Bio-capacitance sensor

Abstract

The present disclosure provides an apparatus and method for measuring tissue biocapacitance. The apparatus includes a sensor having two electrodes, a movable element coupled to the sensor, and a switch disposed between the movable element and the fixed element, the switch electrically closing when a gap between the movable element and the fixed element is equal to or less than a predetermined value. When the switch is closed, the device performs a measurement of biocapacitance between the two electrodes.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims the benefit of priority of U.S. Provisional Application No. 63 / 004,822, filed on 3 April 2020, which is incorporated herein by reference in its entirety.

[0002] This disclosure provides an apparatus and method for non-invasive evaluation of the biocapacitance of biological tissues. [Background technology]

[0003] Current approaches to measuring biocapacitance require manual control of the pressure applied by the sensing device, as the measured value fluctuates depending on the applied pressure. A means of automatically measuring with the appropriate pressure without the user having to actively control it would improve the reproducibility of the measurements. [Overview of the project]

[0004] In one embodiment, the present disclosure provides and includes an apparatus for measuring the biocapacitance of tissue, the apparatus comprising: a sensor having two electrodes; a movable element coupled to the sensor; a switch positioned between the movable element and a fixed element and configured to close electrically when the gap between the movable element and the fixed element is less than or equal to a predetermined value; a device coupled to the sensor and configured to measure the capacitance between the two electrodes; and a processor coupled to the switch and the device and configured to receive a measurement from the device when the switch is electrically closed.

[0005] In one embodiment, the electrodes are configured such that when the sensor is positioned in close proximity to the tissue, the electric field between the electrodes penetrates into the tissue.

[0006] In one embodiment, the device is configured to repeatedly measure the capacitance between two electrodes at predetermined intervals.

[0007] In one embodiment, the sensor further comprises an insulating cover layer coupled to an electrode, wherein the insulating cover layer is configured to prevent conductive contact between the electrode and the tissue when the sensor is positioned in close proximity to the tissue.

[0008] In one embodiment, the measurement includes comparing the capacitance between electrodes with the capacitance of a reference capacitor.

[0009] In one embodiment, the comparison involves using a sigma-delta method to compare the capacitance between electrodes with the capacitance of a reference capacitor.

[0010] In one embodiment, the device further comprises a visual indicator coupled to a processor, the processor further configured to activate the visual indicator when a switch is closed.

[0011] In one embodiment, the movable element is configured to move along a translation axis relative to the fixed element, and the gap is located on the translation axis.

[0012] In one embodiment, the device further comprises a spring positioned between a movable element and a fixed element, and configured to separate the movable element and the fixed element by providing a force that increases monotonically along the translation axis.

[0013] In one embodiment, the movable element is further configured to allow rotation about at least one of a first axis of rotation perpendicular to the translation axis and a second axis of rotation perpendicular to both the translation axis and the first axis of rotation.

[0014] In one embodiment, the processor is further configured such that the switch is electrically opened after a first measurement is received when the switch is first closed, but before a second measurement can be received.

[0015] In one embodiment, the present disclosure provides and includes an apparatus for measuring the biocapacitance of tissue, the apparatus comprising: a sensor having two electrodes; a device coupled to the sensor and configured to measure the capacitance between the two electrodes; a barcode scanning engine configured to optically scan a machine-readable image and determine a first encoded alphanumeric string in the machine-readable image; and a processor coupled to the device and the engine and configured to receive the measurement from the device and receive the first alphanumeric string from the engine.

[0016] In one embodiment, the processor is further configured to receive a plurality of sequential alphanumeric strings and to associate each of the sequential alphanumeric strings with one of the following: patient, user, examination, intervention, consumable element, endurance element, location, and time.

[0017] In one embodiment, the processor is further configured to associate a first alphanumeric string of the patient with a sequential alphanumeric string.

[0018] In one embodiment, the processor is further configured to transfer the associated alphanumeric string to a data system.

[0019] In some embodiments, the present disclosure provides and includes a method for measuring the biocapacitance of tissue, the method comprising: positioning a sensor comprising a first electrode and a second electrode relative to the patient's skin on the tissue; measuring the capacitance between the two electrodes; optically scanning a primary machine-readable image associated with the patient; determining an encoded primary alphanumeric string in the primary machine-readable image; and associating the capacitance with the primary alphanumeric string.

[0020] In one aspect, the method further includes optically scanning one or more secondary machine-readable images associated with one of a user, an examination, an intervention, a consumable element, a durable element, a location, and a time; determining each encoded secondary alphanumeric character string in each of the one or more secondary machine-readable images; and associating the secondary alphanumeric character string with a primary alphanumeric character string.

[0021] In one aspect, the method further includes transferring the primary alphanumeric character string and the secondary alphanumeric character string to a data system.

Brief Description of the Drawings

[0022] As merely an example, aspects of the present disclosure are described herein with reference to the accompanying drawings. Next, referring specifically and in detail to the drawings, it is emphasized that the details shown are by way of example and for purposes of illustrative discussion of aspects of the present disclosure. In this regard, the description and the drawings, considered separately and together, will make apparent to those skilled in the art how aspects of the present disclosure may be practiced.

