Biological capacitive sensor

Abstract

The present disclosure provides devices and methods for measuring biocapacitance of tissue. The apparatus comprises: a sensor comprising two electrodes; a movable element, the movable element being coupled to the sensor; and a switch disposed between the movable element and a fixed element, where the switch is electrically closed when a gap between the movable element and the fixed element is less than or equal to a predetermined value. When the switch is closed, the device measures biological capacitance between the two electrodes.

Description

[0001] This application is a divisional application of patent application 202180025319.8, which has entered the Chinese national phase of PCT application with international application number PCT / US2021 / 023818 and international application date March 24, 2021.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 004,822, filed April 3, 2020, which is incorporated herein by reference in its entirety. Technical Field

[0004] The present disclosure provides apparatus and methods for non-invasive assessment of biocapacitance of living tissue. Background Art

[0005] Current methods for measuring biocapacitance require manual control of the pressure applied by the sensing device, as measurements vary depending on the applied pressure. A method that automatically performs measurements at the appropriate applied pressure without requiring the user to actively control pressure would improve measurement repeatability. Summary of the Invention

[0006] In one aspect, the present disclosure provides and encompasses an apparatus for measuring biocapacitance of tissue, the apparatus comprising: a sensor comprising two electrodes; a movable element coupled to the sensor; a switch disposed between the movable element and a fixed element and configured to be electrically closed when a gap between the movable element and the fixed element is less than or equal to a determined 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 the measurement from the device when the switch is electrically closed.

[0007] In one aspect, the electrodes are configured such that when the sensor is positioned proximate to the tissue, the electric field between the electrodes penetrates into the tissue.

[0008] In one aspect, the apparatus is configured to repeatedly measure the capacitance between the two electrodes at predetermined intervals.

[0009] In one aspect, the sensor further comprises an insulating cover coupled to the electrode, and wherein the insulating cover is configured to prevent conductive contact between the electrode and the tissue when the sensor is positioned proximate to the tissue.

[0010] In one aspect, the measuring comprises comparing the capacitance between the electrodes to the capacitance of a reference capacitor.

[0011] In one aspect, the comparing includes using a sigma-delta method of comparing the capacitance between the electrodes to a capacitance of the reference capacitor.

[0012] In one aspect, the device further comprises a visual indicator coupled to the processor, wherein the processor is further configured to activate the visual indicator when the switch is closed.

[0013] In one aspect, the movable element is configured to move along a translation axis relative to the fixed element, and the gap is disposed on the translation axis.

[0014] In one aspect, the apparatus further includes a spring positioned between the movable element and the fixed element and configured to provide a monotonically increasing force along the translation axis to separate the movable element from the fixed element.

[0015] In one aspect, the movable element is further configured to allow rotation about at least one of a first rotation axis perpendicular to the translation axis and a second rotation axis perpendicular to both the translation axis and the first rotation axis.

[0016] In one aspect, the processor is further configured to cause the switch to be electrically opened after receiving a first measurement when the switch is first closed and before a second measurement can be received.

[0017] In one aspect, the present disclosure provides and encompasses an apparatus for measuring biocapacitance of tissue, the apparatus comprising: a sensor comprising two electrodes; a device coupled to the sensor and configured to measure capacitance between the two electrodes; a barcode scanning engine configured to optically scan a machine-readable image and determine a first alphanumeric string encoded 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 the first alphanumeric string from the engine.

[0018] In one aspect, the processor is further configured to receive a plurality of consecutive alphanumeric character strings, and to associate each of the consecutive alphanumeric character strings with one of a patient, a user, an observation, an intervention, a consumable element, a durable element, a location, and a time.

[0019] In one aspect, the processor is further configured to associate the patient's first alphanumeric string with the sequential alphanumeric string.

[0020] In one aspect, the processor is further configured to transmit the associated alphanumeric string to a data system.

[0021] In one aspect, the present disclosure provides and encompasses a method of measuring biocapacitance of tissue, the method comprising positioning a sensor comprising a first electrode and a second electrode against the skin of a patient over the tissue, measuring a capacitance between the two electrodes, optically scanning a primary machine-readable image associated with the patient, determining a primary alphanumeric string encoded in the primary machine-readable image, and associating the capacitance with the primary alphanumeric string.

[0022] In one aspect, the method further includes optically scanning one or more secondary machine-readable images associated with one of a user, an observation, an intervention, a consumable element, a durable element, a location, and a time; determining a secondary alphanumeric string encoded in each of the one or more secondary machine-readable images; and associating the secondary alphanumeric string with the primary alphanumeric string.

[0023] In one aspect, the method further comprises transmitting the primary and secondary alphanumeric character strings to a data system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Various aspects of the present disclosure are described herein by way of example only with reference to the accompanying drawings. With specific reference now to the drawings in detail, it should be emphasized that the details shown are by way of example and are intended for illustrative discussion of various aspects of the present disclosure. In this regard, the description and drawings, taken individually and together, will make apparent to those skilled in the art how various aspects of the present disclosure may be practiced.

[0025] Figure 1A is a plan view of a ring sensor according to the present disclosure.

[0026] Figure 1B is a plan view of another aspect of a sensor according to the present disclosure.

