Coil positioning system for non-invasive brain sensors

Abstract

A fixed or worn helmet-like medical diagnostic device has a motorized gimbal that automatically pivots into position around the patient's head. An end effector extends radially from the gimbal toward the head and positions a coil or other directional sensor flush against the scalp. The coil sensor may be part of a sensitive circuit for measuring eddy currents in the brain. To determine the sensor's precise 3D orientation when placed on the head, an accelerometer or other tilt-measuring gauge is compared between the sensor and the base of the device. The orientation can compensate for coil measurements, rediscover a precise point, or map the opposite side of the patient's skull, even in an unconscious or restless patient. The head can be scanned in its entirety, or other diagnostic data may prompt a spot scan.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 449,238, filed March 1, 2023, and U.S. Provisional Patent Application No. 63 / 588,278, filed October 5, 2023, the contents of which are incorporated herein by reference in their entirety for all purposes.

[0002] STATEMENT OF RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT Not applicable

[0003] Embodiments of the present invention generally relate to an apparatus for diagnostically detecting and measuring electromagnetic anomalies in a subject's head by specially adapted head-mounted means including means for indicating the position of the sensor on the body. Specifically, embodiments of the present invention relate to robotically positioning and repositioning a coil or other directional sensor relative to the subject's scalp, detecting the precise anatomical location and orientation of the sensor relative to the head, and outputting calibrated measurements. [Background technology]

[0004] Diagnosing a patient's possible stroke is often difficult because stroke victims are often unconscious and there are few, if any, visible signs of what is happening inside the patient's skull. Additionally, treating physicians are under time pressure to continue the treatment process. Every minute that passes without treatment, or with incorrect treatment, can result in more severe, often permanent, brain damage.

[0005] Incorrect treatment can be life-threatening. Treatment for ischemic stroke includes administering anticoagulants. However, if the patient is actually having a hemorrhagic stroke, anticoagulants can worsen the problem by allowing the blood's natural clotting properties to allow the intracerebral hemorrhage to continue unabated.

[0006] Currently, computed tomography (CT) and magnetic resonance imaging (MRI) are the two gold standards for diagnosing and monitoring brain health in stroke patients. When available, they are extremely helpful by providing treating physicians with an inside view of the patient's brain, and they are used repeatedly on patients to track progression, or lack thereof.

[0007] However, these devices are large, expensive, often require specialized staff, and are primarily limited to larger hospital systems. CT scans expose patients to significant amounts of radiation, which increases their risk of cancer. Neither can be used continuously at the patient's bedside. Summary of the Invention [Problem to be solved by the invention]

[0008] There is a need in the art for, among other things, a portable and less expensive system that can detect and monitor fluid abnormalities over time within a patient's head. [Means for solving the problem]

[0009] A medical diagnostic device for a patient's head includes a temporarily or permanently fixed headrest base with a gimbal assembly that can pivot in latitude and longitude over the patient's spherical skull. An end effector mounted on the gimbal assembly can be robotically extended inward from the gimbal to position a coil or other directional sensor against the patient's scalp. The sensor may tilt slightly when pressed against the scalp to match the scalp's local topology. A tilt sensor affixed to the coil sensor measures this tilt relative to the base, and then, due to magneto-electric measurements of the coil, the precise orientation and position of the coil sensor relative to the headrest is known.

[0010] Precisely placed measurements, such as eddy current measurements, can be compared over time or for the left and right hemispheres of the brain. Computed tomography (CT) or magnetic resonance imaging (MRI) data can be uploaded into the device for spot checking.

[0011] Some embodiments of the present invention relate to an inductive sensor device for brain diagnosis, the device including: a headrest base configured to hold a subject's head, the subject's head having a center point of a notional sphere; a first tilt gauge rigidly attached to the base; a gimbaled armature pivotally attached to the base and configured to pivot a mounting point on the gimbaled armature in latitude and longitude about the center point; a radial expander attached to the mounting point of the gimbaled armature, the radial expander configured to extend an end effector inward along a radial line relative to the center point; a coil sensor affixed to the end effector; and a second tilt gauge affixed to the sensor.

[0012] The device may further include a memory and a computer processor operably coupled with a machine-readable non-transitory medium embodying information representing instructions for causing the computer processor to perform operations including comparing tilt angles from the first tilt gauge and the second tilt gauge to determine a relative orientation of the coil sensor, and calculating a three-dimensional (3D) anatomical location of measurements from the coil sensor based on the orientation.

[0013] The operations may further include adjusting measurements from the sensor based on the orientation. The adjusting may include compensating for movement of the subject's head between measurements at the same anatomical location. The operations may further include instructing the gimbal to rotate to a specified latitude and a specified longitude, instructing the radial expander to extend the sensor to the specified latitude and longitude, generating measurements based on outputs produced by the sensor, and correlating the measurements with the 3D anatomical location to create anatomically-located measurements. The anatomically-located measurements may be from the left hemisphere of the brain / head, and the operations may further include making anatomically-located measurements on the right hemisphere of the brain / head, comparing the measurements from the left and right hemispheres of the head, and outputting a display based on the comparison. The anatomically-located measurements may be from a previous time, and the operations may further include making a later anatomically-located measurement, comparing the previous measurement with the later measurement, and outputting a display based on the comparison. The operations may further include accessing computed tomography (CT) or magnetic resonance imaging (MRI) data from a head scan and determining anatomical coordinates on the head based on the CT or MRI data, where the specified latitude and the specified longitude are based on the anatomical coordinates. The operations may further include creating an anatomically located measurement set including the anatomically located measurements and generating a physical topography of the head from the measurements or rendering an image based on the measurements. The device may further include a resistive, inductive, and capacitive (RLC) circuit electrically connected to the coil sensor and a frequency counter electrically connected to the RLC circuit, and the operations may further include generating measurements based on output from the frequency counter when the coil sensor is in a cranial position on the head.The coil sensor may be a first coil sensor, the RLC circuit may be a first RLC circuit, the frequency counter may be a first frequency counter, and the apparatus may further include a second coil sensor having a larger or smaller diameter than the first coil sensor, wherein the first coil sensor and the second coil sensor share a housing; a second RLC circuit electrically connected to the second coil sensor; and a second frequency counter electrically connected to the second RLC circuit.

