https://www.secure.biosign.de/

Seems so me the most cost effective solution.

Best, Dan

BIoreactance has been used in athletes (and published in the Journal of Appl Physiol) .

You may bargain the device for free if you pay the consumable for an acceptable number of experiments (20-50$ per patients according to the total number)

Good luck

you may also see the Physioflow (bioimpedance device; http://www.physioflow.com/), validated both at rest and during exercise. Limited in some disease.

Charloux, A., Lonsdorfer-Wolf, E., Richard, R., Lampert, E., Oswald-Mammosser, M., Mettauer, B., ... Lonsdorfer, J. (2000). A new impedance cardiograph device for the non-invasive evaluation of cardiac output at rest and during exercise: comparison with the "direct" Fick method. Eur J Appl Physiol, 82, 313-320.

Tordi, N., Mourot, L., Matusheski, B., & Hughson, R.L. (2004). Measurements of cardiac output during constant exercises: comparison of two non-invasive techniques. Int J Sports Med, 25, 145-149.

why don't you check on the new device from Edwards Lifesciences hemodynamic monitoring. If I remember correctly, the device can do that non-invasively….but not 100% sure (I work for Edwards and could find out)

Best regards

PD Dr. Martin Thoenes

Nyon, Switzerland

We use BIOPAC devices for impedance cardiography. They work quite well and would cost less than the price you quoted. http://www.biopac.com/impedance-cardiography-icg-cardiac-output

Yes, echocardiographic methods as are Doppler assessment (VTI x cross sectional area x HR) and real-time three-dimensional echocardiography based measurents of SV are meanwhile very reliable and effordable.

The answer is probably no unless you can get a company to lone you a machine with dispossibles. Then you have to answer a very critical question, do you want to show accuracy to measure CO or ability to detect changes in CO? None of the current technology is that reliable. If you want accuracy stick with single bolus thermodilution, but invasive. All the other systems require calibration using patient data and assumes everyone is Mr average so depending on your cohort great variability can occur. For showing changes USCOM is undoubtedly the best as it does not use a surrogate like arterial waveforms or electrical resistance changes. It measure flow directly across the valve the area of which is pretty constant and there are no expensive dispossibles. Of course one has to master using the probe to get the correct signal which requires experience and is pretty subjective. With bioimpedance/reactance you have to think about patient factors that will change the electrical flux pathways such as posture and the position of the diaphragm.

Have a look at our paper... I hope it helps. Hill, LK., Sollers, J. J., & Thayer, J. F. (2012). Evaluation of a simple estimation method for the derivation of cardiac output from arterial blood pressure and heart rate. Biomedical Sciences Instrumentation, 107-112.

Hill paper as mentioned above

I have talked to a guy from innovision once, but I have no idea about their pricing. http://www.innovision.dk/Products/Innocor-1.aspx

The answer depends in part on the conditions you want to measure. If you are interested in rest then the impedance methods identified in the other answers are probably your best bet. If you are interested in exercise there are number of non-invasive methods based on the Fick principle for a gas that work well. The CO2 rebreathe method is very good from light through moderate exercise and has the advantage of being based on measures that most respiratory gas exchange systems can make. You can also use non-resident gas methods such as those based on acetylene which are useful for making measures right up to maximal intensity exercise.

There are several references but a good starting place is Warburton, DE et al Sports Med 27(1): 23-41, 1999

For validation of a new approach you probably need something which is accepted as gold standard. Thats only inert gas rebreathing (Innocor) or Echo. The dilemma of absolute values versus relative changes however, remains. Rebreathing requires faster and deeper breathing, which might change your stroke volume values. Echo is difficult to get with normal breathing too and the body position to get access to the apex of the heart is not comparable with being supine. A compromise could be the bioimpedance (Biopac, Niccomo or others) or the pulse contour method using finger blood pressure (Finometer midi, Nexfin etc..). Prices are always high. The only solution is leasing for a short period of time.

