The basic problem: two air paths, one patient connector
With mechanical insufflation/exsufflation (MI-E, the switch between positive and negative pressure that supports the cough thrust in the cough assist device) and with oscillating airway clearance therapy, air has to flow in two directions: in towards the patient, and back out again, carrying secretions with it. Depending on how a device is built, this can be solved in different ways. Both BiWaze Cough and BiWaze Clear work with a dual air path that keeps inhaled and exhaled air separate [1][2]. This is not a new feature of these devices, it has been their working principle from the start.
What is new is the way this dual path can be built structurally: as a Dual Lumen Breathing Circuit, that is, a tube within a tube. An inner tube carries one air stream, and the outer ring-shaped space around it carries the other. At the patient, both come together at a single, shared connector; towards the device, the two paths stay separate right up to their respective connection ports.
What the Dual Lumen Breathing Circuit actually is
The same basic principle applies to both devices, though the function behind it differs:
- With BiWaze Cough: the dual air path separates inhaled and exhaled air [1]. According to the manufacturer, this reduces the risk of cross-contamination between the two air streams [1] and allows more targeted control of pressure and flow during therapy [1].
- With BiWaze Clear: a dual-lumen filter and breathing circuit system likewise separates the inhalation and exhalation paths [2]. Sensors in each path measure pressure and flow to keep the programmed therapy stable [2].
Why separating the air paths matters at all
The reason for the dual air path is not simply a matter of comfort. Secretions that the patient brings up while coughing or during exsufflation (the active suction of air that reproduces the cough thrust) should not be carried back through the same path used for the next inhalation. For the BiWaze Cough, this means the dual air path can lower the risk of cross-contamination [1]. For the BiWaze Clear, the separated paths are described as the basis for measuring pressure and flow in each path individually and adjusting therapy accordingly [2].
Who this is relevant for
The Dual Lumen Breathing Circuit is intended for the same areas of use as the devices themselves: nursing staff and respiratory therapists who use BiWaze Cough with patients who have a weak or ineffective cough due to reduced mobility or diaphragm weakness [1], and anyone using BiWaze Clear for secretion mobilisation, lung expansion therapy, or the treatment and prevention of atelectasis [2]. The indications for either device do not change with the new circuit set; it is an additional accessory option for the existing scope of use.
Whether a Dual Lumen Breathing Circuit or a classic dual-tube set is the better choice in a given case depends, among other things, on the patient setting and on handling at the bedside. The instructions for use of the respective devices give no blanket recommendation for particular patient groups on this point; the choice remains up to the user on site.
What to clarify before requesting one
Anyone wanting to use the Dual Lumen Breathing Circuit should first clarify which of the two devices, BiWaze Cough or BiWaze Clear, the set is needed for, since it is device-specific accessory. Also relevant: the CE marking applies to the European market and to all regions that recognise CE marking. Questions about compatibility with existing devices, replacement intervals, or reprocessing are best clarified directly using the current instructions for use of the relevant device. Alternatively, you are welcome to contact us or your distribution partner.
If you would like to know whether the Dual Lumen Breathing Circuit fits your setting, your patient population, or your existing workflows, please get in touch. We are happy to put you in contact with your local partner, arrange a hands-on demonstration at the device, or answer technical questions about setup, handling, and reprocessing directly.
Sources
[1] BiWaze Cough User Manual, EU (multilingual), Abschnitte zum dualen Luftweg / IFU
[2] BiWaze Clear User Manual, Abschnitte zum Doppellumen-Filter- und Atemschlauchsystem / IFU
Note
This article is provided for professional information and does not replace clinical judgement. Statements on device settings are orientation only; the device's instructions for use and the assessment of the treating clinician prevail.
Frequently asked questions
Is the Dual Lumen Breathing Circuit the same for both devices?
The basic principle, a tube within a tube with a shared patient connector, is the same. However, the exact design is device-specific, since BiWaze Cough and BiWaze Clear have different connector geometries and therapy principles. A set for BiWaze Cough does not automatically fit BiWaze Clear.
Do I have to replace my existing standard circuit set?
No. The Dual Lumen Breathing Circuit is an additional accessory option, not a mandatory changeover. According to the manufacturer, both options remain available.
Does the Dual Lumen Breathing Circuit change anything about how the device is set up?
The manufacturer's documentation describes the Dual Lumen Breathing Circuit as an accessory for air routing, not as a change to the therapy parameters. Settings for pressure, flow, or cycle times are still primarily based on the patient's condition.
Where can I find details on cleaning and replacement intervals?
This information is in the current instructions for use for BiWaze Cough or BiWaze Clear, respectively. If you have questions about this, we are happy to help directly or to put you in touch with your local partner.
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