AU2021105691A4 - Wearable ring for measuring biometrics - Google Patents

Abstract

Wearable ring biometricmonitorinnovation patent Abstract [0001] Provided here is a non-invasive wearable device for measuring and monitoring glucose levels (i.e., concentration) and other biometrics using bioimpedance measurement. The present invention relates to a wearable device in ring form, and a method for measuring blood glucose concentrations/levels by measuring bioimpedance data and processing that data through an artificial intelligence algorithm model to produce a measurement result. Wearable ring biometricmonitorinnovation patent Drawings [0001] Diagram 1: Present version of wearable ring to non-invasively measure and monitor biometrics such as blood glucose 9 o'clock- - - - - 3 o'clock /1mm space square 5mm between electrodes, electrodes [0002] 1mm thick

Description

Wearable ring biometricmonitorinnovation patent

Drawings

[0001] Diagram 1: Present version of wearable ring to non-invasively measure and monitor biometrics such as blood glucose

9 o'clock- - - - - 3 o'clock

square 5mm /1mm space between electrodes, electrodes 1mm thick

[0002]

EDITORIAL NOTE

2021105691

THERE ARE 11 PAGES OF DESCRIPTION ONLY

Wearable ring biometricmonitorinnovation patent

Description

[0001] The present invention relates to a non-invasive wearable device for measuring biometrics including glucose levels (i.e., concentration) in a subject, preferably a human subject.

[0002] In particular, the present disclosure relates to a wearable device and method for measuring blood glucose concentrations/levels. These non-invasive devices can be used as wearable devices, such as a ring, smart band or watch, to monitor biometrics including blood glucose levels in diabetics without discomfort and stress by measuring bio-impedance data.

[0003] Studies have shown that obesity can increase the likelihood of developing diabetes (diabetes mellitus). Diabetes is a chronic disease characterised by high levels of glucose in the blood. Blood sugar levels are controlled by insulin, a hormone produced by the pancreas. Diabetes occurs when the pancreas is (i) unable to produce enough insulin, (ii) the body becomes resistant to insulin, or (iii) both. The two common forms of diabetes are: • Type 1 diabetes: an auto-immune disease where the body's immune system attacks the insulin producing cells of the pancreas. Type 1 diabetes is a result of the pancreas's failure to produce enough insulin due to loss of beta cells. People with type 1 diabetes cannot produce insulin and require lifelong insulin injections for survival; and * Type 2 diabetes: a condition in which cells fail to respond to insulin appropriately and typically begins with insulin resistance. In some cases or as the disease progresses, a lack of insulin may occur. Type 2 diabetes is typically related to hereditary factors and lifestyle risk factors including poor diet, insufficient physical activity and being overweight or obese.

[0004] Diabetics who need treatment try to maintain blood glucose levels within a specified range prescribed by a health professional. Currently, the only reliable way to self measure blood glucose levels is to use a conventional blood glucose monitor. However, conventional blood glucose monitors are invasive, inconvenient, painful and can cause discomfort. To monitor blood glucose concentration, a user pricks their finger with a lancet and a droplet of blood is added onto a blood glucose checking strip. This strip is then inserted into the meter, which reads the strip and displays the blood glucose concentration.

[0005] The present invention provides a method and device which can accurately measure blood glucose concentration in a subject.

[0006] Although the invention will be described with reference to a specific example it will be appreciated that the invention may be embodied in many other wearable forms.

[0007] Bio-electrical impedance (bio-impedance) measurements have been used to measure physiological parameters in biological applications to characterise cells. These measurements include measuring body composition (such as body fat and muscle mass), total body water and other applications. Bioimpedance measurements have also been used for disease diagnostic applications.

[0008] However, there has been limited application of bioimpedance measurements to measure other biometrics such as blood glucose concentration. The Applicant believes there are currently no commercial products on the market that use impedance to measure blood glucose concentration in a subject.

