Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B7/00—Instruments for auscultation
  • A61B7/02—Stethoscopes
  • A61B7/04—Electric stethoscopes
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/0002—Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/02—Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow
  • A61B5/0205—Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
  • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
  • A61B5/683—Means for maintaining contact with the body
  • A61B5/6832—Means for maintaining contact with the body using adhesives
  • A61B5/6833—Adhesive patches
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
  • A61B5/7271—Specific aspects of physiological measurement analysis
  • A61B5/7278—Artificial waveform generation or derivation, e.g. synthesizing signals from measured signals
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B2560/00—Constructional details of operational features of apparatus; Accessories for medical measuring apparatus
  • A61B2560/04—Constructional details of apparatus
  • A61B2560/0406—Constructional details of apparatus specially shaped apparatus housings
  • A61B2560/0412—Low-profile patch shaped housings
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
  • A61B2562/02—Details of sensors specially adapted for in-vivo measurements
  • A61B2562/0204—Acoustic sensors
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
  • A61B2562/16—Details of sensor housings or probes; Details of structural supports for sensors
  • A61B2562/164—Details of sensor housings or probes; Details of structural supports for sensors the sensor is mounted in or on a conformable substrate or carrier
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
  • A61B2562/22—Arrangements of medical sensors with cables or leads; Connectors or couplings specifically adapted for medical sensors
  • A61B2562/225—Connectors or couplings
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/0002—Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network
  • A61B5/0004—Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network characterised by the type of physiological signal transmitted
  • A61B5/0006—ECG or EEG signals
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/08—Measuring devices for evaluating the respiratory organs
  • A61B5/0816—Measuring devices for examining respiratory frequency
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/08—Measuring devices for evaluating the respiratory organs
  • A61B5/083—Measuring rate of metabolism by using breath test, e.g. measuring rate of oxygen consumption
  • A61B5/0833—Measuring rate of oxygen consumption
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B7/00—Instruments for auscultation
  • A61B7/003—Detecting lung or respiration noise
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B7/00—Instruments for auscultation
  • A61B7/02—Stethoscopes
  • A61B7/026—Stethoscopes comprising more than one sound collector

Definitions

• Described herein are several alternative medical monitoring devices, systems and/or methods for parameter determination, in some instances for long-term sensing and/or recording of cardiac and/or respiratory and/or temperature and/or audio data of one or more individuals, such as a neonate, infant, mother/parent, athlete, or patient.
• a number of alternative implementations and applications are summarized and/or exemplified herein below and throughout this specification.
• the developments hereof may include an implementation wherein a health device is configured for monitoring one or a plurality of physiological parameters of one or more individuals from time-concordant measurements collected by one or a plurality of sensors, including one or a variety of one or more of, but not limited to, electrodes for measuring ionic potential changes for electrocardiograms (ECGs), and/or one or more light sources and one or more photodetectors, in some cases including LED-photodiode pairs, for optically based oxygen saturation measurements, and/or one or more temperature sensors, and/or one or more x-y-z accelerometers for movement and exertion measurements, and/or one or more audio or acoustic pickups or sensors or microphones and/or the like.
• ECGs electrocardiograms
• methods and devices of the developments hereof may be used to generate a respiration waveform.
• Other implementations may include a circuit that mimics a driven right-leg circuit (sometimes referred to herein as“a proxy driven right-leg circuit”) that may permit reduction in common mode noise in a small-footprint device conveniently adhered or having the capacity to be adhered to an individual.
• a proxy driven right-leg circuit sometimes referred to herein as“a proxy driven right-leg circuit”
• a blood pressure determination may in some cases be made from a determination of pulse transit time.
• the pulse transit time is the time for the cardiac pressure wave to travel from the heart to other locations in the body. Measurements of pulse transit time may then be used to estimate blood pressure.
• Heart beat timing from ECG or otherwise and photoplethysmogram (aka PPG) signals can be used to generate pulse transit time.
• PPG signals may be generated from conventional or other to-be-developed processes and/or devices or systems; or, such signals may be taken from one or more wearable health monitoring devices such as those also described hereinbelow.
• the developments hereof may include in some instances one or more methods and/or devices for measuring and/or determining oxygen saturation parameters from time concordant pulse oximetry signals and ECG signals.
• ECG signals may be used to define intervals, or“frames” of pulse oximetry data that are collected and averaged for determining the constant and main periodic components (e.g., DC and AC components) of the pulse oximetry signals from which, in turn, values for oxygen saturation may be determined.
• Patient-wearable devices of such implementations with pulse oximetry and ECG sensors may be particularly useful when placed on a patient’s chest for such signal acquisition.
• Fig. 1 which includes and is defined by sub-part Figs. 1 A-1W, illustrates several alternatives of the present developments, including a variety of isometric, top and bottom plan and elevational views of devices and alternative conductive adhesive structures.
• Fig. 2A-2D which includes and is defined by sub-part FIGs. 2A-2D, provides circuit diagrams of alternatives to, in FIGs. 2A-2C, a driven right leg circuit, and in FIG. 2D, pulse oximetry.
• Fig. 3 is a flow chart including alternative methods of use.
• FIG. 4 illustrates an exemplary computer system or computing resources with which implementations hereof may be utilized.
• FIG. 5 which includes and is defined by sub-part FIGs. 5A-5D, provides alternative screenshots of alternative software implementations according hereto.
• FIGs. 6A and 6B illustrate features of one embodiment for measuring oxygen saturation using pulse oximetry signals and electrocardiogram signals.
• Fig. 6C is a flow chart showing steps of one embodiment for determining oxygen saturation values.
• FIGs. 6D and 6E illustrate an embodiment for determining depth of respiration values.
• FIGs. 7A, 7B and 7C set forth flow diagrams for alternative methodologies hereof.
• on-body, multi-function, biometric sensors included here are on-body, multi-function, biometric sensors.
• the devices monitor bodily functions such as one or more or all of ECG, PPG, temperature, respiration, and activity among other possible options.
• Such devices may in many cases be configured for operational attachment to, on, adjacent to, or nearby a subject’s sternum or on a subject’s chest with an adhesive, often a disposable adhesive.
• Such devices may typically be in many instances, but not limited hereto, small and thin relative to a user (e.g., on the order of approx.
• a system hereof may include a device for monitoring physiological parameters such as one or more or all of electrocardiogram (aka ECG or EKG),
• PPG photoplethysmogram
• pulse oximetry temperature and/or patient acceleration or movement signals and/or audio or sound signals as for example heartbeat sounds.
• systems hereof may be established to measure and/or process such signals of a patient using or including any one or more of the following elements: (a) a circuit, sometimes flexible as in or on or forming a flexible or flex circuit board, embedded in or on a flat elastic substrate or board having a top surface and a bottom surface, the circuit having one or more of (i) at least one sensor mounted in or on or adjacent the bottom surface of the flat elastic substrate, the at least one sensor being capable of electrical or optical communication with the patient.
• a circuit may include (ii) at least one signal processing module for receiving and/or accepting signals from the at least one sensor in some implementations also providing for transforming such signals for storage as patient data; and/or (iii) at least one memory module for receiving and/or accepting and storing patient data, and/or (iv) at least one data communication module for transferring patient data, stored or otherwise to an external device, and/or (v) a control module for controlling the timing and operation of the at least one sensor, one or more of the at least one signal processing module, the at least one memory module, the at least one data communication module, and/or the control module capable of receiving commands to implement transfer of patient data by the at least one data communication module and to erase and/or wipe patient data from the at least one memory module.
• a system hereof may include (b) a conductive adhesive removably attached to the bottom surface of the flat elastic substrate, the conductive adhesive capable of adhering to skin of the patient or other user and in some non-limiting examples a system hereof may be capable of conducting an electrical signal substantially only in a direction perpendicular to the bottom surface of the flat elastic substrate, and/or in some implementations may include a conductive portion adjacent the sensor or sensors and a non-conductive portion.
• the conductive adhesive is an anisotropically conductive adhesive in that it comprises regions of material that conducts current substantially only in a direction perpendicular to the skin (i.e.“z-axis” conduction).
• devices hereof will be for comprehensive long-term cardiac monitoring, inter alia.
• Features of such may but not necessarily include any one or more of a Lead 1 ECG, PPG, pulse oximeter, accelerometer, temperature sensor and/or a button or other indicator for manual patient event marking.
• Such a device may be adapted to store up to, for example, about two weeks of continuous data (though more or less will also be feasible in alternative implementations), which may in some implementations be downloaded to a clinic or other computer in a short time period, as for one example, in only about 90 seconds (though more or less time will be viable in alternative implementations) via computer connection, whether wireless or wired as in one example by USB or other acceptable data connection.
• a companion software data analysis package may be adapted to provide automated event capture and/or allow immediate or delayed, local data interpretation.
• a device hereof may address this problem with what in some implementations may be a continuous or substantially continuous monitoring of one or a number of vital signs.
• Some alternative features may include but not be limited to one or more of (i) a driven “Right Leg” circuit with electrodes located only on the chest, and/or (ii) a“z-Axis” or anisotropic conductive adhesive electrode interface that may permit electrical communication only between an electrode and a patient’s skin immediately beneath the electrode, and/or (iii) data transmission to and interpretation by a local computer accessible to CCU/ICU personnel, and/or (iv) a unique combination of hardware that may allow correlation of multiple data sources in time concordance to aid in diagnosis.
• devices and systems hereof may provide 1) reusability (in some cases near or greater than about 1000 patients) that may allow recouping cost of the device in just about 10-15 patient tests; and/or 2) one or more of ECG waveform data, inertial exertion sensing, manual event marking, temperature sensing and/or pulse oximetry, any one or all of which in time concordance to better detect and analyze arrhythmic events; and/or 3) efficient watertightness or waterproofing (for the patient/wearer to be able to swim while wearing the device); and/or 4) a comprehensive analysis package for typically immediate, local data interpretation.
• An alternative device may be adapted to take advantage of flex-circuit technology, to provide a device that is light-weight, thin, durable, and flexible to conform to and move with the patient’s skin during patient/wearer movement.
• FIGs. 1 and 2 illustrate examples of alternative implementations of devices that may be so adapted.
• Fig. 1 which is defined by and includes all of sub-part FIGs. 1 A-1W, shows a device 100 that has a component side or top side 101, patient side or circuit side 102, and one or more inner electrical layer(s), generally identified by the reference 103 and an elongated strip layer 105.
• the strip layer 105 may have electronics thereon and/or therewithin.
• FIG. 1 A shows isometrically these in what may in some non-limitative implementations be considered a substantially transparent device together with some other elements that may be used herewith.
• FIG. IB is more specifically directed to a top side 101 plan view and FIG. 1C to an underside, patient side 102 plan view and FIG. ID a first elevational, side view.
• the optional electronics hereof may be disposed in the electronics layer or layers 103, and as generally indicated here, the electronics may be encapsulated in a material 104 (see FIGs. 1A, IB, ID and IS for some examples, and see Figs. 1T2, 1U, 1U1 and 1U2 described further below, e.g.), medical grade silicone, plastic or the like, or potting material, to fix them in operative position on or in or otherwise functionally disposed relative to the elongated strip layer 105.
• the potting or other material may in many implementations also or alternatively provide a waterproof or watertight or water resistant coverage of the electronics to keep them operative even in water or sweat usage environments.
• One or more access points, junctions or other functional units 106 may be provided on and/or through any side of the encapsulation material 104 for exterior access and/or communication with the electronics disposed therewithin, or thereunder.
• FIGs. 1 A, IB and ID show four such accesses 106 on the top side. These may include high Z data communication ports and/or charging contacts, inter alia.
• This upper or component side 101 of device 100 may be coated in a silicone compound for protection and/or waterproofing, with only, in some examples, a HS USB connector exposed via, e.g., one or more ports 106, for data communication or transfer and/or for charging.
• the elongated strip layer 105 may be or may include a circuit or circuit portions such as electrical leads or other inner layer conductors, e.g., leads 107 shown in FIG. ID, for communication between the electronics 103 and the electrically conductive pads or contacts 108, 109 and 110 described further below (108 and 109 being in some examples, high impedance/high Z silver or copper/silver electrodes for electrocardiograph, ECG, and 110 at times being a reference electrode).
• the strip layer 105 may be or may include flex circuitry understood to provide acceptable deformation, twisting, bending and the like, and yet retain robust electrical circuitry connections therewithin.
• the electronics 103 and electrodes 108, 109, 110 are shown attached to layer 105; on top for electronics 103, and to the bottom or patient side for electrodes 108, 109, 110; it may be that such elements may be formed in or otherwise disposed within the layer 105, or at least be relatively indistinguishably disposed in relative operational positions in one or more layers with or on or adjacent layer 105 in practice.
• the leads or traces 107 are shown embedded (by dashed line representation in FIG. ID); however, these may be on the top or bottom side, though more likely top side to insulate from other skin side electrical communications. If initially top side (or bottom), the traces may be subsequently covered with an insulative encapsulant or like protective cover (not separately shown), and/or in many
• a flexible material to maintain a flexible alternative for the entire, or majority of layer 105.
