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Deltex Medical's ODM+ is the world’s first fluid management and cardiac output monitoring system to measure both flow and pressure directly

Oesophageal Doppler, PPWA and HD-ICG in one monitoring solution

Deltex Medical’s ODM+ is the world’s first fluid management and cardiac output monitoring system to directly measure both flow and pressure in adults and paediatrics. Exciting new upgrades see the addition of “best-in-class” Pulse Pressure Waveform Analysis (PPWA) and High Definition Impedance Cardiography (HD-ICG) to the proven ODM Doppler flow-based platform.

Oesophageal Doppler

The ODM+ system monitors an unparalleled range of functional haemodynamic parameters. The system is purpose-designed for clinicians to guide fluid and drug administration during surgery and critical care.

The monitor is highly responsive in tracking changes in Stroke Volume and Cardiac Output during intervention. Indeed only oesophageal Doppler has been shown to have the precision to drive the 10% Stroke Volume Optimisation algorithm, widely acknowledged as the basis for Intraoperative Fluid Management (IOFM).

Patients can be continuously monitored for extended periods between intervention and calibration episodes.


The Pulse Pressure Waveform (PPWA) mode is quickly and easily calibrated from the Doppler signal and provides continuous monitoring in postoperative and medical patients in critical care. The highly sensitive “Flow Monitoring Mode” guides intervention, combined with the simpler calibration of a “Pressure Monitoring Mode” for extended continuous monitoring.

In sedated patients, the PPWA algorithm can be recalibrated at any time from the Doppler waveform.


In yet another first, Deltex has added High Definition Impedance Cardiography (HD-ICG), thereby adding a non-invasive central blood flow monitoring option for the awake patient. HD-ICG provides continuous, accurate and sensitive measurements of cardiac output and other haemodynamic parameters.

HD-ICG disposable electrodes are placed on the neck and chest. The electrodes transmit and detect electrical and impedance changes in the thorax. After stabilising, using HD-Z signal filter technology, these electrical currents are then utilised to measure and calculate haemodynamic parameters.

Deltex’s ODM+ leads the haemodynamic monitoring field by combining the real-time accuracy of oesophageal Doppler with PPWA and HD-ICG.

In surgery the CardioQ-ODM+ offers the following advantages:
  • Only surgical CO monitor offering both ODM & PPWA
  • Ease of PPWA calibration and recalibration
  • Continuous monitor ‘bridge’ during diathermy episodes
  • ‘Bridge’ in surgical cases where oesophagus is displaced or removed
  • Only device able to guide 10% SVO (Doppler guided)
  • Offers fluid responsiveness parameters including:
    • Corrected flow time (FTc)
    • Stroke volume variation (SVV –  flow and pressure)
    • Pulse pressure variation (PPV)
  • Provides post operative monitoring for 6 to12 hrs in awake patients in recovery/ICU (dependent on probe type)
In the Intensive Care Unit CardioQ-ODM+ offers the following advantages:
  • Only critical care monitor offering both ODM & PPWA
  • Ease of PPWA calibration and recalibration
  • Continuous monitor capability
  • Only device able to guide 10% SVO (Doppler)
  • Offers fluid responsiveness parameters including:
    • Corrected flow time (FTc)
    • Stroke volume variation (SVV flow and pressure)
    • Pulse pressure variation (PPV)
  • Offers Cardiac power output (CPO) and Cardiac power index (CPI), combined flow and pressure parameters (German regulations indicate a benefit in managing and monitoring patients at risk of Cardiogenic shock)

For further information or for any sales enquires please contact Customer Services quoting part code 9051-7104.

How it Works

The ODM+ monitor measures central blood flow directly by way of a Doppler ultrasound probe. In addition the device takes the standard Arterial Blood Pressure (ABP) measurement and calculates a range of Pressure-Based Parameters. It is unique in that it can take the Cardiac Output as measured by Doppler flow to calibrate a Pulse Pressure Waveform Analysis algorithm. The PPWA algorithm provides secondary pressure based measures of Stroke Volume and Cardiac Output as well as new flow and pressure combined parameters.

