The present disclosure is directed generally to wearable and insertable electronic devices and components thereof. More particularly, but not exclusively, the various apparatus, methods, and systems disclosed herein relate to microneedles that are simultaneously used for radio frequency (RF) energy harvesting, communication, and/or transdermal fluid delivery and/or collection.
In 2001, the Federal Communications Commission (FCC) allocated 7 GHz in the 57-64 GHz band (“the 60 GHz band”) for unlicensed use. This allocation, in combination with advances in wireless communication technologies, allows for the possibility of miniaturized radio frequency (RF) systems. The 60 GHz band is of particular interest because of the specific attenuation characteristic caused by atmospheric oxygen of 10 to 15 dB/km, which makes the 60 GHz band unsuitable for long-range, for example longer than two kilometers, communications. Thus, the 60 GHz band can be dedicated entirely to short-range, for example less than one kilometer, communications.
Generally, high frequencies are associated with both advantages and disadvantages. High propagation attenuation at 60 GHz classifies a set of short-range applications, but also indicates dense frequency reuse patterns. Higher frequencies lead to a miniaturization of sizes of RF components, including antennas. At millimeter wave (MMW) frequencies (between 30 GHz to 300 GHz), not only are the antennas very small, but they may also be quite directional, which may be desired. Typically, high antenna gains for 60 GHz systems come, in part, from the Friis Equation for Path Loss. This equation, also known as Friis' Law, holds that as the frequency of operation increases, the effective area of any particular antenna decreases proportionately to the frequency squared. With the continued miniaturization of antennas for 60 GHz and other high frequency bands, on-chip silicon antenna arrays may be designed to provide excellent directionality. This miniaturization and possibility for phased array antennas with high gain may make 60 GHz antennas extremely efficient as compared to traditional antennas in industrial, scientific, and medical radio frequency bands.
Reliable microneedles have broad applications to fluid sampling, fluid delivery, and precisely localized chemical-reaction stimulation. Where robust enough to penetrate biological tissue, microneedle applications may have many biomedical uses. Where microneedles are fabricated from an integrated circuit (IC) compatible process they have a distinct advantage owed to the feasibility of on-chip electronics which may form a part of a chemical design and analysis system and/or may drive various electronics for pumps, valves, and the like. It has been proposed that microneedles of about 150 μm in length could cross the stratum corneum permeability barrier to enhance transdermal drug delivery, and it has been further hypothesized that this needle insertion should be painless given that the needles are not long enough to reach the nerves.
The present disclosure is directed to methods and apparatus for wearable or insertable devices with microneedles that are simultaneously used for radio frequency (RF) energy harvesting, communication, and transdermal fluid delivery and collection. Generally, in one aspect a wearable or insertable device is disclosed, where the device contains: a substrate that is affixable to or insertable into tissue of a patient; radio frequency circuitry disposed on the substrate, where the radio frequency circuitry is operable to generate (transmit) or process (receive) a signal with a frequency that is modulated to carry information; and, an array of microneedles extending from at least one surface of the substrate, where one or more microneedles of the array of microneedles defines a micro-fluidic channel that fluidly couples the tissue of the patient with a conduit of the substrate, and where one or more microneedles of the array of microneedles are electrically coupled with the radio frequency circuitry and radiate or process electromagnetic waves based on the signal.
In some embodiments, the substrate comprises a multi-layer silicon substrate that includes a first layer with the radio frequency circuitry and a second layer that supports the array of microneedles. In other embodiments, the wearable or insertable device further comprises one or more through silicon vias that fluidly couple the micro-fluidic channels of the array of microneedles through the first layer to the conduit. In still other embodiments, the conduit leads to an additional layer of the multi-layer silicon substrate that is a fluid analysis layer that analyzes fluid extracted through the micro-fluidic channels of the array of microneedles. In additional embodiments, the conduit leads to an additional layer of the multi-layer silicon substrate that is a fluid chamber containing fluid for injection into tissue via the micro-fluidic channels of the array of microneedles.
In some embodiments, the array of microneedles are formed as a phased antenna structure that combines signals from one or more of the plurality of microneedle arrays to achieve beamforming of at least some of the electromagnetic waves. In other embodiments, the plurality of microneedles are oriented perpendicularly to the substrate. In still other embodiments, the plurality of microneedles are oriented parallel to the substrate. In some embodiments, the plurality of microneedles are laterally oriented with respect to a patient's skin surface. In other embodiments, the array of microneedles are arranged in concentric rings following a profile of a corrugated horn antenna.