[0027] Figure 1C According to the present disclosure Figure 1A Cross-sectional view of the sensor.

[0028] Figure 1D Depicted according to the present disclosure Figure 1A Illustrative example of the electric field between two electrodes of a sensor.

[0029] Figure 2 Depicted is the classic model of a capacitor.

[0030] Figure 3A An aspect of a biocapacitive scanner according to the present disclosure is depicted.

[0031] Figures 3B-3CDepicted are construction details of a biocapacitive scanner according to the present disclosure.

[0032] Figures 4A-4C Depicted is a state sequence of a portion of the scanner of FIG. 3 in accordance with the present disclosure.

[0033] Figure 5 Depicted is a portion of an alternative aspect of the scanner of FIG. 3 in accordance with the present disclosure.

[0034] Figure 6 An aspect of a visual indicator according to the present disclosure is depicted.

[0035] Figure 7A Another aspect of a biocapacitive scanner according to the present disclosure is depicted.

[0036] Figure 7B Depicted is an exploded view of components of a biocapacitive scanner according to the present disclosure.

[0037] Figures 8A-8D Depicted is a state sequence of a device configured to perform a sigma-delta method of measuring capacitance according to the present disclosure.

[0038] Figure 9A Depicted is a hardware block diagram for measuring capacitance of a sensor according to the present disclosure.

[0039] Figure 9B Depicted is a diagram of a system for measuring, storing, transmitting, and accessing measurement data in accordance with the present disclosure.

[0040] Figure 10 A workflow including scanning primary and secondary barcodes according to the present disclosure is depicted. DETAILED DESCRIPTION

[0041] The present disclosure provides an apparatus and method for measuring the biocapacitance of tissue. In one aspect, the present disclosure provides and encompasses an apparatus for measuring the biocapacitance of tissue, the apparatus comprising: a sensor comprising two electrodes; a movable element coupled to the sensor; a switch disposed between the movable element and a fixed element and configured to electrically close when a gap between the movable element and the fixed element is less than or equal to a determined 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 the measurement from the device when the switch is electrically closed.

[0042] In one aspect, the present disclosure provides and encompasses an apparatus for measuring biocapacitance of tissue, the apparatus comprising: a sensor comprising two electrodes; a device coupled to the sensor and configured to measure capacitance between the two electrodes; a barcode scanning engine configured to optically scan a machine-readable image and determine a first alphanumeric string encoded 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 the first alphanumeric string from the engine.

[0043] In one aspect, the present disclosure provides and encompasses a method of measuring biocapacitance of tissue, the method comprising positioning a sensor comprising a first electrode and a second electrode against the skin of a patient over the tissue, measuring a capacitance between the two electrodes, optically scanning a primary machine-readable image associated with the patient, determining a primary alphanumeric string encoded in the primary machine-readable image, and associating the capacitance with the primary alphanumeric string.

[0044] This description is not intended to be an exhaustive list of all the different ways in which the present disclosure may be implemented or all the features that may be added to the present disclosure. For example, features illustrated in relation to one aspect may be incorporated into other aspects, and features illustrated in relation to a particular aspect may be deleted from the aspect. Therefore, the present disclosure contemplates that, in some aspects of the present disclosure, any feature or combination of features set forth herein may be excluded or omitted. In addition, many variations and additions to the various aspects suggested herein will be apparent to those skilled in the art, in light of the present disclosure, and these many variations and additions will not depart from the present disclosure. In other cases, well-known structures, interfaces, and processes are not shown in detail to avoid unnecessarily obscuring the present invention. No part of this specification is intended to be construed as denying any part of the full scope of the present invention. Therefore, the following description is intended to illustrate some specific aspects of the present disclosure, rather than exhaustively specifying all permutations, combinations, and variations thereof.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terms used herein when describing the present disclosure are for the purpose of describing particular aspects or embodiments only and are not intended to limit the present disclosure.

[0046] All publications, patent applications, patents, and other references cited herein are incorporated by reference in their entirety for the teachings relevant to the sentence and / or paragraph in which the reference is found. References to techniques employed herein are intended to refer to techniques commonly understood in the art, including variations thereto or substitutions of equivalent techniques that would be apparent to those skilled in the art.

[0047] U.S. Patent Application Serial No. 14 / 827,375 discloses a device that uses radio frequency (RF) energy to generate a signal similar to that of a Figure 1A The '375 application also discloses arrays of these bipolar sensors of various sizes.

[0048] US patent application serial number 15 / 134,110 discloses a device for measuring subepidermal moisture (SEM) by transmitting and receiving RF signals at a frequency of 32 kHz through a single coaxial sensor and generating a bioimpedance signal, which is then converted to generate a SEM value.

[0049] Both U.S. Patent Application Serial Nos. 14 / 827,375 and 15 / 134,110 are incorporated herein by reference in their entirety.

[0050] Unless the context indicates otherwise, it is clearly intended that the various features of the present disclosure described herein can be used in any combination. In addition, the present disclosure also contemplates that, in some aspects of the present disclosure, any feature or feature combination set forth herein can be excluded or omitted.

[0051] The method disclosed herein comprises and includes one or more steps or actions for realizing the described method.Method steps and / or actions can be interchangeable with each other without departing from the scope of the present invention.In other words, unless the correct operation aspect requires a specific order of steps or actions, otherwise, without departing from the scope of the present invention, the order and / or use of specific steps and / or actions can be modified.

