Abstract:
A power source delivers oscillating electrical energy to an electrical conductor, such as a wire or catheter, which is coated circumferentially with a ferromagnetic material in a selected region. With high frequency electrical energy, the ferromagnetic material has a quick response in heating and cooling adjustable by the controllable power delivery. The ferromagnetic material can be used for separating tissue, coagulation, tissue destruction or achieving other desired tissue effects in numerous surgical procedures.
Abstract:
A system and method for evaluating neural shunt functionality is provided. Accordingly, in one aspect a method for monitoring neural shunt functionality may include measuring a first intracranial pressure pulse inside the shunt, measuring a second intracranial pressure pulse outside the shunt, and comparing pulsatile characteristics from the first measurement to the second measurement in order to determine shunt functionality.
Abstract:
Systems and methods for measuring intracranial pressure and brain compliance are provided. In one aspect, for example, a method for noninvasive measurement of brain compliance in a subject may include calculating a phase shift between an intracranial pulsatile perfusion flow measured from the subject and an extracranial pulsatile perfusion flow measured from the subject, and determining brain compliance of the subject from the phase shift between the intracranial pulsatile perfusion flow and an extracranial pulsatile perfusion flow. Though various methods of calculating phase shift are contemplated, in one aspect such a calculation may include calculating an intracranial frequency waveform corresponding to the intracranial pulsatile perfusion flow, calculating an extracranial frequency waveform corresponding to the extracranial pulsatile perfusion flow, and calculating a phase difference between the intracranial frequency waveform and the extracranial frequency waveform.
Abstract:
A system and method for evaluating neural shunt functionality is provided. Accordingly, in one aspect a method for monitoring neural shunt functionality may include measuring a first intracranial pressure pulse inside the shunt, measuring a second intracranial pressure pulse outside the shunt, and comparing pulsatile characteristics from the first measurement to the second measurement in order to determine shunt functionality.
Abstract:
A power source delivers oscillating electrical energy to an electrical conductor, such as a wire or catheter, which is coated circumferentially with a ferromagnetic material in a selected region. With high frequency electrical energy, the ferromagnetic material has a quick response in heating and cooling adjustable by the controllable power delivery. The ferromagnetic material can be used for separating tissue, coagulation, tissue destruction or achieving other desired tissue effects in numerous surgical procedures.
Abstract:
A method and system to determine brain stiffness is disclosed. A probe to measure tissue water content is inserted through an aperture (burr hole) in the cranium into brain tissue. The probe has two electrically separated plate conductors with a dielectric which forms a capacitor plane. One conductor has a surface mount resistor to allow exact impedance matching to the core of a coaxial cable. The other conductor attaches electrically to the shield of the coaxial cable. The probe is stabilized in the brain tissue through a plastic ventriculostomy bolt which has been secured by screw tapping into the cranium. The coaxial cable connects to a spectrum analyzer. Brain water content and blood congestion alter the resonant frequency of the probe, allowing a realtime readout of apparent tissue water content. By monitoring the momentary shift in center resonant frequency or, alternatively, the standing wave ratio slightly off resonant frequency, a beat-to-beat pulsatile waveform is derived relating to the perfusion of the brain. A strain gauge intracranial pressure sensor (ICP) is separately affixed through the bolt and adjacent to the water content probe. By comparing the phase angle or lag time difference between the pressure tracing and the perfusion tracing, a realtime measurement of organ stiffness or compliance is derived.