A common user interface
The Ventilation Cockpit user interface on all Hamilton Medical ventilators is operated in the same way - independent of the device and its use in the ICU, in the MR suite, or during transport.
Designing a better user interface
In recent years, the capabilities of modern ICU ventilators have increased, leading to improved performance. These changes also increased complexity and the amount of data that clinicians need to process. As a result, more and more clinicians ask for more intuitive user interfaces (Richard 2009).
When Hamilton Medical designed the Ventilation Cockpit user interface, our engineers worked in close cooperation with users, ventilation experts, and usability specialists. We identified three important issues that required improvement:
- Because of different operating concepts, switching between different devices is difficult – for example, between a transport ventilator and ICU ventilator.
- Monitored data displayed as numbers and curves is difficult to interpret.
- Assessment of weaning criteria is difficult with conventional monitoring.
The Ventilation Cockpit — commonality in interface design
When designing the Ventilation Cockpit, we looked at parallels in other fields of work: manufacturers of aircrafts aim at providing commonality by using identical cockpits across several airplanes. This allows a qualified pilot to fly any aircraft with the same cockpit at any time – independent of the size of the airplane (Airbus 2014). The results are reduced effort and costs required for training and increased flexibility. Similarly, the Ventilation Cockpit on Hamilton Medical ventilators is operated in the same way – independent of the device and its use in the ICU, in the MR suite, or during transport.
Studies have shown that numerical and waveform displays do not optimally support clinicians. A more helpful alternative provides graphical displays that integrate data into visualizations (Drews 2006). In aircraft cockpits, complex data is integrated and visualized on large screens. The Ventilation Cockpit common to all Hamilton Medical ventilators features similar visualizations.
Dynamic Lung panel
The Dynamic Lung panel is part of the Ventilation Cockpit. It displays the following important monitoring data in real time:
- Tidal Volume: The Dynamic Lung expands and contracts to show tidal volume in real time. It moves in synchrony with actual breaths, based on the proximal flow sensor signal. The lung size shown is relative to the "normal" size for the patient’s ideal body weight (IBW).
- Compliance: The Dynamic Lung shows compliance (Cstat) breath by breath relative to “normal” values for the patient’s height. The shape of the lungs changes with compliance. The numeric value is also displayed.
- Patient triggering: The muscle in the Dynamic Lung shows patient triggering.
- Resistance: The bronchial tree in the Dynamic Lung shows resistance breath by breath relative to “normal” values for the patient’s IBW. The numeric value is also displayed. The gray portion of the image shows the relative degree of resistance.
If the SpO2 option is installed and enabled, the panel also shows SpO2 and pulse rate.
Vent Status panel
The Vent Status panel displays six parameters related to the patient’s ventilator dependence, including oxygenation, CO2 elimination, and patient activity. A floating indicator moving up and down within the column shows the value for a given parameter. When the indicator is in the light blue weaning zone, a timer starts, showing how long that value has been in the weaning zone. When all values are in the weaning zone, the Vent Status panel is framed in green, indicating that spontaneous breathing trials should be considered. The panel is updated breath by breath.
You can define the weaning zone ranges during configuration of the device to adapt it to the weaning protocol of your institution.
User-friendliness of medical devices has only recently gained interest from the scientific community. Thus, few relevant studies are available today.
- Current numerical and waveform displays do not optimally support clinicians (Drews 2006).
- Clinicians detected and treated adverse respiratory events faster with graphical rather than conventional displays. They also reported a perceived decrease of workload (Wachter 2006).
- In a study that evaluated the user-friendliness of seven ICU ventilators, the HAMILTON-G5 was scored by physicians to be the easiest to use (Vignaux 2009).
Availability of the Ventilation Cockpit
The Ventilation Cockpit is standard on all current Hamilton Medical mechanical ventilators.
Airbus [Internet]. Blagnac: Airbus; [no date, cited 2014 Oct 28]. Available from: http://www.airbus.com/innovation/proven-concepts/in-design/commonality/
Drews FA, Westenskow DR. The right picture is worth a thousand numbers: data displays in anesthesia. Hum Factors. 2006 Spring;48(1):59-71.
Richard JC, Kacmarek RM. ICU mechanical ventilators, technological advances vs. user friendliness: the right picture is worth a thousand numbers. Intensive Care Med. 2009 Oct;35(10):1662-3.
Vignaux L, Tassaux D, Jolliet P. Evaluation of the user-friendliness of seven new generation intensive care ventilators. Intensive Care Med. 2009 Oct;35(10):1687-91.
Wachter SB, Johnson K, Albert R, Syroid N, Drews F, Westenskow D. The evaluation of a pulmonary display to detect adverse respiratory events using high resolution human simulator. J Am Med Inform Assoc. 2006 Nov-Dec;13(6):635-42.