[0052] As used in the description of the present disclosure and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0053] As used herein, "and / or" and "or" refer to and encompass any and all possible combinations of one or more of the associated listed items.

[0054] As used herein, the terms "about" and "approximately" when referring to a measurable value such as a length, a time interval or period, a frequency, or a SEM value are meant to encompass variations of ±20%, ±10%, ±5%, ±1%, ±0.5%, or even ±0.1% of the specified amount.

[0055] As used herein, phrases such as "between X and Y" and "between about X and Y" should be interpreted to include X and Y. As used herein, phrases such as "between about X and Y" mean "between about X and about Y" and phrases such as "from about X to Y" mean "from about X to about Y."

[0056] As used herein, the term "subepidermal water" or "SEM" refers to the level of water contained in the tissue beneath the epidermis. Increases in interstitial fluid and localized edema can result from sustained stress on the tissue, including but not limited to the presence of apoptotic, necrotic, and inflammatory processes, due to vascular leakage and other changes that modify the underlying structure of the damaged tissue.

[0057] As used herein, the term "tissue biocapacitance" refers to a biophysical marker used to detect incipient tissue injury based on increased levels of fluid accumulated in the interstitial space.

[0058] As used herein, a "system" may be a collection of devices that are physically coupled or in wired or wireless communication with each other.

[0059] As used herein, a "patient" can be a human or animal subject.

[0060] As used herein, "healthy" may describe tissue that does not exhibit symptoms of damage to cell walls or blood vessels, where the presence of increased extracellular fluid (ECF) volume is indicative of such damage.

[0061] As used herein, a "switch" refers to a device that selectively provides an electrical connection between two elements or contacts. In one aspect, "closing," or deforming a portion of a switch, creates an electrical connection between the two contacts, thereby closing a circuit, and "opening," or reversing the switch to its original position, breaks the electrical connection, thereby opening a circuit. In one aspect, applied pressure creates an electrical connection, and removing the force breaks the connection.

[0062] As used herein, "tissue" refers to a part of the body of a living person or animal. Tissue can include one or more layers from the outermost stratum corneum, subepidermal layer, epidermis and deeper layers of muscle, fat and bone, as well as internal structures such as veins, arteries, capillaries, lymphatic vessels and nerves.

[0063] As used herein, "biocapacitance" refers to the capacitance of a sensor whose active field projects into tissue.

[0064] As used herein, "spring" refers to an element having a force-deformation characteristic, wherein an applied force produces a deformation and / or the deformation produces a restoring force.

[0065] As used herein, "insulating" and like terms refer to a property of a component that prevents significant electrical conduction through the component.

[0066] As used herein, a "machine-readable image" refers to a pattern containing encoded information that can be observed by a machine and autonomously converted into information, such as an alphanumeric string. In one aspect, the machine can project a light beam and capture a portion of the reflected light. In one aspect, the machine can capture a 2D record of the image and process the image to extract the encoded information. In one aspect, the "machine-readable image" can be a radio frequency-sensitive device, such as a radio frequency identification (RFID) tag, whether passive or active.

[0067] As used herein, an "alphanumeric string" refers to a sequence of characters that may include uppercase or lowercase letters of any language and numbers. An alphanumeric string may also be encoded in digital form, such as a string of 0s and 1s that is uniquely associated with the alphanumeric string.

[0068] As used herein, "optical" refers to a range of radiation wavelengths that includes, in one aspect, the "visible" spectrum from approximately 380 nanometers to 740 nanometers (nm). In one aspect, this range can include a portion of the infrared spectrum above approximately 740 nm. In one aspect, this range can include a portion of the ultraviolet spectrum below approximately 380 nm. In one aspect, a radio frequency system can be replaced with an equivalent optical system.

[0069] As used herein, a "data system" refers to a system that includes one or more of data processing capabilities, data transmission capabilities, and / or data storage capabilities. This data system may be directly coupled to a first processor or may be coupled to a second processor that is communicatively coupled to the first processor. The storage element may utilize any available volatile or non-volatile technology, including but not limited to solid-state drives (SSDs), rotating hard drives, and flash memory.

[0070] Figure 1A is a plan view of an aspect of a sensor 90 according to the present disclosure. The ring sensor 90 includes a first electrode 110 embodied as a circular pad and a second electrode 120 embodied as a ring surrounding the electrode 110 . Figure 1A The aspect is axisymmetric and therefore insensitive to angular rotation.

[0071] Figure 1B is a plan view of another aspect of a sensor 91 according to the present disclosure. In this aspect, two electrodes 111 and 121 are configured with a plurality of interleaved fingers.

[0072] Figure 1C According to the present disclosure Figure 1A1. A cross-sectional view of sensor 90 is shown. In this aspect, electrodes 110 and 120 are disposed on a common surface of substrate 100 and are therefore coplanar with each other. In one aspect, the electrodes may be disposed on different layers or non-planar surfaces of substrate 100. In one aspect, an insulating cover layer 130 may be disposed over electrodes 110 and 120, such as Figure 1C As shown. When the sensor 90 is positioned against the skin, the insulating cover 130 can prevent conductive contact between the electrodes 110, 120 and the skin. In one aspect, when the sensor 90 is positioned against the skin, one or more of the electrodes 110 and 120 are exposed and in conductive contact with the skin. In one aspect, a plurality of electrodes ( Figure 1C ), and the sensor 90 is formed by placing the measuring circuit ( Figure 1C (not shown) is selectively connected to a first electrode and a second electrode from a plurality of electrodes for control.

