View Full Version : FW: biomech-l summary

11-27-2009, 04:40 AM
Dear BIOMCH-L subscribers:

I sent out a request for help regarding information for portable oxygen consumption systems a couple of weeks ago. The original post is as follows:

I am a pre-registration clinical scientist working in a gait laboratory in Southwest London, UK.
We are currently looking to purchase a new portable oxygen consumption system for our lab and would like to request your views / opinion on a number of products.

Currently, we have been looking at 4 different systems: The Cosmed K4b2, the Oxycon Mobile, The Cortex Metamax and the VO2000 from Medical Graphics.

I found a similar request in the biomech-l archives made by another subscriber back in 2004, who reported a number of comments from subscribers regarding the Cosmed, Metamax and VO2000 products. But at that time, she received no comments about the Oxycon Mobile, possibly because it was a fairly new system.

I was wondering if anyone had any experience (good or bad) with the Oxycon Mobile that they would be willing to share. In particular on how easy it is to use, maintenance / repairs issues recurring costs and reliability.
I would also welcome any further comments on the other systems as it is 5 years since the previous request for information and any problems identified at that time may now have been rectified.

We would greatly appreciate any suggestions / recommendations you have

Thank to all subscribers who responded to my request. I also sent out a similar information request to members of the Clinical Movement Analysis Society (www.cmasuki.org) which I thought may also be helpful to share.

Below is a summary of all the responses received:

Oxycon Mobile
“conducted validation experiments initially and found good agreement between the Mobile and our Parvo metabolic cart during exercise”
“Clearly, the strength of the system is it's portability”
“software relatively easy to use during standard data collection protocols, but not particularly user friendly when customizing the system. More importantly, we have discovered several software bugs that took some time to resolve”
“Although the technical support team was helpful, they often had to wait for engineers in Germany to provide solutions. As a result, we had delays in collecting data. We seem to have resolved most of the problems now and the system works fine”
“All in all, we have been moderately satisfied.”

“We have had the Oxycon Mobile for a couple of years and it has worked well for us”
“Operation is easy and mostly dependable”
“critical to fit the face mask well to the subject”

“compared the Oxycon Mobile with a SensorMedics VMax29c and there appears to be some differences in data values between the two instruments“

“Carefusion team in UK - very helpful”
“Training - very good. Had to be clear what we wanted the system for, rather than what the system was capable of doing. “
“Calibration - much more helpful in terms of understanding what is happening.”
“Software - more sophisticated than cosmed, but easy to use once you get used to it. The training session will include them setting up the front page measurement page with the parameters you are interested in and creation of custom reports.”
“Oxycon comes with own sterilisation kit - not sure about new cosmed system”

“used to have a Jaeger Oxycon Pro desktop analyser and based on the atrocious reliability and the shocking level of support i would never recommend or buy jaeger again”

Cosmed K4b2
“It works only periodically, data is not reliable, the calibration procedure often fails, our brand new batteries last 20 minutes instead of the reported 2 hours from Cosmed, the sampling pump has begun to intermittently pump, it often does not establish a connection to the computer, 2000USD on a hardware upgrade which has not fixed the problems that it was supposed to. “
“In addition to all this, the unit is frequently shipped to the company for which we pay shipping, and of course cannot be used at that time. “
“We are not at all happy with the unit.”
“The system works well and is relatively easy to use.
“The operating manual can sometimes be a little confusing as it is a translation from Italian into English.”
“Even so, this is still a good system and we will continue to use it.”
“We use a K4b2 from Cosmed. It is very easy to set up ( you can only plug each lead into one place which is helpful)! “

“Originally purchased ~12 years ago and using up until last year.”
“Technical support not particularly satisfactory as UK distributors didn’t necessarily know how to fix problems. Ended up contacting Italy direct But problem when things went wrong in August as the factory was closed!”
“Cosmed yearly charge is high but normally includes shipping, replacement of components, software updates and oxygen cell.”

“often found cosmed hid information in obscure places in their file structure”

Cortex Metamax
“other than the usual replacement of o2 sensors and gas lines it is a very reliable system for a portable unit”

“Relationship with Cranlea very good - very helpful”
“Havent had any major hardware issues - mainly due to user error (connections can be fidely, but actually less of a problem with the ambulatory system)”
“Cranlea always very helpful and supportive AND they are based in the UK”

MedGraphics VO2000

“Our experiences with the MedGraphics VO2000 was about 10 years ago and we had a lot of problems with it”
“think they have a new system but this might not yet be well established so query software and hardware updates and things going wrong. Also query available support”


The three front runners for portable oxygen consumption equipment still seem to be the Metamax, K4b2 and the Oxycon Mobile. There doesn’t seem to be a lot of current experience with the MedGraphics VO2000, so I guess the only way to evaluate would be to test it ourselves.

The comments on the K4b2 and the Oxycon Mobile are mixed, with both good and particularly bad experiences reported. From the responses received, there were only good reports on the Metamax, but fewer centres responded.

>From a functional view, all three systems appear to offer the same measurement features with not a lot to choose between them.

It is clear from the responses that the technical support available is a particularly important consideration. That is both in terms of the cost of repairs and consumables and also the knowledge of the technical support team. And lets be honest, no system is perfect so you can expect to have to contact the suppliers at some point during its lifetime for help. A number of subscribers also commented on the importance of finding out if equipment is being used in labs local to where you are, for somewhere to get advice and help when something goes wrong.

Finally, these systems all look good on paper, but it is important to get the companies to bring the equipment to your workplace for a demonstration session and if possible ask to keep it for a week to trial. Then you will be able to make your own judgements on how easy it is to use.

I hope this summary has been helpful to others

Helen Wheeler
Pre-Registration Clinical Scientist
Gait Laboratory
Queen Mary’s Hospital
Roehampton Lane
London SW15 5PN
020 8487 6101
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