• Sophisticated electronics may be preferred for many of the functionalities described herein; indeed, many implementations may include large numbers and/or combinations of functions on the respective devices and sophisticated electronics may even be required to achieve same in many cases.
• Flexible Circuit Boards aka FCB or FCBs
• Flexible Printed Circuits aka FPC or FPCs
• FCB or FCBs Flexible Circuit Boards
• FPC or FPCs Flexible Printed Circuits
• FCB or FCBs Flexible Circuit Boards
• FPC or FPCs Flexible Printed Circuits
• the soldered connections of larger integrated circuits (IC’s) can in many cases be unreliable or become unreliably soldered under constant or otherwise significant flexure of the flexible substrate.
• FIGs. IE - IN may be used to address these flexibility and reliability issues of manufacturing a multi -function, wearable biometric monitor.
• FIGs. 1 A - ID In the implementations of FIGs. 1 A - ID (among others also shown and described below), all the circuitry is shown attached relatively directly to the flexible circuit board 105, still viable options, though perhaps less preferred with current flexible substrates. However, in some alternatives, in order to make the subject-facing FPC relatively more flexible than the board 105 of FIGs. 1A - ID, many if not all of the large IC’s and other components can be relocated to another, relatively rigid, Printed Circuit Board (aka PCB) that can be nevertheless operably connected to a flexible circuit board. These are shown in FIGs. 1E-1N in the devices 500 and 500a.
• PCB Printed Circuit Board
• FIGs. 1E-1N show a device 500 or an alternative device 500a that each have a component side or top side 501, patient side or circuit side 502, and one or more generally electrical layer(s), generally identified by the reference 503, generally. Also here included is an elongated strip layer or circuit layer 505 disposed therewithin. The circuit layer 505 may have electronics thereon and/or therewi thin, see e.g., components 519 described further below.
• FIGs. IE and IF show isometrically these in what may in some non-limitative implementations be as shown a substantially transparent or translucent device together with some other elements that may be used herewith.
• IE and IF show two or more layers, generally one on top of the next, here including a first layer 503a which is a flexible or flex circuit layer shown noticeably flexed, here shown arched as it might be in use on a subject user (a user or wearer 1000 is identified generally in FIG. IF).
• the second or middle circuit layer 505 is here a relatively rigid material board not intended to arc or arch or otherwise flex to more readily maintain the electrical connections and/or circuit components connected thereon, thereto and/or therewithin.
• An optional third layer 503b also here a flexible layer is also shown, here above the circuit layer 505; the third layer 503b here having data communication capability, via one or more data communication devices 506, here via an antenna 506.
• FIGs. 1G and 1H and II Cross-sectional views of respective versions of devices 500 and 500a are shown in respective FIGs. 1G and 1H and II. These also each have the top or external side 501, patient side 502, and the one or more generally electrical layer(s), generally identified by the reference 503, generally, including the elongated strip layer or circuit layer 505 therewithin.
• the reference 503 generally, including the elongated strip layer or circuit layer 505 therewithin.
• FIGs. 1H and II are shown in FIGs. 1H and II as well but left off the implementation of FIG. 1G merely for ease in showing/viewing other operational parts thereof as described below.
• a battery 520 and battery compartment or cage 520a Off to the side relative to these stacked circuit layers is a battery 520 and battery compartment or cage 520a.
• Other optional and/or preferred components are further described.
• this layer 503a With many electrical components removed from the bottom, subject facing layer, here layer 503a, this layer 503a remains extremely flexible and has the capability to conform to a wide variety of body types, sizes and shapes and body motions. Only a few components remain on this lower layer 503a; typically, in this implementation, the actual sensors themselves. These are the ECG electrodes 508 and 509, the PPG (photoplethysmograph) device/sensor 511, a temperature sensor 515 and a microphone 516, e.g., a piezo microphone.
• ECG electrodes 508 and 509 the PPG (photoplethysmograph) device/sensor 511
• a temperature sensor 515 e.g., a piezo microphone.
• the signals received by and/or through these sensors can then be passed to the next layer 505 thereabove, the“floating” relatively rigid PCB, through a micro-connector 517 placed in such a fashion to be a mechanical hinge point with electrical communication therebetween.
• the processing electronics 519 may be disposed to reside on this rigid PCB 505, which may thereby increase solder reliability, and thereby reliability and robustness of the electrical communications; the electronic and/or processing components 519 having little cause for movement relative to the PCB 505.
• taking electronic devices 519 such as ICs from the flexible layer 503a may remove or reduce rigidity in or from the subject facing layer 503a disposed below the more rigid layer 505.
• another flexible layer 503b may be disposed above the rigid layer 505, another flexible layer 503b may be disposed.
• this may be an antenna 506, as for example, a Bluetooth antenna, connected to Layer 505 by a micro coaxial connector 518, placed adjacent the above-mentioned hinge point 517.
• This Third Layer 503b may be configured to be flexible in order to keep the overall stack of three circuit boards flexible.
• FIGs. 1H and II An exterior housing 530 is shown in FIGs. 1H and II as it might be disposed over and contain the other parts. This might be made of a pliable or flexible silicone, typically of a medical grade, and may be a molded part to provide shape substantially as shown. Also shown is a pleat 531 or fold, or tuck or crease in such a housing 530; such a pleat providing even further allowance for bending movement, here near the center of the device, and/or near the connection of the rigid board 505 to the flexible substrate 503a. This connection area is shown and described in more detail in FIG. II, et seq; the FIG. II generally being an enlarged approximate portion of FIG. 1H taken at about circle C1I of FIG. 1H.
• the primary substrate 503a is shown with adhesive 513.
• the rigid board 505 Connected to the substrate 503a is the rigid board 505, connected via the electrical/data connector 517.
• Generic electrical components 519 are shown on both sides of board 505; both sides being optionally usable to maximize usage of real estate on board 505, yet keeping the overall size, width and length, of board 505 to a relative minimum. This is optional; only one side may be used in some
• FIG. II for general reference are the sensor components 511 and 515 on substrate 503a, the battery 520 and battery cage 520a (which may take other forms, not shown), inter alia.
• the third level, layer 503b is shown housing the antenna 506, and as connected to PCB 505 via connector 518.
• FIG. 1H a better view of pleat 531 of cover 530 is shown in FIG. II, pleat 531 allowing for greater flexure of substrate 503a.
• more visible are two gaps, or hinges 503h and 513h, formed in the respective substrate 503a and adhesive 513; each gap at the hinge being disposed to allow flexibility.
• an adhesive may be formed by six layers strategically disposed, and for the relative gap/hinge 513h, only 1 or another number of few of the 6 layers, may be/remain existing at this point 513h; the reduction of material being representative of the concept.) It is noted that the gap and the adhesive are not shown in the alternative implementation shown in FIG. 1G.
• FIG. 1 J a more schematic view showing some options, shows the gap/hinge 503h in substrate 503a and an optional representation (dashed lines) of a gap/hinge 513h in adhesive 513.
• a representative sensor element, here temperature sensor 515 is shown as it may be schematically attached to substrate 503a.
• Relatively rigid board 505 is shown as it might be attached via connector 517 to flexible substrate 503a.
• An electrical component 519 is shown on the top/external side of board 505, with a dashed line/optional representation of s second component 519 on the underside of board 505; this to schematically show the optionality of these connections/dispositions; the top side being just as optional as the bottom side, though not so indicated here.
• FIG. IK is not unlike FIG. 1 J, though with even more schematical representation, by removal of the adhesive, and removal of the optionality/dashed line representations.
• the FIG. IK implementation shows a relatively un-flexed flexible circuity board 503a.
• the FIG. 1K1 implementation shows the same componentry with a flexed disposition of the substrate 503a.
• the flex arrows generally show the movement.
• FIG. 1K1 shows what may not be ideal depending upon the type of connector 517.
• a connector 517 is chosen which may allow for some rotational movement; however, the preferred implementation will provide a robust secure electrical connection at 517.
• FIG. 1K1 some space may be seen to perhaps demonstrate a disconnect; however, the intent is to show a connection device, if available, that may allow for some relative rotational movement and yet continue to provide a robust electrical and/or data communication connection.
• the flexible circuit board 503a may be disposed to be relatively rigid in the area under/adjacent the connector 517; this relative rigidity may be a feature of the board 503a or may be imposed thereon by the connector 517.
• this implementation of a "Flexible Stack - Rigid Connector" may provide a relative correction over the FIG. 1K1 implementation which shows instead the connector mating surfaces not distorting during flexure.
• the device may be more relatively flexible in the regions identified generally as 503al and 503a3 and may be more relatively rigid in the region 503a2.
• the connector itself will, in this implementation, have little or no movement.
• the connector parts appeared to skew slightly; and this may also occur, though more slightly in FIG. 1L1; but, in many implementations, the connector 517 will have locking ears to prevent any movement within the connector, keeping all 60 pins in contact with each other.
• Some connectors found to meet some preferences include the 60 pin connector 517, male and female made by Samtech. Hirose is a manufacturer for the Coax connector on/from the antenna 506 to the connector 518 (as in FIG. 1H and II), where the mating coax connector 518 on double sided board 505 may come from Amphenol (also depicted in FIG. 1H and II).
• the temperature sensor 515 which may in many implementations be an "Insulated Skin Temp Sensor"
• the location of the sensor may be found to have a more desirable disposition located near the rigid portion of the stack, and/or as well as in the center of area of the device.
• the location near the rigid portion may provide better if not optimum skin contact, while the location at the center of area may allow maximum distance in the x and y direction from the edges.
• the adhesive stack which in this application, may act as a thermal insulator, allows the temperature sensor to come to thermal equilibrium with the skin quickly, thus increasing accuracy.
• FIGs. 1M and 1M1 show a“Flexible Microphone" as may be implemented herein.
• the microphone technology used herein may be a flexible piezo strip 516 which will emit a voltage whose amplitude is proportional to the amount of flexure it is subjected to.
• a thin-film piezo 516 connected to the substrate 503a by electrical connection 516a may be employed allowing the device to be sensitive in two bandpasses: 0 to 10 Hz, and centered around a bandpass of 1100 Hz.
• the placement of the piezo 516 as shown in FIG. 1M is of interest.
• the Piezo 516 may be placed on the patient side of the substrate 503a such that it crosses the hinge point.
• the microphone 516 may be sensitive to the relatively large chest movement that occurs during breathing (in the 10 Hz range) yielding respiration rate from ultra-low frequency sound.
• the portion over the less flexible portion is sensitive to mid-range sound of 1100 Hz, yielding breath sound data such as wheezing, obstruction volume of air etc. Since the hinge point is where the maximum flexure will occur, it will generate the maximum voltage possible during respiration of the patient. This modulated voltage is then processed using DSP techniques to provide an accurate measure of the patient's respiration rate and depth.
• a description of the antenna 506 is that it may preferably be designed to fit, e.g., may be custom fit, within the envelope of the device 500/500a. It may be resonant at 2.4 GHz with a Minimum Standing Wave Ratio and Maximum Forward Power. In order to achieve this, active element length, width, and dielectric thickness may be optimized in-situ, on the human body, with the circuit boards, silicone cover 530, and adhesives 513 in place.
• a novel feature may normally be a dipole antenna is normally constructed with two elements of equal length at the resonant frequency (one passive, one active). This implementation of a dipole uses an active element at the resonant frequency, but the human body as the passive element.
• FIGs. IN and INI - 1N6 show various external views of a device 500 or 500a or the like.
• FIG. IN is a three-dimensional top view;
• FIG. 1N1 is more specifically directed to a top side 501 plan view and FIG. 1N2 to an underside, patient side 502 plan view and
• FIG. 1N3 a first elevational, side view, and
• FIG. 1N4 is a second elevational side view.
• FIG. 1N5 is a front elevational view, and FIG. 1N6 is a back side elevational view.
• FIG. IN provides a three-dimensional top view of a device 500 or 500a or the like, including optional third electrode 510, electrode extender 504, silicone cover 530, pleat 531, battery cage 520, and removable battery cage cover 533.
• the removable battery cage-cover 533 may be a turn-able friction-fit type (or alternatively a bayonet style) of cap that allows the cap to be secured in place relative to the battery cage 520.
• the removable battery cage-cover 533 may have an unlock indicator 534 and lock indicator 535, that align with a point of reference marking 536 to help a user determine whether the removable battery cage cover 533 is secured in place relative to the battery cage and the device more generally.
• the battery cage cover 533 may further have a handle 537 that protrudes from the surface of the battery cage cover that may assist the user in turning (screwing or unscrewing) and securing the battery cage cover.
• the battery cage cover 533 may also have one or more indentations 538 to assist the user in turning (screwing or unscrewing) the battery cage cover.
• the battery cage cover may have a sealing material of silicon, rubber, or other suitable material (not shown in diagrams) around the circumference of the bottom-side of the cap to provide for waterproofing of the battery compartment from the exterior conditions.