[0014] The first tilt gauge and the second tilt gauge can include three-dimensional (3D) accelerometers. The radial expander can include a scissor device or a telescoping mechanism. The apparatus can further include a motor, a pulley wheel on the mounting point, and a pulley cable extending through the pulley wheel between the motor and the radial expander, the motor being positioned away from the mounting point to avoid electromagnetic interference with the coil sensor.

[0015] Some embodiments relate to a method for anatomically locating measurements within a subject's brain, the method including the steps of: providing a headrest base configured to hold the subject's head, the subject's head having a center point of a notional sphere; a first tilt gauge rigidly attached to the base; a gimbal armature pivotally attached to the base and configured to pivot a mounting point on the gimbal armature in latitude and longitude about the center point; a radial expander attached to the mounting point of the gimbal armature, the radial expander configured to extend an end effector inward along a radial line relative to the center point; a coil sensor affixed to the end effector; and a second tilt gauge affixed to the sensor; comparing tilt angles from the first tilt gauge and the second tilt gauge to determine a relative orientation of the sensors; and calculating a three-dimensional (3D) anatomical location of measurements from the sensors based on the orientations.

[0016] The method may further include adjusting measurements from the sensor based on the orientation. The method may further include commanding the gimbal to a specified latitude and longitude, commanding the radial expander to extend the sensor to the specified latitude and longitude, generating measurements based on output produced by the sensor, and correlating the measurements with a 3D anatomical location to create anatomically-located measurements. The anatomically-located measurements may be from the left hemisphere of the brain / head, and the method may further include making anatomically-located measurements on the right hemisphere of the head, comparing the measurements from the left and right hemispheres of the head, and outputting a display based on the comparing step. The anatomically-located measurements may be from a previous time, and the method may further include making a later anatomically-located measurement, comparing the previous and later measurements, and outputting a display based on the comparing step.

[0017] Some embodiments relate to a method of manufacturing an inductive sensor device for brain diagnosis, the method including the steps of: providing a headrest base configured to hold a subject's head, the subject's head having a center point of a notional sphere; rigidly mounting a first tilt gauge to the base; pivotally mounting a gimbaled armature to the base such that the gimbaled armature is configured to pivot a mounting point on the armature in latitude and longitude about the center point; attaching a radial expander to the mounting point on the gimbaled armature such that the radial expander configures the radial expander to extend the end effector inward along a radial line relative to the center point; securing a coil sensor to the end effector; and securing a second tilt gauge to the sensor.

[0018] The methods may include combinations of device features, and the devices and methods may include described and undescribed aspects in various combinations. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a perspective view of a medical diagnostic device according to one embodiment. [Figure 2] FIG. 1 is a horizontal cutaway view of a device according to one embodiment. [Figure 3A] FIG. 1 illustrates a human subject in a device according to one embodiment. [Figure 3B] FIG. 3B illustrates coil sensors extending radially on the scalp of the subject of FIG. 3A. [Figure 3C] FIG. 3C is a perspective view of a face shield extending over the device of FIG. 3B. [Figure 4] FIG. 1 illustrates a gimbal covering the temples of a human subject according to one embodiment. [Figure 5A] 10A-10C are top and side perspective views of a radial dilator retracted according to one embodiment. [Figure 5B] FIG. 5B illustrates the radial dilator of FIG. 5A extended according to one embodiment. [Figure 6] 1 is a vertical cross-sectional view of a medical diagnostic device according to one embodiment. [Figure 7] FIG. 1B is a vertical cross-sectional view of a device showing the nominal out-tilt of a directional coil sensor according to one embodiment. [Figure 8A] 1 is a screen rendering of a lateral image of a patient's head and brain according to one embodiment. [Figure 8B] 1 is a screen rendering of a ventral image of a patient's head and brain according to one embodiment. [Figure 9A] 1 is a screen rendering of a lateral image of a patient's head and brain according to one embodiment. [Figure 9B] 1 is a screen rendering of a ventral image of a patient's head and brain according to one embodiment. [Figure 10] FIG. 1 is a connection diagram for a gimbal control system according to one embodiment. [Figure 11]1 is a flowchart illustrating a process according to one embodiment. [Figure 12] 1 is a flowchart illustrating a process according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] A medical device is described for positioning and orienting coil-based or other types of directional sensors at locations around a patient's head. The positioning device can be small enough to be placed at the bedside or worn by the patient for point-of-care or continuous monitoring or diagnosis. The sensor's scanning can, to some extent, replace much larger computed tomography (CT) or magnetic resonance imaging (MRI) machines, and its size and low operating cost allow for more frequent use. It may also have utility in ambulatory care, acute triage, military, nursing facilities, sports, ambulance, and emergency care settings.

[0021] The coil sensors use eddy current decay (ECD) to compare the conductivity of different parts of a patient's brain and can compare those conductivities in the left and right hemispheres, over time, or with other people's brains. In this application, "head" and "brain" are sometimes used interchangeably in the diagnostic realm.

