX acceleromyograph

  • Ashraf A. Dahaba
  • Ismet Suljevic
  • Zhao Yang Xiao
  • Kun Wang
Original Research


Recently introduced Mindray “3-directional” neuromuscular transmission transducer (NMT, Shenzhen, China) acceleromyograph) claim to monitor thumb movement in 3 different directions. We compared NMT with the gold standard Relaxometer® mechanomyograph (MMG, Groningen University, Netherlands) in Study-1 and with TOF-Watch SX™ (WTCH) acceleromyograph from which it was developed in Study-2. We used first twitch (T1%) and train-of-four (TOF) ratio rocuronium 0.6 mg kg−1 neuromuscular block to evaluate NMT diagnostic accuracy in indicating 3 clinically relevant time points namely; MMG T1 5% (95% twitch depression) for tracheal intubation, MMG T1 25% for repeat neuromuscular blocking agents (NMBAs) administration, and MMG 0.9 TOF ratio full neuromuscular block recovery. We compared onset time (time from beginning of rocuronium administration until maximal depression), Dur25 (time until T1 25% recovery) and Dur0.9 (time until 0.9 TOF ratio recovery). In Study-1, NMT showed low sensitivity in indicating MMG time for tracheal intubation, repeat NMBAs administration and full neuromuscular block recovery (6.25%, 38.9% and 38.9% respectively). NMT onset time, Dur25 and Dur0.9 (2:51 ± 00:57, 36:50 ± 24:25, 70:08 ± 25:27 min:s) were significantly longer than MMG (1:56 ± 00:46, 30:26 ± 20:24, 62:03 ± 20:01). In Study-2, NMT onset time, Dur25 and Dur0.9 (02:37 ± 00:53, 35:38 ± 11:54, 53:40 ± 13:49) were not significantly different than WTCH (02:23 ± 00:45, 33:27 ± 12:51, 53:57 ± 12:47). NMT could not efficaciously detect MMG time for tracheal intubation; NMBAs repeat dose administration or full neuromuscular block recovery. Data from NMT cannot be used interchangeably with MMG. Our study revealed that NMT Tri-axial acceleromyography seems to offer no advantage over the MMG gold standard or the classic Mono-axial TOF-Watch SX monitor.


Neuromuscular block Monitoring Neuromuscular function Equipment Mechanomyograph Diagnostic accuracy 



All authors would like to thank Mr. Elfid Pasovic our freelancer computer specialist at Sarajevo, Bosnia and Herzegovina for his great efforts in the data preparation and patients’ data management. Thanks to him we have all the patients data successfully recorded and downloaded. We would like also to thank graduate student Miss Fengyan Xu at Shanghai, People’s Republic of China for her great efforts in data preparation and statistical analysis.

Clinical trial registry numbers Our clinical trial was registered by Primary Investigator: Ashraf Dahaba prior to patient enrollment at Food and Drug Administration Clinical Trials Database; trial Registration Number: NCT02892045. Date of registration: protocol record NMT1 released and made public on 8th September 2016 on Sarajevo Medical University, Sarajevo Bosnia and Herzegovina ethics committee approval (0406-19256 at 5th May 2016 meeting chaired by Doc. Dr. Sci. Med Jasmina Krehic), and Dalian University Second affiliated Hospital ethics committee Dalian, People’s Republic of China (2015-106 at 14th January 2016 meeting chaired by Prof Dr. Ren Ping), Dalian, People’s Republic of China.

Author contributions

Primary investigator AAD conducted the study, participated in data collection, data analysis and manuscript writing. IS participated in perioperative anesthesia management, conducting the study, data collection, data analysis and manuscript writing. ZX participated in perioperative anesthesia management, conducting the study, data collection, data analysis and manuscript writing. KW is the statistician who designed the Bland and Altman scatterplots and regression plots as well as statistical analysis.


The study was financed from National Natural Science Foundation of China (Beijing, People’s Republic of China), grant No: 81471373, and the National Natural Science Foundation of China (Beijing, People’s Republic of China), Grant No: 81071052, both grants awarded to Professor Dr. Zhao Yang Xiao, Department of Anesthesiology, Xijing First Affiliated Hospital of Fourth Military Medical University, Xi’an, Shaanxi, and Department of Emergency Intensive Care Unit, Second Affiliated Hospital of Dalian Medical University, Dalian, People’s Republic of China.

Compliance with ethical standards

Conflict of interest

All authors attest to the validity and legitimacy of the data and its interpretation, and agree to its submission. All authors have significantly contributed to the manuscript and no person or group of persons who actively contributed were excluded from the study. All authors confirm that they have read and approved the paper, have met the criteria for authorship as established by the International Committee of Medical Journals Editors, believe that the paper represents honest work, and are able to verify the validity of the results reported. All authors state that we have absolutely no conflicts of interest (including financial, consultant, institutional and other relationships that might lead to bias or a conflict of interest). None of the authors received honoraria from a company or were on the speaker’s bureau for any Organization, and there were no sources of financial support, corporate involvement or patent holdings other than above mentioned grants from the Scientific Research Fund of Ministry of Health - Major Plan of Science and from above mentioned departmental sources. There was no support whatsoever from a pharmaceutical company or a manufacturer in any role whatsoever such as editing of the protocol, financial support, drug supply, data analysis or writing of the paper.


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Copyright information

© Springer Nature B.V. 2018

Authors and Affiliations

  1. 1.Department of Anaesthesiology and Intensive Care MedicineMedical University of GrazGrazAustria
  2. 2.Department of AnaesthesiologySarajevo University Clinical CentreSarajevoBosnia and Herzegovina
  3. 3.Department of Emergency MedicineDalian Medical UniversityDalianPeople’s Republic of China
  4. 4.Laboratory of Pharmacometrics, Centre for Drug Clinical ResearchShanghai University of Traditional Chinese MedicineShanghaiPeople’s Republic of China

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