Device for in vivo measurement of pressures and pressure variations in or on bones
First Claim
1. Device for the in vivo measurement of pressures and pressure variations in or on a body, more particularly inside or outside bones or on dental implants, the device comprising an implantable probe and an evaluating unit, characterized in that the probe (1;
- 33) comprises an oscillating circuit (L-C) including a pressure sensor (8, 30) and a coil (13), and the evaluating unit (3) comprises a resonance oscillating circuit (7) capable of detecting the natural frequency (Fe) of the oscillating circuit, the natural frequency (Fe) of the oscillating circuit (L-C) being determined by the momentary pressure acting on the pressure sensor (8), or variable according to variations of a dimension of the pressure sensor (8) caused by pressure variations, and capable of being detected, and the pressure sensor (8, 30) being in the form of a capacitor having a deformable membrane (9), spatially separated from the coil (13), and connected thereto by an electric conductor (15, 31, 35).
0 Assignments
0 Petitions
Accused Products
Abstract
The device for the in vivo measurement of pressures and pressure variations in or on the human or animal body, more particularly inside or outside bones, is composed of an implantable probe (1) and of an evaluating unit (3), the probe (1) comprising an oscillating circuit (L-C) including a capacitor in the form of a pressure sensor (8, 30) and a coil (13), and the evaluating unit (3) comprising a resonance oscillating circuit capable of detecting the natural frequency (Fe) of the oscillating circuit, is variable according to variations of a dimension of the capacitor caused by pressure variations. The pressure sensor (8) is spatially separated from the coil (13) and connected to the latter by an electric conductor (15). On one hand, this allows small dimensions of the implantable pressure sensor, and on the other hand, a clear signal transmitted over a relatively long distance. In the first place, such a measuring device allows to monitor the accretion of a bone to a prosthesis, or quite generally, to detect the behaviour of a bone or another organ e.g. under load.
-
Citations
13 Claims
-
1. Device for the in vivo measurement of pressures and pressure variations in or on a body, more particularly inside or outside bones or on dental implants, the device comprising an implantable probe and an evaluating unit, characterized in that the probe (1;
- 33) comprises an oscillating circuit (L-C) including a pressure sensor (8, 30) and a coil (13), and the evaluating unit (3) comprises a resonance oscillating circuit (7) capable of detecting the natural frequency (Fe) of the oscillating circuit, the natural frequency (Fe) of the oscillating circuit (L-C) being determined by the momentary pressure acting on the pressure sensor (8), or variable according to variations of a dimension of the pressure sensor (8) caused by pressure variations, and capable of being detected, and the pressure sensor (8, 30) being in the form of a capacitor having a deformable membrane (9), spatially separated from the coil (13), and connected thereto by an electric conductor (15, 31, 35).
- View Dependent Claims (2, 3, 4, 5, 6, 7, 11, 12, 13)
- 8. Device for the in vivo measurement of pressures and pressure variations inside or outside bones, comprising an implantable probe and an evaluating unit, characterized in that the probe (16) comprises an housing containing a capacitor (19) and a coil (22) which form an oscillating circuit (L-C), and the evaluating unit (3) includes a resonance oscillating circuit (7) capable of detecting the natural frequency (Fe) of the oscillating circuit, the natural frequency (Fe) of the oscillating circuit (L-C) being determined by the momentary pressure acting on the capacitor (19), or variable according to variations of a dimension of the capacitor (19) caused by pressure variations, and capable of being detected, and the housing of the capacitor including thinner portions (25) in order to be compressible.
Specification