[0022] Unlike traditional eddy current decay (ECD) sensors used in the industry for metal crack inspection, which consist of a bridge circuit that measures the impedance of a coil sensor, some embodiments may have a coil sensor paired with a capacitor to form an electrical resonant circuit.

[0023] Automated eddy current-based technologies have a wide variety of applications for assessing brain health. These devices can be used to measure changes in cerebral fluid status, either continuously or at intervals, and can be used in settings to evaluate ischemic or hemorrhagic stroke, brain tumors, cerebral edema, arteriovenous malformations, congenital anomalies, traumatic brain injury, concussion, vascular neurosurgery, endovascular neurosurgery, neurodegenerative conditions (i.e., Alzheimer's disease), and to monitor brain health during infusion of brain-targeted drugs, among other brain-health-related conditions.

[0024] Using information about the shift in conductivity in the brain as cerebral fluid volume changes, such a device can provide information about the depth, location, size, volume, progression, type, and conductivity of fluid changes.

[0025] Additionally, when the device is used in the operating room, it can also provide information about the location, size, and motion of surgical tools, which can be used in either endovascular neurosurgery (i.e., thrombectomy, coiling, etc.), cardiac surgery (i.e., ischemic stroke by injecting a blood clot into the brain), or general neurosurgery (i.e., assessing bleeding or implant location).

[0026] Embodiments of the described devices may have several design forms. The device may resemble a helmet and be placed on a patient's head for point-of-care or continuous diagnosis or monitoring of brain health. Alternatively, the automated device may be bedside and resemble a robotic arm or other attachment. In either case, the automated device may include gimbaled armatures and motors to move the sensor in the x, y, and / or z plane, cylindrical or spherical coordinates, to capture one-dimensional (1D), two-dimensional (2D), or three-dimensional (3D) conductivity information about the brain. More specifically, aside from movement around the center point of a notional sphere on the patient's head, the device may also move radially (i.e., toward or away from the center point) to obtain additional depth information about the tracked object. Radial movement may also enable varying spatial, temporal, and depth resolution.

[0027] Various other types of sensors can be incorporated on or alongside the inductive damping sensor, such as an accelerometer, gyroscope, piezoelectric sensor, or temperature sensor. The automated device can include an encoder or precision stepper motor to package the conductivity information with the spatial information. These additional sensors and machines can be used to improve the overall accuracy or precision of the inductive damping sensor. For example, an accelerometer and gyroscope can enable positioning and trajectory mapping of the device as it moves around the body, while a temperature sensor can enable temperature compensation to improve signal accuracy.

[0028] Data acquired by the device can be stored locally, remotely, in the cloud, or on a cell network. Data transmission may be via wires, Bluetooth signals, radio frequency, or infrared. This allows for the possibility of remote diagnosis based on patient data and reporting information directly to an electronic medical record (eMR). This also allows for the integration of data for analysis.

[0029] After or during data collection, the data can be displayed to the healthcare provider in several forms. The output can be shown on a local computer or tablet, or can be stored on the eHR for later review. Images of the brain's conductivity distribution can be collected and displayed in 2D or 3D diagrams. There may be a "scrubbing" feature, where the user can temporarily go through multiple images over a period of time. Additionally, the probability and likelihood of the presence of damage or changes can be displayed to the user.

[0030] 1 is a perspective view of an inductive sensor medical diagnostic device assembly 100 for brain diagnostics according to one embodiment. The inductive sensor device 102 includes a headrest base 104 on which a headrest 106 is mounted.

[0031] The headrest 106 is curved and positioned to gently hold the human subject's head so that the notional center point 110 of the subject's skull is somewhat centered within the larger device's positioning envelope for the head. A head strap 108 helps securely fasten the subject's head to the headrest 106. A neck cradle 124 can gently secure the patient's neck in place to minimize larger head movements and help keep the rest of the patient's body in place.

[0032] Secured to the headrest base 104 is a gimbal armature 112, which in this case is an assembly of two gimbal arms: an outer gimbal arm 114 and an inner gimbal arm 116. The outer gimbal arm 114 is secured to a ridge on the headrest base 104 and pivots about a notional axis that extends vertically through the top of the patient's head. The outer gimbal arm 114 can orbit to different longitudes around the patient's head. The inner gimbal arm 116 is secured to the outer gimbal arm 114 by two pivots, each on an opposite side of the head. By pivoting up and down relative to the outer gimbal arm 114 and the patient's head, the inner gimbal arm 116 can reach different latitudes of the patient's head. That is, the inner gimbal arm 116 can rotate up and down the attachment point 120 to different latitudes. The outer gimbal arm 114 rotates the inner gimbal arm 116, and therefore the mounting point 120, to different longitudes. The assembly of the gimbal armature 112 with the outer gimbal arm 114 and inner gimbal arm 116 thus allows the mounting point 120 to pivot to various latitudes and longitudes about the notional center point 110.

[0033] Radial expander 118 is attached to and oriented to extend inwardly at mounting point 120 on gimbal armature 112. This particular radial expander extends its end effector along a radial line to notional center point 110.

[0034] The coil sensor 122 is mounted on the end effector of the radial expander 118 so that the coil sensor 122 moves along a radial line in latitude and longitude that is stopped by the gimbal armature 112. When extended, the coil sensor can be pressed against the subject's head so as to be as close as possible to the patient's brain without getting in the way.

[0035] To allow depth mapping of readings within the head, several separate coils of different diameters can be nested inside each other. Smaller coils generally measure shallower than larger coils. To obtain a good signal-to-noise ratio with small coils, it may be important to press the small coils as close to the subject's brain as possible and tightly against the head.