[0023] [Figure 1A] A plan view of a toroidal sensor according to the present disclosure. [Figure 1B] A plan view of another aspect of a sensor according to the present disclosure. [Figure 1C] A cross-sectional view of the sensor of FIG. 1A according to the present disclosure. [Figure 1D] A diagram showing an exemplary example of an electric field between two electrodes of the sensor of FIG. 1A according to the present disclosure. [Figure 2] Shows an old model of a capacitor. [Figure 3A] Shows an aspect of a bio-capacitance scanner according to the present disclosure. [Figure 3B-3C] Shows details of the structure of a bio-capacitance scanner according to the present disclosure. [Figure 4A-4C] Shows a series of states of a portion of the scanner of FIG. 3 according to the present disclosure. [Figure 5] Shows a portion of an alternative aspect of the scanner of FIG. 3 according to the present disclosure. [Figure 6] This disclosure illustrates certain aspects of visual indicators. [Figure 7A] This disclosure illustrates another aspect of the biocapacitance scanner. [Figure 7B] This disclosure shows an exploded view of the components of the biocapacitance scanner. [Figures 8A-8D] This disclosure shows a series of states of an apparatus configured to perform the sigma-delta method for measuring capacitance. [Figure 9A] This disclosure shows a hardware block diagram for measuring the capacitance of a sensor. [Figure 9B] This disclosure shows a diagram of a system for measuring, storing, transferring, and accessing measurement data. [Figure 10] This disclosure illustrates a workflow that includes scanning primary and secondary barcodes. [Modes for carrying out the invention]

[0024] This disclosure provides apparatus and methods for measuring the biocapacitance of tissue. In one embodiment, the disclosure provides and includes an apparatus for measuring the biocapacitance of tissue, the apparatus comprising: a sensor having two electrodes; a movable element coupled to the sensor; a switch positioned between the movable element and a stationary element and configured to close electrically when the gap between the movable element and the stationary element is less than or equal to a predetermined value; a device coupled to the sensor and configured to measure the capacitance between the two electrodes; and a processor coupled to the switch and the device and configured to receive a measurement from the device when the switch is electrically closed.

[0025] In one embodiment, the present disclosure provides and includes an apparatus for measuring the biocapacitance of tissue, the apparatus comprising: a sensor having two electrodes; a device coupled to the sensor and configured to measure the capacitance between the two electrodes; a barcode scanning engine configured to optically scan a machine-readable image and determine a first encoded alphanumeric string in the machine-readable image; and a processor coupled to the device and the engine and configured to receive the measurement from the device and receive the first alphanumeric string from the engine.

[0026] In some embodiments, the present disclosure provides and includes a method for measuring the biocapacitance of tissue, the method comprising: positioning a sensor comprising a first electrode and a second electrode relative to the patient's skin on the tissue; measuring the capacitance between the two electrodes; optically scanning a primary machine-readable image associated with the patient; determining an encoded primary alphanumeric string in the primary machine-readable image; and associating the capacitance with the primary alphanumeric string.

[0027] This description is not intended to be a detailed list of all different ways in which the Disclosure may be implemented, or all features that may be added to the Disclosure. For example, a feature illustrated in one aspect may be incorporated into another aspect, and a feature illustrated in a particular aspect may be omitted from that aspect. Accordingly, the Disclosure is intended to allow for the exclusion or omission of any feature or combination of features described herein in some aspects of the Disclosure. In addition, numerous variations and additions to the various aspects suggested herein will be apparent to those skilled in the art from the viewpoint of the Disclosure and will not deviate from the Disclosure. In other examples, well-known structures, interfaces, and processes are not shown in detail so as not to unnecessarily obscure the Invention. Nothing in this Specification is intended to be construed as a negation of any part of the entire scope of the Invention. Accordingly, the following description is intended to illustrate some specific aspects of the Disclosure and not to exhaustively specify all permutations, combinations, and variations thereof.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which this disclosure pertains. Terms used in the descriptions of this disclosure herein are for the purpose of describing specific aspects or embodiments and are not intended to limit this disclosure.

[0029] All publications, patent applications, patents, and other references cited herein are incorporated by reference in their entirety to the teachings relating to the sentences and / or paragraphs in which the references are presented. References to techniques employed herein are intended to refer to techniques commonly understood in the art, including variations of those techniques or substitutions of equivalent techniques that would be apparent to those skilled in the art.

[0030] U.S. Patent Application No. 14 / 827,375 discloses a device that uses radio frequency (RF) energy to measure subcutaneous capacitance using a bipolar sensor similar to sensor 90 shown in Figure 1A. Subcutaneous capacitance correlates with the water content of a target area of ​​the patient's skin. Application 375 also discloses arrays of these bipolar sensors in various sizes.

[0031] U.S. Patent Application No. 15 / 134,110 discloses an apparatus for measuring SEM, which generates a bioimpedance signal by emitting and receiving an RF signal at a frequency of 32 kHz through a single coaxial sensor, and then converts this signal to generate a subcutaneous moisture (SEM) value.

[0032] Both U.S. Patent Applications 14 / 827,375 and 15 / 134,110 are incorporated herein by reference in their entirety.

[0033] Unless otherwise indicated by the context, the various features of this disclosure described herein are specifically intended to be used in any combination. Furthermore, this disclosure also intends to exclude or omit any features or combinations of features described herein in some aspects of this disclosure.

[0034] The methods disclosed herein include one or more steps or actions to achieve the described methods. The steps and / or actions of the methods may be interchangeable with one another without departing from the scope of the invention. In other words, the order and / or use of any particular steps and / or actions may be modified without departing from the scope of the invention, unless a particular order of steps or actions is required for the proper operation of the embodiment.

[0035] Where used in this disclosure and the accompanying claims, the singular forms "a," "an," and "the" are intended to include the plural form unless the context explicitly indicates otherwise.

[0036] As used herein, "and / or" and "or" refer to and encompass any and all possible combinations of one or more of the related enumerated items.

[0037] As used herein, the terms “about” and “approximately” mean that when referring to measurable values ​​such as length, time interval or period, frequency, or SEM values, the specified quantity will include variations of ±20%, ±10%, ±5%, ±1%, ±0.5%, or ±0.1%.

[0038] When used herein, phrases such as "between X and Y" and "about between X and Y" should be interpreted as including X and Y. When used herein, phrases such as "about between X and Y" mean "about between X and about Y," and phrases such as "about X to Y" mean "about X to about Y."