If you are studying a patient at rest in the supine position, then an impedance cardiograph (ICG) is a good choice. The BIOPAC device cited above by Philippe Gilchrist is a good research tool. For a device for a clinical setting, the NICCOMO device by Medis (web site: http://www.medis-de.com/index.php?option=com_content&task=view&id=24&Itemid=49 ) would work. ICG is particularly useful for showing relative changes in cardiac output (CO), but there are certain precautions you should take to obtain good absolute values of CO. First, check that an irregular heartbeat is not used to calculate CO. Second, you will have trouble on morbidly obese patients. (The vertical spacing between the electrodes on the thorax may need to be increased for obese patients.) Third, estimate of absolute value of CO is unreliable when CO is very low. These precautions should not be a problem for apparently healthy adults.

An added benefit is the ability of ICG to provide additional measures of cardiac function. (A pertinent abstract is attached.) If you have questions, you may contact me directly by email at [email protected]

Article Using Impedance Cardiography to Detect Asymptomatic Cardiova...

Dear Martin. I think that is necessary to confirm the acuracy of non invasive methods comparing with invasive direct measure. I think the non invasive methods can be an approximate value, but not always with low cost.

Dear Lutz,

what is the condition of measurement: at rest, during physical exercise (at low, moderate, heavy or supramaximal intensity)? The fitness of subjects?

In my lab, we use the Physioflow, i.e electrical thoracic impedance. This device is validated.

I think that the best for you is a trial. Some companies or lab proposed to try devices.

Regards

I believe that echocardiography, using Doppler methods (VTI Ao * cross sectional area * Hr), represents one of the simplest, non-invasive and low cost tool to mesure CO at bedside. Of course, you need to buy the machine, but it is the only big cost and you can use the same tool for many other hemodynamic measurements.

Automated three-dimensional transthoracic echocardiograohy based real-time LV volumetry provides with reliable stroke volume data. This is a push-button approach to cardiac output. The technique is available in several ultrasound units.

USCOM shows an overall good agreement as compared to cardiac magnetic resonance imaging serving as the non-invasive gold standard. However, there is a trend to underestimate CO and measurements are depending on operator training and experience. In terms of accuracy, inert gas rebreathing seems to be the most promising technique for the time being although extreme cardiac output states pose a problem to most devices. Other techniques such as impedance cardiography are superior when it comes to precision.

Article A Novel Noninvasive Ultrasonic Cardiac Output Monitor: Compa...

Echo using the LV outflow tract diameter and tracing the CVTI of the LVOT is a highly acceptable way to do this. Please see recent publications by Boos C et al using echocardiography. Another non invasive consideration is the thoacic bioimpedance eg NICAS.

What about a collaboration with another team (hospital, research group) which have device for measuring CO?

I am happy to help to consider the proposal. I have a portable GE Vivid I which can be used for this type of work on a short term basis only. Regards

pierre may you explain, please, your method in detail? it seems interesting . Sorry if I use this site .. I would mention here that we have realized anew method for HRV analysis. Visit in case the site www.saistmp.com for details and software. It uses plethysmography and by pulse wave I retain we could arrive to estimate CO.

Elio,

you can find more explanation here: http://www.physioflow.com/sm_icg_technology.php.

In my lab, we have the fixed model of Physioflow with analogic output

Regards

Hello Lutz,

Transthoracic electrical impedance is a reasonable method for this kind of study, and it can be quite low cost. If you have a BME department they could probably make you an instrument.

Regards,

Peter

All the main commercial units for measuring cardiac output sell at around that price. Unless you can find an impedance system that measures using ECG electrodes I would think not.

Concerning operating costs, Aesculon (Osypka Medical) might be an interesting option as standard ECG electrodes can be used.

http://www.osypkamed.com/products/monitors/aesculon

I know a less expensive apparatus whose name is pC-ECG, which costs (in my country) about 1000 Euros. If you are interested (i don't want to use the Research Gate window for trade alerts), write me to [email protected]

In 1990 we have published an article dealing with the assessment of stroke volume (which resembles cardia output). The Journal is no longer published. I enclose a copy of that paper, which may be helpful for those being interested.

I do not know whether electrical impedance devices are still commercially available.

Go for Echo. that's the best noninvasive method to assess cardiac output. Although the machine is costly to buy, still you can search and seek help from the institutes having machine and trained personnel.