In some embodiments, each of the plurality of microneedles further comprise a metal coating. In some embodiments, the metal coating is applied to an interior surface of the micro-fluidic channel of each of the plurality of microneedles. In other embodiments, the metal coating is applied to an exterior surface of each of the plurality of microneedles. In some embodiment, at least some of the plurality of microneedles extend through the silicon substrate by way of metallic vias. In other embodiments, the antenna element is extended to a length of about 250 to about 1500 microns.
In some embodiments, the wearable or insertable device further comprises a fluid detection sensor that detects presence of fluid in the plurality of microneedles and activates the radio frequency circuitry when fluid is present. In other embodiments, the radio frequency circuitry processes the signal in response to a determination, based on a signal from the fluid detection sensor, that there is no fluid in the micro-fluidic channels of the array of microneedles.
Generally, in another aspect a method is described, where the method includes: obtaining an insertable device, where the device comprises a substrate that is affixable to or insertable into tissue of a patient, radio frequency circuitry disposed on the substrate, where the radio frequency circuitry is operable to generate or receive a signal a frequency that is modulated to carry information, and an array of microneedles extending from at least one surface of the substrate, where one or more microneedles of the array of microneedle defines a micro-fluidic channel that fluidly couples the tissue of the patient with a conduit of the substrate, and where one or more microneedles of the array of microneedles are electrically coupled with the radio frequency circuitry and radiate electromagnetic waves based on the signal; inserting the obtained device into the tissue of a patient; orienting the array of microneedles such that at least some of the array of microneedles are oriented with a tip of each microneedle pointing to a surface of the patient's skin; and implanting the device so as to maintain orientation of the tips of one or more microneedles pointing to the surface of the patient's skin.
In some embodiments, the device further comprises a fluid detection sensor that detects presence of fluid in one or more of the plurality of microneedles and signals the radio frequency circuitry when fluid is present. In other embodiments, the method further comprises generating, by the radio frequency circuitry, the signal in response to determining, based on a signal from the fluid detection sensor, that there is no fluid in the microfluidic channels of one or more microneedles of the array of the microneedles.
In the drawings, like reference characters generally, but not exclusively, refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the disclosure.
Wearable/insertable devices are becoming more accepted in clinical settings, and home monitoring is becoming an increasingly important feature of healthcare systems. Wearable and/or insertable devices have traditionally been used to measure vital signs such as heart rate, respiration rate, temperature, oxygen saturation, and so forth. There is also an increasing body of research into using these devices to measure bioanalytes and for use in drug delivery. There is a need for wearable or insertable devices to be able to wirelessly communicate and exchange data with one or more remote computing devices. Such communication may allow the wearable/insertable device to communicate with another device of the patient (e.g. a smart phone or smart watch), devices belonging to caregivers, other monitoring devices, and the like. While the desire for wireless communication is recognized, conventional wireless systems typically require hardware that is often bulky, which may require the host device to be larger than would otherwise be necessary. The use of radio frequency circuitry capable of generating electrical current at frequencies used to carry information incorporated into the wearable/insertable device itself may allow for miniaturized wearable/insertable devices capable of wireless communication.
Referring to
In some embodiments, such as the wearable device 100 illustrated in
In some embodiments, the substrate 102 may further include another layer 102a that supports the microneedles 106. The microneedles 106 themselves may be fabricated on the silicon substrate, e.g., on layer 102a, and each may define a micro-fluidic channel 130 that fluidly couples the tissue 107 of the patient with a corresponding conduit 132 (e.g., a fluid interface, port, opening, etc.) of the silicon substrate 102. The conduits 1321-n may provide a fluid interface to, for instance, an additional fluid analysis layer (see
The orientation of each of the microneedles/antennas 106 relative to the substrate 102 and the surface of the patient's skin may vary depending on the type and use of the device. For example, certain arrangements of the microneedle/antenna may enhance wireless communication with remote devices. In some embodiments, such as illustrated in
In other embodiments, such as that illustrated in
In some embodiments, such as illustrated in
Microneedles 606 may extend from the substrate layers 602a, 602b laterally, so as to be parallel to the skin surface. In
In still other embodiments, such as illustrated in
In some embodiments, such as the embodiment illustrated in
Returning to the radio frequency circuitry 120 of
It may be desirable to increase the sensitivity of the antennas so that they may transmit and/or receive signals from longer distances and/or signals with great clarity. In such instances, the surface area of metal (or more generally, conductive material) may be increased. For example, each microneedle 106 may be coated partially or completely with metal. Types of metal that used may include, but are not limited to, silver, gold, copper, aluminum, zinc, nickel, iron, tin, and/or any metal, or combination thereof, known in the art to be conductive. The metal coating may be applied during a final metallizing step, which may also improve the manufacturability of the device. In some embodiments, the metal coating may be placed on the exterior surface of each of the microneedles/antennas. In other embodiments, the metal coating may be place on an interior surface, e.g., that defines the micro-fluidic channel of each of the microneedles. With a metal coating, an individual microneedle/antenna may have a length of about 200 to about 500 microns. However, there may be instances in which it is desired that the dimensions of a 60 GHz antenna be about 2500 microns. Therefore, in some embodiments, several microneedles/antennas may be connected together to form a desired dimension for use in a 60 GHz band.
