Patent DE-19808105-A1 (DE)
Title: Individual breathing mask for patients with breathing difficulties
IPC: A61M16/06
Filed: 1998-02-26
Abstract: To produce an individual breathing mask, a hard shell (14) is made by modeling directly at the patient's features, using a malleable material which hardens.  The model, covering the required area of the face and mouth, is allowed to set and harden. After the hard shell (14) has set, an inner padding (16) is applied using a material which remains soft, as a lining between the hard shell (14) and the areas of the patient (4) where the mask is fitted directly at the patient. The mask material is a plastics which is set by ultra violet light such as Kulzer Paladisc(TM). The mask material can be modeled as a shell to cover the nose and its bridge, half the cheeks, the mouth and chin zones almost to the neck, to form a mouth mask, or it can be structured into a nose mask with an integrated end support.  The hard shell has a laying surface of at least 15 mm for a nose mask and at least 20 mm circular for a mouth mask and/or the shell material has a thickness of 1.0-1.5 mm over its whole surface. Before modeling a nose mask, the nostrils are tensed by inserted cellulose strips, and the like, and a model is made of the dead zone before the shell is modeled, to cover the tip of the nose and the nostrils to end shortly under the nostril openings, and especially shaped under them. The shell (14) has a reinforcement layer (15) of the same material as the shell, 1.0-1.5 mm thick. The shell material is initially hardened at the patient by a portable ultra violet light unit, and then it is removed for final hardening in a light apparatus, and the reinforcement layer is fitted to the hardened shell. Breathing holes are fitted to the hard shell, in the case of a nose mask, and a silanized twist connector is fitted which can rotate by 360 deg  to the air holes, or an angled connector is fitted projecting forwards for upright patients. The outer surface of the individual mask and its reinforcement layer can be painted, polished and/or otherwise treated. Mountings are fitted to the hard shell, for the holding straps, using silanized wire clips of a chrome-cobalt-molybdenum alloy, held in place by a secondary adhesive or a light-hardened paste. Before modeling, the patient's face is shaved if required, and a barrier is applied to the skin such as of Vaseline(TM) (petroleum jelly), especially at the eyebrows where it is rubbed thickly in place and/or a non-setting material is laid over the relaxed eyes. To form the lining, the hard shell is rotated on the patient's skin, to press surplus soft lining material out between them. When the lining material has set partially, the mask is lifted clear of the patient for final lining setting. Surplus material is removed from the mask edges and the dead zone by grinding or a hot knife. An additional weight can be fitted to the tip of the nose, in a nose mask. The hard shell and the soft lining for the individual mask are modeled on a prone patient.  For a wider mask coverage area, the mouth mask is prepared before the nose mask, to give a mask cap structure. An intermediate piece for insertion between the jaws, if required, is molded from a chrome-cobalt-molybdenum alloy. The bars for the upper and lower jaws are separate and of loose plastics matter together with a bar between the jaws, for use before modeling when the patient wears dentures which have been removed. The retention end (13) has a fixture (9) extending from the mouth and/or is secured to the hard shell (14) by polymerizing such as with a pattern resin. An Independent claim is included for an individual breathing mask, with a hard shell (14) modeled directly from the patient's features.