GM Instruments

GM Instruments

GM Instruments was formed in 1992 by Eric Greig to concentrate on the design and supply of specialist ENT (ORL) electronic instruments and accessories. The initial instrument range focussed on applications which required flow and pressure measurements but rapidly expanded into 3 product categories:

1) Audiometry

2) Nasal Congestion measurements

3) Respiratory Flow measurements


Innovation, prompted by PC development and interaction with medical people working in the field, led to the first versions of the ASRA (automatic self recording audiometer).

This was initially designed in conjunction with personnel from the University of Glasgow and with clinical/diagnostic applications in mind, but it soon became clear that most people working in audiology were not ready to accept such an advanced machine, the like of which has only now started to be used within the past few years. The market potential within industry for an accurate and fully automated screening audiometer, which also performed result categorisation, soon became apparent and significant sales followed.

Our involvement in nasal measurement first came with a rhinomanometer, which measures nasal air flow and pressure to calculate resistance. Before the formation of GM Instruments Eric was involved with Mercury Electronics who introduced the first computer based rhinomanometer (working with a BBC model B computer in 1982). PC based versions running with Windows 3.1 came along in the early 1990's, and have continually been improved and changed to the present day, now running under Windows 8.

Acoustic Rhinometry was the next nasal measurement instrument to follow (again in the early 1990's) and was developed in conjunction with personnel from the University of Aarhus (Denmark). As with rhinomanometry, development has continued to the present day, with improvements in accuracy and reductions in size being achieved.

Rhinospirometry came along in 2006, following the development of prototype units by GMI and the University of Cardiff and successful clinical trials at hospitals local to them. This unique instrument can be used to determine whether or not someone with a deviated septum will benefit from surgery. The potential to save some patients unnecessary trauma and the hospital expense, is significant.

Respiratory Flowheads, sized appropriately for adult use, have become a significant product for GMI with OEM applications in Physiology teaching, Speech analysis systems and home therapy instruments. Our range however is much wider than that with flowheads capable of monitoring the flows produced by baby mice at one end of the scale, up to small horses at the other. Applications in a wide range of research fields are appropriate and constantly provide interesting challenges for us.

The technology required to produce the above instruments has led to the design of further new products, some of which will be released in the near future.

GM Instruments Limited has been assessed and registered by AMTAC Certification Services Limited as conforming to the requirements of: ISO 9001:2008 and EN ISO 13485:2012. The quality management system is applicable to: Design, Manufacture and Inspection of Ear, Nose and Throat diagnostic devices.

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