In some embodiments, the wearable or insertable device further contains one or more through silicon vias. Through silicon vias are electrical connections that may pass through silicon, and may be used as an alternative to bonding wires. Through silicon vias may have a higher density, as compared to other techniques, and thus may not require as long of a connection. In various embodiments, the one or more through silicon vias of the wearable or insertable device may fluidly couple the micro-fluidic channels (130 in
In some embodiments, such as illustrated in
In some instances the presence of fluids in the microneedles—whether the fluids are bodily fluids extracted from the tissue of a patient or pharmaceuticals for injection into the patient—may negatively impact wireless communication with the antennas. Therefore, in some embodiments, the wearable/insertable device may further contain a fluid detection sensor, which is capable of determining if fluid is present or absent in the micro-fluidic channels of the microneedles. Where fluid is present the fluid detection sensor may provide a signal indicating as much. Such a signal may prevent the transmission or reception of data. Alternatively, where no fluid is contained in the microneedles, the fluid detection signal may provide a signal indicating the absence of fluid. Where no fluid is present a signal by the fluid detection sensor may indicate to the radio frequency circuitry that the antenna structure(s) may be used for transmitting and receiving radio frequency signals. In still other embodiments, it may be desirable to maintain constant fluid flow through the microneedles, such as where a pharmaceutical needs to be constantly delivered to the tissue of a patient. In such instances, a fluid detection sensor may not be desirable.
Referring now to
At block 510, an insertable device such as depicted in
The method may further comprises a step illustrated by block 520, wherein the obtained device is inserted into the tissue of the patient. The device may be inserted at varying depths of tissue depending on the desired use of the device. Furthermore, the device may be inserted at varying locations of tissue on/in a patient's body depending on the desired use of the device. For example, the device may be inserted into the dermal layers of a patient's arm, leg, chest area, neck, or anywhere else suitable for the desired use.
The method may further include a step of orienting (530) the array of microneedles illustrated at block 530, wherein the inserted device is oriented so that at least some of the tips of the microneedles/antennas are pointing to the surface of the patient's skin. Alternatively, in some embodiments, a device may be oriented so that the microneedles are positioned essentially parallel to a patient's skin surface, as illustrated in
Further at block 540, the oriented device may be implanted into the patient's tissue, so as to maintain the desired orientation in which the device was placed at block 530. Implanting the device may maintain the quality of the transmission and reception of wireless data. Further, implanting the device into the tissue of the patient may prevent, or minimize, the dislocation of the device from the desired placement/orientation.
The method 500 may further comprises a step of fluid detection, wherein by means of a fluid detection sensor the presence of fluid in one or more of the plurality of microneedles is detected. The sensor is further arranged to active the radio frequency circuitry when fluid is present. Further, this activation step may comprise generating, by the radio frequency circuitry, the signal in response to determining, based on the signal from the fluid detection sensor, that there is no fluid in the microfluidic channels of one or more microneedles of the array of the microneedles.
While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.
All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.
The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”
The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.
As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.
As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.
It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.
In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03. It should be understood that certain expressions and reference signs used in the claims pursuant to Rule 6.2(b) of the Patent Cooperation Treaty (“PCT”) do not limit the scope.
Number | Date | Country | Kind |
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17154928.0 | Feb 2017 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2018/052769 | 2/5/2018 | WO | 00 |