• FIG. INI is a top side 501 plan view of a device 500 or 500a or the like, including optional third electrode 510, flexible electrode extender 504, silicone cover 530, pleat 531, battery cage 520, removable battery cage cover 533, unlock indicator 534, lock indicator 535, reference marking 536, handle 537, and indentations 538.
• FIG. 1N2 provides an underside, patient side 502 plan view of a device 500 or 500a or the like, including optional third electrode 510, flexible electrode extender 504, and silicone cover 530.
• FIG. 1N3 provides a first elevational side view of a device 500 or 500a or the like, including optional third electrode 510, flexible electrode extender 504, silicone cover 530, pleat 531, battery cage 520, removable battery cage cover 533, and handle 537.
• FIG. 1N4 provides a second elevational side view of a device 500 or 500a or the like, including optional third electrode 510, flexible electrode extender 504, silicone cover 530, pleat 531, battery cage 520, removable battery cage cover 533, and handle 537.
• FIG. 1N5 is a front elevational view of a device 500 or 500a or the like, including optional third electrode 510, flexible electrode extender 504, silicone cover 530, pleat 531, battery cage 520, removable battery cage cover 533, and handle 537.
• FIG. 1N6 is a back elevational view of a device 500 or 500a or the like, including optional third electrode 510, flexible electrode extender 504, silicone cover 530, pleat 531, battery cage 520, removable battery cage cover 533, and battery cage cover handle 537.
• FIG. 1N7 provides a top side 501 plan view of the device 500 or 500a or the like, including optional third electrode 510, flexible electrode extender 504, silicone cover 530, pleat 531, battery cage 520, removable battery cage cover 533, unlock indicator 534, lock indicator 535, reference marking 536, battery cage cover handle 537, and indentations 538.
• FIG. 1W Another alternative implementation is shown in FIG. 1W.
• Application of an audio pickup device or sensor or microphone or the like to a patient, the very interaction between the pickup sensor or like device and the skin, and particularly movement of the sensor relative to the skin imparts undesirable noise to the sensor or to the sensitive mechanical membrane of the sensor, if it has one, possibly masking important or desirable physiological sounds. This is even more pronounced on/in/with electronically amplified or otherwise very sensitive audio sensors which may be disposed to introduce noise.
• An implementation hereof may involve a removable, double-sided silicone adhesive, in some implementations with one or both sides initially protected by a release liner.
• application of one adhesive side to the audio sensor, then the other side may be applied to the patient (person to be monitored), and then at least some, and in perhaps other implementations as much as all, of the motion noise that would have been imparted by the movement of the sensor relative to the skin can be eliminated or substantially reduced.
• no other adhesives may typically be included (e.g, without a composite adhesive or without stacked composite adhesive, even typically without conductive areas or layers); however, other uses with or including such other adhesives or adhesive portions in other possible implementations, whether used with an audio sensor, or, as for example when used together with/on a wearable health monitoring device having other sensors and/or electrodes included.
• the adhesive may typically be a single, thin, double-sided silicone adhesive or tape. Typically, this may be a silicone adhesive approved or otherwise acceptable for skin contact thus eliminating mechanical noise.
• the silicone adhesive may be disposed to be applied once or several times on/to a particular patient. Moreover, in some implementations, with appropriate selection of the adhesive, removal of hair may not be required.
• a microphone or other audible, acoustic or audio sensor 150 may be disposed on or in or otherwise operably associated with a substrate 105 of the device 100b for ultimate operational application to or in relation to a patient or other wearer (not shown in FIG. 1W).
• a dashed line representation of an electrical/audio signal connection 151 is also shown for communication of sound data from the patient via the sensor or microphone 150 to the central data collection and/or communication devices of health monitoring device 100b (see other descriptions of optional alternative operational data acquisition and/or manipulation devices that can be disposed on a substrate 105 and used herefor) for appropriate handling.
• An adhesive 113 is shown to be disposed (not unlike description above) over and operationally in position relative to the acoustic sensor or microphone 150 (in this example, the adhesive is configured to be disposed over other devices 108, 109, 110 and substrate 105 as well).
• the adhesive 113 would be exposed by removal of the release liner 114 (not unlike description herein elsewhere) also be connected to the patient for ultimate operation and collection of physiological signals or sounds, as for example heartbeats.
• the adhesive would operate to isolate and/or maintain operational disposition of the device 150 relative to the skin and/or patient to eliminate and/or reduce movement of the device 150 and consequent noise, noise that would otherwise interrupt or potentially obliterate the sound or signal data of interest.
• a particular use may be on a device 100b as shown with one or more other sensors, electrodes and/or optical equipment (emitters and/or receivers); or, alternatively, particular uses may involve only the audio sensor or microphone.
• Infant or child uses are both envisioned with possible enhanced benefit for child heartbeat sensing and/or capture.
• the ECG electrodes 108, 109 and 110 may be left exposed for substantially direct patient skin contact (though likely with at least a conductive gel applied therebetween); and/or, in many implementations, the patient side electrodes 108, 109 and/or 110 may be covered by a conductive adhesive material as will be described below.
• the electrodes may be plated with or may be a robust high conductive material, as for example, silver/silver chloride for biocompatibility and high signal quality, and in some implementations may be highly robust and, for one non-limiting example, be adapted to withstand over about one thousand (1000) alcohol cleaning cycles between patients.
• these silver/silver chloride electrodes may be printed directly on the flexible circuit board or flexible printed circuit, and yet in other instances the silver/silver chloride electrodes may be attached or fastened to the flexible circuit board or flexible printed circuit as a discrete and separate step in the fabrication process.
• Windows or other communication channels or openings 111, 112 may be provided for a pulse oximeter, for example, for LEDs and a sensor.
• Such openings 111, 112 would typically be disposed for optimum light communication to and from the patient skin.
• An alternative disposition of one or more light conduits 11 la/112a (and 11 lb/112b) is shown in a non-limiting example in FIG. ID more nearly disposed and/or connected to the electronics 103.
• a variety of alternative placements may be usable herein/herewith, some of which further described below.
• sampling of the ambient light may be provided, and then subtracting this from each of the pulse-ox signals in order to cancel out the noise caused by sunlight or other ambient light sources.
• the LEDs and one or more photodiode sensors may also and/or alternatively be covered with a layer of silicone to remove any air gap between the sensor/LEDs and the patient skin.
• LED 111c (FIGs. IQ and/or IS and/or one or more of IT, 1T1, 1T2, 1U, 1U1 and/or 1U2) might be a Red LED
• LED 11 Id (FIGs. IQ and/or IS and/or one or more of IT— 1U2) might be an IR
• LEDs. IQ and IS and/or one or more of IT— 1U2 might be a sensor.
• Alternative and/or additional LEDs might be provided; for a first example, one or more additional or alternative colors of LEDs (not shown) might be provided not unlike those shown in FIGs. IQ and/or IS and/or one or more of IT— 1U2, as for example a Green LED (not shown) for additional and/or alternative functionality as described further below.
• FIGs. IT and 1T1 Other alternative LED and sensor arrays or arrangements are shown in FIGs. IT and 1T1 wherein one or more LEDs are more centrally disposed within epoxy /light-pipe 121c on a substrate 105a and one or more sensors or photodiodes are more peripherally disposed.
• FIG. IT two LEDs 111c and 11 Id (not unlike LEDs 111c and 11 Id of Figs. IQ and/or IS, but for positioning/geometry) are shown relatively centrally disposed relative to one or more sensors, here, two sensors or photodiodes 112c and 112d.
• Figs. 1T1 Other alternative LED and sensor arrays or arrangements are shown in FIGs. IT and 1T1 wherein one or more LEDs are more centrally disposed within epoxy /light-pipe 121c on a substrate 105a and one or more sensors or photodiodes are more peripherally disposed.
• two LEDs 111c and 11 Id are shown relatively centrally disposed relative to one
• LED 111c might be a Red LED
• LED 11 Id might be an IR (infrared) LED
• the devices 112c and/or 112d might be one or more sensors, here two sensors or photodiodes 112c and 112d.
• FIG. 1T1 four LEDs 111c,
• 11 Id, l l le and 11 If are shown relatively centrally disposed relative to one or more sensors, here, four sensors or photodiodes 112c, 112d, 112e and 112f. As above-described for Figs.
• LED 111c might be a Red LED
• LED 11 Id might be an IR (infrared) LED
• l l le might also be a Red LED
• photodiodes 112c, 112d, 112e and 112f are photodiodes 112c, 112d, 112e and 112f.
• the combination of LEDs and photodiodes/sensors might also be referred to in some implementations as a High- Efficiency Integrated Sensor.
• This arrangement may be implemented in determination of Sp02 (peripheral capillary oxygen saturation).
• the sensors shown in Figs. IT and 1T1 e.g., may be about 5mm 2 and the diameter of the exterior circle encompassing the sensors and LEDs might be a corresponding about 8 mm.
• the sensors shown in Figs. IT and 1T1 e.g., may be about 5mm 2 and the diameter of the exterior circle encompassing the sensors and LEDs might be a corresponding about 8 mm.
• This silicone layer or covering 121/121a/121b/121c/121d/121e may reduce the light lost to reflection off the skin, and thereby greatly increase the signal and reduce the noise caused by motion of the skin relative to the sensor.
• this silicone might be referred to as a light pipe and in some situations may be clear, colorless, and/or medical grade silicone.
• the silicone layer or covering 121 and/or 121a and/or 121b and/or 121c and/or 121d and/or lens surface 121e (sometimes referred to herein in short by
• 121/121a/121b/121c/121d/121e may also/alternatively be referred to as a light pipe or lens 121/121a/121b/121c/121d/121e herein inasmuch as how it may be involved in light transmitting or to be transmitted therethrough, whether upon emission or received upon reflection or both.
• 121/121a/121b/121c/121d/121e hereof may be made from a medical grade silicone that is one or more of clear, colorless, soft, low durometer.
• exemplary silicones that may be used herewith are known as“tacky gels” (several suppliers), and typically have very high-tack adhesives, preferably embedded on both sides.
• a low durometer silicone combined with double sided adhesive on the tacky gel allows the construction of a lens 121/121a/121b/121c/121d/121e that may be both conforming to the electronic sensors and skin, as well as, in some implementations, exhibiting properties of motion artifact reduction by limiting movement between the skin-lens sensor interface.
• a lens according hereto may also/alternatively be specially shaped such that it can be trapped between layers of the composite adhesive strip (see e.g., alternatives of FIGs. ID, IP and 1R and 1R1), and in some implementations, with a raised portion the size of the opening, often a rectangular opening, in the adhesive strip that allows the lens to protrude slightly on the patient side of the adhesive strip (see further detail relative to FIG. IS, described below).
• an implementation of a further alternative silicone covering or encapsulant 121a for the LEDs and sensor 11 lc/11 ld/112c may include a convex lens at or adjacent the covering external surface 121b.
• the external surface and lens are one and the same and/or the lens may be defined by the surface 121b of the encapsulant material 121a.
• a system and/or device 100 hereof may utilize one or multiple LED emitters 11 lc/1 l id (and/or 11 le and/or 11 If) of selected wavelengths and one or multiple photodiode sensors.
• an encapsulant and/or lens may be utilized in order to maximize coupling of the LED/ sensor combination to the skin 1001 of a wearer 1000.
• 121/121a/121b/121c/121d/121e comprised of optically clear, medical grade silicone may be molded onto or molded such that it may be later attached in covering relationship on the LED/sensor combinationl 1 lc/11 ld/112c.
• the lens 121b may be partially spherical or perhaps hemispherical in nature, though it need not be; see e.g., FIGs. 1T2- 1U2, described below. Curvature of other shapes may be useful as well. Curvature may reduce loss of skin contact when the device 100 may be moved, whether by wearer motion or otherwise. I.e., motion of the wearer 1000 or the device 100 relative to the wearer 1000 in FIG.
• a thin silicone adhesive 113e may be used on and between the silicone layer
• the light piping effect that may be achieved when LEDs and sensors, even of different heights are communicating substantially with little or substantially without air gap interruption through the light pipe of the encapsulant material 121a/121c/121d/121e from the emission to the skin and back from the skin to the sensors.
• the light pipe of the encapsulant material 121a/121c/121d/121e from the emission to the skin and back from the skin to the sensors.
• 121a/121c/121d/121e transmission and reflection both referring to light travel.
• This reduces inefficiencies caused by light wave scattering at air gap interfaces (air gaps allow for light to bounce off the skin or other surface).
• encapsulation of the LEDs and the sensor provides no air- gap and a light pipe effect to and the curved surface provides high quality low scattering transmission into the skin and reception of reflection from the skin and bone.
• the light pipe and curved lens surface maintain uninterrupted contact skin and lens reduces lost signals due skin reflection.
• the signal to noise ratio goes down and data acquisition goes up in quality.
• Such an encapsulant 121/121a/121c/121d and/or a lens 121b/121e may thus serve one or multiple purposes, including in some instances, inter alia: (1) providing a“light-pipe” effect to assure equal or otherwise high quality coupling of the different height LEDs and sensors, as well as substantially constant coupling to the skin to reduce motion artifact; (2) focusing of emitted light through the skin to the bone; and, (3) focusing of reflected light through the skin to the photodiode sensors.
