Abstract: An ophthalmic device includes a lens and an electronic component embedded in the lens to enhance the functionality of the lens. The ophthalmic device includes a first coil to wirelessly receive energy from an external device, such as a wireless charger, and wirelessly transmits the received energy to a second coil coupled to the electronic component so as to power the electronic component. The first coil can function as part of a repeater to facilitate the wireless charging. The repeater can receive electrical energy wirelessly and works with various positions, sizes, and shapes of the electronic component. The wireless power efficiency can also be increased using the repeater to concentrate a magnetic flux within the second coil.

Abstract: A device for correcting or mitigating refractive errors in the eye presents a solution in which desired improvements in eyesight are achieved as far as possible without limiting everyday activities and where performing the treatment itself involves minimum risk. The device creates an aperture diaphragm in an eye, and has a control unit for a laser unit, the control unit being designed to control the laser unit to create the aperture diaphragm in a lens of the eye, wherein the aperture diaphragm is used to increase the depth of focus of the eye and is formed by laser-induced lesions which reduce light transmission through a lens aperture region surrounding an aperture opening.

Abstract: Embodiments of a modulable absorption light adjustable lens (MALAL) comprise a light adjustable lens that is capable of changing its optical properties upon an adjusting irradiation, including a photo-modifiable material; and a modulable absorption front protection layer, including a modulable absorption compound whose absorption properties can be modulated with a modulating stimulus. Other embodiments include a method of adjusting an optical property of a modulable absorption light adjustable lens, the method comprising: reducing an absorption of a modulable absorption compound of a modulable absorption front protection layer of the MALAL by a modulating stimulus, the MALAL having been previously implanted into an eye; and changing an optical property of a light adjustable lens of the MALAL by applying an adjusting irradiation.

Abstract: The present invention pertains to accommodating intraocular lens (AIOL) assemblies including a haptics system for self-anchoring implantation in a human eye's annular ciliary sulcus for retaining an AIOL at a desired position along the human eye's visual axis, and an accommodation measurement implant (AMI) for determining accommodation and accommodation forces in an experimental set-up including an animal's eye.

Abstract: Apparatus and methods are disclosed that relate to contact lenses having multiple power sources. In particular, in one aspect, a contact lens can include a transparent substrate and a circuit. The circuit can include one or more sensors, circuitry, one or more photovoltaic cells disposed on or within at least a portion of the substrate, and a hybrid power component that supplies power to the circuitry that includes solar power.

Abstract: A robotic system includes retrieval of a priori stimulus based on an input that indicates a current health state and a target health state of a user. A set of test stimuli specific for the user is determined and a stimulus device is controlled to provide the set of test stimuli to the user. A first set of responses within the body of the user and a second set of responses discernible on the body of the user are determined, and a set of stimulus parameters for the stimulus device is calibrated based on the combination of the first set of responses, the second set of responses, the current health state, the target health state, and a trained AI-based system. A new stimulus is applied to a portion of the body of the user that shifts a condition of the user from the current health state towards the target health state.

Abstract: A non-sensor type closed-loop stabilization control algorithm comprises the following steps: 1, reading all voltages Vk?1 and currents Ik?1 for driving a multi-axis stabilization motor; 2, calculating and outputting all coil resistances Rk?1 in the multi-axis stabilization motor; 3, reading all the coil resistances, voltages and currents in the steps 1 and 2, and calculating and outputting counter electromotive force Ek?1 of all the coils in the multi-axis stabilization motor; 4, reading an stabilization compensation angle ?k, each coil resistance and the counter electromotive force, and calculating and outputting a closed-loop stabilization control Fk; and 5, then waiting for a time step k=k+1, and repeating the steps in the steps 1 to 4. It aims to add a closed-loop control element to a motor without a sensor to achieve an excellent stabilization effect and to reduce the risk of image blurring caused by resonance.

Abstract: A method of inserting an intraocular optic assembly having at least an optic and ring members that are interconnected to one another with a plurality of stanchions can include winding at least one of the structures relative to at least another one of the other structures about a central optic axis whereby at least some of the stanchions are drawn around an intermediate or middle ring member and in between the optic and an outer ring member. The method can also include folding, after the winding, the intraocular optic assembly in half while retaining the at least some of the plurality of stanchions in between the optic and the outer ring member. The method can also include inserting, after the folding, the intraocular optic assembly in an eye through a slit in a cornea of the eye.