[0036] While coil sensors are shown in the various figures, other types of directional or omnidirectional sensors can also be used, including antenna, infrared, temperature, tactile, topographic, etc. Besides sensors, other end effectors can be used as well, such as robotic graspers, skull drills, needles, etc.

[0037] 2 is a horizontal cutaway view of a gimbal device assembly 200 according to one embodiment. The device 202 includes a neck rest 206 supported by a head rest base and head straps 208 that extend to the left and right sides of the subject's head. Gimbal arms 214 and 216 pivot at a fixed radius about a notional head center point 210 at an attachment point 220, which is approximately at the center of the head strap. A sensor 222 extends inward from attachment point 220 by a radial extender. Both the gimbal arms and the radial extender are driven by motors.

[0038] A pivot point 230 pivotally connects the outer gimbal arm 214 to the fixed headrest base of the assembly 200. A stepper motor 234 precisely rotates the outer gimbal arm 214 about the pivot point 230 to a specified longitude around the patient's head.

[0039] Pivot points 232 and 233 pivotally connect inner gimbal arm 216 to outer gimbal arm 214. A stepper motor 236 precisely rotates the inner gimbal arm about pivot points 232 and 233 to a specified latitude above and below the patient's head.

[0040] A stepper motor 238 pulls on a cable, which passes through pulleys, some of which are shown as pulley 246, to extend or retract the radial expander. There may be one or more pulley and cable systems. In the exemplary embodiment, one cable system with both a pull side and a push side allows the cable to remain taut with no slack.

[0041] By placing the stepper motor 238 far away from the mounting point 220 that holds the sensor 222, ferrous and non-ferrous metals within the motor are kept away from the sensor, thereby minimizing or otherwise avoiding potential electromagnetic interference (EMI) between the otherwise close motor and sensor.

[0042] Although stepper motors are used in the exemplary embodiment, other types of motors with encoders or other precision measurement means can be used. Stepper motors with stop or limit switches have been found to work well to position the gimbal accurately and precisely with the resolution required to acquire patient data.

[0043] 3A-3C illustrate a human head 340 undergoing medical diagnosis in device 302. FIG.

[0044] 3A, the radial expander 318 is retracted so that the sensor 322 is far enough away from the head 340. In this retracted position, the gimbal armature is free to pivot around the head without mechanical interference.

[0045] In Figure 3B, the radial dilator 318 is extended so that the sensor 322 is gently pressed against the head 340. The radial dilator 318 is of a scissor type, with legs that swing apart when opened and bypass each other when closed.

[0046] In this extended position, the sensor 322 may be tilted slightly from its otherwise standard orientation perpendicular to a radial line projected from the notional center of the head. Compensating for the tilt is discussed below.

[0047] In some situations where the sensor is extended, it may be beneficial to rotate the gimbal armature in latitude, longitude, or both to gently drag the sensor along the skull topology. This may be for performing a quick scan in an emergency, for taking successive measurements at intervals, or for pre- or post-calibration of the equipment. Alternatively, the sensor can be fully or partially retracted before each gimbal movement to a different latitude and longitude.

[0048] Some scans can be accomplished more quickly, safely, or accurately if they can be performed without patient interference. Figure 3B shows the face shield 342 in the retracted position.

[0049] FIG. 3C is a perspective view of a face shield 342 in device 302 extending outward over the subject's head. The face shield 342 can help prevent intentional or unintentional interference with the sensors by the subject's hands and fingers. Unconscious patients often cover their faces and make wiping motions if any foreign object touches their eyes, nose, or lips. Covering the head with a face shield can also prevent bed sheets, tubes, or wires in a hospital bed from interfering with an otherwise smooth scanning process and can serve as a reminder for others to refrain from contact while the scan is being performed. The gimbal can thus rotate unimpeded around the head through the scan point.

[0050] Figure 4 illustrates a gimbal covering the temple of a human subject. The same view can be part of a broad scan or as a spot check of the area around the temple.

[0051] Gimbal arms 414 and 416 of device 402 are supported by headrest base 404 and are pivoted over the right temple of the subject's head. Sensor 422 does not yet extend to the patient's skin. The face shield is shown retracted for clarity.

[0052] This is the portion of the scan that may include a spot check of the temple in response to data from a computed tomography (CT) or magnetic resonance imaging (MRI) scan. The data from the CT or MRI can be uploaded into a computer system to automatically or manually determine one or more anatomical coordinates where further scans should be performed.

[0053] For example, upon admission to a hospital, a patient may undergo a CT or MRI scan, which may reveal a blood deficiency at specific 3D coordinates in the patient's brain. After an anticoagulant is administered, the same anatomical coordinates within the patient are monitored with a designated device.

[0054] An "anatomical coordinate," "anatomical location," or "anatomical location" is a point, area, or volume on or within the body that remains relatively stationary relative to the organs and other features of the body, or as otherwise known in the art. The coordinate, location, or position may or may not be a recognizable or named part of the body, as it may be within an otherwise heterogeneous organ volume. An analogous to "anatomical" location is a geographic location or absolute location.

[0055] Smart or adaptive scan patterns can be employed based on the results of previous CT, MRI, or device scans to maximize resolution across specific abnormalities and minimize scan time.

[0056] However, at the beginning of a patient's treatment, a measurement scan may be performed over the head, which is a predefined, mechanical procedure. These measurements, both measuring the sensor tilt angle as the sensor touches the head and measuring the coil-sensor electromagnetic readings, may be performed to establish a baseline skull shape for reference points and a baseline for internal eddy currents. In some embodiments, a set number of individual points, such as 64 individual points, may be measured over the head. Alternatively, the sensor may be slid continuously over the head to obtain a more continuous, analog set of measurements.