[0009] The development of non-invasive blood glucose devices using impedance measurements has been challenging as the measurements typically have poor quality or weak signals resulting in poor reproducibility, repeatability and accuracy of the blood glucose concentration measurements. Therefore, the development of a suitable non-invasive blood glucose device using impedance for commercialisation has remained a significant challenge. This is because electrodes in these devices have been limited to measuring impedance only on the skin tissue which results in poor quality or weak signals.

[0010] According to one aspect, the present invention provides a non-invasive wearable device for determining blood glucose concentration in a subject, the device comprising: at least two electrodes for contacting the subject's skin and adapted to be connected to a receiver for measuring an impedance signal; and a housing adapted to receive the electrodes; wherein the electrodes are configured such that an electrical current passes through a portion of a subject in use.

[0011] The Applicant has found that by placing electrodes in a configuration which provides electrical current to pass through a portion of the body rather than just on the surface of the skin provides a device which can measure high quality signals for reproducible, repeatable and accurate measurement of blood glucose concentration and other biometrics.

[0012] Without being bound by any one theory, the present Applicant has surprisingly found that the electrical current can pass through a portion of the body (for example a finger) through at least one of dermis layers, fat layers, muscles, bone and the like. The electrical current can pass through different portions of the body, for example, portions of the electrical current can pass through the dermis layers, fat layers, body fluid and combinations thereof. Further, electrical currents of different frequencies will have different path combinations. In the present version the non-invasive wearable device is a ring that comprises four electrodes, a temperature sensor and an accelerometer sensor.

[0013] Four electrodes can prevent any electrical issues (short-circuiting) and provide greater sensitivity because each electrode can be independently a separate current injecting electrode (i- and i+) and voltage measurement electrode (v- and v+). As such, a higher sensitivity and reducing or preventing a short circuit can be provided using a preferred embodiment device of four electrodes.

[0014] The electrodes can be positioned in any suitable configuration provided such that an electrical current passes through a portion of a subject.

[0015] In preferred embodiments, the device comprises four electrodes. In this embodiment, two electrodes are substantially opposed to each other along an axis. For example, when the device is in the form a ring, the two electrodes are positioned about 180 from each other. In this embodiment, each of the additional electrodes (i.e., the additional two electrodes) are configured to be radially spaced between about greater than about 50 to less than about 800, between about greater than about 50 to less than about 600, between about greater than about 50 to less than about 50°, between about greater than about 200 to less than about 40°, preferably about 30° or about 600 relative to each of the electrodes. In preferred embodiments, each of the additional electrodes (i.e., the additional two electrodes) are configured to be radially spaced between about greater than about 50 to less than about 800, between about greater than about 50 to less than about 600, between about greater than about 50 to less than about 50°, between about greater than about 200 to less than about 40°, preferably about 30° relative to each of the electrodes and the additional electrodes are substantially opposed to each other. The term "substantially opposed" means that the centre of mass of the electrode and/or additional electrodes are configured to be about 1800 to each other, however, the contact angle of the electrode surface can be any suitable angle.

[0016] In certain embodiments, the two electrodes are current injecting electrodes and the two additional electrodes are voltage measurement electrodes. In other embodiments, the two electrodes are voltage measurement electrodes and the two additional electrodes are current injecting electrodes. In certain embodiments, at least one of the electrodes is a current injecting electrode and at least one of the additional electrodes is a voltage measurement electrode.

[0017] The present inventors have found that a four-electrode non-invasive device is preferable to measure bioimpedance. The present inventors also found that using four electrodes can avoid common mode voltage and as such reduce or prevent the electrode polarisation effect which would be experienced in a two-electrode system. Two electrode systems are the most common systems typically used for bioimpedance measurements.

[0018] A voltage measurement electrode of the invention can be spaced to provide a gap preferably about 1 mm relative to a current injecting electrode.

[0019] The electrode or electrodes can take any geometry or size depending on optimising the impedance signal. In the present invention the electrode is substantially square shaped.

[0020] The electrode can be made from any suitable conductive material. In the present version the electrode is a gold electrode either solid gold or gold coated.