[0039] As used herein, the terms “subepidermal fluid” or “SEM” refer to the water level contained in the tissues beneath the epidermis. Increases in tissue fluid and local edema can be caused by vascular leakage and other changes that alter the basal structure of damaged tissue in the presence of continuous pressure on the tissue, including but not limited to apoptosis, necrosis, and inflammatory processes.

[0040] As used herein, the term “tissue biocapacitance” refers to a biophysical marker for detecting early tissue damage based on increased levels of fluid accumulation in the interstitial space.

[0041] As used herein, “system” may be a collection of devices that are physically connected or that communicate with one another via wired or wireless communication.

[0042] As used herein, “patient” may be a human or animal subject.

[0043] As used herein, “healthy” may describe tissue that does not show signs of damage to the cell wall or blood vessels, and the presence of an increased amount of extracellular fluid (ECF) is an indicator of such damage.

[0044] As used herein, “switch” refers to a device that selectively provides an electrical connection between two elements or contacts. In one embodiment, an electrical connection between two contacts is formed by “closing” or deforming a portion of the switch, thereby closing a circuit, and the electrical connection is interrupted by “opening” or reversing the switch to its original form, thereby opening a circuit. In one embodiment, an electrical connection is formed by applied force, and the connection is interrupted by the removal of force.

[0045] As used herein, “tissue” means a part of the body of a living human or animal. Tissue may include one or more layers from the outermost stratum corneum, subepidermis, epidermis, and deeper layers of muscle, fat, and bone, as well as internal structures such as veins, arteries, capillaries, lymphatic vessels, and nerves.

[0046] As used herein, “biocapacitance” refers to the capacitance of a sensor where the active field protrudes into the tissue.

[0047] As used herein, “spring” refers to an element having force-deformability, where an applied force causes deformation and / or the deformation produces a restorative force.

[0048] As used herein, “insulation” and similar terms refer to the property of an element that prevents significant electrical conduction through it.

[0049] As used herein, “machine-readable image” refers to a pattern containing encoded information that can be observed by a machine and autonomously converted into information, such as a string of alphanumeric characters. In one embodiment, the machine may project a light beam and capture a portion of the reflected light. In one embodiment, the machine may capture a 2D recording of the image, process the image, and thereby extract the encoded information. In one embodiment, the “machine-readable image” may be a radio frequency sensing device, such as a radio frequency identification (RFID) tag, whether passive or active.

[0050] As used herein, “alphanumeric string” means a sequence of characters that may include uppercase or lowercase letters in any language and number. An alphanumeric string may also be encoded in a digital format that is uniquely associated with the alphanumeric string, for example, a string of 0s and 1s.

[0051] As used herein, “optical” in one embodiment refers to the wavelength range of radiation including the “visible” spectrum from about 380 to 740 nanometers (nm). In one embodiment, this range may include a portion of the infrared spectrum above about 740 nm. In one embodiment, this range may include a portion of the ultraviolet spectrum below about 380 nm. In one embodiment, a radio frequency system may be substituted for an optical system.

[0052] As used herein, “data system” means a system comprising one or more of the following: data processing capabilities, data transmission capabilities, and / or data storage capabilities. This data system may be directly coupled to a first processor, or coupled to a second processor that is communicatively coupled to the first processor. Memory elements may include, but are not limited to, solid-state drives (SSDs), spinning hard disk drives, and flash memory, utilizing any available volatile or non-volatile technologies.

[0053] Figure 1A is a plan view of one embodiment of the sensor 90 according to the present disclosure. The toroidal sensor 90 comprises a first electrode 110 embodied as a circular pad and a second electrode 120 embodied as a toroidal around the electrode 110. The embodiment in Figure 1A is axially symmetric and therefore unaffected by angular rotation.

[0054] Figure 1B is a plan view of another embodiment of the sensor 91 according to the present disclosure. In this embodiment, the two electrodes 111 and 121 are composed of a plurality of alternatingly arranged fingers.

[0055] Figure 1C is a cross-sectional view of the sensor 90 of Figure 1A according to this disclosure. In this embodiment, electrodes 110 and 120 are arranged on a common surface of the substrate 100 and are therefore coplanar with each other. In one embodiment, the electrodes may be arranged on different layers or non-planar surfaces of the substrate 100. In one embodiment, an insulating cover layer 130 may be placed on the electrodes 110 and 120 as shown in Figure 1C. The insulating cover layer 130 can prevent conductive contact between either electrode 110, 120 and the skin when the sensor 90 is positioned against the skin. In one embodiment, one or more of electrodes 110 and 120 are exposed and make conductive contact with the skin when the sensor 90 is positioned against the skin. In one embodiment, a plurality of electrodes (not shown in Figure 1C) may be provided on the substrate 100, and the formation of the sensor 90 is controlled by selective connection of measuring circuits (not shown in Figure 1C) from the plurality of electrodes to a first electrode and a second electrode.

[0056] Figure 1D shows an exemplary example of an electric field 140 between two electrodes 110 and 120 of the sensor 90 of Figure 1A, according to this disclosure. The electrodes 110 and 120 are positioned relative to the skin 60 of the patient's tissue 50. A cover layer 130 is omitted from Figure 1D for clarity and may be placed between the electrodes 110, 120 and the skin 60. The field 140 has an effective depth 150 below the skin 60.

[0057] Without being constrained by any theory, the capacitance measured between electrodes 110 and 120 partially depends on the dielectric constant of the tissue 50 within the effective boundary volume of the boundary 140. Since water has a dielectric constant of approximately 81, while dry tissue has a dielectric constant of approximately 4, a slight increase in the amount of water, also called subepidermal water, within the tissue can result in an increase in capacitance measured by the sensor 90.