• the radius of the lens may be designed to maximize (1) through (3).
• the height of the lens may be designed to allow it to protrude above composite adhesive 113 of the device 100 and into the skin, but not deep enough to disturb the capillary bed which would may result in bad data.
• the radius of curvature and the angles of LED light-wave emission are not necessarily highly controlled and need not be because the LEDs used to penetrate the skin, e.g., the red and infra-red and/or green LEDs; provide a very wide array of angles of emission, and thus a large number of reflected array of light-waves will be focused back to the sensor by a large variety of curved surfaces.
• the curved surface is helpful for maintaining contact through movement (accidental or on purpose) and is less important to the angles of transmission through the skin and reflection back to the sensor.
• many different radii of curvature will be effective with very little difference in data/wave transmission and reflection; the wide-angle emission of LED takes care of what might be a variety of radii.
• the curvature may have more limitation in the maintenance of contact due to movement of the device 100 - e.g., flatter curvatures may not roll readily, and very small radii of curvature will not transmit or receive as much data.
• a radius of curvature found useful has been between about 20 and 40 (both 20.34 mm and 39.94 mm radii of curvature have been found useful) for a device having LEDs and sensors in a compartment of about 12.6 mm by 6.6 mm. It may be noted further that LEDs may be on one side or another or on two opposing sides or perhaps at four or more
• substantially equi-distant points around a sensor may provide desirable results.
• pulse oximetry hereof may be with multiple light sources and/or sensors as may be one interpretation of the dispositions of FIGs. IQ and IS, and/or any one or more of 1T-1U2, e.g.
• Typical pulse oximetry circuitry uses one light source (LED) per wavelength (typically red, infrared, and sometimes others including green or long-time averages of red/IR for further examples as described below).
• LED light source
• devices and/or methods hereof may make use of multiple light sources for each wavelength. This may allow for interrogation of a wider area of capillary bed in/on the patient/wearer in order to reduce the effects of a local motion artifact.
• multiple sensors may be used for the same or similar purpose or advantage.
• a combination of driven right leg and/or proxy driven right leg together with pulse oximetry can provide additional benefits.
• the right leg circuit, proxy right leg and/or driven right leg, whether for chest or forehead or other electrode placement, can remove common mode and power line noise that would/might otherwise be capacitively-coupled into the pulse oximetry sensor and reduce effectiveness thereof.
• a combination of driven right leg and/or proxy driven right leg and improved pulse oximetry with a lens as described in and for FIG. IS and/or the light pipes of Figs. IQ and/or any one or more of Figs. IT - 1U2 may significantly reduce such noise, and thereby enhance data acquisition.
• driven electrodes see further detail below.
• optical signals typically from Red and Infra-Red pulsed sources, which exhibit different optical absorptions dependent on oxy-haemoglobin presence or absence.
• a transmissive system is used with light sources and optical detectors.
• a light pipe that encapsulates either or both the light source or sources and the one or more sensors may be employed, particularly a light pipe encapsulating, meaning having substantially no air gaps, may be used for providing either or both increased efficiency in light emission to the skin and/or capturing otherwise lost photons upon collection.
• reflective systems are typical, and these often have some advantages being less intrusive, and perhaps being more portable.
• such reflective systems typically employ a red and an infra-red source and a photo-diode sensor or detector, or multiple arrangements of these components.
• one implementation/method employs one or more central large area photo-diodes/sensors/detectors, with one or more LED sources, often one or more of each of a red, and an infra-red LED sources adjacent to the photo-diode or in an array around it.
• an alternative arrangement uses a central LED set of one or more light sources, with one or more of each wavelength type (Red, InfraRed, Green, etc.), and multiple large area photo-diodes or light sensors surrounding the central LEDs.
• Such an arrangement might use two or three or four such detectors around the LEDs to collect more light scattering from the LEDs through the skin and other tissues; see e.g., FIGs. IT and/or 1T1.
• a further alternative implementation may employ structural enhancements to and/or around the light sources and/or the one or multiple photo-diodes. Described first are one or more such enhancements disposed in relation to the central LED arrangement described above, though the following could be used with or relative to the prior described central sensor arrangement as well.
• the optical enhancing structures may provide minimal intrusion in the collection area and may reduce photo-diode areas or reduce numbers of photodiodes. Cost benefits and/or increased efficiency may thus result.
• the central LED sources 111c and 11 Id are isolated from the peripheral photo-detectors 112c, 112d, 112e and 112f on the substrate 105a by a surrounding barrier wall 122 (here also identified by the alternative reference Bl).
• a surrounding barrier wall 122 here also identified by the alternative reference Bl.
• a further optional external barrier 123 surrounding the sensor area is also shown.
• the barrier wall 122 (or Bl) and/or wall 123 (or B2) is/or preferably opaque and/or reflective to both red and IR (or to whatever other color or wavelength of light is being used, e.g., green etc.) in order to prevent crosstalk between the LEDs and the sensors i.e., it may be preferable and/or desirable to have all of the light leaving the LED area to go into the skin rather than some of the light rays finding a path to enter the sensors directly.
• a preferable surface for the barrier would be diffuse-reflective (as opposed generally to relative absorptive and/or mirror-shiny).
• An example may be clear anodized aluminum. Another would be textured white paint. Operation is shown and described relative to Figs.
• the shape and size of the wall 122 can be chosen appropriate to the shape and size of the LED sources, here sources 111c and 11 Id.
• the wall 122 could be, as shown, a circle, or could be a square or rectangular shape or otherwise (not shown) around the LEDs 111c, 11 Id (noting here also that more or fewer light sources might be included within or enclosed by the wall 122).
• the width or thickness of and the material used for the barrier wall 122 can be variable or varied as needed or desired as well; indeed, the width may depend upon the material and/or vice versa in that the relative opacity of any particular material may mean less or more width necessary to provide a particular level of opacity or relative diffuse reflectivity.
• the particular wavelengths of light i.e., type of light used, and/or the type or types of sensors and/or the relative and/or overall geometrical relationships (sensors to light sources, sensors to sensors, and/or light sources to light sources) may also figure into the relative dimensions and/or material used for and/or due to the relative opacity in relation to the particular wavelengths.
• the barrier/wall may be machined, anodized aluminum, or other similar material, but other implementations are of plastic, e.g., a molded plastic.
• a driving consideration can be that the material would perhaps preferably be opaque or reflective or diffuse reflective to both 660 and 940 nanometers.
• very thin aluminum meets this criteria, and thicker plastic does as well.
• the options for wall 122 will primarily be for the provision of an optical barrier to sideways propagation of either the radiation from the LEDs (e.g., as here thus far, the Red or the Infra-Red light from, e.g., LEDs 11 lc/1 l id), and the wall 122 is preferably level or slightly higher than the optical exit window of the LEDs. It is preferred that the barrier wall 122 also has a width sufficient to prevent optical crosstalk of light rays that never enter the skin or scattering material, but not so wide that light from the LEDs that is scattered from the skin or other flesh material, is prevented from reaching the photo-diode detectors outside the barrier wall.
• An optional external barrier wall 123 might also be employed. This one assisting with collection of light reflected from the patient or user. Similar considerations for size and thickness and material may be employed with wall 123; the difference being primarily in collection as opposed to light generation.
• Figs. 1T2/1U, and/or 1U1/1U2 are that an optical collecting structure is added that can collect light from other regions where detector diodes are not present, and conduct or reflect some of that radiation in such a way as to reach one or more of the detectors.
• central detectors with otherwise separately isolated light sources may also have similar improvements.
• Preferred structures of this type may include a transparent optical medium, here the light pipe material 121d.
• This light pipe material may be molded into a shape within and/or surrounding the relatively opaque barrier wall 122 (see e.g., FIG. 1U2, described further below), and contain sources 111c and 11 Id (and/or others if/when present) within the wall 122 and/or contain outside the wall 122 (between wall 122 and wall 123) the diode detectors 112c, 112d, 112e and/or 112f (and/or others if/when present) embedded in that structure 121d with little or substantially no air gaps between the detectors and the light pipe material.
• the detector devices 112c, 112d, 112e and/or 112f may be molded into the optical medium, i.e., light pipe material, itself, or could be inside pre molded cavities in that optical medium.
• Optical structures of this type may be generally referred to as“light pipes”.
• the shape of the light pipe structure 121d and/or surface 121e can be chosen in a variety of ways, depending on the number and size or shape of the detector diodes, and may be designed in such a way as to capture scattered light received from the skin or flesh material not directly in contact or above any detector diode, and contain it by means of total internal reflection, and using scattering reflective surfaces, to redirect rays in a direction towards one or more of the photo diodes. In this way, light that would be lost in previous designs, is captured by devices of these present implementations.
• the epoxy (light pipe) 121d is relatively flat, i.e., presenting a relatively flat surface 12 le, not concave or convex, though it may be that curvature will work with the barrier wall or walls hereof.
• a relatively or substantially flat surface 121e is shown in FIG. 1U.
• an optional thin silicone adhesive 113e on surface 121e which may be used to relatively adhere the device to the skin (not shown here) to reduce movement of the device relative to the skin and enhance light transmission and reception.
• an adhesive may preferably be as thin as operably possible so as not to interfere with or provide refraction of light waves passing therethrough. A 0.2mm thickness may be so operable. Also, it may be that a similar refractive index of the adhesive to the expoxy/encapsulant/light pipe
• 121/121a/121b/121c/121d/121e might be preferred. This choosing of a similar refractive index may be of assistance or may be related to thickness as well as material of adhesive to be used. E.g., an appropriate refractive index similarity may result from or lead to an operable 0.2mm thickness.
• Figs. 1U1 and 1U2 show some operative examples and/or alternatives.
• light wave emissions A, B and C are shown emanating from the exemplar LED 111c.
• Wave A is a relative direct emission meeting no obstacle on its way from the device to the skin (not shown), whereas wave B is shown as reflected off the wall 122 (note though waves are sometimes described, it is understood that light energy in whatever form is intended herewithin, whether for example it is or may better be understood as photons which are more particularly as understood as emitted and/or collected).
• a wave C shown not reflected off wall 122 is shown merely for highlighting the preference toward most if not all waves leaving the LED finding a way to be reflected to exit the LED area and enter the skin of the user (not shown here).
• Light collection is shown relative to the exemplar sensors 112c and 112d, where in FIGs. 1U1 and 1U2, relatively direct waves D are shown as they might enter the sensor area and be captured by the sensors 112c and/or 112d.
• Reflected waves E are also shown as they might be reflected off the walls 122 and/or 123.
• the floor or top surface of the substrate 105a might also be diffuse reflective to the waves and assist in reflecting these ultimately for sensor collection.
• the light pipe/s 121d are shown as is an optional thin adhesive 113e.
• the relative refractive indices of these materials may or may not affect, or largely affect the light passing therethrough. Preference is for similarity of refractive indices to minimize refraction. Even so, some refraction may occur as shown for example by emitting light wave B in FIG. 1U2 and in collected waves E and F, F differing from E by not also being reflected of the walls 122 and/or 123 as is light wave E. Light wave B is shown both reflected and refracted. Choice of materials and sizes and shapes of relative structures can assist in management of relative reflection and/or refraction toward increasing efficiency in light emission and/or capture.
• FIG. ID provides a first example of an adhesive 113 that may be used herewith.
• the adhesive layer 113 is here a double-sided adhesive for application to the bottom side 102 of the device 100, and a second side, perhaps with a different type of adhesive for adhering to the skin of the human patient (not shown).
• Different types of materials for adhesion might be used in that the material of choice to which the adhesive layer is to be attached are different; typically, circuit or circuit board material for connection to the device 100, and patient skin (not separately shown) on the patient side.
• a protective backing 114 may be employed on the patient side until application to the patient is desired.
• the adhesive 113 is anisotropic in that it may preferably be only conductive in a single or substantially a single direction, e.g., the axis perpendicular to the surface of adhesive contact.
• good electrically conductive contact for signal communication can be had through such adhesive to/through the adhesive to the electrical contacts or electrodes, 108, 109 and 110.
• a corresponding one or more light apertures 11 lb/112b are shown in the adhesive of 113 of the example of FIG. ID to communicate light therethrough in cooperation with the light conduit(s) 11 la/112a in/through layer 105 for communication of light data typically involved in pulse oximetry.
• the adhesive may thus be placed or disposed on the device 100, in some implementations substantially permanently, or with some replaceability.
• the device as shown in FIGs. 1 A-1D and/or IP without (or with in some implementations) the adhesive may be reusable.
• the adhesive layer 113 may be removed and replaced before each subsequent use, though subsequent re-use of and with a layer 113 is not foreclosed.
• a replaceable adhesive layer 113 it may be that the user applying the device to the patient, e.g., the physician or technician or even the patient, him/herself, applies the conductive transfer adhesive 113 to the patient side 102 of the device 100.
• the protective backing 114 may then be removed, and the device adhered to the patient and activated.