[0057] 5A-5B illustrate the radial dilator 518 in two positions: one that does not extend the end effector 544 and sensor 522 downward from the attachment point 520, and one that does extend them.

[0058] In Figure 5A, the scissor mechanism is retracted with the nested legs folding onto each other. A pulley wheel 546 is fixed to a force transmission shaft shared by the segment gears. When a cable 548 is pulled through the pulley wheel 546 by a motor, the pulley wheel 546 rotates the segment gears relative to each other, extending the scissor mechanism. Rotation continues until a limit switch is toggled.

[0059] In Figure 5B, the scissor mechanism is mostly extended. Another pulley wheel 547 is shown, another for retraction. When pulley wheel 547 is rotated by a second cable (not shown), it turns the part gear in the other direction, retracting end effector 544 towards attachment point 520. The cable can also have an end attached to the end effector to pull the end effector towards the attachment point.

[0060] Besides the scissor mechanism, telescoping and other mechanical devices can be used to extend and retract the sensor. The motor can be aligned within the radial expander or, as in the exemplary embodiment shown, can be located remotely.

[0061] 6 is a vertical cross-sectional view of a medical diagnostic device 602 having an expandable radial dilator 650. The radial dilator 650 is shown extended so that the sensor 622 contacts the top of a small subject's head. The radial dilator 650 can be moved to its extreme outward extent as shown, or can be retracted into a limit switch 678.

[0062] A three-dimensional (3D) accelerometer 652 is rigidly fixed to the headrest base 604 and effectively measures the tilt angle 658 between a nominal baseline and a flat table by detecting the gravity vector. The tilt may be due to the bed angle, bedding, support cushions, or other items. The accelerometer 652 outputs the x, y, and z components of acceleration due to gravity. The orientation of the gravity vector gives the accelerometer 652's absolute orientation in space.

[0063] If the measurements from the accelerometer 652 suddenly change during a measurement scan, this may indicate that someone or something has bumped into a table or bed or otherwise moved the device. Motion artifacts in the accelerometer data may indicate the need for a rescan or compensation of the data.

[0064] Another accelerometer pack, a 3D accelerometer 654, is attached to the end effector of the radial dilator 618. This accelerometer pack can provide deflection data at the end of the radial dilator for calibration purposes, etc.

[0065] Accelerometer 656 is rigidly fixed to sensor 622. Comparing the x, y, and z components of the acceleration due to gravity in accelerometer 656 with that of accelerometer 652 allows for the calculation of the orientation of sensor 622 relative to headrest base 604. The orientation can be used to determine the orientation of the sensor relative to the headrest, and therefore relative to the skull itself. Evaluating the orientation of the sensor determines the precise anatomical location within the patient's brain at which the sensor is pointed.

[0066] Although an accelerometer is shown for the tilt gauge, other sensors can be used to indicate tilt, including those employing plumb bobs, level bubbles, or other tools.

[0067] Using successive sensor orientations taken around the scalp, a topological map of the skull can be automatically created, allowing for a "sanity check" to ensure the sensor tilt gauge is functioning precisely and / or accurately.

[0068] An initial scan can be performed to pre-map the head placement, and post-scan mapping can be performed as well. Because the sensors are held at each placement during mapping, recordings of the sensors at all positions can be taken during each scan as well. These scans can allow compensation for patient or device movement during the procedure.

[0069] 7 is a vertical cross-sectional view of a medical diagnostic device 702 showing the nominal out-of-tilt or tilt of a coil sensor 722. A base tilt gauge 752 is fixed to a headrest base 704, which supports the coil sensor 722 through a gimbal armature and radial expanders. A tilt gauge 756 is fixed to the sensor 722 and indicates its orientation relative to gravity.

[0070] The tilt angle is compared against gravity on tilt gauges 756 and 752 to calculate the 3D anatomical placement of each measurement from the coil sensor. That is, even if sensor 756 is pointing at an angle 760 away from its nominal radial direction relative to a notional center point within the skull, the system can determine that it is further forward (inside the head) than where the eddy current measurement would otherwise occur. Measurements from the coil, such as frequency or resistance measurements, can be appropriately adjusted based on orientation.

[0071] 8A-9B show screen renderings of lateral and ventral images of a brain 862 within a subject's head 860.

[0072] Figure 8A shows a lateral image rendering 800A of the brain, and Figure 8B shows a ventral image rendering 800B of the brain. An area of ​​increased conductivity 864 is shown centered between the left and right hemispheres in the occipital lobe. The increased conductivity may be caused by pooling of blood, indicative of a hemorrhagic stroke.

[0073] FIG. 9A shows a lateral image rendering 900A of the brain, and FIG. 9B shows a ventral image rendering 900B of the brain, taken at a later time than those in FIGS. 8A-8B. The area of ​​increased conductivity 964 is in the same anatomical location within the brain as area 864, but is larger in volume. This is a hallmark of a worsening hemorrhagic stroke. This is seen in both the lateral and ventral images.

[0074] This increased pooling of blood could prompt urgent intervention in the patient to drain the blood or at least relieve pressure that may be building up in the brain.

[0075] With eddy current coil sensors, it may be important to determine the baseline conductivity of the entire brain at the start of the procedure. Then, as shown here, conductivity may change over time, and those changes and anatomical locations can be flagged or otherwise indicated to the processing personnel.

[0076] Another way to use eddy current coil sensors is to compare readings from exactly opposite anatomical locations in the left and right hemispheres of the brain. If the readings are essentially the same, this can indicate that both sides are healthy. However, if the measurements differ significantly between the left and right hemispheres, this can indicate a pooling of blood (hemorrhagic) or a lack of blood (ischemic) in either area. Such a finding may prompt further diagnosis, such as a CT or MRI scan.