[0058] Figure 2 shows a traditional model of the capacitor 200 according to this disclosure. The capacitor 200 comprises a first planar electrode 210 and a second planar electrode 220 of the same dimensions, positioned parallel to electrode 210 at a separation distance "d". The space between electrodes 210 and 220 has a relative permittivity ε r The capacitor is filled with a homogeneous material having the following properties, and the charges on electrodes 210 and 220 are indicated by the symbols "-" and "+", respectively. The science of capacitors is well known to those skilled in the art and can be found in standard electrical engineering references.

[0059] Capacitor 200 can hold a charge Q. The voltage difference V between the two electrodes 210 and 220 caused by the charge Q is equal to the relative permittivity ε of the material between the electrodes. r It depends on the capacitance C of capacitor 200, which is calculated by measuring the charge Q supplied to capacitor 200 and the voltage difference V across electrodes 210 and 220 using the equation.

number

[0060] Figure 3A shows one embodiment of the biocapacitance scanner 300 according to the present disclosure. The sensor 310 is located on the "nose" 325 of the main body 320.

[0061] Figure 3B shows details of the structure of the biocapacitance scanner 300 according to this disclosure. The sensor 300, comprising a substrate and electrodes, is fixedly coupled to a carrier 330 comprising an upper part 332 and a shaft 334. The shaft 334 passes through a guide 350. In one embodiment, the shaft 334 can be moved along an axis 336 relative to the guide 350. In one embodiment, the upper part 332 can rotate relative to the shaft 334 around one or more intersecting axes (not shown in Figure 3B) perpendicular to the axis 336. A printed circuit board assembly (PCBA) 340 comprises a substrate 344 positioned below the carrier 330. In one embodiment, the substrate 344 is substantially perpendicular to the axis 336. In one embodiment, a switch 342 is coupled to the substrate 344 and positioned directly below the shaft 334. In one embodiment, the switch 342 is a dome switch that collapses when a force greater than a predetermined value is applied, thereby electrically closing the circuit, where the direction of the force is substantially perpendicular to the substrate 344. In one embodiment, the switch 342 is configured to electrically close the circuit when the force between the sensor 310 and the patient's skin is greater than a predetermined value. In another embodiment, the switch 342 is configured to electrically close the circuit when the gap between a movable element, such as a carrier 330, and a fixed element, such as a guide 350, is less than or equal to a determined value.

[0062] In one embodiment, the switch 342 is coupled to a processor (not shown in Figure 3B), which is also coupled to a device (not shown in Figure 3B) configured to measure the capacitance detected by the sensor 310, such as a capacitance-to-digital converter like Analog Devices' AD7746. In one embodiment, the device is configured to repeatedly measure the capacitance between two electrodes of the sensor 310 at predetermined intervals. In one embodiment, the device measures capacitance at a rate in the range of 1 to 1,000,000 times / second. In one embodiment, the device measures capacitance at a rate in the range of 1,000 to 100,000 times / second. In one embodiment, the device measures capacitance at a rate in the range of 10,000 to 50,000 times / second. In one embodiment, the device measures capacitance at a rate in the range of 20,000 to 40,000 times / second. In one embodiment, the device measures capacitance approximately 34,000 times / second. In one embodiment, the device measures capacitance at this rate regardless of whether switch 342 is electrically open or closed. In one embodiment, the processor accepts the measurement from the device when switch 342 is closed. In one embodiment, the processor records multiple measurements from the device after switch 342 is closed, for example, 10 consecutive measurements. In one embodiment, the processor combines the multiple recorded measurements, for example by averaging, to obtain a single representative "measurement" for further processing. In one embodiment, the processor is reset by opening switch 342 before the processor records another measurement from the device.

[0063] Figure 3C shows details of the structure of the biocapacitance scanner 300 according to the present disclosure. In one embodiment, the guide 350 is fixedly coupled to the main body 320. A bellows 360 (not shown in Figure 3B) is coupled to the guide 350 at its lower edge and to the carrier 330 at its upper edge. In one embodiment, the bellows 360 is made of a flexible material, such as silicone, rubber, or a similar material, which resists compression and functions as a compression spring that applies a force to separate the carrier 330 and the guide 350 along the axis 336. In one embodiment, the spring is positioned between a movable element, such as the carrier 330, and a fixed element, such as the guide 350, and is configured to provide a monotonically increasing force along the translation axis 336 to separate the movable element and the fixed element.

[0064] In one embodiment, the shaft 334 includes a nose 338 adjacent to the switch 342. In one embodiment, when the sensor 310 is pressed against the patient's skin, the carrier 330 (including the shaft 334) is configured to move along the axis 336 toward the PCBA 344 until the nose 338 contacts the switch 342 and compresses the switch 342 with enough pressure to close it. In one embodiment, the capacitance measurement detected by the sensor 310 occurs at a moment when applying higher pressure on the sensor 310 does not affect the capacitance measurement of the sensor 310, such that the measurement is taken when the force reaches a level sufficient to first close the switch 342.

[0065] Figures 4A to 4C show a series of positional states that may be adopted by the portion of the scanner in Figure 3C, indicated by the dashed circle 301, as described herein.

[0066] Figure 4A shows a first configuration of the scanner 300. In this first configuration, the gap 335A between the nose 338 and the PCBA 344 has a first value. The switch 342 protrudes from the surface of the PCBA 344 in the direction of the nose 338, and as a result, the gap between the switch 342 and the nose 338 is smaller. The flange 339 of the carrier 330 is in contact with the stop 352 of the guide 350, which is the highest position of the carrier 330 relative to the guide 350.

[0067] Figure 4B shows a second state of the same scanner 300 as in Figure 4A. A downward force is applied to the carrier 330, thereby moving the carrier 330 downward toward the PCBA 344. The gap 335B is smaller than the gap 335A in Figure 4A, and the switch 342 is compressed sufficiently to electrically close. Further increases in the applied force may move the carrier 330 further downward toward the surface of the PCBA 344, but further compression of the switch 342 does not affect the closing of the switch 342. In this second state, the flange 339 and the stop 352 are not in contact with each other.

