A practical guide to post-laryngectomy
vocal and pulmonary rehabilitation - Fourth Edition
Provox FreeHands HME automatic speaking valve
This device consists
of a disposable HME cassette as its indispensable core with a reusable
multi-magnet automatic speaking valve on top. The HME can be secured to
the bottom of the speaking valve to ensure proper retention in the housing
of the adhesive attached to the peristomal skin and is removed by ‘cracking’
the cassette when it needs changing (at least every 24 hours). The HME
is deliberately placed underneath the valve to ensure protection of the
valve against mucus contamination in case the patient coughs up phlegm.
The reusable automatic speaking valve contains a silicone
membrane, which can occlude the side opening of the device and has a magnet
at its tip. The valve has two positions. In the ‘talk’ position the membrane
can move freely; in the ‘walk’ position (achieved by rotating the device
750 in the housing) the membrane magnet locks against an eccentrically
placed pin, preventing closure of the membrane during physical exertion.
This membrane magnet, in combination with a second magnet near the side
opening, keeps the membrane closed during speech, facilitating voicing
with a low trachea pressure. Furthermore, on top of the device there is
a cough-relief valve, which is hinged with elastic silicone bands. This
valve opens during coughing, to release the pressure built up in the trachea
and to diminish the possibility of the adhesive coming loose. The cough-relief
valve is closed by means of magnets, which allow adjustment of its opening
pressure by varying the distance between the magnets. Preferably, the
Speech-Language Pathologist (SLP) makes this adjustment for the patient
(using the special screwdriver that comes with the system), to achieve
a sufficiently high gradient between the pressures needed for closure
of the speaking valve and for opening of the cough-relief valve. For adhesion
to the skin, patients can use the adhesives for the Provox HME system,
or a special cannula (LaryTube; Atos Medical AB, Sweden). Three types
of easily exchangeable, color-coded membranes are available: white (most
flexible), green (least flexible), and blue (intermediate flexibility).
Together with the SLP, the patient selects the most comfortable and efficient
membrane for voicing. In our development study group, 6 patients chose
the white membrane, 9 the blue one, and none selected the green version.1
The airflow resistance of the HME is adapted to its combination
with the automatic valve, which has some airflow resistance of its own.
A special container is provided for cleaning the device (overnight) with
a standard denture cleanser.