Hallo

we used years ago the device Cardioscreen. It offera a very accurate non-invaseve CO measurement and it is not so expensive.

www.medis-de.com [email protected] Medizinische Messtechnik GmbH Ilmenau, Germany

www.cardioscreen.de Tel. +49 36 77 – 46 29-0 Fax 0 36 77 – 46 29 29

The TensoScreen® (1) is a computer based monitoring system for continuous non-invasive arterial

blood pressure (CNAP) and Cardiac Output (CO) measurement. The device can be used with any

PC on which the CardioScreen Software has been installed.

Depending on the configuration the TensoScreen® can be operated as a single device with

Impedance Cardiography (ICG) as well as in combination with a CardioScreen® 2000 or

Niccomo™ system to establish a highly sophisticated cardiovascular monitoring system.

Software

The CardioScreen Software provides an easy and clear presentation of the measured parameters

and curves. In the trending screen changes of the patient’s status can be observed. An integrated

database allows the offline analysis and evaluation.

Device

TensoScreen® equipped with all

available options:

• ICG (Impedance Cardiography)

• NIBP (non-inv. Blood Pressure)

• CNAP (cont. Arterial Pressure)

As a cerdiologist the only method I can reasonebly advise to Yuo is echocardiography. Mentioned cost od US device seems to be too high, I'm sure You can find not so expensive apparatus . If your only aim is to evaluate CO you can choose a quite simple model of echocardiograph ( it may be also refurbished). You will get a reliable and widely approved method. On the other hand you will need a qualified person to perform an ivestigation. Best regards

Yes, there is a reliable ICG tool for measuring CO, SV, TPR, TBW etc..

I reccomend you to be in direct touch with Raya, e-mail: [email protected]

I've a very good experience with this instrument.

Yours,

Prof. E. Klainman, mail: [email protected]

If you do not need to eveluate CO in real time, you can use ejection fraction ratio by using USG dopler in a cardiology clinique.

Yes, I'd recommend the ICG instrument in our laboratory use. For more specific details it will be better to be in contact with Raya trough e-mail: [email protected]

Determination of EF just represents one aspect of cardiac function and does not allow calculation of TPR. When being restricted to echocardigraphy, determination of CO using VTI and LVOT area would be an interesting option. Nevertheless, this basically is what the USCOM does, however, omitting the 2D visualization and taking LVOT diameter from nomogramms.

I've just developed an App to measure advanced hemodynamic parameters through your smartphone: Capstesia. You need to take a picture of a-line curves of patient monitoring screen with your phone, and this App will digitize, analyse and show PPV, CO, dP/dt... trend charts, derivated parameters...

I think it is an interesting way to find and easy tool for many patients in need.

You can use this device with pletysmographic waves to get POP variation.

You will find more information and a video in:

www.capstesia.com

Hi Borja

Interesting approach. Couple of questions: 

1) does your system do sample averaging over the number of captured pulse pressure cycles? 

2) what's your algorithm's approach to derive stroke volume? And have you been able to validate? Is this published?

I will probably have more questions, but these are the ones which come immediately to mind. 

Cheers

Lutz

Hi Dr Kraushaar.

I'm glad you find interesting this App.

Regarding the questions:

1) Yes, both CO and dPmax / dt is an average of the results for each curve. PPV is calculated of curves which appear in the picture (We suggest to include 6-8 waves).

2) PPV = PPmáx - PPmin / PPmax + PPmin / 2 x 100; CO is related to the area under the curve up to the beginning of the dicrotic wave.

Currently, there are  two validation studies running (in USA and Spain, this last in our hospital). But we would be happy to support any new study.

We have an article published this month in the Spanish Journal of Anesthesiology.

Any suggestions or questions, feel free to send to me.

I think this App opens a door to an cheap and available way to goal directed therapy.

Thanks.

Borja.

Hi Borja

Thanks for the prompt reply and detail. May I ask, what is the reference method for validating the CO in your 2 studies?

Cheers

Lutz

I'm trying to validate the method, I mean, I'm comparing my software analysing the curves through a computer and through Capstesia, to show that this way is right.

The american study is a clinic assay, but I can't provide more information about it.

Thanks for your interest in our App.

Borja.

I do not think so.  Reliability is the problem, but I am not up to date on validation studies.

Thanks, Mark. That's the conclusion I have come to, too, after having investigated and tried several methods.