[0068] Figure 4C shows a third state of the same scanner 300 as in Figure 4B, after some of the force applied to separate the nose 338 from the switch 342 has been removed so that the switch 342 is electrically open. In one embodiment, the third state is the same as the first state in Figure 4A, with the flange 339 in contact with the stop 352. In one embodiment, the gap 335C is smaller than the gap 335A, and there is a gap (not shown in Figure 4C) between the flange 339 and the stop 352.

[0069] Figure 5 shows details of the configuration of the biocapacitance scanner 500 according to the present disclosure. The scanner 500 has a head 525 equipped with a sensor 510. In this embodiment, the sensor 510 is mounted on a removable cap 512 which is detachably coupled to a holder 540. In one embodiment, the convex surface 532 of the holder 540 has a radius of curvature "R" about a center 538. In one embodiment, the center 538 is on the surface of the interface PCBA 550. In one embodiment, the center 538 is on the surface of the sensor 510. In one embodiment, the center 538 is positioned on an axis 526.

[0070] In one embodiment, the carrier 530 is constrained by a guide mechanism 522 of the body 520 to translate along the axis 526. In one embodiment, the surface 532 of the carrier 530 is concentric with a surface 542 having a radius of curvature slightly larger than R, thus allowing the holder 540 to rotate about a center 538 while maintaining partial contact between the surfaces 532 and 542. The bellows 560 is flexible and allows the holder 540 to rotate about at least one of a first axis of rotation 527 perpendicular to the translation axis 526 and a second axis of rotation 528 (not visible in Figure 5) perpendicular to both the translation axis 526 and the first axis of rotation 527. Since the sensor 510 is fixed to a cap 512 similarly coupled to the holder 540, the rotation of the holder 540 further rotates the sensor 510. In one embodiment, the bellows 560 imparts a restorative rotational force to the holder 540, guiding the holder 540 back to its center position relative to the axes 527 and 528. In one embodiment, this restorative rotational force increases monotonically with increasing rotational angle of the holder 540 about one or both of the axes 527 and 528.

[0071] Figure 6 shows one embodiment of a visual indicator 627 according to the present disclosure. The body 620 includes a front section 624 and a rear section 626. In one embodiment, a translucent gasket 627 is positioned between the front section 624 and the rear section 626. In one embodiment, one or more light sources, for example, one or more light-emitting diodes (LEDs), are positioned close to the inside of the gasket 627 such that when the LEDs are activated, light from the LEDs passes through the gasket 527, causing a portion of the gasket 627 to appear to glow. This glowing mechanism is the visual indicator. In one embodiment, the LEDs are coupled to a scanner processor (not shown in Figure 6), which is also coupled to a switch, for example, switch 342 in Figure 4A. In one embodiment, the processor is configured to activate the LEDs and thus activate the visual indicator when switch 342 is closed. In one embodiment, the visual indicator is provided by internal illumination, for example, a portion of the body 620 that glows from internal LEDs.

[0072] Figure 7A shows another embodiment of the biocapacitance scanner 700 according to the present disclosure. This embodiment includes a barcode scanning engine 730 mounted inside a body 720. The scanning engine 730 includes, for example, an illuminator that emits radiation having a visible light frequency range, and an imager that is sensitive to the radiation across the frequency range emitted by the illuminator. The body 720 includes a window 722, which is positioned such that a portion of the radiation projected by the illuminator passes through the window to the outside, and the field of view of the imager includes a portion of the window. In this way, the radiation from the illuminator can illuminate an object, for example, a machine-readable image printed on a patient's wristband, and the imager can acquire an image of the object, for example, a barcode. In other words, the scanning engine 730 optically scans a barcode, a 2D matrix code, or other machine-readable encoded image. In one embodiment, the scanning engine includes a signal processor that converts the image acquired by the imager into a string of alphanumeric characters. In one embodiment, the scan engine 730 is coupled to a processor and provides the processor with an alphanumeric string, which the processor is configured to receive an alphanumeric string from the scan engine. In one embodiment, the alphanumeric string encodes one of the following: patient, user, examination, intervention, consumable element, endurance element, location, and time. In one embodiment, the processor is further configured to receive a plurality of sequential alphanumeric strings. In one embodiment, the processor is further configured to associate each of the sequential alphanumeric strings with one of the following: patient, user, examination, intervention, consumable element, endurance element, location, and time. In one embodiment, the processor is further configured to associate a first alphanumeric string of a patient with a sequential alphanumeric string. In one embodiment, the processor is further configured to transfer the associated alphanumeric strings to a data system.

[0073] Figure 7B shows an exploded view of the scanner 700 according to the present disclosure. The body 720 includes a front section 721 and a rear section 723, with a gasket 727 sandwiched between them when the front section 721 and the rear section 723 are in contact with each other. In this embodiment, the front section 721 is coupled to a guide 725 coupled to a bellows 726 and a carrier 728 coupled to a sensor 710. The two electrodes of the sensor 710 are coupled via wires (not visible in Figure 7B) to a device 744, for example, a capacitance-to-digital converter (CDC) located on the main board 740 in this example. The device 744 is then communicatively coupled to a processor 742. The processor 742 is also coupled via cables and wires (not visible in Figure 7B) to a display 760, which may further include a touchscreen. In one embodiment, the processor 742 may also be coupled to one or more of the following: a barcode scanning engine 730, a battery 764, a wireless power supply coil 766, and an audible indicator 768. In this embodiment, the audible indicator 768 is a piezoelectric buzzer. The display 760 is visible to the user through a transparent window 762 mounted in an opening in the front section 721. The processor 744 is also operably coupled in this embodiment via a cable to a light-emitting diode (LED) 752 mounted on the headboard 750. The LED is positioned adjacent to the gasket 727 so that when the scanner 700 is assembled, light from the LED 752 shines through the translucent gasket 727, providing a visual indicator.