Abstract: Methods and apparatus are provided for adaptively focusing a lens. In one approach, electromagnetic energy is employed to modify a shape or thickness of a lens such that its refractive power and focal length are modified. In one aspect, a lens embodying adaptive focus features requires low power, and can be adjusted quickly. One or a plurality of electromagnets can be employed to compress or separate end portions of an embedded haptic, the force from which acts to alter the shape of the haptic, thus modifying the refractive power and focal length of a lens.

Abstract: Certain exemplary embodiments can provide a system, machine, device, manufacture, circuit, composition of matter, and/or user interface adapted for and/or resulting from, and/or a method and/or machine-readable medium comprising machine-implementable instructions for, activities that can comprise and/or relate to, via a device implanted in a mammal, sensing a ciliary muscle movement and/or force and/or converting the ciliary muscle movement and/or force to a signal and/or a predetermined form of power.

Abstract: An intraocular implant device is operable in augmented reality and virtual reality configurations. The intraocular implant device includes an intraocular implant body shaped for positioning inside a lens chamber in an eye. The intraocular implant body has an anterior side facing the cornea of the eye and a posterior side facing the retina of the eye. A photoelectric sensor is disposed on the anterior side of the intraocular implant body. The photoelectric sensor is operable to receive natural, optimized or enhanced incident light through the cornea and to convert the received light into electrical energy for use with one or more circuit components disposed on the intraocular implant body.

Abstract: Systems and methods for improving vision of a subject implanted with an intraocular lens (IOL). In some embodiments, a method of treating an ocular disease of a subject having an implanted intraocular lens (IOL) includes determining visual needs of a subject that are associated with an ocular disease of the subject determining a pattern of a plurality of pulses of radiation to apply, by refractive index writing, and applying the plurality of pulses of radiation to the one or more selected areas of the IOL.

Abstract: A method for producing an accommodative intraocular lens includes providing first and second components and a support body with an interior space and open to the top, fastening the first component to the support body, generating pressure which is higher in the exterior space than in the interior space such that the first component deforms downward, producing an adhesive surface on the upper side of the first component and/or on the second component, applying a liquid to the first component from above into the latter's downwardly deformed region, the liquid at no time contacting the adhesive surface, fastening the second component to the first component with the adhesive surface, as a result of which the accommodative intraocular lens is formed and the liquid is encapsulated with the first component and the second component in a cavity arranged in the interior of the intraocular lens.

Abstract: An intraocular lens (IOL) has a clear optic and means for actuating change in curvature in at least a portion the clear optic. The intraocular lens (IOL) can have anterior and posterior portions spaced apart by a cavity, and an actuator for urging change in curvature in at least one of said portions, with energy provided by an energy harvesting mechanism incorporated into haptics of said IOL.

Abstract: Modular IOL removal systems and methods that cut an optic portion of an intraocular in a single motion such to facilitate removal of the optic portion from an eye through an incision, for example a corneal incision, without increasing the size of the corneal incision. Various cutting tools having one or more blades may be utilized. The cut intraocular lens may have one continuous cut or be cut into multiple smaller pieces. The single cutting step may apply balanced forces and torque to avoid damaging the surrounding eye anatomy, reducing the risk of trauma.

Abstract: Ophthalmic systems and methods of changing an optical power of an ophthalmic system are described. In an example, the ophthalmic system includes an accommodating intraocular device shaped to be implantable in an eye and an extraocular device separate from the accommodating intraocular device shaped to be removably mountable to a portion of the eye outside a bulb of the eye, such as an underlid portion of the eye. In an example, the method includes wirelessly transmitting power from a power source of an extraocular device removably mounted outside a bulb of an eye to an accommodating intraocular device implanted in the eye.

Abstract: An artificial eye lens (1) having an optical part (2) which has a first optical side (4) and an opposite, second optical side (5). The optical part (2) has a diffractive grating structure that contributes to an optical imaging property of the optical part (2). The diffractive grating structure is an amplitude grating (6) formed in the optical part (2) as a laser structure. A method for producing an artificial eye lens (1) where the amplitude grating (6) is produced with a laser apparatus (17), and a pulsed laser beam (22) having a pulse length of between 100 fs and 20 ps, a wavelength of between 320 nm and 1100 nm, a pulse repetition rate of between 1 kHz and 10 MHz, a focus diameter of less than 5 ?m, and a power density of greater than 106 W/cm2.