• Activation of the device after application to a patient/wearer may occur in a number of ways; in some, it may be pre-set that an affirmative activation interaction may not be necessary from the doctor or patient or like due to either an inertial and/or a pulse oximeter activation which may be substantially automatically activating, e.g., upon receiving sufficient minimum input (movement in case of inertial system or light reflection of blood flow for pulse oximetry); however, a button may be provided at an access 106 or in some other location adjacent the electronics to allow the patient to start or stop the device or otherwise mark an event if desired.
• the device may be worn for a period such as two weeks for collection of data substantially continuously, or at intervals as may be preferred and established in or by the systems hereof.
• a physician, technician, patient or other person may then remove the device from the patient body, in some instances remove the adhesive, in some instances with alcohol, and may establish a data communication connection for data transfer, e.g., by wireless communication or by insertion/connection of a USB or like data connector to download the data.
• the data may then be processed and/or interpreted and in many instances, interpreted immediately if desired.
• a power source on board may include a battery and this can then also be re charged between uses, in some implementations, fully recharged quickly as within about 24 hours, after which the device could then be considered ready for the next patient or next use.
• FIGs. 10, 01 and IP show one such alternative conductive adhesive 113a; a bottom plan view in FIG 10 and elevational side views thereof in FIGs. 101 and IP (as being connected to a device 100 in FIG. IP).
• the conductivity may be anisotropic as introduced above; in some conductive primarily if not entirely in the direction of the Z-Axis; perpendicular to the page (into and/or out of the page) in FIG. 10, and/or vertically or transversally relative to the long horizontal shown axis of device 100 in the implementation view of FIG. 101.
• the implementation of this example includes a composite adhesive 113a which itself may include some non-conductive portion(s) 113b and some one or more conductive portions 113c.
• the adhesive composite 113a may, as described for adhesive 113 above be double sided such that one side adheres to the patient while the other side would adhere to the underside 102 of the device 100 (see FIG. IP) so that one or more conductive portions 113c may be disposed or placed in electrically communicative and/or conductive contact with the integrated electrodes on the electronic monitoring device 100. Since the electrodes would operate better where they may be electrically isolated or insulated from each other, yet each making electrical contact or communication with the patient’s skin, the adhesive may further be more specifically disposed in some implementations as follows.
• three isolated conductive portions 113c may be disposed separated from each other by a body portion 113b which may be non-conductive. These could then correspond to the electrodes 108, 109, 110 from the above-described examples, and as more particularly shown schematically in FIG. IP (note the scale is exaggerated for the adhesive 113a and thus, exact matching to the electrodes of device 100 is not necessarily shown).
• the electrode areas 113c may be a conductive hydrogel that may or may not be adhesive, and in some examples, may be made of a conductive an adhesive conductive material such as 3M
• a composite adhesive strip can ensure not only device adhering to the patient, but also that the electrodes whether two or as shown three electrodes are conductively connected by conductive portions of the adhesive strip, where the combination of conductive and non-conductive portions can then reduce signal noise and/or enhance noise free characteristics. Electrodes that move relative to skin can introduce noise; that is, electrodes electrically communicative/connected to the skin via a gel may move relative to the skin and thus introduce noise.
• a further optional connective and/or insulative structure 113d may be implemented as shown in FIGs. 101 and/or IP, to provide further structural and insulative separation between electrodes with connected to a device 100 on the underside 102 thereof (see FIG. IP). Though shown separate in FIGs. 101 and IP, it may be contiguous with the insulative adhesive 113b of these views.
• a composite adhesive strip may be used having properties to reduce one or more motion artifacts.
• Typical ECG attachment systems use a conductive gel located over the electrode.
• a hydrogel adhesive may be used which is embedded in a continuous sheet of laminated adhesives that cover the selected regions or the entire footprint of the device. The fact that the hydrogel itself has strong adhesive properties coupled with the complete coverage of the device with adhesives may assure a strong bond between the device and the patient’s skin.
• Contributing to motion artifact reduction may be an alternative vertical placement of the device on the sternum which results in reduced motion artifacts for one or more of ECG signals, photoplethysmography waveforms, and oxygen saturation signals.
• composite adhesive improvements may include water-proof encapsulation of the hydrogel adhesive to prevent ohmic impedance reduction resulting in reduction of signal amplitude. This may also help prevent hydrocolloid adhesive degradation.
• Layer 1 ( 113 h) may be a hydrocolloid that is an adhesive designed for long term skin contact by absorbing sweat and cells.
• Layer 2 (113i) may then also be a layer designed for long-term skin contact, however, this Layer 2 (113i) isolates Layer 3 ( 113 j ) from contacting the skin.
• Layer 2 (113i) create a gap between Layer 1 ( 113 h) and Layer 3 ( 113 j ) .
• Layer 1 ( 113 h) and Layer 3 ( 113 j ) bond together, it forms a water-tight seal around Layer 2 (113i).
• This layer, Layer 2 (113i) also isolates the Hydrocolloid from the Hydrogel Adhesive, protecting the adhesive properties of the Hydrocolloid.
• Layers 3 ( 113 j ) and 5 (1131) would then generally be waterproof layers that are electrically isolating, double-sided adhesives. These two layers encapsulate the hydrogel adhesive, preventing a“short circuit” described relative to Layer 4 (113k) below.
• Layer 4 (113k) is the hydrogel adhesive that is the conductive element hereof.
• the three islands of hydrogel adhesive of Layer 4 (113k) must be kept electrically isolated from each other.
• the hydrocolloid in Layer 1 ( 113 h) absorbs sweat, it too becomes conductive and creates a potential“short circuit” between the three islands of hydrogel adhesive in Layer 4 (113k), reducing signal amplitude. Nevertheless, this“short circuit” may be prevented by Layers 3 ( 113 j ) and 5 (1131), described above.
• temperature may be a parameter determined hereby. This may be by a single sensor or plural sensors as described herein. In some temperature implementations, infant or neonate temperature may be sought data for capture hereby, or temperature may be used with other users, adult or otherwise.
• Infant and/or neonate temperature sensing can be of significant assistance in health monitoring. Forehead or other use may be one such application. Another set of possible
• applications may include methods and apparatuses for sensing the temperature of both an infant and a mother engaged in so-called“Kangaroo Care”. There is evidence that pre-mature infants may benefit more from constant contact with a parent’s or the mother’s skin than from being placed in an incubator. There is also evidence of lower mortality rates.
• the substrate 1105 is preferably a small, flexible circuit board, in some examples, approximately twenty (20) mm X thirty (30) mm.
• the board 1105 may be disposed to contain circuitry 1103 for, for example, sensing relative X-Y-Z position and/or acceleration, and/or Bluetooth or other wireless data/signal connectivity, as well as, in many examples, a replaceable and/or rechargeable battery for extended use, as for example, seven (7) days of continuous monitoring (circuit element alternatives not all separately shown in FIG. IV).
• the apparatus 100a may be held to the infant with an adhesive, such as the composite adhesive 1113 shown in FIG. IV, which may further be, for example, a disposable, medical grade, double-sided adhesive.
• Each of two temperature sensors 1111a and 1111b may be disposed on alternative opposing sides 1101, 1102 of the apparatus 100a, and may be thermally isolated from each other, as well as often being waterproof, water tight or water resistant.
• a thermally insulating or isolation layer 1103a may provide the thermal isolation of the electronics 1103 and/or sensors 1111a and 1111b.
• a further spacer 1103b may be disposed through the insulating/isolating layer 1103a to provide a throughway for electronic communication of the sensor 111 lb to the electronics layer 1103.
• a silicone bead 1104 may be provided for isolating and assisting in giving a waterproof or water-resistant seal on the“infant side” 1102, and a silicone cover 1121 may provide a waterproof or waterproof barrier on the“mother side” 1101.
• the sensor 111 lb on the“mother side” or top or exterior side 1101 may be slightly protruding relative to the cover 1121 with in many
• a thin/thinner layer of covering material and/or silicone thereover may be protruding past, or through the adhesive and/or disposed exposed or also/alternatively covered with a thin protectant layer for water proofness, or tightness or resistance.
• the thermally insulating layer may provide one or two or more functions. It may provide for or allow the“infant side” sensor 111 la to reach equilibrium, thus providing an accurate“core temperature” of the infant. It may also or alternatively isolate the infant’s temperature reading from the mother’s or ambient.
• The“mother side” sensor 1111b does not have to provide an accurate core temperature for the mother. Typically, the function of sensor 1111b would be to differentiate whether or not the infant is in the correct direct contact with the mother’s skin; i.e., to provide a relative measurement for determining whether the infant is in relative contact or not in relative contact with the mother. If the infant is facing the wrong way but is still in the“pouch” the sensor will read that environment’s ambient temperature.
• the infant If the infant is out of the pouch, it will read the room ambient temperature. The relative differences would be interpretable to provide an indication of what position the infant is in; whether in contact, or in close association in a controlled“pouch” environment (but not in contact), or outside the pouch in a further removed environment.
• An alarm from a Bluetooth or otherwise wirelessly connected device may be used to alert the mother (or health care professional) that the infant is no longer in the correct desired position, or no longer in the“pouch”.
• Some alternative implementations hereof may include a driven right leg ECG circuit with one or more chest only electrodes (“Driven Chest Electrode”).
• Driven Chest Electrode In addition to the electrodes used to measure a single or multiple lead electrocardiogram signal, a device 100 may use an additional electrode, as for example the reference electrode 110 (see FIGs. 1A, 1C, ID and IP, e.g.) to reduce common mode noise.
• Such an electrode may function in a manner similar to the commonly-used driven right leg electrode, but may here be located on the patient’s chest rather than on the patient’s right leg but nevertheless this third/reference electrode may play the role of the leg electrode.
• This chest electrode may thus mimic a right leg electrode and/or be considered a proxy driven right leg electrode.
• a circuit, or portion of an overall circuit, adapted to operate in this fashion may include one, two, three, or more of a number of amplifier stages to provide gain, as well as filtering to ensure circuit stability and to shape the overall frequency response.
• Such a circuit may be biased to control the common mode bias of the electrocardiogram signal.
• This driven chest electrode implementation may be used in conjunction with a differential or instrumentation amplifier to reduce common mode noise.
• the sense electrode may be used as one of the electrocardiogram electrodes.
• a single-ended electrocardiogram amplifier may be used where the differential electrocardiogram signal is referenced to ground or to some other known voltage.
• a circuit or sub-circuit 200 using a transistor 201 as shown in FIGs. 2A-D may be such a circuit (aka module) and may thus include as further shown in FIG. 2A, a sense electrode 202, a drive electrode 203, and an amplifier 204. Both the sense and drive electrodes 202, 203 are placed on the patient’s chest such that they provide an electrical connection to the patient.
• the amplifier 204 may include gain and filtering. The amplifier output is connected to the drive electrode, the inverting input to the sense electrode, and the non-inverting input to a bias voltage 205. The amplifier maintains the voltage of the sense electrode at a level close to the bias voltage. An electrocardiogram signal may then be measured using additional electrodes.
• this third electrode as a proxy for a right leg electrode (i.e., proxy driven right leg electrode) can provide signal reception otherwise unavailable. Clean signals may thus allow for receiving cardiac P waves which enhances the possibility to detect arrhythmias that could’t otherwise be detected.
• circuitry include that which is shown in FIGs. 2B and 2C; in which are shown non-limiting alternatives in which three adjacent electrodes El, E2, and E3 may be used to pick up the ECG signal, one of which electrodes playing the role of the distant limb electrode of traditional ECG monitors. Because the electrode-patient interface has an associated impedance (Rel and Re2), current flowing through this interface will cause a difference in voltage between the patient and the electrode. The circuit may use a sense electrode (El) to detect the patient voltage. Because this exemplar circuit node has a high impedance to circuit ground (GND), very little current flows through the electrode interface, so that the voltage drop between the patient and this node is minimized.
• GND circuit ground
• the first of these alternative, non-limiting circuits also contains an amplifier (Ul) whose low-impedance output is connected to a separate drive electrode (E2).
• the amplifier uses negative feedback to control the drive electrode such that the patient voltage (as measured by the sense electrode El) is equal to the bias voltage (VI). This may effectively maintain the patient voltage equal to the bias voltage despite any voltage difference between the driven electrode (E2) and the patient. This can include voltage differences caused by power line-induced current flowing between the drive electrode and the patient (through Re2).
• This arrangement differs from a traditional‘driven-right-leg’ circuit in at least two ways: the driven electrode is placed on the patient’s chest (rather than the right leg), and the ECG signal is a single-ended (not differential) measurement taken from a third electrode (E3). Because all electrodes are located on the patient’s chest in a chest-mounted example, a small device placed there may contain all the necessary electrodes for ECG measurement.
• One possible benefit of the single-ended measurement is that gain and filtering circuitry (U2 and associated components (FIG. 2C)) necessary to condition the ECG signal prior to recording (ECG Output) requires fewer components and may be less sensitive to component tolerance matching.
• FIGs. 2 A, 2B and 2C are non-limiting examples and not intended to limit the scope of the claims hereto as other circuits with other circuit elements can be formed by skilled artisans in view hereof and yet remain within the spirit and scope of claims hereof.