[0073] Figure 1D Depicted according to the present disclosure Figure 1A 1 and 120 are positioned against the skin 60 of the patient's tissue 50. For clarity, Figure 1D The cover layer 130 is omitted in FIG. 1 and may be positioned between the electrodes 110 , 120 and the skin 60 . The field 140 has an effective depth 150 below the skin 60 .

[0074] Without being bound by any theory, the capacitance measured between electrodes 110 and 120 depends in part on the dielectric constant of tissue 50 within the effective field volume of field 140. Because the dielectric constant of water is approximately 81, while the dielectric constant of dry tissue is approximately 4, a small increase in the amount of water within the tissue (also known as subcutaneous water) may result in an increase in the capacitance measured by sensor 90.

[0075] Figure 2 A classical model of a capacitor 200 according to the present disclosure is depicted. The capacitor 200 includes a first planar electrode 210 and a second planar electrode 220 of the same size placed parallel to the electrode 210 at a spacing distance "d". The space between the electrodes 210 and 220 is filled with a dielectric having a relative dielectric constant ε r The charge on electrodes 210 and 220 is shown as "-" and "+" symbols, respectively. The science of capacitors is well known to those skilled in the art and can be found in standard electrical engineering references.

[0076] The capacitor 200 can hold a charge Q. The voltage difference V between the two electrodes 210 and 220 generated by the charge Q depends on the relative dielectric constant ε of the material between the electrodes.r The capacitance C of capacitor 200 can be determined by measuring the charge Q supplied to capacitor 200 and the voltage difference V across electrodes 210 and 220 and using the equation C=Q / V.

[0077] Figure 3A An aspect of a biocapacitive scanner 300 according to the present disclosure is depicted. A sensor 310 is positioned on the "nose" 325 of a body 320.

[0078] Figure 3B Depicts the construction details of a biocapacitive scanner 300 according to the present disclosure. The sensor 300, including the substrate and electrodes, is fixedly coupled to a carrier 330 including a top 332 and a shaft 334. The shaft 334 passes through a guide 350. In one aspect, the shaft 334 can move relative to the guide 350 along an axis 336. In one aspect, the top 332 can move relative to the shaft 334 about one or more intersecting axes ( Figure 3B (not shown) rotates. A printed circuit board assembly (PCBA) 340 includes a substrate 344 positioned below the carrier 330. In one aspect, the substrate 344 is substantially perpendicular to the axis 336. In one aspect, a switch 342 is coupled to the substrate 344 and positioned directly below the axis 334. In one aspect, the switch 342 is a dome switch that can collapse, thereby electrically closing a circuit, when a force greater than or equal to a predetermined value is applied, wherein the direction of the force is substantially perpendicular to the substrate 344. In one aspect, 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 one aspect, the switch 342 is configured to electrically close the circuit when the gap between the movable element (e.g., the carrier 330) and the fixed element (e.g., the guide 350) is less than or equal to a determined value.

[0079] On the one hand, the switch 342 is coupled to the processor ( Figure 3B ), the processor is also coupled to the device ( Figure 3BIn one aspect, the device is configured to repeatedly measure the capacitance between the two electrodes of the sensor 310 at predetermined intervals. In one aspect, the device measures the capacitance at a rate ranging from 1 to 1,000,000 times per second. In one aspect, the device measures the capacitance at a rate ranging from 1000 to 100,000 times per second. In one aspect, the device measures the capacitance at a rate ranging from 10,000 to 50,000 times per second. In one aspect, the device measures the capacitance at a rate ranging from 20,000 to 40,000 times per second. In one aspect, the device measures the capacitance approximately 34,000 times per second. In one aspect, the device measures the capacitance at this rate regardless of whether the switch 342 is electrically open or closed. In one aspect, the processor accepts the measurement from the device when the switch 342 is closed. In one aspect, the processor records multiple measurements, e.g., ten consecutive measurements, from the device after switch 342 is closed. In one aspect, the processor combines the multiple recorded measurements, e.g., by averaging, to obtain a single representative "measurement" for use in further processing. In one aspect, the processor is reset by opening switch 342 before the processor records another measurement from the device.

[0080] Figure 3C Depicts the construction details of the biocapacitive scanner 300 according to the present disclosure. In one aspect, the guide 350 is fixedly coupled to the body 320. The bellows 360 ( Figure 3B 350) is coupled at a lower edge to the guide 350 and at an upper edge to the carrier 330. In one aspect, the bellows 360 is comprised of a flexible material, such as silicone, rubber, or the like, that resists compression and acts as a compression spring, applying a force to separate the carrier 330 from the guide 350 along the axis 336. In one aspect, the spring is positioned between the movable element (e.g., the carrier 330) and the fixed element (e.g., the guide 350) and is configured to provide a monotonically increasing force along the translation axis 336 to separate the movable element from the fixed element.