[0074] Figure 8A shows a schematic diagram of circuit 800 configured to perform the sigma-delta method for measuring capacitance according to this disclosure. Since the sigma-delta method is well known to those skilled in the art and can be found in standard electrical engineering references, only a simplified explanation is provided herein. In this figure, symbols [ka] represents a controllable switch. In one embodiment, circuit 800 is part of another device, for example, CDC744 in Figure 7B.

[0075] Voltage reference V REF (+) and V REF (-) are selectively coupled to the reference capacitor C through the switch pair 850, and then the reference capacitor C REF is selectively coupled to either ground or the input of the integrator 810. The operating configuration of these switches will be described with reference to FIGS. 8C to 8D. In this embodiment, the off-chip capacitor C REF , for example, a capacitor formed by two electrodes of the sensor 710 of the scanner 700 in FIG. 7B, is connected between a first terminal that provides the square-wave excitation voltage 830 and an input of a switch pair 854 that selectively couples the input to either ground or the input of the integrator 810. The output of the integrator 810 is coupled to the integrating capacitor C SENSOR and the input of the comparator 820. The output of the comparator 820 is supplied to the digital filter 840 and becomes either a "0" or "1" signal that controls the configuration of the switch pair 850 as described with respect to FIGS. 8C to 8D. INT

[0076] FIG. 8B shows the voltage states over the sample interval of the circuit of FIG. 8A according to the present disclosure. The upper line "ph1" shows the configuration of the switch pair 850, and the "1" configuration indicates that the switch connected to V REF (+) is closed and the switch connected to V REF (-) is open, and the "0" configuration indicates the reverse. The lower line "ph2" shows the configuration of the switch pair 852, and the "1" configuration indicates that the switch connected to the input of the integrator 810 is closed and the switch connected to ground is open, and the "0" configuration indicates the reverse.

[0077] ​Comparator 820 responds to the input voltage only when the "strobe" signal is "HI" and is inactive when the strobe signal is "LO". When the input is a positive voltage when the strobe is "HI", the output of comparator 820 is a voltage associated with the "1" state. When the input is a negative input when the strobe is "HI", the output is a voltage associated with the "0" state.

[0078] The sequence of states of circuit 800 during a single sampling cycle is as follows:

[0079] At time T0, as shown in Figure 8C, switch pair 850 is in the "1" state, while switch pairs 852 and 854 are in the "0" state, where a solid bar intersecting the switch symbol indicates that the switch is closed. This state is maintained for a duration "D" long enough for the circuit voltage to settle into a steady state. During this time, C REF Charge Q1 is accumulated in C SENSOR A charge Q2 is accumulated in it. Assuming Q = V × C, the amount of charge Q1 is equal to the voltage V. REF (+) and C REF The value of Q1 is known because it is determined by the capacitance of the voltage, and both are known. Similarly, the value of Q2 is determined by the known excitation voltage 830 and the unknown capacitance C. SENSOR It is determined by and

[0080] Around time T1, switch pair 850 reverses to state "0", while the other switch pairs 852 and 854 remain in state "0". This buffer interval prevents both switches in each switch pair from conducting simultaneously.

[0081] At time T2, the switch pair 852 and 854 change to configuration "1" as shown in Figure 8D, and immediately thereafter, charges Q1 and Q2 are both supplied to the input of integrator 810. This configuration is connected to the reference capacitor C REF The known capacitance of C SENSORThis effectively compares with the unknown capacitance. If the sum of Q1 and Q2 is a positive voltage, i.e., greater than the ground connected to the other input of comparator 810, then the output of integrator 810 will be negative. If the sum of Q1 and Q2 is a negative voltage, then the output of integrator 810 will be positive.

[0082] At time T3, the strobe rises, and comparator 820 can change its output to "1" or "0" in response to its input voltage. Over a series of sampling cycles, this creates a string of 1s and 0s as input to digital filter 840. This is processed within the filter and C SENSOR A digital value corresponding to the measured capacitance is determined. This measurement may then be provided to an external device, for example, the processor 742 in Figure 7B.

[0083] Figure 9A shows a hardware block diagram 900 for measuring the capacitance of sensor 910 according to this disclosure. The coupling of the sensor to device 920, e.g., CDC as described with reference to Figure 7B, may consist of an analog signal related to the capacitance measured by sensor 910, as described with reference to Figures 8A-8D. The digital representation of the measured capacitance is obtained between integrated circuits (I 2 C) The data may be provided via the communication line 925 to the host system 930, for example, the processor 744 in Figure 7B.

[0084] Figure 9B shows a schematic diagram of an integrated system 950 for measuring, evaluating, storing, and transferring SEM values ​​according to the present disclosure. In this example, the system 950 includes a scanner 951 having the ability to wirelessly communicate with a WiFi access point 962, as discussed with respect to Figure 7B. The scanner 951 may also communicate with one or more of the following: an SEM application running on a server 960, an application running on a laptop computer 964, a smartphone 970, and other digital devices. In one embodiment, the laptop computer 964 and the smartphone 970 are held by a user of the scanner 951, for example, a nurse, and the application provides feedback and information to the user. In one embodiment, information received from the scanner 951 regarding a patient is recorded in a database 954. In one embodiment, information received from the scanner 951 is transferred via a network 958 to another server 956 that stores some of the information in the patient's electronic health record (EMR) 952. In one embodiment, information retrieved from the scanner 951 or from the database 954 or EMR 952 is transferred to an external server 966, and then to a computer 968, for example, a computer in the office of a doctor providing care for a patient.

[0085] Figure 10 shows a workflow 1000 according to this disclosure, which includes scanning primary and secondary barcodes. The steps shown may be performed in any order, and any step may be omitted or modified.