[0077] FIG. 10 illustrates a gimbal control system 1000 that is controlled by a tablet device or personal computer (PC) 1080.

[0078] A computer processor microcontroller 1070 processes machine instructions and data from machine-readable non-transitory memory 1072. Memory 1072 contains instructions, such as a programming language, that cause the microcontroller 1070 to command gimbal and radial expander movement via motor drivers 1068, power the coils via coil sensor drivers 1080, read accelerometers 1052, 1054, and 1056, process data, and indicate functions and measurements via a screen, light-emitting diodes (LEDs) 1074, audio, or other output devices.

[0079] The microcontroller 1070 powers a first resistive, inductive, and capacitive (RLC) circuit 1082 that is connected to a first frequency counter 1086. The first RLC circuit is connected to the outer coil 1022A. A measurement based on the output from the frequency counter 1086 is made for the large coil. The microcontroller 1070 also powers another resistive RLC circuit 1084 that is connected to another frequency counter 1088. This second RLC circuit is connected to the inner coil 1022C. For simplicity, the circuit for coil 1022B is not shown. A measurement based on the output from the frequency counter 1088 is made for the small coil.

[0080] Motors 1034 , 1036 , and 1038 are controlled by a microcontroller 1070 via their respective motor drivers 1068 .

[0081] Suitable computer hardware systems for implementing or controlling a microcontroller include personal computers (PCs), front-end or back-end server systems, or other types of computer systems. A computer system can include a central processing unit (CPU) for running software applications and optionally an operating system. The CPU can be composed of one or more homogeneous or heterogeneous processing cores. Memory can store applications and data for use by the CPU. Storage can provide non-volatile storage and other computer-readable media for applications and data, and can include fixed disk drives, removable disk drives, flash memory devices, and CD-ROM, DVD-ROM, Blu-ray, HD-DVD, or other optical storage devices, as well as signal transmission and storage media. User input devices can communicate user input from one or more users to the computer system, and examples include a keyboard, mouse, joystick, touchpad, touchscreen, still or video camera, and / or microphone. Network interfaces can enable the computer system to communicate with other computer systems over electronic communication networks, including wired or wireless communications over local area networks and wide area networks such as the Internet. The audio processor may be adapted to generate analog or digital audio output from instructions and / or data provided by the CPU, memory and / or storage. The components of the computer system, including the CPU, memory, data storage, user input devices, network interface and audio processor, may be connected via one or more data buses.

[0082] A graphics subsystem can be connected to the data bus and components of a computer system. The graphics subsystem can include a graphics processing unit (GPU) and graphics memory. The graphics memory can include display memory (e.g., a frame buffer) used to store pixel data for each pixel of an output image. The graphics memory can be integrated into the same device as the GPU, connected as a separate device from the GPU, and / or implemented in memory. The pixel data can be provided to the graphics memory directly from the CPU. Alternatively, the CPU can provide data and / or instructions defining a desired output image to the GPU, from which the GPU can generate pixel data for one or more output images. The data and / or instructions defining the desired output image can be stored in memory and / or graphics memory. In one embodiment, the GPU can include 3D rendering functionality for generating pixel data for output images from instructions and data defining a scene's geometry, lighting, shading, texturing, motion, and / or camera parameters. The GPU can further include one or more programmable execution units capable of executing shader programs.

[0083] The graphics subsystem can periodically output pixel data from the graphics memory for display on a display device. The display device can be any device capable of displaying visual information in response to signals from the computer system, including cathode ray tubes (CRTs), liquid crystal displays (LCDs), plasma, and organic light-emitting diode (OLED) displays. The computer system can provide analog or digital signals to the display device.

[0084] According to various embodiments, the CPU may be one or more general-purpose microprocessors having one or more processing cores. Further embodiments can be implemented using one or more CPUs having a microprocessor architecture that is particularly adapted for highly parallel, computationally intensive applications such as media and interactive entertainment applications.

[0085] In different embodiments, the components of the system may be connected via a network. The network may be any combination of the following: the Internet, an Internet Protocol (IP) network, an intranet, a wide area network (WAN), a local area network (LAN), a virtual private network (VPN), a public switched telephone network (PSTN), or any other type of network that supports data communication between the devices described herein. The network may include both wired and wireless connections, including optical links. Many other examples are possible and will be apparent to those skilled in the art in light of this disclosure. In the discussion herein, a network may or may not be specifically mentioned.

[0086] FIG. 11 is a flowchart illustrating a process 1100 according to one embodiment. In operation 1101, a headrest base configured to hold a subject's head is provided, the subject's head having a center point of a notional sphere. Also provided are a first tilt gauge rigidly attached to the base, a gimbal armature pivotally attached to the base and configured to pivot a mounting point on the gimbal armature in latitude and longitude about the center point, a radial expander configured to extend the end effector inward relative to the center point, a coil sensor affixed to the end effector, and a second tilt gauge affixed to the coil sensor. In operation 1102, computed tomography (CT) data or magnetic resonance imaging (MRI) data from a scan of the head is received, read, or otherwise accessed. In operation 1103, anatomical coordinates of the head are determined based on the CT or MRI data. In act 1104, the gimbal armature is commanded to a specified latitude and a specified longitude, where the specified latitude and the specified longitude are based on anatomical coordinates. In act 1105, the radial expander is commanded to extend the sensor to the specified latitude and the specified longitude. In act 1106, measurements are generated based on the output produced by the sensor. In act 1107, tilt angles from the first tilt gauge and the second tilt gauge are compared to determine a relative orientation of the sensor. In act 1108, a three-dimensional (3D) anatomical location of the measurements from the sensor is calculated based on the relative orientation. In act 1109, the measurements are correlated with the 3D anatomical location to produce an anatomically located measurement.