[0021] The present inventors found that use of a gold or gold-plated electrode can provide the least impedance at the skin-electrode interface for monitoring biometric information of a user, such as, blood glucose levels and other biometrics.

[0022] The coating of the electrode can be any suitable thickness to provide sufficiently conductive contact and each electrode has substantially about the same surface area, in the present version about 50 mm 2 .

[0023] These surface area of the electrode should be chosen such that they are large enough to produce a signal, but small enough as to be sufficiently spaced apart for a range of non-invasive device sizes. IEC 60601 provides international technical standards for the safety and performance of medical electrical equipment and limits current for DC and AC frequencies less than 1 kHz to 10 pA, and for AC currents above 1 kHz as per equation 1. This standard specifies the limits of patient leakage currents and patient auxiliary currents under normal conditions and single fault conditions. These current limits are important parameters in the circuit design of an electrical medical device.

[0024] Equation 1. Maximum AC current for frequencies above 1 kHz.

FE ACMAX 1000 Hz - 1uAnus

[0025]

[0026] wherein IAC s the maximum AC current, 10 ptARMS is 10 pA (root mean square

value) and FE is the excitation frequency.

[0027] For comfort of a subject when using the non-invasive device, the electrode should in certain embodiments have no surface or textural inconsistencies which can be tactually felt on a surface by a finger. This can prevent or ameliorate skin sensitisations which may occur during use.

[0028] The housing can take any geometry or size depending on the size of the electrode and the ultimate configuration of the non-invasive device, and is adapted to minimise electrical interference to improve signal quality such as physical and/or electrical isolation. The housing is made from a material selected from the group consisting of a ceramic, silicone rubber, rubber, copper, aluminium, platinum, titanium, gold, silver, iron, steel, stainless steel, brass, bronze, nickel, polymer, and combinations thereof. Polymers can contain antioxidants and thermostabilisers.

[0029] The housing can be made by injection moulding, carving, extrusion, blowing, rotational moulding, thermoforming, calendering, stamping, CNC machining, embossing, 3D printing, casting and extrusion.

[0030] Where the electrode and housing are both conductive materials, the non-invasive device comprises an insulator disposed between the electrode and housing to prevent or ameliorate the risk of a short circuit or electrical interference.

[0031] It is preferable that the electrodes of the non-invasive device should substantially be in contact with the surface of the skin of a subject under constant pressure during use to minimise artefacts and poor data measurements. In certain embodiments, the non-invasive device comprises an adjustable electrode contact mechanism to ensure measurement of high-quality impedance signals while maintaining comfort to the subject. In this embodiment, the contact area of the electrode can be automatically adjusted to ensure sufficient contact between the electrode and skin of the subject to receive high quality impedance signals. For example, the adjustable electrode contact mechanism can be a screw, spring fastener, or flexible housing. This can ensure that the electrodes protrude from the housing to improve contact between the electrode and skin of the subject to receive high quality impedance signals. In the present version the wearable ring device can be made a of resilient material and optionally comprise a break or webbing to accommodate different sizes of a portion of a body such as a finger. For example, the device such as a ring can in some embodiments accommodate expansion over a knuckle and then contraction at the base of the finger to ensure sufficient contact.

[0032] In certain embodiments, the function of the electrode can be adjusted without physical modification using a printed circuit board (PCB) which is connected to the non invasive device such that the electrodes can be controlled by the PCB to function as a stimulating electrode, a sensing electrode or a sink. In these embodiments, adjustment of the function of the electrodes on-the-fly by the PCB can ensure measurement of high-quality impedance signals.

[0033] The non-invasive device can be in any suitable form such as a wearable device. In some embodiments, the non-invasive device can be a smart watch, belt, band (such as a waist or arm band), bracelet, ring, clip (such as for the ear or finger) or benchtop device. The present version is a ring with electrodes fitted into the housing such that the device can be connected to a mobile electronic device (such as a mobile/cell phone, tablet, laptop, personal computer and the like).

