Method and apparatus for examining human periodontal tissues

Apparatus for examining the human periodontium in which a force acts on the tooth to be examined and the movement of the tooth resulting from the force is determined, the force being transmitted to the tooth by a rigid tube medium sliding in a transducer head and the deflection of the tooth is measured, comprising:

• a conductor through which current flows;
• a means for producing magnetic flux passing through the conductor at right angles;
• a source of supply of electric current connected to the conductor such that the flux density of the magnetic flux is constant within a certain area in the direction in which the resultant force acts between the rigid medium and the transducer head;
• and
• a dynamic displacement pickup installed in the transducer head including a coil connected to the tube and a permanent magnetic circuit having an air gap in which said coil is movably located, and in which the pickup coil is interconnected with a filter and integrator serially arranged, the integrator output being fed to a first pair of deflection plates of a cathode-ray tube;
• and an electric signal proportional to the sinusoidal current through the force coil is connected to a second pair of deflection plates of the cathode-ray tube.

Apparatus for examining the human periodontium in which a force acts on the tooth to be examined and the movement of the tooth resulting from the force is determined, the force being transmitted to the tooth by a rigid tube medium sliding in a transducer head and the deflection of the tooth is measured, comprising:

• a conductor through which current flows;
• a means for producing magnetic flux passing through the conductor at right angles;
• a source of supply of electric current connected to the conductor such that the flux density of the magnetic flux is constant within a certain area in the direction in which the resultant force acts between the rigid medium and the transducer head;
• and
• a dynamic displacement pickup installed in the head;
• and transducer head including a coil connected to the tube and a permanent magnetic circuit having an air gap in which said coil is movably located, in which the pickup coil is connected in series with a filter, an integrator and a phase detector, said detector having a control input including the sinusoidal current from the force coil.

Apparatus for examining the human periodontium in which a force acts on the tooth to be examined and the movement of the tooth resulting from the force is determined, the force being transmitted to the tooth by a rigid tube medium sliding in a transducer head and the deflection of the tooth is measured, comprising:

• a conductor through which current flows;
• a means for producing magnetic flux passing through the conductor at right angles;
• a source of supply of electric current connected to the conductor such that the flux density of the magnetic flux is constant within a certain area in the direction in which the resultant force acts between the rigid medium and the transducer head;
• and
• a dynamic displacement pickup installed in the transducer head including a coil connected to the tube and a permanent magnetic circuit having an air gap in which said coil is movably located, in which the pickup coil is serially interconnected, in the order stated, with a filter, and an integrator, the output of the integrator is supplied to both first and second phase detectors, the control inputs for said phase detectors being two electrical signals taken from the sinusoidal current through the force coil and having a respective phase relationship of 90.degree..

Apparatus for examining the human periodontium in which a force acts on the tooth to be examined and the movement of the tooth resulting from the force is determined, the force being transmitted to the tooth by a rigid tube medium sliding in a transducer head and the deflection of the tooth is measured, comprising:

• a conductor through which current flows;
• a means for producing magnetic flux passing through the conductor at right angles;
• a source of supply of electric current connected to the conductor such that the flux density of the magnetic flux is constant within a certain area in the direction in which the resultant force acts between the rigid medium and the transducer head;
• and
• a dynamic displacement pickup installed in the transducer head including a coil connected to the tube and a permanent magnetic circuit having an air gap in which said coil is movably located, in which the pickup coil is serially interconnected, in the order stated, with a filter and an integrator, the output of the integrator is supplied to both first and second phase detectors, the control inputs for said phase signals taken from the sinusoidal current in the force coil and having a respective phase relationship of 90-degrees;
• the output of the first phase detector is applied to a pair of deflection plates of a cathode-ray tube, and the output voltage of the second phase detector is applied to the other pair of deflection plates of the cathode-ray tube.

Apparatus for examining the human periodontium in which a force acts on the tooth to be examined and the movement of the tooth resulting from the force is determined, the force being transmitted to the tooth by a rigid tube medium sliding in a transducer head and the deflection of the tooth is measured, comprising:

• a conductor through which current flows;
• a means for producing magnetic flux passing through the conductor at right angles;
• a source of supply of electric current connected to the conductor such that the flux density of the magnetic flux is constant within a certain area in the direction in which the resultant force acts between the rigid medium and the transducer head;
• a dynamic displacement pickup installed in the transducer head including a coil connected to the tube and a permanent magnetic circuit having an air gap in which said coil is movably located;
• and
• a cap of a ferromagnetic material open at the sides is attached to the crown of the tooth to be examined and a magnet attached to the end of the tube temporarily connects the tube with the tooth during the examination.