[0086] In this example, in the first steps 1010, 1020, and 1030, identification information associated with one or more of the patient, caregiver, and current date and time is obtained. In this example, this information is encoded in a barcode or other machine-readable image such as a 2D matrix code and obtained by scanning the barcode.

[0087] Step 1040 includes obtaining information, which may include, but is not limited to, a physical examination, health status, other measurements such as body temperature or weight, and / or other physical artifacts such as photographs or data relating to nutritional intake and hydration. In this example, this information is obtained by scanning barcodes associated with various attributes, for example, a set of barcodes for each element of a meal, scanning the barcode of the item consumed by the user, or a set of barcodes for various amounts of liquid ingested. Step 1040 may also include scanning barcodes associated with other aspects of patient care, which may include, but is not limited to, barcodes associated with medications administered to the patient, barcodes associated with gowns or other general clothing, barcodes associated with medical fluids or medications administered with the IV pump, barcodes associated with treatment protocols, or other activities or items that can be identified by machine-readable images such as barcodes.

[0088] Step 1050 includes activities related to measuring subdural fluid (SEM) values ​​in the patient's body at various locations. Step 1050 includes several executable steps, shown in this example as steps 1051-1056. Step 1051 includes positioning a sensor, such as the sensor 310 of the scanner 300 in Figure 3B, which has first and second electrodes, such as electrodes 110 and 120 in Figure 1A, against a tissue area, such as the patient's skin over the sacrum. Step 1052 includes increasing the pressure on the sensor on the patient's skin until an internal switch, such as switch 342 in Figure 4B, is closed, initiating step 1053 for recording the capacitance measured by the sensor. Step 1054 includes the user removing the sensor from the skin, thereby resetting the measurement circuit. The user then decides in step 1055 whether to perform additional measurements or close the series of measurements at this point. In step 1056, the SEM measurements are transferred to a database that associates capacitance measurements with patient IDs captured in step 1010. In one embodiment, step 1056 may further include storing the data in non-volatile local memory. In one embodiment, no data may be stored in step 1056. In one embodiment, step 1056 may further include storing other information obtained in one or more of steps 1010 to 1050 in the database or local memory.

[0089] Step 1060 involves branching the activity depending on whether treatment is to be performed for this patient. These treatments may include, but are not limited to, the application of bandages, ointments, or other consumables, as well as the use of durable products such as foot orthoses or special mattresses. These treatments may also include, but are not limited to, procedural treatments, such as repositioning the patient at 2-hour intervals compared to a standard 8-hour interval. The treatments performed may relate to the tissue injury being assessed by the scanner, but do not exclude treatments related to other types of injury or health conditions. In Step 1070, in this example, these treatments are identified by scanning barcodes associated with the initiation, modification, or cessation of treatment. In Step 1080, this information retrieval is repeated for all treatments.

[0090] While the present invention has been described with reference to specific embodiments, those skilled in the art will understand that various modifications can be made and equivalents can be substituted for their elements without departing from the scope of the invention. Furthermore, many modifications can be made to the teachings of the invention for specific situations or materials without departing from the scope of the invention. Accordingly, the present invention is not limited to the specific embodiments disclosed, and is intended to encompass all embodiments within the scope and spirit of the appended claims.

[0091] As stated above, this disclosure can be embodied in a variety of ways, including but not limited to the following:

[0092] Embodiment 1: An apparatus for measuring the biocapacitance of tissue, the apparatus comprising: a sensor having two electrodes; a movable element coupled to the sensor; a switch positioned between the movable element and a fixed element and configured to close electrically when the gap between the movable element and the fixed element is less than or equal to a predetermined value; a device coupled to the sensor and configured to measure the capacitance between the two electrodes; and a processor coupled to the switch and the device and configured to receive a measurement value from the device when the switch is electrically closed.

[0093] Embodiment 2: The apparatus according to Embodiment 1, wherein the electrodes are configured such that the electric field between the electrodes penetrates into the tissue when the sensor is positioned in close proximity to the tissue.

[0094] Embodiment 3: The apparatus according to Embodiment 1 or 2, wherein the device is configured to repeatedly measure the capacitance between two electrodes at predetermined intervals.

[0095] Embodiment 4: The apparatus according to any one of Embodiments 1 to 3, wherein the sensor further comprises an insulating cover layer coupled to an electrode, the insulating cover layer being configured to prevent conductive contact between the electrode and tissue when the sensor is positioned in close proximity to tissue.

[0096] Embodiment 5: The apparatus according to any one of Embodiments 1 to 4, wherein the measurement includes a comparison of the capacitance between electrodes with the capacitance of a reference capacitor.

[0097] Embodiment 6: The apparatus according to Embodiment 5, wherein the comparison includes the use of a sigma-delta method to compare the capacitance between electrodes with the capacitance of a reference capacitor.

[0098] Embodiment 7: The apparatus according to any one of Embodiments 1 to 6, further comprising a visual indicator coupled to the processor, wherein the processor is further configured to activate the visual indicator when a switch is closed.

[0099] Embodiment 8: The apparatus according to any one of Embodiments 1 to 7, wherein a movable element is configured to move along a translation axis relative to a fixed element, and a gap is located on the translation axis.

[0100] Embodiment 9: The apparatus according to Embodiment 8, further comprising a spring positioned between a movable element and a fixed element and configured to provide a monotonically increasing force along a translation axis to separate the movable element and the fixed element.

[0101] Embodiment 10: The apparatus according to Embodiment 8, wherein the movable element is further configured to allow rotation about at least one of a first axis of rotation perpendicular to the translation axis and a second axis of rotation perpendicular to both the translation axis and the first axis of rotation.

[0102] Embodiment 11: The apparatus according to any one of embodiments 1 to 10, wherein the processor is further configured such that the switch is electrically opened after a first measurement is received when the switch is first closed, but before a second measurement can be received.