By combining both flow and pressure-based measurements, ODM+ allows the user to quickly and simply calibrate and recalibrate from the Doppler flow-based measurements of Cardiac Output. This minimises the inherent weaknesses of PPWA systems.

Access the Training Workbook for a deeper understanding of how to use this technology.

Flow and Pressure Monitoring Modes

The CardioQ-ODM+ user interface provides two new screens for Flow Monitoring Mode and Pressure Monitoring Mode.

Users selecting Pressure Monitoring Mode initially calibrate the parameters by pressing the calibrate button. In a matter of seconds the proven Liljestrand and Zander Pulse Pressure Waveform Analysis algorithm is calibrated from the current flow based Cardiac Output.

Pulse Pressure Waveform Analysis (PPWA)

PPWA is a group of methods which use Arterial Blood Pressure (ABP) as a means of estimating Cardiac Output. The techniques have been called Pulse Contour Analysis, Pulse Pressure Analysis and Pulse Power Analysis, however all are variations in their approach to use ABP to estimate flow. Any measure from the artery includes the changes in pressure associated with changes in arterial function (compliance, impedance etc). Pressure based estimates of Cardiac Output are inherently limited by confounding blood pressure changes which may accompany actual output flow staying the same or decreasing.

Physiologic or therapeutic changes in vessel diameter are assumed to reflect changes in flow. Pulse Pressure (PP) methods measure the combined performance of the heart and the vessels thus limiting the application of PP methods for measurement of flow. This has to be compensated for by regular calibration of the waveform (as CardioQ-ODM+) to another flow measurement method (such as Doppler) and then monitoring the PP waveform. Recalibration is recommended after changes in patient position, therapy or condition, including known or suspected arterial compliance changes.

These methods use characteristics of the pulse pressure waveform to calculate aspects of heart function. The basic Pulse Contour method provides the following information; a. relates to myocardial contractility (similar to Mean Acceleration from Doppler), b. the area under the curve can be calibrated against another source of cardiac output to estimate cardiac output, c. systolic time (similar to Flow Time from Doppler), d. diastolic time.


Uncalibrated pulse pressure devices utilise an algorithm that is based on the principle that pulse pressure is proportional to Stroke Volume (SV). The algorithm uses statistical analysis of the arterial pressure wave to generate an estimate of stroke volume. These systems use a multivariate polynomial equation that continuously quantifies arterial compliance and vascular resistance. By analysing the shape of the arterial pressure waveform, the effect of vascular tone is assessed allowing calculation of SV and Cardiac Output is then derived.

All PPWA systems have limitations in that measurement of pressure in the artery to calculate the flow in the heart is physiologically irrational, simply pressure and flow do not necessarily rise and fall together and often are in opposition. For example, as impedance increases pressure may rise and flow may fall.

The dynamic variables SVV and PPV displayed with arterial pressure monitoring is also limited to patients with an invasive arterial line, who are fully mechanically ventilated, with closed chest, a tidal volume of >7-8 ml/Kg, are in sinus rhythm. Changing the patient’s position or altering PEEP or tidal volumes may alter the ‘cut off’ or ‘grey zone’ threshold.

ODM+ Technical Specification

Find technical specification for the ODM+ monitor here

For detailed information concerning Arterial Lines please click the following link: Arterial Line

Contact Customer Services direct 0845 085 001 to find out more or click here to find your local Deltex Regional Sales Manager or Clinical Sales Specialist.

Further information

Click here to see the range of GCX mounting arms available for attachment of the monitor to the anaesthetic workstation.

Note that when making a connection to the ODM+ to the High End Monitor (HEM), an interface cable is required.  Deltex Medical provide a Blood Pressure (ABP) Cable Guide which is available here; Download Guide.

ODM+ Product Brochure (PDF)

ODM+ Parameters Explained

ODM+ uses proven Doppler technology to control both its Flow Monitoring mode and the calibration of the chosen Pulse Pressure Waveform Analysis (PPWA) algorithm for its Pressure Monitoring mode of cardiac output(CO). The ODM+ system monitors pressure-based and flow-based parameters.