[0087] 12 is a flowchart illustrating a process 1200 according to one embodiment. In operation 1201, a headrest base configured to hold a subject's head is provided, the headrest base having a center point of a notional sphere. In operation 1202, a first tilt gauge is rigidly attached to the base. In operation 1203, a gimbaled armature is pivotally attached to the base such that the gimbaled armature is configured to pivot a mounting point on the gimbaled armature in latitude and longitude about the center point. In operation 1204, a radial expander is attached to the mounting point on the gimbaled armature to configure the radial expander to extend the end effector inward relative to the center point. In operation 1205, a coil sensor is secured to the end effector. In operation 1206, a second tilt gauge is secured to the sensor.

[0088] While the above describes what is believed to be the best mode and / or other examples, it is understood that various modifications can be made thereto and that the subject matter disclosed herein can be embodied in various forms and examples, and that the present teachings can be applied in many applications, only a few of which are described herein. It is the intent of the following claims to claim any and all applications, modifications, and variations that fall within the true scope of the present teachings.

[0089] Unless otherwise indicated, all measurements, values, ratings, locations, dimensions, sizes, and other specifications set forth in this specification, including the following claims, are approximate and not exact. They are intended to have a reasonable range consistent with the function to which they pertain and consistent with what is customary in the art to which they pertain. The term "about" with respect to temperature or other engineering units includes measurements or settings that are within ±1%, ±2%, ±5%, ±10%, or other tolerances of the specified engineering unit as known in the art.

[0090] The scope of protection is limited only by the claims that follow, which are intended and should be interpreted as broad as consistent with the ordinary meaning of the terms used in the claims when interpreted in light of this specification and the prosecution history that follows, and to include all structural and functional equivalents.

[0091] Except as noted immediately above, nothing described or illustrated, whether claimed or not, is intended to, or should be construed to, dedicate to the public any element, step, feature, object, benefit, advantage, or equivalent.

[0092] The terms and expressions used herein will be understood to have the ordinary meanings consistent with such terms and expressions with respect to their respective fields of inquiry and study, unless a special meaning is otherwise stated herein. Relative terms, such as first and second, may be used only to distinguish one entity or act from another and do not necessarily require or imply any actual relationship or order between such entities or acts. The terms "comprises," "comprising," or any other variations thereof, are intended to cover non-exclusive inclusions, such that a process, method, article, or apparatus comprising a list of elements does not include only those elements, but may also include other elements not expressly listed or inherent in such process, method, article, or apparatus. An element preceded by "a" or "an" does not, without further constraints, exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0093] The Abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Additionally, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method disclosure should not be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Accordingly, the following claims are incorporated into the Detailed Description herein, with each claim standing on its own as separately claimed subject matter. [Explanation of symbols]

[0094] 100 Inductive Sensor Medical Diagnostic Device Assembly 102 Inductive Sensor Devices 104 Headrest base 106 Headrest 108 Head Strap 110 center point 112 Gimbal Armature 114 Outer gimbal arm 116 Inner gimbal arm 118 Radial dilator 120 mounting points 122 Coil Sensor 124 Neck Cradle 200 Gimbal device assembly 202 devices 206 Neckrest 208 Head Strap 210 center point 214 Outer Gimbal Arm 216 Inner gimbal arm 220 mounting points 222 Sensor 230 Pivot point 232 Pivot point 233 Pivot point 234 Stepping Motor 236 Stepping Motor 238 Stepping Motor 246 Pulley 302 Devices 318 Radial dilator 322 Sensors 340 Head 342 Face Shield 402 Device 404 Headrest base 414 Gimbal Arm 416 Gimbal Arm 422 Sensors 518 Radial dilator 520 mounting points 522 Sensors 544 End Effector 546 Pulley Wheel 547 Pulley Wheel 548 Cable 602 Medical diagnostic devices 604 Headrest base 618 Radial dilator 622 Sensors 650 Radial Dilator 652 Three-dimensional (3D) accelerometer 654 3D accelerometer 656 Accelerometer 658 Tilt Angle 678 Limit Switch 702 Medical diagnostic devices 704 Headrest base 722 Coil Sensor 752 Base Tilt Gauge 756 Inclination Gauge, Sensor 760 angle 800A Rendering of a Lateral Image of the Brain Rendered ventral image of the 800B brain 860 Head 862 Brain 864 Areas with increased conductivity 900A Rendering of a Lateral Image of the Brain Rendered ventral image of the 900B brain 964 Areas with increased conductivity 1000 Gimbal Control System 1022A outer coil 1022B coil 1022C Inner Coil 1034 Motor 1036 Motor 1038 Motor 1052 Accelerometer 1054 Accelerometer 1056 Accelerometer 1068 Motor Driver 1070 Computer Processor Microcontroller 1072 Machine-readable non-transitory memory 1074 Light Emitting Diode, LED 1080 Tablet Device, Personal Computer, PC, Coil Sensor Driver 1082 First Resistive, Inductive, and Capacitive (RLC) Circuit 1084 Second Resistive RLC Circuit 1086 First Frequency Counter 1088 Frequency Counter

Claims

1. 1. An inductive sensor device for brain diagnostics, comprising: a headrest base configured to hold a subject's head, the subject's head having a center point of a notional sphere; a first tilt gauge rigidly attached to the headrest base; a gimbal armature pivotally mounted to the headrest base and configured to allow a mounting point on the gimbal armature to pivot in latitude and longitude about the center point; a radial expander attached to the attachment point of the gimbal armature, the radial expander configured to extend an end effector inward relative to the center point; a coil sensor fixed to the end effector; a second tilt gauge fixed to the coil sensor; An apparatus comprising:

2. Memory and 1. A computer processor comprising: comparing the tilt angles from the first tilt gauge and the second tilt gauge to determine a relative orientation of the coil sensor; calculating a three-dimensional (3D) anatomical location of measurements from the coil sensors based on the orientation; and a computer processor operatively coupled to a machine-readable non-transitory medium embodying information representing instructions for causing said computer processor to perform operations including: The apparatus of claim 1 further comprising:

3. The operation is adjusting measurements from the coil sensor based on the orientation. The apparatus of claim 2 further comprising:

4. The apparatus of claim 3 , wherein the adjusting comprises compensating for movement of the subject's head between measurements at the same anatomical location.

5. The operation is commanding the gimbal armature to rotate to a specified latitude and a specified longitude; directing the radial expander to extend the coil sensor to the specified latitude and the specified longitude; generating a measurement based on an output produced by the coil sensor; correlating the measurements with the 3D anatomical location to generate anatomically located measurements; The apparatus of claim 2 or 3, further comprising:

6. the anatomically located measurements are from the left hemisphere of the head, and the motion is making anatomically located measurements on the right hemisphere of the head; comparing the measurements from the left and right hemispheres of the head; outputting an indication based on said comparing; The apparatus of claim 5 further comprising:

7. the anatomically located measurements are prior, and the operation comprises: making subsequent anatomically aligned measurements; comparing the earlier and later measurements; outputting an indication based on said comparing; The apparatus of claim 5 further comprising:

8. The operation is accessing computed tomography (CT) or magnetic resonance imaging (MRI) data from a scan of the head; determining anatomical coordinates in the head based on the CT data or MRI data; further comprising The apparatus of claim 5 , wherein the designated latitude and designated longitude are based on the anatomical coordinates.

9. The operation is creating an anatomically positioned measurement set that includes the anatomically positioned measurements; generating a physical topography of the head from the measurements or rendering an image based on the measurements; The apparatus of claim 5 further comprising:

10. a resistive, inductive, and capacitive (RLC) circuit electrically connected to the coil sensor; a frequency counter electrically connected to the RLC circuit; Furthermore, The operation is generating a measurement based on an output from the frequency counter when the coil sensor is in a cranial position on the head; 10. The apparatus of claim 2, further comprising:

11. the coil sensor is a first coil sensor, the RLC circuit is a first RLC circuit, and the frequency counter is a first frequency counter; The device, a second coil sensor having a diameter larger or smaller than that of the first coil sensor, the first coil sensor and the second coil sensor sharing a housing; a second RLC circuit electrically connected to the second coil sensor; a second frequency counter electrically connected to the second RLC circuit; The apparatus of claim 10 further comprising:

12. The apparatus of claim 1 , wherein the first tilt gauge and the second tilt gauge comprise three-dimensional (3D) accelerometers.

13. The apparatus of claim 1 , wherein the radial expander comprises a scissor device or a telescoping mechanism.

14. A motor; a pulley wheel on said attachment point; a pulley cable extending through the pulley wheel between the motor and the radial expander; Furthermore, 14. The apparatus of claim 1, wherein the motor is located away from the mounting point to avoid electromagnetic interference with the coil sensor.

15. 1. A method for anatomically locating measurements within a subject's brain, comprising: providing a headrest base configured to hold a subject's head, the subject's head having a center point of a notional sphere; a first tilt gauge rigidly attached to the headrest base; a gimbal armature pivotally attached to the headrest base and configured to pivot a mounting point on the gimbal armature in latitude and longitude about the center point; a radial expander attached to the mounting point of the gimbal armature, the radial expander configured to extend an end effector inwardly relative to the center point; a coil sensor secured to the end effector; and a second tilt gauge secured to the coil sensor; comparing the tilt angles from the first tilt gauge and the second tilt gauge to determine the relative orientation of the coil sensor; calculating a three-dimensional (3D) anatomical location of measurements from the coil sensors based on the orientation; A method comprising:

16. adjusting measurements from the coil sensor based on the orientation.

16. The method of claim 15, further comprising:

17. commanding the gimbal armature to a specified latitude and a specified longitude; directing the radial expander to extend the coil sensor to the specified latitude and the specified longitude; generating measurements based on outputs produced by the coil sensors; correlating the measurements with the 3D anatomical location to generate anatomically located measurements; 17. The method of claim 15 or 16, further comprising:

18. the anatomically located measurements are from the left hemisphere of the head, and the method comprises: making anatomically located measurements on the right hemisphere of the head; comparing the measurements from the left and right hemispheres of the head; outputting an indication based on said comparing step; 20. The method of claim 17, further comprising:

19. the anatomically located measurements are previous, and the method comprises: making subsequent anatomically aligned measurements; comparing the earlier and later measurements; outputting an indication based on said comparing step; 20. The method of claim 17, further comprising:

20. 1. A method of manufacturing an inductive sensor device for brain diagnostics, comprising: providing a headrest base configured to hold a subject's head, the subject's head having a center point of a notional sphere; rigidly attaching a first tilt gauge to the headrest base; pivotally mounting a gimbal armature to the headrest base such that the gimbal armature is configured to allow a mounting point on the gimbal armature to pivot in latitude and longitude about the center point; attaching a radial expander to the attachment point of the gimbal armature such that the radial expander is configured to extend an end effector inwardly relative to the center point; affixing a coil sensor to the end effector; fastening a second tilt gauge to the coil sensor; A method comprising:

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