Abstract: A Light Adjustable Lens (LAL) comprises a central region, centered on a central axis, having a position-dependent central optical power, and a peripheral annulus, centered on an annulus axis and surrounding the central region, having a position-dependent peripheral optical power; wherein the central optical power is at least 0.5 diopters different from an average of the peripheral optical power, and the central axis is laterally shifted relative to the annulus axis. A method of adjusting the LAL comprises implanting a LAL; applying a first illumination to the LAL with a first illumination pattern to induce a position-dependent peripheral optical power in at least a peripheral annulus, centered on an annulus axis; determining a central region and a corresponding central axis of the LAL; and applying a second illumination to the LAL with a second illumination pattern to induce a position-dependent central optical power in the central region of the LAL.

Abstract: An ophthalmic device includes an enclosure, an electromyography sensor, and a controller. The enclosure is configured to mount in or on an eye. The enclosure further includes a first material and a second material disposed within the first material. The electromyography sensor is adapted to measure electrical activity of a muscle of the eye proximate to a first annular region of the ophthalmic device when the ophthalmic device is mounted in or on the eye. The electromyography sensor includes a first electrode and a second electrode, each positioned within the first annular region between the first material and at least a portion of the second material. The controller, coupled to the electromyography sensor, stores instructions that when executed causes the ophthalmic device to perform operations including acquiring a first signal representative of the electrical activity of the muscle by measuring the electrical activity with the electromyography sensor.

Abstract: A composite light adjustable intraocular lens, can include an intraocular lens (IOL), a light adjustable lens, attached to the intraocular lens, and haptics. In some cases, a composite light adjustable intraocular lens can include an intraocular lens, and haptics, attached to the IOL with light-adjustable hinges. A method of adjusting an implanted composite light adjustable intraocular lens can include planning a targeted optical outcome of an implantation of the composite light adjustable intraocular lens into an eye; implanting, the composite light adjustable intraocular lens into the eye; performing a diagnostic measurement to evaluate an implanted optical outcome of the implantation; determining a correction based on a comparison of the planned optical outcome and the implanted optical outcome; and applying a stimulus to adjust an optical characteristic of the composite light adjustable intraocular lens to induce the determined correction.

Abstract: Techniques and mechanisms for the wireless transmission of power and sensor information between two components of an implantable ophthalmic device are disclosed herein. An example device includes an accommodating intraocular lens (aIOL) and separate auxiliary electronics, both enclosed in biocompatible materials. The aIOL includes a dynamic optic, control logic, a battery and an antenna. The auxiliary electronics include an antenna, an energy storage cell, and a sensor. The auxiliary electronics may be wirelessly coupled to the aIOL for the wireless transmission of power and sensor information.

Abstract: Adjustable vision modification using various systems, devices, and processes are provided. Adjustable vision modification may include sensing ocular related physiological activities of a user and making adjustments in an ocular device or ocular system to change the vision of the user. Various sensors and sensor locations may be employed in embodiments to sense or otherwise obtain these physiological activities. Likewise, various ocular devices, ocular processes, and ocular systems may be employed for improving vision.

Abstract: One aspect of the present disclosure relates to a remotely controllable lens device. The lens device can include a lens material and a circuit physically coupled to the lens material. The circuit can be configured to be powered based on an energy signal from a power source to perform a function (e.g., release of drug, generation of electromagnetic radiation, detection of electromagnetic radiation, and/or control of an optical refractive property). For example, the power source can be an external power source and/or an auto-powered source. The external power source can be, for example, a power source that utilizes synchronized magnetic flux phase coupling (e.g., WiTricity). The auto-powered source can be provided on-site (e.g., on-chip) using a harvesting system (e.g., solar-cell, photo-cell, piezoelectric, etc.

Abstract: Improved devices, systems, and methods for planning cataract surgery on an eye of a patient incorporate results of prior corrective surgeries into a planned cataract surgery of a particular patient by driving an effective surgery vector function based on data from the prior corrective surgeries. The exemplary effective surgery vector employs an influence matrix which may allow improved refractive corrections to be generated so as to increase the overall efficacy of a cataract surgery by specifying one or more parameters of an intraocular lens (IOL) to be implanted during the cataract surgery.