[0081] In one aspect, shaft 334 includes a nose portion 338 that is proximate to switch 342. In one aspect, when sensor 310 is pressed against the patient's skin, carrier 330 (including shaft 334) is configured to move along axis 336 toward PCBA 344 until nose portion 338 contacts switch 342 and compresses switch 342 with a pressure sufficient to close switch 342. In one aspect, the measurement of the capacitance detected by sensor 310 occurs at a moment when the application of a higher pressure to sensor 310 does not affect the capacitance measurement of sensor 310 because the measurement is taken when the force first reaches a level sufficient to close switch 342.

[0082] Figures 4A-4C Describes the Figure 3C The sequence of position states adopted by the scanner portion is indicated by the dashed circle 301 .

[0083] Figure 4A The first configuration state of the scanner 300 is depicted. In this first state, 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 toward the nose 338, resulting in a smaller gap between the switch 342 and the nose 338. The flange 339 of the carrier 330 contacts the stop 352 of the guide 350, indicating the highest position of the carrier 330 relative to the guide 350.

[0084] Figure 4B Depicts Figure 4A A second state of the same scanner 300 is shown. A downward force is applied to the carrier 330, causing the carrier 330 to move downward toward the PCBA 344. The gap 335B is smaller than Figure 4A The gap 335A is removed, and the switch 342 has been compressed sufficiently to electrically close the switch 342. Further increases in the applied force may cause the carrier 330 to move further downward toward the surface of the PCBA 344, but further compression of the switch 342 will not affect the closure of the switch 342. In this second state, the flange 339 and the stopper 352 are not in contact with each other.

[0085] Figure 4C Depicts Figure 4B The third state of the same scanner 300 after removing some of the applied force to separate the nose 338 from the switch 342, causing the switch 342 to be electrically disconnected. Figure 4A The first state is the same as that of the first state, and the flange 339 is in contact with the stopper 352. On the one hand, the gap 335C is smaller than the gap 335A and there is a gap between the flange 339 and the stopper 352 (at Figure 4C not shown).

[0086] Figure 5Depicted are construction details of a biocapacitive scanner 500 according to the present disclosure. Scanner 500 has a head 525 with a sensor 510. In this aspect, sensor 510 is mounted in a removable cap 512, which is removably coupled to a holder 540. In one aspect, convex surface 532 of holder 540 has a radius of curvature "R" about a center 538. In one aspect, center 538 is on the surface of interface PCBA 550. In one aspect, center 538 is on the surface of sensor 510. In one aspect, center 538 is positioned on axis 526.

[0087] In one aspect, the carrier 530 is constrained by the guide feature 522 of the body 520 to translate along the axis 526. In one aspect, the surface 532 of the carrier 530 is concentric with the surface 542 and has a radius of curvature slightly greater than R, thereby enabling the holder 540 to rotate about the center 538 while maintaining contact between portions of the surfaces 532 and 542. The bellows 560 is flexible and allows the holder 540 to rotate about a first rotation axis 527 perpendicular to the translation axis 526 and a second rotation axis 528 perpendicular to both the translation axis 526 and the first rotation axis 527 (at Figure 5 At least one of the two axes (not visible in the figure) rotates. Because sensor 510 is fixed to cap 512, which is in turn coupled to retainer 540, rotation of retainer 540 also rotates sensor 510. In one aspect, bellows 560 applies a restoring rotational force to retainer 540 to induce retainer 540 to return to a centered position relative to axes 527 and 528. In one aspect, this restoring rotational force increases monotonically as the angle of rotation of retainer 540 about one or both axes 527 and 528 increases.

[0088] Figure 6 An aspect of a visual indicator 627 according to the present disclosure is depicted. The body 620 includes a front portion 624 and a rear portion 626. In one aspect, a translucent gasket 627 is positioned between the front portion 624 and the rear portion 626. In one aspect, one or more light sources, such as one or more light emitting diodes (LEDs), are positioned proximate the inside of the gasket 627 such that when the LEDs are activated, light from the LEDs passes through the gasket 627 and a portion of the gasket 627 appears to glow. This glowing feature is a visual indicator. In one aspect, the LEDs are coupled to a processor of the scanner (in Figure 6 ), the processor is also coupled to a switch, e.g. Figure 4A In one aspect, the processor is configured to activate the LED, and thereby the visual indicator, when the switch 342 is closed. In one aspect, the visual indicator is provided by a portion of the body 620 that is internally illuminated, such as by an internal LED.