[0034] In certain embodiments, the non-invasive device comprises a notification indicator. The notification indicator can be in the form of a light (such as an LED), a screen, a visual alarm, a tactile alarm (vibration), an audio alarm and combinations thereof. The indicator can show for example the operating status of the non-invasive device such as if the device is powered on/off, normal operating status, error status and the like. In some embodiments, the notification indicator can alert a subject or remote user if the blood glucose concentration is outside a predetermined range such as above or below a normal threshold range. In certain embodiments where the indicator is a screen, the indicator can provide information such as duration of operation, real-time blood glucose concentration, impedance signal strength and quality, connection status and the like.

[0035] In some embodiments, the receiver is an electrochemical impedance spectroscopy (EIS) device, a microprocessor or a microcontroller to receive the impedance signal from the electrode of the non-invasive device. In certain embodiments, non-invasive device comprises a receiver (i.e., the receiver is integral to the device). In certain embodiments, the receiver is external to the non-invasive device. In these embodiments, the receiver can be connected to the non-invasive device using a wired connection or a wireless connection to transmit the impedance data.

[0036] In certain embodiments, the non-invasive device comprises a Faraday shield to reduce interference and improve impedance signal quality.

[0037] In some embodiments, the non-invasive device comprises a probe to measure an additional physiological parameter (i.e., biometric) of a subject. For example, the probe can be used to measure body fat, muscle mass, body composition, body temperature, skin pH, skin temperature, blood pressure, heart rate and the like. In these embodiments, the probe can be an electrode, a thermocouple or a spectrophotometer. For example, if measuring heart rate, an LED source can be provided and the light signal can be measured using an LED sensor with the difference in signals compared using an algorithm to output a subject's heart rate.

[0038] In some embodiments, the non-invasive device can be formed integrally with, attached to, or at least partially surround or encompass a third-party device. Any suitable third-party device can be used which can contact the skin of a subject such that an impedance signal can be measured. For example, the third-party device can be a phone; a phone case; a computer peripheral such as a keyboard or mouse; furniture such as a chair, couch or recliner; audio equipment such as headphones; eyewear; clothing; footwear; a container such as a beverage or food container.

[0039] In certain embodiments, the non-invasive device comprises a communication device. The communication device can be a communication transmitter or communication receiver to transmit or receive data. In these embodiments, the communication device can transmit or receive data with a wireless or cellular network. Advantageously, the communication device can transmit the raw impedance data to a remote or cloud-based computer such as a supercomputer, base station, server or another device such as a smart phone, laptop or tablet to compute and determine blood glucose concentration remotely. In this embodiment, the blood glucose concentration of a subject can be monitored even without access to a computer or phone, such as children, the elderly or at-risk individuals. This could be used to provide an alarm to a remote user that the subject had passed a pre determined blood glucose concentration threshold. In other embodiments, the computation can be processed by the non-invasive device and the data can be transmitted to a remote or cloud-based computer.

[0040] In use, the non-invasive device is worn such that the electrodes make conductive skin contact with the subject. For example, the skin site can be located on the volar forearm, down to the wrist, behind an ear, on an ear, on an earlobe, or the finger of a subject. In some cases, the skin can be pre-treated, such as using a saline or alcohol solution (such as isopropanol solution) or shaved, prior to the measuring step or before being worn. An electrically conductive gel can be optionally applied to the skin to enhance the conductive contact of the electrodes with the skin surface during the measuring step.

[0041] The electrodes can be in operative connection with a microprocessor programmed to determine the amount of blood glucose (or other biometrics) based upon the measured impedance. There can be an indicator operatively connected to the microprocessor for indication of the determined amount of blood glucose to the subject. The indicator can provide a visual display to the subject.

[0042] In certain embodiments, the microprocessor can be operatively connected to an insulin pump and the microprocessor is programmed to adjust the amount of insulin flow via the pump to the subject in response to the measured amount of blood glucose.

