A possible application of such breathing masks is represented by so-called CPAP (continuous positive airway pressure) respirators. Patients who require breathing support for various reasons, for example, sleep apnea or COPD (chronic obstructive pulmonary disease), are frequently treated with such CPAP respirators. A settable overpressure for supporting the respiration is made available here to the patient. The supply is usually with constant pressure over the entire breathing cycle, the pressure set being made available for a breathing mask. These breathing masks are usually designed as nose or mouth-and-nose masks, which are connected with flexible tubes for supplying breathing gas, via which the supply takes place from a CPAP device. The air to be breathed in is drawn in for this purpose by the CPAP device usually through a filter arranged in the front and is sent under a slight overpressure into the flexible supply tubes. The breathing air breathed out usually escapes through an expiration valve, which is frequently directly integrated with the mask. In addition, a humidifier or a combined heat/humidity exchanger may be optionally present. The devices are frequently designed such that the breathing gas must be led over rather long flexible tubes.
Acceptance of the auxiliary means used, which is determined by the comfort, safety and problem-free integration in everyday life, is especially important in case of applications whose consistent implementation is extensively the responsibility of the user.
If longer flexible tubes are used to guide the breathing gas, these must have a considerable cross section with a diameter of approx. 15 mm to 20 mm in order to have tolerable flow resistances. A desired constancy of the pressure in the area of a patient's nose can be achieved only if pressure measurement is performed in the mask or if the pneumatic resistance of the flexible tubes is kept so low that the pressure drop is sufficiently low in case of the volume flows necessary for the desired breathing support. An additional signal is to be transmitted pneumatically or electrically in case of pressure measurement in the mask. Furthermore, highly dynamic adjustment of the pressure source in the breathing support device is necessary. This increases the technical effort and consequently the costs. Moreover, the flexible tubes hinder the mobility of the user of the mask. Furthermore, the flexible tubes create a highly technical impression and thus compromise the recognizability of the patient's face with its characteristic zones, especially the area around the eyes. As a result, an inhibition threshold may be built up, which prevents regular use in everyday life.
There have been attempts at arranging portable devices for breathing support close to the patient in order to eliminate the above-mentioned drawbacks. A device of this class has been known from DE 102 10 878 A1. A miniaturized breathing support device with a suction filter was integrated directly in a mask body in this device.
A breathing support device carried by the patient also must meet high requirements concerning safety besides the requirements in terms of overall size, weight, the avoidance of noise and energy supply.
The risk of coverage of the suction openings represents a possible source of error and a safety risk especially for breathing support during sleep. This also applies to devices according to the state of the art which are integrated in the mask body.