• a system hereof may include other circuitry operative together with the ECG electrodes, which may thus be accompanied by other sensors to provide time concordant traces of: i) ECG p-, qrs-, and t- waves; ii) 02 Saturation, as measured by Pulse Oxymetry; and/or iii) xyz acceleration, to provide an index of physical activity.
• Such circuitry may be implemented to one or more of the following electrical specifications.
• the overall system might in some implementations include as much as two weeks (or more) of continuous run time; gathering data during such time. Some implementations may be adapted to provide as many or even greater than 1000 uses.
• Alternatives may include operability even after or during exposure to fluids or wetness; in some such examples being water resistant, or waterproof, or watertight, in some cases continuing to be fully operable when fully submerged (in low saline water).
• Other implementations may include fast data transfer, as for an example where using an HS USB for full data transfer in less than about 90 seconds.
• a rechargeable battery may typically be used.
• a further alternative implementation may include an electronic "ground”: In a device hereof, mounted entirely on a flexible circuit board, the ground plane function may be provided by coaxial ground leads adjacent to the signal leads. The main contribution of this type of grounding system may be that it may allow the device the flexibility required to conform and adhere to the skin. Note that this alternative implementation is not depicted in the drawings hereof.
• EKG or ECG some implementations may include greater than about 10 Megohms input impedance; some implementations may operate with a 0.1 - 48 Hz bandwidth; and some with an approximate 256 Hz Sampling Rate; and may be implementing 12 Bit Resolution.
• operation may be with 660 and 940 nm Wavelength; about 80 - 100 Sp02 Range; a 0.05 - 4.8 Hz Bandwidth; a 16 Hz Sampling Rate; and 12-bit resolution.
• an accelerometer a 3-Axis Measurement may be employed, and in some
• PPG ambient light subtraction For pulse oximetry, an option for PPG ambient light subtraction may be included. A method and circuitry for reducing errors in pulse oximetry caused by ambient light is described and a circuitry option shown in FIG. 2D. Here a correlated double sampling technique is shown for use to remove the effect of ambient light, photo- detector dark current, and flicker noise.
• FIG. 2D The schematic shown in FIG. 2D may be used where, first, the noise signal may be measured.
• the light sources are turned off, switch SI is closed, and switch S2 is open. This allows charge proportional to the noise signal to accumulate on Cl. Then switch SI is opened. At this point the voltage on Cl is equal to the noise signal voltage.
• the light signal may be measured. The light source is turned on, switch S2 is closed, and charge is allowed to flow through Cl and C2 in series. Then, S2 is opened, and the voltage is held on C2 until the next measurement cycle when the whole process is repeated.
• This circuit may be used with a trans-impedance amplifier in place of resistor R, a phototransistor in place of the photodiode, and FETs in place of the switches.
• the output may be followed by additional buffering, amplification, filtering and processing stages.
• a flow chart 300 as in FIG. 3 may demonstrate some of the alternatives; where an initial maneuver 301 might be the application of the device 100 to the patient. Indeed, this might include some one or more of the alternatives for adhesive application as described here above, whether by/through use of an adhesive such as that 113 of FIG. ID, or that of FIGs. 10, 101 and/or IP. Then, as shown, in moving by flow line 311, a data collection operation 302 may be implemented. Note, this might include a continuous or substantially continuous collection or an interval or periodic collection or perhaps even a one-time event collection.
• This may depend upon the type of data to be collected and/or be dependent upon other features or alternatives, as for example whether a long term quantity of data is desired, for ECG for example, or whether for example a relative single data point might be useful, as in some cases of pulse oximetry (sometimes a single saturation point might be of interest, as for example, if clearly too low, though comparison data showing trending over time, may indeed be more typical).
• flow chart 300 a first such might be the following of flowline 312 to the transmission of data operation 303, which could then involve either wireless or wired (e.g., USB or other) data communication from the device 100 to data analysis and/or storage devices and/or systems (not separately shown in FIG. 3; could include computing devices, see e.g., FIG. 4 described below, or the like). Options from this point also appear; however, a first such might include following flow line 313 to the data analysis operation 304 for analyzing the data for determination of the relative health and/or for condition diagnosis of a patient.
• wireless or wired e.g., USB or other
• Computing systems e.g., a computer (could be of many types, whether hand-held, personal or mainframe or other; see FIG. 4 and description below) could be used for this analysis; however, it could be that sufficient intelligence might be incorporated within the electronics 103 of device 100 such that some analysis might be operable on or within device 100 itself.
• a non-limiting example might be a threshold comparison, as for example relative to pulse oximetry where when a low (or in some examples, perhaps a high) threshold level is reached an indicator or alarm might be activated all on/by the electronics 103 of the device 100.
• a similar such example might be considered by the optional alternative flow path 312a which itself branches into parts 312b and 312c. Following flow path 312 a, and then, in a first example path 312b, a skip of the transmit data operation 303 can be understood whereby analysis 304 might be achieved without substantial data transfer. This could explain on board analysis, whether as for example according to the threshold example above, or might in some instances include more detailed analysis depending upon how much intelligence is incorporated on/in the electronics 103.
• Another view is relative to how much transmission may be involved even if the transmission operation 303 is used; inasmuch as this could include at one level the transmission of data from the patient skin through the conductors 108, 109 and/or 110 through the traces 107 to the electronics 103 for analysis there.
• the transmission may include off- board downloading to other computing resources (e.g., FIG. 4). In some cases, such off-loading of the data may allow or provide for more sophisticated analysis using higher computing power resources.
• Further alternatives primarily may involve data storage, both when and where, if used. As with intelligence, it may be that either some or no storage or memory may be made available in/by the electronics 103 on-board device 100. If some storage, whether a little or a lot, is made available on device 100, then, flow path 312a to and through path 312c may be used to achieve some storing of data 305.
• flow path 315a may be followed for stored data which may then be transmitted, by path 315b to operation 303, and/or analyzed, by path 315c to operation 304.
• data can be collected then stored in local memory and later off-loaded/transmitted to one or more robust computing resources (e.g., FIG. 4) for analysis.
• this can include long term data collection, e.g., in the manner of days or weeks or even longer, and may thus include remote collection when a patient is away from a doctor’s office or other medical facilities.
• data can be collected from the patient in the patient’s real-world circumstances. Then, after collection, the data can be transmitted from its storage on device 100 back to the desired computing resource (FIG.
• Such transmission might be wireless or wired or come combination of both, as for example a blue tooth or Wi-Fi connection to a personal computer (FIG. 4 for one example) which might then communicate the data over the internet to the designated computer for final analysis.
• a personal computer FIG. 4 for one example
• Another example might include a USB connection to a computer, either to a PC or a mainframe (FIG. 4)and may be to the patient computer or to the doctor computer for analysis.
• a feature hereof may include an overall system including one or more devices 100 and computing resources (see FIG. 4, for example) whether on-board device(s) 100, or separate, as for example in personal or mobile or hand-held computing devices (generally by FIG. 4), the overall system then providing the ability for the physician or doctor to have immediate, in-office analysis and presentation of collected test data. This would in some implementations allow for on-site data analysis from the device without utilization of a third party for data extraction and analysis.
• a device 100 hereof includes hardware that monitors one or more of various physiologic parameters, then generates and stores the associated data representative of the monitored parameters. Then, a system which includes hardware such as device 100 and/or the parts thereof, and software and computing resources (FIG. 4, generally) for the processing thereof. The system then includes not only the collection of data but also interpretation and correlation of the data.
• an electrocardiogram trace that reveals a ventricular arrhythmia during intense exercise may be interpreted differently than the same arrhythmia during a period of rest.
• Blood oxygen saturation levels that vary greatly with movement can indicate conditions that may be more serious than when at rest, inter alia.
• Many more combinations of the four physiologic parameters are possible, and the ability of software hereof to display and highlight possible problems will greatly aid the physician in diagnosis.
• a system as described hereof can provide beneficial data interpretation.
• data analysis time may be relatively quick, at approximately less than 15 minutes, less than 10 minutes, and less than 5 minutes in some implementations, and might be achieved with a user-friendly GUI (Graphic User Interface) to guide the physician through the analysis software.
• GUI Graphic User Interface
• the analysis/software package may be disposed to present the physician with results in a variety of formats.
• an overview of the test results may be presented, either together with or in lieu of more detailed results.
• a summary of detected anomalies and/or patient-triggered events may be provided, either as part of an overview and/or as part of the more detailed presentation. Selecting individual anomalies or patient-triggered events may provide desirable flexibility to allow a physician to view additional detail, including raw data from the ECG and/or from other sensors.
• the package may also allow data to be printed and saved with annotations in industry-standard EHR (Electronic Health Record) formats.
• patient data may be analyzed with software having the one or more of the following specifications.
• Some alternative capabilities may include: l.Data Acquisition; i.e., loading of data files from device; 2. Data Formatting; i.e., formatting raw data to industry standard file formats (whether, e.g., aECG (xml); DICOM; or SCP-ECG) (note, such data formatting may be a part of Acquisition, Storage or Analysis, or may have translation from one to another (e.g., data might be better stored in a compact format that may need translation or other un-packing to analyze)); 3.
• aECG xml
• DICOM DICOM
• SCP-ECG SCP-ECG
• Data Storage (whether local, at a clinic/medical facility level or e.g., in the Cloud (optional and allows offline portable browser based presentation/analysis); 4. Analysis which inter alia, may include, e.g., noise filtering (High pass/Low pass digital filtering); and/or QRS (Beat) detection (in some cases, may include Continuous Wave Transform (CWT) for speed and accuracy); and/or 5. Data/Results Presentation, whether including one or more graphical user interface(s)
• GUIs perhaps more particularly with an overall Summary and/or General Statistics and/or
• One on-device software package may be adapted to store the measurements from the data signals acquired from one or more of EKG/ECG (whether right leg and/or p-, qrs- and/or t- waves), or 02 saturation, or x-y-z acceleration, in a time concordant manner, so that a physician may access a temporal history of the measurements (say, in some examples, over a 1-2 week interval), which would provide useful information on what the patient’s activity level was prior to, during, and after the occurrence of a cardiac event; (ii) an alternative to alternately manage the real-time transmission of the real-time measured parameters to a nearby station or relay; and/or, (iii) an off-device ECG analysis software aimed at recognizing arrhythmias.
• the software mentioned above may be industry understood software provided by a 3rd party, or specially adapted for the data developed and transmitted by and /or received from a wearable device 100 hereof. Thorough testing using standard (MIT-BIH/AHA/NST) (Massachusetts Institute of Technology - Beth Israel Hospital / American Heart Association - Noise Stress Test) arrhythmia databases, FDA 510(k) approvals preferred. Such software may be adapted to allow one or more of automated ECG analysis and interpretation by providing callable functions for ECG signal processing, QRS detection and measurement, QRS feature extraction, classification of normal and ventricular ectopic beats, heart rate measurement, measurement of PR and QT intervals, and rhythm interpretation. [0125] In many implementations, the software may be adapted to provide and/or may be made capable of supplying one or more of the following measurements:
• ST deviation average and, may be adapted to recognize a broad range of arrhythmias such as those set forth here: Table 2A:
• This first group of 8 given above are arrhythmia types that may be recognizable even if there is no discernible P wave. They are the ones typically recognized by existing products in the outpatient monitoring market that the devices, systems, and methods hereof propose to address.
• a second set or group of arrhythmias may require a discernible and measurable P wave.
• Some implementations hereof may be adapted to be able to detect and recognize them, as device 100 may be able as described above to detect P waves, depending of course, and for example, on whether the strength of the P wave which may be affected by device 100 placement or patient physiology.
• FIG. 5A is an example screenshot showing ECG and Oxygen Saturation data taken by using a patch device such as a device 100 hereof. An extremely clean signal is shown (no filtering or smoothing has been done on this data). Distinct p- waves are also shown (3 of which are shown as an example with arrows). P wave detection can be extremely important for ECG anomaly detection. Oxygen Saturation, as measured by Pulse
• Oxymetry is shown on the bottom plot. This is data taken by a device on the chest and is taken in time concordance with the ECG data.
• FIG. 5B is an example screenshot of Analysis Software.
• This is a sample of ECG data taken from the MIT-BIH Arrhythmia Database, Record 205.
• the Event Occurrences Summary list top, left
• five (5) anomaly types plus normal sinus rhythm.
• This list also shows the number of occurrences of each anomaly, total duration of the anomaly in the complete ECG, and the percent time this anomaly occurs in the complete ECG.
• the user double clicks the specific row in the Event Occurrences Summary list, as shown in Figure 5C.
• FIG. 5C is an example screenshot showing specific instance of Ventricular Tachycardia.
• the ECG plot automatically navigates to the specific time in the ECG waveform and marks the beginning and end of the event. More detailed data about this specific event is now shown in the Occurrence Details: HR Average, HR Max, etc. for the duration of this event. To show the instances of another anomaly in this ECT, the user can click on the Premature Ventricular
• FIG. 5D is an example screenshot showing specific instance of Premature Ventricular Contraction. This shows occurrences of the PVC.
