Intracranial pressure monitoring system
First Claim
1. A system for monitoring the pressure within the cranium of a living being, said system comprising an cavity resonator means and transceiver means, said cavity resonator means being a hollow member defining an interior cavity and having a first wall in the form of a deflectable diaphragm, and a second wall including slot antenna means, said cavity resonator means having a predetermined resonance frequency for high frequency electromagnetic waves and being arranged to be implanted within the cranium of the being, whereupon said deflectable diaphragm is in communication with the interior of the being'"'"'s cranium, said deflectable diaphragm being arranged to be deflected in response to the pressure within the being'"'"'s cranium to alter said resonance frequency, said transceiver means being arranged to be located outside of the cranium of the being and having means for transmitting a high frequency electromagnetic excitation wave through said slot antenna means into said cavity to cause said cavity to resonate at an altered resonance frequency, whereupon a resonance wave is reflected out of said cavity, said transceiver means having means for receiving said resonance wave and for providing an electrical signal indicative thereof.
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Accused Products
Abstract
A system for monitoring intracranial pressure by an implantable cavity resonator unit and an associated externally located transceiver unit. The resonator unit includes a dielectric-filled cavity having a predetermined resonance frequency for high frequency electromagnetic waves. The cavity is bounded by a wall having a pair of intersecting slots forming a slot antenna and a deflectable diaphragm in communication with the interior of the cranium to deflect as a function of intracranial pressure. The deflection alters the resonance frequency of the cavity. The transceiver unit includes a linear wave guide having a pair of electrically conductive probes located in it. At least one of the probes is arranged to transmit an electromagnetic excitation wave from an associated transmitter through the slot antenna to cause the cavity to resonate at an altered resonance frequency, whereupon a resonance wave is reflected out of the cavity through the slot antenna. At least a second of the probes picks up the resonance wave and provides it to a receiver which provides an electrical signal indicative of the reflected wave. This signal is representative of the intracranial pressure. The cavity is sealed to prevent the ingress of body fluids therein.
167 Citations
18 Claims
- 1. A system for monitoring the pressure within the cranium of a living being, said system comprising an cavity resonator means and transceiver means, said cavity resonator means being a hollow member defining an interior cavity and having a first wall in the form of a deflectable diaphragm, and a second wall including slot antenna means, said cavity resonator means having a predetermined resonance frequency for high frequency electromagnetic waves and being arranged to be implanted within the cranium of the being, whereupon said deflectable diaphragm is in communication with the interior of the being'"'"'s cranium, said deflectable diaphragm being arranged to be deflected in response to the pressure within the being'"'"'s cranium to alter said resonance frequency, said transceiver means being arranged to be located outside of the cranium of the being and having means for transmitting a high frequency electromagnetic excitation wave through said slot antenna means into said cavity to cause said cavity to resonate at an altered resonance frequency, whereupon a resonance wave is reflected out of said cavity, said transceiver means having means for receiving said resonance wave and for providing an electrical signal indicative thereof.
Specification