Abstract: Improved devices, systems, and methods for planning cataract surgery on an eye of a patient incorporate results of prior corrective surgeries into a planned cataract surgery of a particular patient by driving an effective surgery vector function based on data from the prior corrective surgeries. The exemplary effective surgery vector employs an influence matrix which may allow improved refractive corrections to be generated so as to increase the overall efficacy of a cataract surgery by specifying one or more parameters of an intraocular lens (IOL) to be implanted during the cataract surgery.

Abstract: Improved devices, systems, and methods for planning cataract surgery on an eye of a patient incorporate results of prior corrective surgeries into a planned cataract surgery of a particular patient by driving an effective surgery vector function based on data from the prior corrective surgeries. The exemplary effective surgery vector employs an influence matrix which may allow improved refractive corrections to be generated so as to increase the overall efficacy of a cataract surgery by specifying one or more parameters of an intraocular lens (IOL) to be implanted during the cataract surgery.

Abstract: The present invention provides an accommodative intraocular lens (AIOL) system and method for improving accommodation with an intraocular lens. The method involves insertion into the capsular bag of a flexible optic holder comprising a plurality of haptics configured to allow the capsular bag to be sectioned at regular intervals following fusion of the capsular bag. The haptics of the optic holder are designed to allow maximum fusion of the anterior and posterior leaves of the capsular bag following placement of the optic holder in the capsular bag. Following introduction of the optic holder into the capsular bag, the natural or assisted process of fibrosis/fusion of the capsular bag occurs, thereby sealing and securely capturing the haptics within the capsular bag.

Abstract: A liquid crystal optical device is provided including at least two LC cells. A first LC cell layer has a predominant director orientation imparting a transversally non-uniform phase delay to a first polarization of an unpolarized incident light field passing therethrough while incident light of a second polarization orthogonal to the first light polarization passes therethrough undergoing transversally uniform phase delay. The first LC cell is configured to project a center extraordinary ray onto an optical axis of the device at the image surface. A second LC cell layer has a predominant director oriented orthogonally to the other predominant director in a plane perpendicular to the optical axis. The second LC layer imparts a transversally non-uniform phase delay to the second polarization of the incident light passing therethrough, the second LC cell being configured to project a center ordinary ray onto the optical axis at the image surface.

Abstract: The present disclosure provides intraocular artificial lenses having a variable optical strength and methods of treating an eye disorder, such as presbyopia, using same. In some embodiments, the intraocular artificial lens comprises two optical elements that are moveable along the optical axis in relation to each other, for example in response to the accommodative process of the eye.

Abstract: Disclosed are powered or electronic ophthalmic devices or lenses which can have the ability to monitor and sense extreme gaze angle. Also disclosed is the use of extreme gaze angles to control the focal state of the lens as well as for augmenting, control of, or input to, other device parameters of the powered or electronic ophthalmic lens. Applicants have researched and determined what are believed to be acceptable ranges of both upward and downward extreme gaze angles which are not only measurably distinguishable from normally occurring gaze angles associated with everyday activities, but which are still achievable by the wearer if purposeful, as they are still within human eye movement capability.

Abstract: Disclosed is a varifocal lens module. A varifocal lens module according to an embodiment includes a lens formed of a flexible and transparent material and having a focal length varying according to a variable shape thereof; at least one driving part expanded or contracted in response to an electric signal; and at least one structural body configured to physically or chemically connect the lens and each driving part.

Abstract: A method for producing an optical coupling element made of elastomer includes filling a free-flowing elastomer formulation or its constituents into a mold so as to produce a flat sheet whose thickness is adapted to a thickness of the optical coupling element that is to be produced. The elastomer formulation or its constituents is cured to form an inherently stable elastomer. Individual optical coupling elements are cut out of the flat sheet.

Abstract: An intraocular lens (IOL) device includes a lens configured to be positioned along the optical axis of a patient's eye and at least one haptic configured to engage an area within the patient's eye in order to position the lens along the optical axis. The IOL device further includes an expandable haptic-lens junction coupling the at least one haptic to the lens, the expandable haptic-lens junction configured to displace the lens relative to the haptic in response to an applied energy.

