Detection and analysis of spatially varying fluid levels using magnetic signals
Inventors
WYETH, Richard Warren • LEVINSON, Mitchell Elliott • Weber, Bryan Jon
Assignees
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Publication Number
US-11723597-B2
Publication Date
2023-08-15
Expiration Date
Abstract
A device for detecting spatial differences in fluid level changes in a tissue of a patient may include a support structure for securing the device to a body part of the patient, a processing element operably connected to the support structure, a wireless networking interface operably connected to the support structure and in communication with the processing element and an external computing device via a network, a first transmission module operably connected to the support structure and in communication with the processing element, a second transmission module and a third transmission module operably connected to the support structure and in communication with the processing element. When activated, the first transmission module transmits a first time varying magnetic field through the tissue of the patient. The second and third transmission modules, which are spatially separated from one another, receive first and second versions, respectively, of the first time varying magnetic field.
Core Innovation
The invention is a noninvasive device and system for detecting a spatial difference in fluid in a head of a patient by transmitting time varying magnetic fields through the brain hemispheres. The system uses a headset that secures transmitters on opposite sides of the head and a receiver on the forehead to receive the transmitted magnetic fields after passage through the first and second hemispheres. Distinguishing the received signals is based on a difference between the first frequency and the second frequency and a difference in phase shifts of the first time varying magnetic field and the second time varying magnetic field.
The approach is described as VIPS-based phase shift spectroscopy and magnetic induction phase shift spectroscopy using multi-frequency operation. The invention provides processing that distinguishes first received signals from the first transmitter versus second received signals from the second transmitter based on frequency, and detects the spatial difference between fluid in the first hemisphere and the second hemisphere based on phase-shift differences.
It further includes motion artifact reduction and handling of phase stability, such as using pitch, roll and yaw detection from an accelerometer and analyzing position or movement so that patient movement can be accounted for during processing. System-level diagnostics use baseline phase shifts, trends, and phase and attenuation relationships to distinguish different fluid-related conditions described in the document, and the system includes wireless networking interface for communication between the headset processing element and an external computing device.
Claims Coverage
The patent includes one independent claim and several dependent claims that refine the independent claim by adding features such as attenuation measurement, Fast Fourier Transform translation, transceiver operation, and integration with a Doppler ultrasound device. The independent claim contains inventive features focused on multi-frequency, hemisphere-separated magnetic field transmission and phase-shift based detection of spatial fluid differences, combined with accelerometer-based motion context and wireless networking.
Hemisphere-separating dual-frequency time varying magnetic fields
A headset secures the device to the patient’s head, with a first transmitter on a first side of the head transmitting a first time varying magnetic field at a first frequency through a first hemisphere of the patient’s brain, and a second transmitter on a second side opposite the first transmitter transmitting a second time varying magnetic field at a second frequency different from the first through a second hemisphere of the patient’s brain.
Forehead receiver receiving first and second hemisphere magnetic fields
A receiver attached to the headset at a third location so that the receiver resides on the patient’s forehead when the headset is placed on the patient, configured to receive the first time varying magnetic field after it passes through the first hemisphere and the second time varying magnetic field after it passes through the second hemisphere.
Phase-shift based spatial difference detection using frequency separation
A processing element in the headset processes received magnetic field data from the receiver, distinguishes first received signals from the first transmitter versus second received signals from the second transmitter based on a difference between the first frequency and the second frequency, and detects a spatial difference between fluid in the first hemisphere and the second hemisphere based on a difference in phase shifts.
Accelerometer-based determination of patient position or movement
The processing element processes pitch, roll and yaw data from the accelerometer to determine at least one of patient position or patient movement.
Wireless networking interface with external computing device
A wireless networking interface in the headset is in communication with the processing element and an external computing device via a wireless network.
Attenuation measurement for partial spatial difference detection
The processing element measures attenuation of voltage and/or current signals between respective transmitter-receiver pairs and uses the measured attenuation to partially detect a spatial difference in fluid between a first and second hemisphere.
Fast Fourier Transform translation of received magnetic data
The processing element translates received magnetic field data from the receiver using a Fast Fourier Transform.
Transceiver functionality for transmitter and/or receiver
At least one of the first transmitter, the second transmitter, or the receiver functions as a transceiver.
Integration with Doppler ultrasound for cerebrovascular response monitoring
The system includes the device and a Doppler ultrasound device configured to measure blood flow in a carotid artery to monitor changes in cerebrovascular response.
Across the independent and dependent claims, the main inventive features revolve around a hemisphere-separated, multi-frequency, time varying magnetic field arrangement with a forehead receiver, phase-shift based detection of spatial fluid differences using frequency separation, and accelerometer-based patient position or movement determination, together with wireless networking. Dependent claims further add attenuation-based partial detection, Fast Fourier Transform translation, transceiver operation, and an explicit system combination with a Doppler ultrasound device for carotid blood-flow and cerebrovascular response monitoring.
Stated Advantages
Motion artifact reduction and handling of phase stability.
System-level diagnostics using baseline phase shifts, trends, and phase and attenuation relationships to distinguish different fluid-related conditions.
Phase stability improvement concepts, including stabilization and shielding related to coil and transmission line arrangements.
Documented Applications
Integration with a Doppler ultrasound device configured to measure blood flow in a carotid artery to monitor changes in cerebrovascular response.
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