[0043] The microprocessor can be programmed to compare the measured impedance with a predetermined correlation between impedance and blood glucose concentration. The non-invasive device can include a receiver for measuring impedance at a plurality of frequencies.

[0044] In operation, the non-invasive device can calibrate the device against a directly measured glucose concentration of a subject. The device can input the value of the directly measured glucose concentration in conjunction with impedance measured about the same time, for use by the operating software to determine the blood glucose level of that subject at a later time based solely on subsequent impedance measurements.

[0045] In some embodiments, data produced by the non-invasive device can be collected, stored (for example remotely), and compiled for analysis.

[0046] According to another aspect, the present invention provides a method for non invasively determining blood glucose concentration in a subject, the method comprising the steps of: measuring impedance through a portion of the subject using at least one electrode in conductive contact with the subject's skin; and determining the amount of blood glucose in the subject based upon the measured impedance, wherein the at least two electrodes are in a configuration which passes electrical current through the portion of the subject.

[0047] According to a further aspect, the present invention provides a method for non invasively determining blood glucose concentration of in a subject, the method comprising the steps of: measuring impedance through a portion of the subject using at least two electrodes in conductive contact the subject's skin; determining the amount of blood glucose in the subject based upon the measured impedance; and measuring at least one additional physiological parameter of the subject.

[0048] Any suitable frequency can be used to measure the impedance. In some embodiments, the impedance is measured at a plurality of frequencies. In some embodiments, the amount of blood glucose concentration is determined by determining the ratio of the impedance at a plurality of frequencies, such as the ratio of two frequencies. In certain embodiments, the method is performed at a frequency range of between about 0.1 Hz to about 1 MHz, between about 5 Hz to about 1 MHz, between about 20 Hz to about 1 MHz, between about 5 Hz to about 800 kHz, between about 5 Hz to about 500 kHz, between about2 Hz toabout500 kHz.

[0049] In some embodiments, the method of the present invention is performed using alternating current (AC). In some embodiments, the method of the present invention is performed using direct current (DC).

[0050] In some embodiments, the portion of the subject is a body part of a subject. In some embodiments, the portion of the subject is selected from the group consisting of a finger, an ear, a waist, a leg, an arm, a wrist and combinations thereof.

[0051] In certain embodiments, the method of the present invention is continuous. In some embodiments, the method of the present invention is measured at intervals. In some embodiments, the duration of each single measurement of blood glucose concentration is between about 2 seconds to about 1 minute.

[0052] In some embodiments, the method of the present invention measures impedance at intervals between about 2 seconds and 15 minutes. In some embodiments, the method of the present invention measures impedance continuously or repeatedly to provide substantially continuous measurements at intervals.

[0053] In certain embodiments, the method of the present invention further comprises measurement of at least one additional physiological parameter of a subject. In certain embodiments, the physiological parameter (i.e., biometric) is selected from the group consisting of body fat, muscle mass, body composition, body temperature, skin pH, skin temperature, blood pressure, heart rate, respiratory rate and combinations thereof.

[0054] In certain embodiments, the method of the present invention comprises use of an artificial neural network. In certain embodiments, the method of the present invention comprises use of an artificial neural network (ANN) to process the impedance signal to improve signal quality. In certain embodiments, the method of the present invention comprises use of an artificial neural network to perform a non-linear regression. In certain embodiments, the method of the present invention comprises use of an artificial neural network to predict and/or determine blood glucose concentration of a subject. In certain embodiments, the artificial neural network (ANN) model correlates the measured biometrics (including but not limited to bioimpedance, body temperature, skin pH, blood pressure and the like) to blood glucose concentration. In certain embodiments, a different ANN architecture or model can be used depending on the form factor of the non-invasive device such as whether the device is a ring, a bracelet, a smart watch or other form). In certain embodiments, the method of the present invention comprises a dynamic adaptive ANN. In this embodiment, the dynamic adaptive ANN enables the non-invasive device to adapt to the specific physiological parameter patterns of the subject which increases the accuracy of the blood glucose concentration measurement while in use and being worn by the subject.