Abstract: In general, the present invention relates to optical elements, which can be modified post-manufacture such that different versions of the element will have different optical properties. In particular, the present invention relates to lenses, such as intraocular lenses, which can be converted into aspheric lenses post-fabrication. Also, the present invention relates to a method for forming aspheric lenses post-fabrication.

Abstract: Prosthetic capsular devices (e.g., bag, bowl, housing, structure, cage, frame) include technology devices such as a computer, virtual reality device, display device, WiFi/internet access device, image receiving device, biometric sensor device, game device, image viewers or senders, GPSs, e-mail devices, combinations thereof, and/or the like. The technology devices can be used in combination with an intraocular lens. The output from the technology device(s) can be fed to the retina of the user to provide a visual image, can be otherwise connected to the user, and/or can be used to control the properties of the intraocular lens or of the prosthetic capsular device.

Abstract: This invention discloses methods and apparatus for providing a variable optic insert into an ophthalmic lens. A liquid crystal layer may be used to provide a variable optic function and in some examples, an alignment layer for the liquid crystal layer may be patterned in a cycloidally dependent manner. The patterning may allow for a polarization dependent lens in some examples. An energy source is capable of powering the variable optic insert included within the ophthalmic lens. In some examples, an ophthalmic lens is cast-molded from a silicone hydrogel. The various ophthalmic lens entities may include electroactive liquid crystal layers to electrically control optical characteristics.

Abstract: This invention discloses methods and apparatus for providing a variable optic insert into an ophthalmic lens. A liquid crystal layer may be used to provide a variable optic function and in some examples, an alignment layer for the liquid crystal layer may be patterned in a cycloidally dependent manner. The patterning may allow for a polarization dependent lens in some examples. An energy source is capable of powering the variable optic insert included within the ophthalmic lens. In some examples, an ophthalmic lens is cast-molded from a silicone hydrogel. The various ophthalmic lens entities may include electroactive liquid crystal layers to electrically control optical characteristics.

Abstract: This invention discloses methods and apparatus for providing a variable optic insert into an ophthalmic lens. A liquid crystal layer may be used to provide a variable optic function and in some examples, an alignment layer for the liquid crystal layer may be patterned in a cycloidally dependent manner. The patterning may allow for a polarization dependent lens in some examples. An energy source is capable of powering the variable optic insert included within the ophthalmic lens. In some examples, an ophthalmic lens is cast-molded from a silicone hydrogel. The various ophthalmic lens entities may include electroactive liquid crystal layers to electrically control optical characteristics.

Abstract: This invention discloses methods and apparatus for providing a variable optic insert into an ophthalmic lens. A liquid crystal layer may be used to provide a variable optic function and in some examples, an alignment layer for the liquid crystal layer may be patterned in a cycloidally dependent manner. The patterning may allow for a polarization dependent lens in some examples. An energy source is capable of powering the variable optic insert included within the ophthalmic lens. In some examples, an ophthalmic lens is cast-molded from a silicone hydrogel. The various ophthalmic lens entities may include electroactive liquid crystal layers to electrically control optical characteristics.

Abstract: Example methods and devices are disclosed for generating life-logs with point-of-view images. An example method may involve: receiving image-related data based on electromagnetic radiation reflected from a human eye, generating an eye reflection image based on the image-related data, generating a point-of-view image by filtering the eye reflection image, and storing the point-of-view image. The electromagnetic radiation reflected from a human eye can be captured using one or more video or still cameras associated with a suitably-configured computing device, such as a wearable computing device.

Abstract: Techniques and mechanisms to power automatic accommodation by an eye-mountable device. In an embodiment, the eye-mountable device includes an accommodation actuator to change an optical strength of the eye-mountable device. Control logic of the eye-mountable device is to transition a supply voltage between different levels to drive operation of the accommodation actuator, including the control logic to perform a step-wise transition of the supply voltage from a first voltage level to a second voltage level. In another embodiment, the control logic includes a bidirectional direct current to direct current (DC-DC) converter. During the step-wise transition of the supply voltage, the bidirectional DC-DC converter is configured to aid in recharging a battery of the eye-mountable device with charge from the accommodation actuator.

