The award-winning

Humphrey ADE-circle®

the only ultra-low flow universal anaesthetic breathing system

Guaranteed to cut
running costs
BY UP TO
80%

Automatic exhaust valve – no need to close or adjust.
No risk of barotrauma

SO SIMPLE
TO USE
Minimal nurse
training

ALL FRESH GAS
FLOWS ARE
EVIDENCE
BASED

All ventilation
modes including
IPPV &
automatic ventilator

A highly innovative advance in the design of anaesthetic breathing systems.

This anaesthetic breathing system uses the lowest flows compared to all other systems.
For example, in recycling mode with sevo, the minimum flow only 5ml/kg/min!

Two main modes of use:

Semi-closed mode:

Animals under 7kgs

Significant advantages

Circuit factor is 0.5, less than any other system. The T-piece circuit factor is 2-3 i.e. 6 times more!
Only uses a 1/2 litre reservoir bag
ADE-circle® saves an average of 70-80% less fresh gas flow
ADE-circle® saves ALL warm moist airway dead space gas
Uses 15mm smoothbore tubing with special Y connector.
ADE-circle® reduces pollution by using ultra-low flows
Immediate response to vaporiser changes
Automatic, self-adjusting variable orifice exhaust valve, maximum pressure of 2cm of H2O pressure
Lowest resistance compared to ALL other circuits
“PEEP” benefit – ADE-circle® keeps lung alveoli expanded, improving gas exchange and preventing post-op lung infection.
Pressure limiting valve prevents barotrauma
Fail-safe manual IPPV function without having to close the valve
Automatic ventilator mode, simple switch of the lever. Ventilator can be left attached at all times ready for use.
Useful for exotics, birds, zoos and wildlife
Uses both oxygen cylinders and concentrators
Easy scavenging with ADE-circle® valve – no danger of twisting & causing airway obstruction
Easy to use, fresh gas flow chart by weight and simple instructions

Recycling mode:

Animals 7kgs and over

Significant advantages

Circuit factor is 0.1, less than any other system. A conventional circle would be 0.5 at best though longer operations require more with ordinary circuits.
Mainly uses a 1 & 2 litre reservoir bag. 1 litre between 7 and 50 kgs, 2 litre between 50-100kgs, and 3 litre between 100-260kgs.
Easily attached canister
No back flow & loss of fresh gas
Soda lime lasts twice as long
Refilling very simple – just pour & fill
ADE-circle® saves an average of 70-80% less fresh gas flow
ADE-circle® saves ALL warm moist airway dead space gas
ADE-circle® reduces pollution by using ultra-low flows
Immediate response to vaporiser changes
Automatic, self-adjusting variable orifice exhaust valve, maximum pressure of 2cm of H2O pressure
Lowest resistance compared to ALL other circuits
Uses 15mm smoothbore tubing with special Y connector, up to 100kgs. 22mm smoothbore tubing above 100kgs.
“PEEP” benefit – ADE-circle® keeps lung alveoli expanded, improving gas exchange and preventing post-op lung infection.
Pressure limiting valve prevents barotrauma
Fail-safe manual IPPV function without having to close the valve
Easy to use, fresh gas flow chart by weight and simple instructions
Automatic ventilator mode, simple switch of the lever. Ventilator can be left attached at all times ready for use.
Useful for animals over 7kgs including zoos and wildlife – even a lion!
Uses both oxygen cylinders and concentrators

The Royal College of Veterinary Surgeons (RCVS) has accepted that the Humphrey ADE-circle as the sole anaesthetic breathing system required for inspection and regulatory compliance. This designation is grounded in the system’s robust evidence base, which demonstrates its efficacy, safety, and consistency in clinical medical and veterinary applications. The ADE-circle’s design principles are supported by peer-reviewed research and empirical data, confirming its ability to optimise anaesthetic delivery while maintaining minimal resistance and maximal control. As such, the RCVS’s position reflects both the scientific validity and the clinical practicality of the Humphrey ADE-circle in contemporary veterinary anaesthesia.

A revolutionary breakthrough in anaesthesia — the Humphrey ADE-Circle System transforms clinical practice with precision and efficiency. Born from years of intensive research uniting anaesthesia and respiratory physiology, this innovative system has been successfully adopted across major hospitals and the NHS. With over 27 independent, peer-reviewed studies — including those from Great Ormond Street Hospital and The Royal Postgraduate Medical School, London — the Humphrey ADE-Circle stands as a proven advancement in anaesthetic delivery. Its most recent recognition appears in Veterinary Anaesthesia and Analgesia, a leading USA and European journal, underscoring its global scientific credibility. Dr Humphrey has been included in a chapter on his work in recent book in 2021, called “More Notable Names in Anaesthesia”. No other veterinary or medical anaesthetist has such high credentials both in academic or manufacturing world where there are many unsubstantiated claims.  

Award-Winning Design, Pioneering Innovation. The Humphrey ADE-circle system has earned multiple prestigious accolades for its ground-breaking design and engineering. In 1985, it received the Shell Design Award for excellence in design, and in October 1999, it was honoured with an Engineering Design Award from the SABS. Dr Humphrey’s pioneering research on this system also won the top research awards in 1980 from both the Royal College of Medicine London and the Association of Anaesthetists of South Africa.

Still built on its original visionary design, the Humphrey ADE-circle system has evolved with significant enhancements over the years, maintaining its status as the leading solution for the most advanced ultra low-flow anaesthetic multipurpose breathing system.

PROVEN TO BE MORE EFFICIENT & VERSATILE THAN ALL OTHER SYSTEMS & USED BY OVER 5000 VETS AND IN 27 MILLION ANAESTHETICS IN HUMANS

This versatile and simple-to use system covers the range that meets all requirements of a medical or veterinary anaesthetist for good safe anaesthesia.

WE ARE THE GREENEST The Humphrey ADE-circle system® is the most environmentally friendly system. It reduces pollution by using anaesthetic gases at the lowest fresh gas flows possible, usually a quarter of all other systems.

Engineering Award

Design Award

MRI compatible

Made to

Standards

Made to

Standards

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