[0055] As discussed previously, the present invention provides a non-invasive device which can measure impedance with high-quality signals. This enables a user (which can also be the subject) to monitor the quality of the output electrical current signals before using the data to determine the blood glucose concentration. This allows selection of quality data by removing the noisy and low-quality signals and only using the high-quality data for the ANN to increase the accuracy or enable the ANN's functionality when determining the blood glucose concentration.

[0056] According to another aspect, the present invention provides a kit comprising: at least two electrodes adapted to be connected to a receiver for measuring an impedance signal; and a housing adapted to receive the electrode.

[0057] In some embodiments, the kit comprises a receiver. In some embodiments, the receiver is an electrochemical impedance spectroscopy (EIS) device. In some embodiments, the kit comprises an insulin pump. Definitions

[0058] In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments of the invention only and is not intended to be limiting. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one having ordinary skill in the art to which the invention pertains.

[0059] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

[0060] As used herein, the phrase "consisting of' excludes any element, step, or ingredient not specified in the claim. When the phrase "consists of' (or variations thereof) appears in a clause of the body of a claim, rather than immediately following the preamble, it limits only the element set forth in that clause; other elements are not excluded from the claim as a whole. As used herein, the phrase "consisting essentially of"limits the scope of a claim to the specified elements or method steps, plus those that do not materially affect the basis and novel characteristic(s) of the claimed subject matter.

[0061] With respect to the terms "comprising", "consisting of', and "consisting essentially of', where one of these three terms is used herein, the presently disclosed and claimed subject matter may include the use of either of the other two terms. Thus, in some embodiments not otherwise explicitly recited, any instance of "comprising" may be replaced by "consisting of' or, alternatively, by "consisting essentially of'.

[0062] Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients or reaction conditions used herein are to be understood as modified in all instances by the term "about", having regard to normal tolerances in the art. The examples are not intended to limit the scope of the invention. In what follows, or where otherwise indicated, "%" will mean "weight %", "ratio" will mean "weight ratio" and "parts" will mean "weight parts".

[0063] The term "substantially" as used herein shall mean comprising more than 50% by weight, where relevant, unless otherwise indicated.

[0064] The recitation of a numerical range using endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0065] The terms "preferred" and "preferably" refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of the invention.

[0066] It must also be noted that, as used in the specification and the appended claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

[0067] The prior art referred to herein is fully incorporated herein by reference. Although example embodiments of the disclosed technology are explained in detail herein, it is to be understood that other embodiments are contemplated. Accordingly, it is not intended that the disclosed technology be limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The disclosed technology is capable of other embodiments and of being practiced or carried out in various ways.

Claims (1)

1. EDITORIAL NOTE

   2021105691

   THERE IS ONE PAGE OF CLAIMS ONLY

   Wearable ring biometricmonitorinnovation patent

   Claims

   [0001] 1. A wearable non-invasive ring using bioimpedance to measure a range of biometrics or physiological parameters such as blood glucose, body fat, muscle mass, body composition, body temperature, skin pH, skin temperature, blood pressure, heart rate, respiratory rate and combinations thereof.

   [0002] 2. Combination of sensors including bioimpedance, temperature, GPS, 3D axis movement (accelerometer) and a vibrator motor.

   [0003] 3. Power management including RF harvesting and super capacitors.

   [0004] 4. Radio transceiver capability including Bluetooth, WiFi (2.4 Ghz and 5 Ghz), cellular including 2G/3G/4G/5G, satellite, and NFC including capability for RFID contactless payments.

   [0005] 5. Use of an inductive wireless charger.

   EDITORIAL NOTE 17 Aug 2021

   2021105691

   THERE IS ONE PAGE OF DRAWINGS ONLY

   Wearable ring biometric monitor innovation patent 17 Aug 2021

   Drawings

   [0001] Diagram 1: Present version of wearable ring to non-invasively measure and monitor biometrics such as blood glucose 2021105691

   [0002]