• the Start Times list (middle top) shows all instances of PVC occurrences in this ECG and lists the start time for each occurrence. In this case, the user can click on the PVC that starts at 00: 15:27 (the 11 th occurrence).
• the ECG plot is automatically taken to this point in time to show and indicate the PVC instances in the waveform. Since there are 3 instances of a PVC in this timeslot, all 3 occurrences are marked.
• ECG signals collected in time concordance with pulse oximetry signals may be used to reduce the noise in the pulse oximetry signals and to permit the calculation of values for oxygen saturation, particularly in circumstances where sensors pulse oximetry data are placed on noise-prone locations of a patient, such as the chest.
• this aspect may be implemented by the following steps: (a) measuring an electrocardiogram signal over multiple heart beats; (b) measuring one or more pulse oximetry signals over multiple heart beats such that the electrocardiogram signal and the one or more pulse oximetry signals are in time concordance over one or more heart beats; (c) comparing a portion of the electrocardiogram signal and the one or more pulse oximetry signals in time concordance over one or more heart beats to determine a constant component and a primary periodic component of each of the one or more pulse oximetry signals; and (d) determining oxygen saturation from the constant components and primary periodic components of the one or more pulse oximetry signals.
• Measurement of the ECG signals and pulse oximetry signals may be implemented by embodiments of devices hereof.
• pulse oximetry signals may be a reflective infrared signal and a reflective red-light signal collected by a photodetector in a device hereof.
• Alternatives may include other colors, as for example green in addition to or in lieu of one or both of red and infrared. Such alternatives are described further below.
• Intervals of pulse oximetry signals corresponding to heart beats may be determined by comparing such signals to the time concordant ECG signals. For example (not intended to be limiting), successive R-wave peaks of a time concordant ECG signal may be used to identify such intervals, although other features of the ECG signal may be used as well. Once such intervals are identified, values at corresponding times within the intervals may be averaged to reduce signal noise and to obtain more reliable values for the constant components (sometimes referred to as the“DC components”) and the main periodic components (sometimes referred to as the“AC components”) of the pulse oximetry signals, e.g. Warner et al, Anesthesiology, 108: 950-958 (2008).
• the constant components sometimes referred to as the“DC components”
• the main periodic components sometimes referred to as the“AC components”
• the number of signal values recorded in an interval depends on the signal sampling rate of the detectors and processing electronics employed. Also, as the intervals may vary in duration, the averaging may be applied to a subset of values in the intervals. As described below, oxygen saturation values may be computed from such DC and AC components using conventional algorithms.
• the number of heart beats or intervals over which such averages may be computed may vary widely, as noted below.
• signals from one or more heart beats or intervals may be analyzed; in other embodiments, signals from a plurality of heart beats or intervals may be analyzed; and in some embodiments, such plurality may be in the range of from 2 to 25, or in the range of from 5 to 20, or in the range of from 10 to 20.
• a method of pulse oximetry measures photoplethysmogram (PPG) signals at red and infrared wavelengths.
• the DC or mean value is estimated and subtracted, and the ratio of AC or pulsatile signal is estimated and/or averaged. Linear regression between the two signals can be used as described below.
• performance is limited because similar noise exists in both the red and infrared signals.
• Photoplethysmography taken using green light ⁇ 550nm
• Photoplethysmography taken using green light is more resilient to motion noise because the light is absorbed much more by blood than by water or other tissue.
• the difference between oxygenated and deoxygenated blood in the green region of the spectrum is much less than red.
• a green PPG signal (or long time average of red/IR (see below)) may be used to determine the shape of the pulsatile signal.
• a weighted average of any number of different wavelengths (such as green, red and infrared) may be used to estimate the shape of the pulsatile waveform.
• ECG signal may be used to determine when heart beats occur. The beat locations allow correlated time averaging of each of the two photoplethysmogram signals. A linear regression of the ensemble averages may then be used to determine the linear gain factor between the two signals. This gain factor can be used to determine the patient oxygen saturation.
• the PPG signal may be used to determine the shape of the pulsatile signal.
• This lower-noise signal may then be used as the independent variable for linear regression with both the red and infrared signals.
• the ratio of these two regression results is an estimate of the correlation between the red and infrared signals. Noise can be reduced by ensemble averaging over multiple heart beats as disclosed herein (see e.g., description of frames below).
• the green wavelength PPG signal may be used.
• a weighted average of any number of different wavelengths may be used.
• the ensemble averaging may be improved by detecting and removing outlier beats, possibly by discarding beats that have less correlation to the estimated ensemble average than others, or by estimating noise and weighting beats from areas of high noise less. Noise can also be improved through longer averaging periods.
• a method for health monitoring comprising: (a) determining from either or both a user’s ECG and/or a first photoplethysmogram PPG signal and/or a weighted combination of wavelengths when heart beats occur; (b) time averaging the first photoplethymogram PPG signal to generate a first pulse shape template or dataset; (c) time averaging each of two additional photoplethysmogram signals correlated to the beat locations; one of the additional signals being red, the other additional signal being IR; (d) generating ensemble averages for each of the red and IR signals; (e) comparing each of the red and IR ensemble averages to the first pulse shape template or dataset; (f) using a linear regression of each of the red and IR ensemble average comparisons to the first pulse template or dataset to determine the linear gain factor between the two signals; and, (g) determining from the gain factor the patient oxygen saturation.
• included may be a method for determining pulse oxygenation
• ensemble average of multiple wavelengths over significantly longer than the amount of time as for either red or IR can use ensemble average gives beat shape; or a long time average of a single wavelength of any color; (c) obtaining a red pulse shape template or dataset representing same and an IR pulse shape template or dataset representing same, and compare each of these to the first pulse shape above; and, (d) correlating via linear regression between red ensemble average with the first pulse shape template or dataset to the IR ensemble average with the first pulse shape or dataset, where the ratio of these correlations is then used as the AC ratio for oxygen saturation.
• the pulse shape template or dataset is in some implementations may be similar to the reference frame template described herein as well in that the pulse shape template represents a long term ensemble average of the PPG signal. However, a difference is that the reference frame template described elsewhere herein was there designated for pulse transit time, while in the present description related to a first pulse shape or dataset or the like, is for oxygen saturation.
• a first method may be one where green light is used for the beat detection
• other methods will be viable as well, as where ECG is used for heartbeat detection.
• the alternatives include green or a long red and IR average used for the first pulse shape, and a shorter red and IR is used for the oxygen saturation comparisons to the first pulse shape. It may be helpful to understand that a long red and IR average used for the first pulse waveform shape (or dataset) is in relation to the relatively shorter red/IR signals used for the oxygen saturation measurement. Because the shape is expected to change slower than the oxygen saturation, a long average can be used for the shape, while still using a shorter average (and thus getting faster response times) for the oxygen saturation part.
• green has been found desirable because it has a high signal to noise ratio; the pulse signal is strong relative to other possible motion noise.
• other wavelengths could be used instead of green, i.e. green could be replaced by other colors in the spectrum of light, keeping in mind, some colors will behave better or other colors worse in the relationship of signal to noise.
• red and/or IR wavelengths have been that it has been found that red and/or IR have provided good relative reflectivity to the particular oxygenation of hemoglobin blood in a test subject.
• Each of oxygenated blood reflects an effective amount comparatively of red light
• de-oxygenated blood reflects an effective amount comparatively of infrared, IR, light.
• Other colors can be used instead of red and IR throughout, though the other colors may have less (or more) effectiveness in particular applications.
• ECG or green PPG (or like) or long time average of red/IR (see below) data may be recorded in time-concordance with two or more photoplethysmographs of different light
• the heart beats are detected in the ECG or green PPG signal. These heart beats allow for definition of a‘frame’ of photoplethysmogram data for the time between two adjacent heart beats. Two or more of these frames can then be averaged together at each point in time to create an average frame for the time interval. Because the photoplethysmogram is correlated with the heartbeat, the photoplethysmograph signal is reinforced by this averaging. However, any motion artifact or other noise source that is uncorrelated in time with the heartbeat is diminished. Thus, the signal-to-noise ratio of the average frame is typically higher than that of the individual frames.
• linear regression can then be used to estimate the gain between the two average frame signals.
• This gain value may be used to estimate blood oxygen saturation information or other components present in the blood such as hemoglobin, carbon dioxide or others.
• the process may be repeated for additional and/or alternative light wavelengths in order to do so.
• Exemplar/alternative methods hereof may include determining the gain between particular and/or discrete signals, as between the red and IR and/or green frame signals, if/when such may be used. These may be found by averaging the two frames together first. This may result in a signal with reduced noise. The gain is found by performing linear regression of the red versus combined and IR versus combined and then finding the ratio of these two results; or linear regression of the red versus combined with green and IR versus combined with green and then finding the ratio of these two results; or linear regression of red versus green and IR versus green and then finding the ratio of these two results; or by linear regression of combining green with each of red and IR and using the ratio of these results.
• Another method involves selecting a possible gain value, multiplying the average frame signal by it, and determining the residual error with respect to an average frame of a different wavelength. This process may be repeated for a number of potential gain values. While simple linear regression finds the global minimum gain value, this method allows for finding local minima. Thus, if it is likely that the global minimum represents correlation caused by motion artifact, venous blood movement or another noise source, it may be ignored, and a local minimum may be selected instead.
• Yet another method uses an ensemble average of the red and/or IR signals over a much longer time to determine the pulse waveform shape, then fitting shorter time averaged signals to that waveform shape.
• the green light signal or ECG signal described above may be replaced with a long time average of red/IR.
• patient wearable devices hereof for implementing the above aspects may be particularly useful for monitoring oxygen saturation in noisy regions for such measurements, for example, where there is significant local skin movement, such as the chest location.
• FIGs. 6A-6C One embodiment of the above aspect hereof is illustrated in FIGs. 6A-6C.
• curve A (600) illustrates time varying output of the photodiode of a device hereof for infrared (IR) reflection
• curve B (602) illustrates time varying output of the photodiode of the device for red light reflection.
• the skin is alternatively illuminated by the red and IR LEDs to generate the signals collected by the same photodiode.
• time synchronized (i.e. time concordant) ECG data or alternatively/additionally green PPG data or long time average of red/IR as introduced above
• curve C (604) is added to the plot of FIG. 6B.
• Peak values in the ECG data may be used to define frames or intervals of pulse oximetry data. Additional consecutive frames or intervals are indicated by 612 and 614, and further frames may be similarly determined.
• pulse oximetry data from a plurality of frames is collected. The magnitude of the plurality may vary widely depending on particular applications. In some embodiments, the plurality of frames collected is from 5 to 25; in one embodiment, a plurality is between 8 and 10 frames. Typically, frames or intervals of pulse oximetry data contain different numbers of signal samples. That is, output from the sensors may be sampled at a predetermined rate, such a 32 samples per second.
• ECG ECG
• green PPG or long time average of red/IR features in the ECG (or green PPG or long time average of red/IR) data serving as the starting points of a frame are selected so that an associated peak in the pulse oximetry data is approximately in the mid point, or center, of the frame, after which a predetermined number of signal samples are recorded for each frame.
• the predetermined number is selected to be large enough to ensure that the pulse oximetry signal peak is roughly mid-frame. Sample values corresponding to time points above the predetermined value are not used. After a plurality of frames of data is collected, averages of the values at corresponding time points of the frames are computed.
• the values from such averages AC and DC components of the pulse oximetry data are determined and are then used to compute relative oxygen saturation by conventional methods, such as the ratio-of- ratios algorithm, e.g. Cypress Semiconductor document No. 001-26779 Rev A (January 18, 2010).
• This basic procedure is summarized in the flow chart of FIG. 6C.
• frame size in terms of number of samples
• values of samples at corresponding time points within each frame are summed (622), after which average values for each time point of each frame are computed (624) which, in turn, give the AC and DC components of IR and red and/or green light reflection with reduced noise.
• values for these components can be used to compute oxygen saturation using conventional algorithms (626).
• Relative values for oxygen saturation may be converted into absolute values by calibrating the measurements for particular embodiments. Calibration may be carried out in controlled environments where individuals are exposed to varying atmospheric concentrations of oxygen and measured oxygen saturation values are related to corresponding oxygen levels.
• the essential information about the AC component of the pulse oximetry signal may be obtained by repeated measurements of just two values of pulse oximetry signals.
• values for IR or red reflection measured by the photodiode may be used to estimate depth and/or rate of respiration.
• FIG. 6D a curve (630) of Red or IR or green values over time is illustrated.
• FIG. 6E maximum values and minimum values of curve (630) are shown by dashed curves (632) and (634), respectively.
• the difference between the maximum and minimum values at a time point is monotonically related to the depth of breath in an individual being monitored.
• breaths at time (636) are shallower than those at time (638).
• depth of breath versus time may be computed and monitored in an individual. Over time, the rate of respiration can be evaluated from the curve of maximum and minimum values over time.
• a PPG and/or pulse oximeter as described herein can be used to relatively directly estimate a respiration waveform.