[0089] Figure 7AAnother aspect of a biocapacitive scanner 700 according to the present disclosure is depicted. This aspect includes a barcode scanning engine 730 mounted within a body 720. The scanning engine 730 includes an illuminator that emits radiation in a frequency range, such as visible light, and an imager sensitive to radiation in the frequency range emitted by the illuminator. The body 720 includes a window 722 positioned so that a portion of the radiation projected by the illuminator passes outward through the window, and the imager's field of view encompasses a portion of the window. In this manner, radiation from the illuminator can illuminate an object, such as a machine-readable image printed on a patient wristband, and the imager can obtain an image of the object, such as a barcode. In other words, the scanning engine 730 optically scans an image of a barcode, 2D matrix code, or other machine-readable code. In one aspect, the scanning engine includes a signal processor that converts the image obtained by the imager into an alphanumeric string of features. In one aspect, the scanning engine 730 is coupled to a processor and provides the alphanumeric string to the processor, which is configured to receive the alphanumeric string from the scanning engine. In one aspect, the alphanumeric string encodes one of a patient, a user, an observation, an intervention, a consumable element, a durable element, a location, and a time. In one aspect, the processor is further configured to receive a plurality of consecutive alphanumeric strings. In one aspect, the processor is further configured to associate each consecutive alphanumeric string with one of a patient, a user, an observation, an intervention, a consumable element, a durable element, a location, and a time. In one aspect, the processor is further configured to associate a first alphanumeric string of the patient with the consecutive alphanumeric strings. In one aspect, the processor is further configured to transmit the associated alphanumeric strings to a data system.

[0090] Figure 7B Depicted is an exploded view of a scanner 700 according to the present disclosure. The body 720 includes a front portion 721 and a rear portion 723, with a gasket 727 sandwiched between the front portion 721 and the rear portion 723 when they contact each other. In this regard, the front portion 721 is coupled to a guide 725, which is coupled to a bellows 726 and a carrier 728, which is coupled to a sensor 710. The two electrodes of the sensor 710 are connected by wires (at Figure 7B 742 is coupled to a device 744, such as, in this example, a capacitance-to-digital converter (CDC) located on the motherboard 740. The device 744 is then communicatively coupled to the processor 742. The processor 742 is also coupled to the device 744 via cables and wires (in Figure 7BThe processor 742 is coupled to a display 760 (not visible in the scanner 700), which may further include a touch screen. In one aspect, the processor 742 may also be coupled to one or more of the barcode scanning engine 730, the battery 764, the wireless power transmission and reception coil 766, and the audible indicator 768. In this aspect, the audible indicator 768 is a piezoelectric buzzer. The display 760 is visible to the user through a transparent window 762 mounted within an opening in the front portion 721. In this aspect, the processor 744 is also operably coupled to a light-emitting diode (LED) 752 mounted on the head plate 750 via a cable. When the scanner 700 is assembled, the LED is positioned near the gasket 727 so that light from the LED 752 shines through the translucent gasket 727 to provide a visual indicator.

[0091] Figure 8A A schematic diagram of a circuit 800 configured to perform a Σ-Δ method for measuring capacitance according to the present disclosure is depicted. The Σ-Δ method is well known to those skilled in the art and can be found in standard electrical engineering references, so only a simplified explanation is provided herein. In this figure, the symbol In one aspect, circuit 800 is part of another device, such as Figure 7B CDC 744.

[0092] Reference voltage V 参考 (+) and V 参考 (-) is selectively coupled to the reference capacitor C via switch pair 850 参考 , the reference capacitor is in turn selectively coupled to ground or the input of integrator 810. The operation of these switches configures the reference Figures 8C-8D In this regard, the off-chip capacitor C 传感器 , for example by Figure 7B The two electrodes of the sensor 710 of the scanner 700 form a capacitor connected between the first terminal providing the square wave excitation voltage 830 and the input of the switch pair 854, which selectively couples the input to the ground or the input of the integrator 810. The output of the integrator 810 is coupled to the integrating capacitor C 积分 and the input of comparator 820. The output of comparator 820 will be a "0" or "1" signal that is fed to digital filter 840 and controls the configuration of switch pair 850, as described with respect to FIG. Figures 8C-8D described.

[0093] Figure 8B Demonstrates the Figure 8A The upper row "ph1" shows the configuration of the switch pair 850, where the "1" configuration indicates that the switch is in the same state as V 参考 (+) connected to the switch closed and V 参考The lower row "ph2" shows the configuration of switch pair 852, where the "1" configuration indicates that the switch connected to the input of integrator 810 is closed and the switch connected to ground is open, while the "0" configuration indicates the opposite situation.

[0094] Comparator 820 responds to the input voltage only when the "strobe" signal is "HI" and is inactive when the strobe signal is "LO." If the input is a positive voltage when strobe is "HI," the output of comparator 820 is a voltage associated with a "1" state. If the input is a negative input when strobe is "HI," the output is a voltage associated with a "0" state.

[0095] The sequence of states of circuit 800 during a single sampling period is as follows:

[0096] At time T0, switch pair 850 becomes "1", while switch pairs 852 and 854 are in the "0" state, as shown in FIG. Figure 8C As shown, the solid line across 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 to a steady state. During this period, the charge Q1 is 参考 and the charge Q2 accumulates on C 传感器 Since Q = V x C, the charge on Q1 is determined by the voltage V 参考 (+) and C 参考 The value of Q1 is known. Similarly, the value of Q2 is determined by the known excitation voltage 830 and the unknown capacitance C. 传感器 Sure.

[0097] At around time T1, switch pair 850 flips to state "0," while the other switch pairs 852 and 854 remain in state "0." This buffer interval prevents both switches of each switch pair from being on at the same time.