[0103] Embodiment 12: An apparatus for measuring the biocapacitance of tissue, the apparatus comprising: a sensor having two electrodes; a device coupled to the sensor and configured to measure the capacitance between the two electrodes; a barcode scanning engine configured to optically scan a machine-readable image and determine an encoded first alphanumeric string in the machine-readable image; and a processor coupled to the device and the engine and configured to receive a measurement from the device and receive the first alphanumeric string from the engine.

[0104] Embodiment 13: The apparatus according to Embodiment 12, wherein the processor is further configured to receive a plurality of sequential alphanumeric strings and to associate each of the sequential alphanumeric strings with one of the following: patient, user, examination, intervention, consumable element, endurance element, location, and time.

[0105] Embodiment 14: The apparatus according to Embodiment 13, wherein the processor is further configured to associate a first alphanumeric string of a patient with a sequential alphanumeric string.

[0106] Embodiment 15: The apparatus according to Embodiment 13, wherein the processor is further configured to transfer an associated alphanumeric string to a data system.

[0107] Embodiment 16: A method for measuring the biocapacitance of tissue, the method comprising: positioning a sensor comprising a first electrode and a second electrode relative to the patient's skin on tissue; measuring the capacitance between the two electrodes; optically scanning a primary machine-readable image associated with the patient; determining an encoded primary alphanumeric string in the primary machine-readable image; and associating the capacitance with the primary alphanumeric string.

[0108] Embodiment 17: The method according to claim 16, further comprising optically scanning one or more secondary machine-readable images associated with one of a user, examination, intervention, consumable element, durability element, location, and time; determining a two-dimensional alphanumeric string encoded in each of the one or more secondary machine-readable images; and associating the two-dimensional alphanumeric string with a primary alphanumeric string.

[0109] Embodiment 18: The method according to claim 17, further comprising transferring a primary alphanumeric string and a secondary alphanumeric string to a data system.

Claims

1. 1. An apparatus for measuring biocapacitance of tissue, said apparatus comprising: a sensor comprising two electrodes; a movable element coupled to the sensor; a switch disposed between the movable element and the fixed element, the switch being configured to electrically close when a gap between the movable element and the fixed element is equal to or smaller than a predetermined value; a device coupled to the sensor and configured to perform a measurement of capacitance between the two electrodes; a processor coupled to the switch and the device and configured to receive a measurement from the device when the switch is electrically closed.

2. The device of claim 1 , wherein the electrodes are configured such that an electric field between the electrodes penetrates into the tissue when the sensor is positioned proximate to the tissue.

3. The apparatus of claim 1 , wherein the device is configured to repeatedly measure the capacitance between the two electrodes at predetermined intervals.

4. 10. The device of claim 1, wherein the sensor further comprises an insulating cover layer coupled to the electrode, the insulating cover layer configured to prevent conductive contact between the electrode and the tissue when the sensor is positioned adjacent to the tissue.

5. The apparatus of claim 1 , wherein the measuring comprises comparing the capacitance between the electrodes to the capacitance of a reference capacitor.

6. 6. The apparatus of claim 5, wherein the comparison comprises using a sigma-delta method to compare the capacitance between the electrodes with the capacitance of the reference capacitor.

7. The apparatus of claim 1 , further comprising a visual indicator coupled to the processor, the processor further configured to activate the visual indicator upon closure of the switch.

8. the movable element is configured to move along a translational axis relative to the fixed element; The apparatus of claim 1 , wherein the gap is disposed on the translation axis.

9. 10. The apparatus of claim 8, further comprising a spring positioned between the movable element and the fixed element and configured to provide a monotonically increasing force along the translational axis to separate the movable element and the fixed element.

10. 9. The apparatus of claim 8, wherein the movable element is further configured to permit rotation about at least one of a first axis of rotation that is perpendicular to the translational axis and a second axis of rotation that is perpendicular to both the translational axis and the first axis of rotation.

11. 2. The apparatus of claim 1, wherein the processor is further configured such that after a first measurement is received upon a first closure of the switch, the switch is electrically opened before a second measurement can be received.

12. 1. An apparatus for measuring biocapacitance of tissue, said apparatus comprising: a sensor comprising two electrodes; a device coupled to the sensor and configured to perform a measurement of capacitance between the two electrodes; a barcode scan engine configured to optically scan a machine-readable image to determine a first alphanumeric string encoded in the machine-readable image; a processor coupled to the device and the engine, the processor configured to receive measurements from the device and receive the first alphanumeric string from the engine.

13. the processor: receiving a plurality of sequential alphanumeric strings; 13. The device of claim 12, further configured to associate each of the sequential alphanumeric strings with one of a patient, a user, a consultation, an intervention, a wear factor, a durability factor, a location, and a time.

14. the processor:

14. The device of claim 13, further configured to associate the first alphanumeric string of a patient with the sequential alphanumeric string.

15. the processor:

14. The apparatus of claim 13, further configured to transfer the associated alphanumeric string to a data system.

16. 1. A method for measuring biocapacitance of tissue, said method comprising: positioning a sensor comprising a first electrode and a second electrode against the patient's skin over the tissue; measuring the capacitance between the two electrodes; optically scanning a primary machine-readable image associated with the patient; determining an encoded primary alphanumeric string in the primary machine-readable image; and associating said capacitance with said primary alphanumeric string.

17. optically scanning one or more secondary machine-readable images associated with one of a user, an encounter, an intervention, a wear factor, a durability factor, a location, and a time; determining a respective encoded secondary alphanumeric string in each of the one or more secondary machine-readable images; 17. The method of claim 16, further comprising associating the secondary alphanumeric string with the primary alphanumeric string.

18. 18. The method of claim 17, further comprising transferring the primary alphanumeric string and the secondary alphanumeric string to a data system.

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