• the respiration signal may be isolated by filtering out the PPG data to focus on the breathing/respiration signal. This may be particularly so with a chest-mounted PPG.
• a chest mounted accelerometer may also or alternatively be used to measure the respiration waveform, especially when the user is lying on his/her back. As the chest expands and contracts, the chest accelerates up and down (or transversely, or otherwise depending upon orientation), which can be measured by the accelerometer.
• Either of these, PPG and/or accelerometer, devices and/or methods may be used discretely or in combination with each other and/or with the above-described ECG-based respiration estimation technique. Using multiple methods may improve accuracy when compared to estimates based on a single method. Respiration rate and depth may then be estimated from the respiration signal using time-domain and/or frequency domain methods.
• heart beat timing e.g., from ECG
• PPG signals can be used to determine pulse transit time; i.e., the time for the pressure wave to travel from the heart to other locations in the body. Measurements of pulse transit time may then be used to determine or estimate blood pressure.
• the heartbeat timing, ECG and/or PPG signals may be generated by conventional or other to-be-developed methods, systems or devices, or may be developed by wearable devices such as those otherwise described herein. I.e., the algorithms hereof may be separately usable, as well as being usable in the wearable cardiac device.
• the PPG signals of several heart beats may be averaged by correlating each with a respective heartbeat.
• the result is a PPG frame where the heart rate- correlated PPG signal is reinforced while uncorrelated noise is diminished.
• pulse transit time may be estimated by determining the location of either the peak or minimum with respect to either the beginning or end of the frame itself. This may be done either by finding the minimum and/or maximum sample(s), or by interpolating the signal to find points between measured samples. For example, interpolation may be done with a quadratic fit, a cubic spline, digital filtering, or many other methods.
• the pulse transit time may also be estimated by correlating the PPG frame with a sample signal. By shifting the two signals with respect to each other, the time shift resulting in the maximum correlation may be determined. If the sample signal is an approximation of the expected PPG frame, then the time shift with maximum correlation may be used to determine the pulse transit time.
• FIGs. 7A, 7B and 7C An exemplar methodology or algorithm herefor is described here and shown in the drawing FIGs. 7A, 7B and 7C.
• a method 710 (which includes and/or is defined by parts 710a, 710b and/or 710c) takes at least one heartbeat (typical ECG) signal 712 and at least one PPG signal 711 as input as shown in FIG. 7A, e.g.
• the heartbeat timing information/signal 712 is used to generate heartbeat timing information by detecting the R-wave or other ECG feature from each beat; multiple ECG signals (i.e. different leads from locations on the body) may be used to obtain a better estimate of the heartbeat timing information.
• the PPG signal(s) 711 may use a single light wavelength or signals from multiple light wavelengths. Using the corresponding heartbeat timing information related to each PPG signal(s) 711, each PPG signal(s) 711 is segmented into “frames,” see PPG Frame 1, PPG Frame 2 and PPG Frame N in FIG. 7A, where each frame contains the PPG signal of a single wavelength for the duration of one corresponding beat of the heart.
• a PPG signal quality estimate may also be performed.
• An example of this is shown as method part 710b in FIG. 7B.
• This estimate may consider the variance of the PPG signal, the estimated signal-to-noise ratio of the PPG signal, PPG signal saturation, patient motion information from an accelerometer or gyroscope, an ECG or impedance measurement noise estimate, or other information about the PPG signal quality.
• Shown in FIG. 7B is an exemplar using accelerometer signal 713 in conjunction with PPG signal 711 to generate a PPG Signal Quality Value/Estimate 714.
• This signal quality estimate 714 may then be used in conjunction with the heartbeat timing information 712 to generate the gain for each frame, see PPG Frame 1 Gain, PPG Frame 2 Gain and PPG Frame N Gain in FIG. 7B, where lower signal quality results in a lower gain. To reduce computation time, the signal quality estimate 714 may be omitted and a constant may be used for the gain information.
• the gain information (PPG Frame 1 Gain, PPG Frame 2 Gain and PPG Frame N Gain from FIG. 7B) may be used (here shown as combined/manipulated) with the frame information (PPG Frame 1, PPG Frame 2 and PPG Frame N from FIG. 7A) to create a weighted, n-sample moving-average frame 715, where the PPG signal that is correlated with the heartbeat timing is reinforced while the uncorrelated noise is reduced.
• the number of samples included in the frame (n) 715 may be adapted to reduce noise or decrease response time.
• the frames may be additionally weighted by time in order to increase the contribution of recent or near-future frames with respect to frames that are further away and potentially less-relevant. This additional weighting by time may be implemented using an IIR (Infinite Impulse Response) or FIR (Finite Impulse Response) filter.
• the pulse transit time 716 may be determined by finding the shift in the frame signal with respect to the heartbeat. This may be done simply by finding the sample index 717 where the signal is at a minimum or maximum and comparing it with the frame boundary (heartbeat timing) to determine the pulse transit time. For a more precise result, the signal may be interpolated 718 using a spline or polynomial fit around the minimum or maximum values, allowing the minimum or maximum to be determined with greater precision than the sample rate. Finally, the frame may be compared 719 to a reference frame template, where the average frame is shifted with respect to the template. The shift with the highest correlation between the average frame and the template indicates the transit time 716. This reference template may be a predetermined signal, or it may be allowed to adapt by using a long-term frame average with a known transit time.
• PPG and heartbeat timing information obtained from a variety of sources, including but not limited to conventional and/or to-be-developed technologies; or, may be obtained one or the other alone or together and/or together with quality signal (PPG variance, estimated PPG signal-to-noise ratio, PPG signal saturation, patient motion accelerometer or gyroscope data, an ECG or impedance measurement noise estimate, or other information about the PPG signal quality) obtained from a wearable device and/or system as described further hereinbelow.
• quality signal PPG variance, estimated PPG signal-to-noise ratio, PPG signal saturation, patient motion accelerometer or gyroscope data, an ECG or impedance measurement noise estimate, or other information about the PPG signal quality
• Some further alternatives may include data transmission and/or interpretation by local medical facilities, whether physician or doctor offices or e.g., ICU/CCU (Intensive Care
• a device 100 hereof that will measure one or more of a variety of physiologic signals, possibly including electrocardiogram, photoplethysmogram, pulse oximetry and/or patient acceleration signals will be placed on the patient’s chest and held with an adhesive as described herein.
• the device transmits the physiologic signals wirelessly or by wire (e.g., USB) to a nearby base station for interpretation and further transmission, if desired.
• the wireless transmission may use Bluetooth, Wi-Fi, Infrared, RFID (Radio Frequency IDentification) or another wireless protocol.
• the device may be powered by wireless induction, battery, or a combination of the two.
• the device 100 monitors physiological signals and/or collects data representative thereof. The collected data may then be transmitted wirelessly or by wire connection, in real time, to the nearby base station.
• the device may be wirelessly powered by the base station or by battery, removing the need for wires between the patient and the station.
• patients or wearers may be monitored wirelessly in a hospital, including an ICU (Intensive Care Unit) or other facility.
• an ECG signal may be measured on a patient using a small, wireless patch device hereof.
• the signal is then digitized and transmitted wirelessly to a receiver.
• the receiver converts the signal back to analog, such that it approximates the original ECG signal in amplitude.
• This output is then presented to an existing hospital ECG monitor through the standard electrode leads. This allows the patient to be monitored using existing hospital infrastructure without any lead wires necessarily connecting the patient to the monitor.
• Patient chest impedance may be measured as well, allowing the reconstructed signal to approximate the ECG signal not only in amplitude, but in output impedance as well.
• the output impedance may be continuously variable, or it may have discrete values that may be selected (e.g. one low value for a connected device and one high value to signify the patch has come loose).
• the impedance may also be used to signify problems with the wireless transmission.
• Other alternative implementations may include coupling one or multiple sensors mounted to the forehead of an infant. Initially, a method of obtaining oxygen saturation data by mounting a device in the forehead of an infant might be used as introduced. However, an expansion or alternative may include coupling oxygen saturation sensors with relative position and temperature sensors on the same forehead-mounted device. The combined data can be utilized to ascertain if an infant is in any danger of suffocation due to a face-down position.
• some of the alternative combinations hereof may include one or more of: (1) medical grade adhesives (from many possible sources) selected for their ability to maintain in intimate contact with the skin without damaging it, for several days (up to, say 10 days or two weeks in some examples), as well as operability with different types of sensors; (2) conductive electrodes or photo-sensitive detectors able to supply electrical signals from the skin or from the photo response of cutaneous or subcutaneous tissues to photo-excitation; (3) amplifiers, microprocessors and memories, capable of treating these signals and storing them; (4) power supply for the electronics hereof with stored or with wirelessly accessible re-chargeability; (5) flex circuits capable of tying the above elements together within a flexible strip capable of conforming to a cutaneous region of interest.
• medical grade adhesives from many possible sources
• conductive electrodes or photo-sensitive detectors able to supply electrical signals from the skin or from the photo response of cutaneous or subcutaneous tissues to photo-excitation
• amplifiers, microprocessors and memories capable of treating these signals and storing them
• recordation/collection and/or analyzing may include one or more of: electrocardiograms, photo responses of photo-excited tissues for e.g., oxygen saturation of blood; pulse rates and associated fluctuations; indications of physical activity/acceleration.
• electrocardiograms photo responses of photo-excited tissues for e.g., oxygen saturation of blood
• pulse rates and associated fluctuations indications of physical activity/acceleration.
• One or more of these may be used in monitoring ambulatory cardiac outpatients over several days and nights, which could thereby provide for recording, for post-test analysis, several days' worth of continuous ECG signals together with simultaneous recording of 02 saturation and an index of physical exertion.
• one or more of these may be used in monitoring ambulatory pulmonary outpatients over several days and nights for recording, for post-test analysis, 02 saturation together with simultaneous recording of an index of physical activity.
• one or more of these could be used for monitoring in-patients or other patients of interest, as for example neonates, wirelessly (or in some cases wired), whether in clinics, emergency rooms, or ICUs, in some instances detecting the parameters of EKG, 02 and/or physical exertion, but instead of storing them would transmit them wirelessly to either a bedside monitor or a central station monitor, thus freeing the patient from attachment to physical wires.
• devices hereof may be adhered to the forehead of a neonate for monitoring respiration and oxygen saturation.
• devices hereof may be used to monitor respiration and ECG of patients suffering from sleep apnea.
• devices hereof may be used to remotely monitor physiological parameters of athletes, first-responders (e.g. firefighters), soldiers, or other individuals that may be subjected to physical conditions that may warrant surveillance and monitoring of physiological parameters.
• FIG. 4 is an example of computing resources or a computer system 400 with which implementations hereof may be utilized.
• a sample such computer system 400 may include a bus 401, at least one processor 402, at least one communication port 403, a main memory 404, a removable storage media 405, a read only memory 406, and a mass storage 407. More or fewer of these elements may be used in the particular implementations hereof.
• Processor(s) 402 can be any known processor, such as, but not limited to, an Intel® Itanium® or Itanium 2® processor(s), or AMD® Opteron® or Athlon MP® processor(s), or Motorola® lines of processors.
• Communication port(s) 403 can be any of an RS-232 port for use with a modem based dialup connection, a 10/100 Ethernet port, a Universal Serial Bus (USB) port, or a Gigabit port using copper or fiber.
• Communication port(s) 403 may be chosen depending on a network such a Local Area Network (LAN), Wide Area Network (WAN), or any network to which the computer system 400 connects or may be adapted to connect.
• LAN Local Area Network
• WAN Wide Area Network
• Main memory 404 can be Random Access Memory (RAM), or any other dynamic storage device(s) commonly known in the art.
• Read only memory 406 can be any static storage device(s) such as Programmable Read Only Memory (PROM) chips for storing static information such as instructions for processor 402.
• PROM Programmable Read Only Memory
• Mass storage 407 can be used to store information and instructions.
• hard disks such as the Adaptec® family of SCSI drives, an optical disc, an array of disks such as RAID, such as the Adaptec family of RAID drives, or any other mass storage devices may be used.
• Bus 401 communicatively couples processor(s) 402 with the other memory, storage and communication blocks.
• Bus 401 can be a PCI/PCI-X or SCSI based system bus depending on the storage devices used.
• Removable storage media 405 can be any kind of external hard-drives, floppy drives, IOMEGA® Zip Drives, Compact Disc— Read Only Memory (CD-ROM), Compact Disc— Re- Writable (CD-RW), Digital Video Dis— Read Only Memory (DVD-ROM), and/or microSD cards .
• CD-ROM Compact Disc— Read Only Memory
• CD-RW Compact Disc— Re- Writable
• DVD-ROM Digital Video Dis— Read Only Memory
• microSD cards microSD cards
• Embodiments of the present inventions relate to devices, systems, methods, media, and arrangements for monitoring and processing cardiac parameters and data, inter alia. While detailed descriptions of one or more embodiments of the inventions have been given above, various alternatives, modifications, and equivalents will be apparent to those skilled in the art without varying from the spirit of the inventions hereof. Therefore, the above description should not be taken as limiting the scope of the inventions, which is defined by the appended claims.

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