[0098] At time T2, switch pair 852 and 854 are changed to the "1" configuration, as shown in FIG. Figure 8D As shown, both charges Q1 and Q2 are provided to the input of integrator 810. This configuration effectively connects the reference capacitor C 参考 The known capacitance and C 传感器 If the sum of Q1 and Q2 is a positive voltage, that is, greater than the voltage with the other input of comparator 810 connected to ground, the output of integrator 810 will become negative. If the sum of Q1 and Q2 is a negative voltage, the output of integrator 810 will become positive.

[0099] At time T3, the strobe signal goes high and the comparator 820 responds to its input voltage and can change its output to "1" or "0". Over a series of sampling cycles, this creates a string of 1s and 0s that serve as the input to the digital filter 840. This is processed within the filter to determine the difference between the C 传感器 This measurement can then be provided to external devices such as Figure 7B Processor 742.

[0100] Figure 9A A hardware block diagram 900 is depicted for measuring capacitance of a sensor 910 according to the present disclosure. The sensor is coupled to a device 920, such as a reference Figure 7B The CDC described herein may consist of an analog signal related to capacitance measured at sensor 910, as shown in FIG. Figures 8A-8D The digital representation of the measured capacitance can be obtained by the internal integrated circuit (I 2 C) Communication lines 925 are provided to a host system 930, e.g. Figure 7B Processor 744.

[0101] Figure 9B A schematic diagram of an integrated system 950 for measuring, evaluating, storing, and transmitting SEM values according to the present disclosure is depicted. In this example, the system 950 includes Figure 7B Scanner 951 is discussed, including the ability to wirelessly communicate with a WiFi access point 962. Scanner 951 can also communicate with one or more of a SEM application running on a server 960, an application running on a laptop 964, a smartphone 970, and other digital devices. In one aspect, laptop 964 and smartphone 970 are held by a user of scanner 951 (e.g., a nurse), and the application provides feedback and information to the user. In one aspect, patient information received from scanner 951 is stored in database 954. In one aspect, the information received from scanner 951 is transmitted via network 958 to another server 956, which stores a portion of the information in the patient's electronic medical record (EMR) 952. In one aspect, information from scanner 951 or retrieved from database 954 or EMR 952 is transmitted to an external server 966 and then to a computer 968, such as a computer in the doctor's office providing care for the patient.

[0102] Figure 10 Depicted is a workflow 1000 that includes scanning primary and secondary barcodes in accordance with the present disclosure. The steps shown may be performed in any order, and any step may be omitted or modified.

[0103] In this example, first steps 1010, 1020, and 1030 obtain identification information associated with one or more of the patient, caregiver, and current date and time. In this example, this information is encoded in a barcode or other machine-readable image such as a 2D matrix code and is obtained by scanning the barcode.

[0104] Step 1040 includes acquiring information, which may include, but is not limited to, observations, conditions, other measurements such as temperature or weight, and / or other physical artifacts such as pictures or data regarding nutrition and hydration. In this example, this information is acquired by scanning barcodes associated with various attributes, such as a set of barcodes for each element of a meal, where the user scans barcodes for items consumed, or a series 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 are not limited to, barcodes associated with medications administered to the patient, barcodes associated with a gown or other general clothing, barcodes associated with equipment, such as an intravenous (IV) pump used to treat the patient and the liquids or medications administered by the IV pump, barcodes associated with a treatment regimen, or any other activity or item that can be identified using a machine-readable image such as a barcode.

[0105] Step 1050 includes activities associated with measuring subdural moisture (SEM) values of a patient's body at various locations. Step 1050 includes a plurality of possible steps, depicted in this example as steps 1051 through 1056. Step 1051 includes placing a first electrode and a second electrode (e.g., Figure 1A of electrodes 110 and 120) of a sensor (e.g. Figure 3B The sensor 310 of the scanner 300 is positioned against the patient's skin above a tissue area (e.g., sacrum). Step 1052 includes increasing the pressure of the sensor on the patient's skin until the internal switch (e.g., Figure 4B The user then removes the sensor from the skin, which resets the measurement circuit. The user then decides in step 1055 whether to take another measurement or to close the series of measurements at this location. Step 1056 transmits the SEM measurement to a database that associates the capacitance measurement with the patient identification captured in step 1010. In one aspect, step 1056 may further include saving the data to a non-volatile local memory. In one aspect, step 1056 may not save the data at all. In one aspect, step 1056 may further include saving other information acquired in one or more of steps 1010 to 1050 to a database or local memory.

[0106] Step 1060 includes an activity branch depending on whether treatment will be administered to 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 two-hour intervals compared to the standard eight-hour interval. The treatment administered may be related to the tissue injury being assessed by the scanner, but treatments related to other types of injuries or conditions are not excluded. For this example, step 1070 identifies these treatments by scanning bar codes associated with the start, change, or stop of treatments. Step 1080 repeats this information acquisition for all treatments.

[0107] Although the present invention has been described with reference to specific aspects, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements of the present invention without departing from the scope of the present invention. Additionally, many modifications may be made to the specific circumstances or materials of the teachings of the present invention without departing from the scope of the present invention. Therefore, it is intended that the present invention not be limited to the specific aspects disclosed, but rather that the present invention encompasses all aspects coming within the scope and spirit of the appended claims.