Abstract: A deformable membrane assembly comprises a deformable membrane (70) in contact with a body of fluid (90) and a selectively operable adjuster for adjusting the pressure of the fluid (90) for causing distension of the membrane (70) in accordance with a predefined form. The membrane is held peripherally by a bendable supporting member (50) that is coupled to a fixed support by at least three engaging members (82) at spaced locations round the supporting member (50). An engaging member (82) is provided at or proximate at least one point round the supporting member (50) where the profile of the supporting member (50) corresponding to the predefined form of the membrane (70) exhibits locally maximum or minimum curvature in the direction of distension of the membrane (70).

Abstract: Provided herein are forward-imaging tunable lens systems and probes. A lens assembly is disclosed herein and comprises at least one tunable lens.

Abstract: A wake circuit is designed to minimize leakage current from a battery or other suitable energy source connected to various electronic components. The wake circuit essentially connects/disconnects or couples/decouples the battery or other power source from the other components when the device is in a storage state or otherwise idle.

Abstract: This invention discloses methods and apparatus for providing a variable optic insert into an ophthalmic lens. The variable optic insert may have surfaces within that have differing radii of curvature. A liquid crystal layer may be used to provide a variable optic function and in some embodiments, the liquid crystal layer may comprise droplets that are nano-scaled. An energy source is capable of powering the variable optic insert included within the ophthalmic lens. In some embodiments, an ophthalmic lens is cast-molded from a silicone hydrogel. The various ophthalmic lens entities may include electroactive liquid crystal layers to electrically control refractive characteristics.

Abstract: This invention discloses methods and apparatus for providing a variable optic insert into an ophthalmic lens. An energy source is capable of powering the variable optic insert included within the ophthalmic lens. In some embodiments, an ophthalmic lens is cast-molded from a silicone hydrogel. The various ophthalmic lens entities may include electroactive liquid crystal layers to electrically control refractive characteristics.

Abstract: An accommodating intraocular lens (AIOL) assembly (10) including an optics assembly (12) including an inflatable member (14), and characterized by an extra-capsular-bag interface structure (16) for interfacing with ocular structure of an eye external to a capsular bag for implanting the AIOL (10) outside the capsular bag, the extra-capsular-bag interface structure (16) including a less-rigid portion (18) and a more-rigid portion (20) that define a volume therebetween which is at least partially filled with a fluid (22) and which is in fluid communication with the inflatable member (14) via at least one conduit (24), and wherein the less-rigid portion (18) is responsive to movement of the ocular structure to apply a pumping force on the fluid (22) to cause the fluid (22) to flow via the at least one conduit (24) to the inflatable member (14) so as to change the optical power of the optics assembly (12).

Abstract: An intraocular lens (IOL) that provides for optical power adjustment following its implantation, for example, for use in treating cataract patients. The lens body has first and second surface portions that bound at least one interior chamber or space that extends from the central optic portion to the lens periphery. The interior chamber or space has a microporous body that is intermediate inner and outer portions of the space. In one embodiment, the microporous body is capable of cooperating with an external Rf or light source to expose a charge to a charge-carrying fluid within the interior chamber. By this system, fluid flows are induced to alter the optical parameters of the lens.

Abstract: Many modern implantable ophthalmic devices include electronic components, such as electro-active cells, that can leak harmful substances into the eye and/or surrounding tissue. In the implantable ophthalmic devices disclosed herein, electronic components are hermetically scaled within cavities formed by bonding together two or more glass wafers. Bonding the glass wafers together with laser fusion bonding, pressure bonding, or anodic bonding creates a seal that leaks at a rate of less than about 5×10?12 Pa m3 s?1 when subjected to a helium leak test. Hermetically sealed feedthroughs formed of conductive material running through channels in the wafers provide electrical connections to components inside the sealed cavities. In some cases, the conductive material has a coefficient of thermal expansion (CTE) that is roughly equal to (e.g., within 10% of) the CTE of the glass wafers to minimize leakage due to thermally induced expansion and contraction of the conductive material and the glass wafer.

Abstract: Systems and methods of the disclosure relate to managing power consumption of an implantable device, such as an implantable ophthalmic device, that includes one or more rechargeable batteries and a processor operably coupled to the rechargeable batteries. The processor can be configured to implement a quick-charge process that includes charging each rechargeable battery for a first time interval using a first constant current, for a second time interval using a second constant current less than the first constant current, and for a third time interval using a constant voltage. This quick charge process is faster than conventional charging. The processor also manages discharge of two batteries in an alternating fashion so as to increase time between charging cycles, reduce the total number of charging cycles, and extend battery life.