Manfred Müller

Microarrayed allergen molecules: diagnostic gatekeepers for allergy treatment

Type I allergy is an immunoglobulin E (IgE)‐mediated hypersensitivity disease affecting more than 25% of the population. Currently, diagnosis of allergy is performed by provocation testing and IgE serology using allergen extracts. This process defines allergen‐containing sources but cannot identify the disease‐eliciting allergenic molecules. We have applied microarray technology to develop a miniaturized allergy test containing 94 purified allergen molecules that represent the most common allergen sources. The allergen microarray allows the determination and monitoring of allergic patients’ IgE reactivity profiles to large numbers of disease‐causing allergens by using single measurements and minute amounts of serum. This method may change established practice in allergy diagnosis, prevention, and therapy. In addition, microarrayed antigens may be applied to the diagnosis of autoimmune and infectious diseases.

Miniature hearing aid

The housing is essentially spherically shaped, formed with a flattened end wall (14), through which a sound receiving opening (42) extends in axial direction, located eccentrically with respect to the spherical housing. A volume control button (50) covers the sound receiving opening, the volume control button being maintained by a small distance (h) spaced from the spherical end wall to permit entry of sound to the sound receiving opening, while preventing masking of the sound receiving opening by the finger of a user, and free entry of contamination thereto. Preferably, the button is connected to the volume control element by an inwardly extending collar (52) which snaps over an adjustment rim (35) on a volume control positioned axially centrally on a printed circuit board (31) secured within the housing and passing through a central opening (47) formed therein. The flat end wall (14) can be formed with additional openings to permit access to adjustment screwdriver heads (36) of trimmer resistors, the additional openings likewise being masked by the volume control button for protection and to prevent contamination.

Modular hearing aid

A hearing aid has a circuit board having conductor strips thereon; first plug-in elements mounted on the circuit board and being electrically connected to selective conductor strips; a plurality of circuit board-supported modular structural units; and second plug-in elements mounted on each circuit board-supported modular structural unit. The first plug-in elements cooperate with respective second plug-in elements for securing selected circuit board-supported modular structural units on the circuit board.

Audiometer with photo sensitive, digitally tunable, low distortion oscillator

To provide for tuning of an oscillator circuit, a plurality of resistors are selectively connectable in the circuit. To provide for reproducible, accurate oscillation frequency in accordance with switching of a respective resistor in dependence on a digital input signal, electronic switches are respectively connected to the resistors to connect them in circuit in the oscillator to thereby eliminate variable contact resistances of mechanical switches. A digital frequency control signal is generated by placing a movable mask or pattern with openings therein between an array, for example a linear strip of light emitting diodes, and a similar strip of photo transistors, the respective energization of which is determined by openings in the diaphragm. The signals from the photo transistors are stored in a memory, typically a group of flip-flops, for application to the electronic switches controlling connection of the respective resistors in the oscillator circuit.