[0108] From the foregoing, it will be appreciated that the present disclosure can be embodied in various ways, including but not limited to the following:

[0109] Embodiment 1: A device for measuring the biocapacitance of tissue, the device comprising: a sensor comprising two electrodes; a movable element coupled to the sensor; a switch disposed between the movable element and a fixed element and configured to be electrically closed when a 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 the measurement from the device when the switch is electrically closed.

[0110] Embodiment 2: The device of Embodiment 1, wherein the electrodes are configured such that when the sensor is positioned proximate to the tissue, the electric field between the electrodes penetrates into the tissue.

[0111] Embodiment 3: The apparatus of any one of embodiments 1 to 2, wherein the device is configured to repeatedly measure the capacitance between the two electrodes at predetermined intervals.

[0112] Embodiment 4: The device of any one of embodiments 1 to 3, wherein the sensor further comprises an insulating covering layer coupled to the electrode, and wherein the insulating covering layer is configured to prevent conductive contact between the electrode and the tissue when the sensor is positioned proximate to the tissue.

[0113] Embodiment 5: The apparatus of any one of Embodiments 1 to 4, wherein the measuring comprises comparing the capacitance between the electrodes to the capacitance of a reference capacitor.

[0114] Embodiment 6: The apparatus of Embodiment 5, wherein the comparing comprises using a sigma-delta method of comparing the capacitance between the electrodes to a capacitance of the reference capacitor.

[0115] Embodiment 7: The apparatus of 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 the switch is closed.

[0116] Embodiment 8: The apparatus of any one of Embodiments 1 to 7, wherein the movable element is configured to move along a translation axis relative to the fixed element, and the gap is disposed on the translation axis.

[0117] Embodiment 9: The apparatus of embodiment 8, further comprising a spring positioned between the movable element and the fixed element and configured to provide a monotonically increasing force along the translation axis to separate the movable element from the fixed element.

[0118] Embodiment 10: The apparatus of Embodiment 8, wherein the movable element is further configured to allow rotation about at least one of a first rotation axis perpendicular to the translation axis and a second rotation axis perpendicular to both the translation axis and the first rotation axis.

[0119] Embodiment 11: The apparatus of any one of Embodiments 1 to 10, wherein the processor is further configured to cause the switch to be electrically opened after receiving a first measurement when the switch is first closed and before a second measurement can be received.

[0120] Embodiment 12: A device for measuring the biocapacitance of tissue, the device comprising: a sensor comprising 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 alphanumeric string encoded 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 the first alphanumeric string from the engine.

[0121] Embodiment 13: The apparatus of embodiment 12, wherein the processor is further configured to: receive a plurality of consecutive alphanumeric character strings, and associate each of the consecutive alphanumeric character strings with one of a patient, a user, an observation, an intervention, a consumable element, a durable element, a location, and a time.

[0122] Embodiment 14: The apparatus of Embodiment 13, wherein the processor is further configured to associate the first alphanumeric string of characters of the patient with the continuous alphanumeric string of characters.

[0123] Embodiment 15: The apparatus of Embodiment 13, wherein the processor is further configured to transmit the associated alphanumeric string to a data system.

[0124] Example 16: A method of measuring biocapacitance of tissue, the method comprising: positioning a sensor comprising a first electrode and a second electrode against the skin of a patient above the tissue, measuring a capacitance between the two electrodes, optically scanning a primary machine-readable image associated with the patient, determining a primary alphanumeric string encoded in the primary machine-readable image, and associating the capacitance with the primary alphanumeric string.

[0125] Embodiment 17: The method of embodiment 16, further comprising: optically scanning one or more secondary machine-readable images associated with one of a user, an observation, an intervention, a consumable element, a durable element, a location, and a time; determining a secondary alphanumeric string encoded in each of the one or more secondary machine-readable images; and associating the secondary alphanumeric string with the primary alphanumeric string.

[0126] Embodiment 18: The method of embodiment 17, further comprising: transmitting the primary and secondary alphanumeric character strings to a data system.

Claims

1. A device for measuring biocapacitance of tissue, the device comprising: A sensor comprising 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 the machine-readable image and determine a first alphanumeric string encoded in the machine-readable image, A processor is coupled to the device and the engine and is configured to receive the measurement from the device and the first alphanumeric string from the engine.

2. The apparatus of claim 1 , wherein the processor is further configured to: Receives multiple consecutive alphanumeric strings, Each of the sequential alphanumeric character strings is associated with one of a patient, a user, an observation, an intervention, a consumable element, a durable element, a location, and a time.

3. The apparatus of claim 2, wherein the processor is further configured to: The first alphanumeric string of characters of a patient is associated with the consecutive alphanumeric string of characters.

4. The apparatus of claim 2, wherein the processor is further configured to: Transfers the associated alphanumeric string to the data system.

5. A method for measuring biocapacitance of tissue, the 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 said patient, determining a primary alphanumeric string encoded in said primary machine-readable image, and The capacitance is associated with the primary alphanumeric string.

6. The method according to claim 5, further comprising: optically scanning one or more secondary machine-readable images associated with one of a user, an observation, an intervention, a consumable element, a durable element, a location, and a time, determining a secondary alphanumeric string respectively encoded in each of the one or more secondary machine-readable images, and The secondary alphanumeric string is associated with the primary alphanumeric string.

7. The method according to claim 6, further comprising: The primary and secondary alphanumeric character strings are transmitted to a data system.

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