Systems and methods for collecting sensor data obtained by monitoring or treatment devices

Abstract

A medical monitoring and / or treatment system can include a sensor configured to collect physiological data from a patient. The sensor can include processing circuitry configured to generate a record including a physiological data value, a data quality value indicative of accuracy of the physiological data value, a timestamp value associated with time of collection of the physiological data value, and a timestamp quality value indicative of accuracy of the timestamp value. The system can include an electronic device configured to receive the record, compare at least one of the data quality value or the timestamp quality value to a threshold, process the physiological data value to assess health of the patient in response determining that the threshold is satisfied, and perform a remedial action in response to determining that the threshold is not satisfied.

Description

[0001] SYSTEMS AND METHODS FOR COLLECTING SENSOR DATA OBTAINED BY MONITORING OR TREATMENT DEVICES

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to U.K. Patent Application No. 2409990.5, filed on 10 July 2024, which is incorporated by reference in its entirety.

[0004] Field

[0005] Embodiments of the present disclosure relate to apparatuses, systems, and methods for the monitoring and / or treatment of tissue with medical devices, such as sensor integrated or sensor-enabled dressings.

[0006] Description of the Related Art

[0007] Nearly all areas of medicine may benefit from improved information regarding the state of the tissue, organ, or system to be treated, particularly if such information is gathered in realtime during treatment, many types of treatments are still routinely performed without the use of sensor data collection. Instead, such treatments rely upon visual inspection by a caregiver or other limited means rather than quantitative sensor data. For example, in the case of wound treatment via dressings and / or negative pressure wound therapy, data collection is generally limited to visual inspection by a caregiver and often the underlying wounded tissue may be obscured by bandages or other visual impediments. Even intact, unwounded skin may have underlying damage that is not visible to the naked eye, such as a compromised vascular or deeper tissue damage that may lead to an ulcer or injury. Similar to wound treatment, during orthopedic treatments requiring the immobilization of a limb with a cast or other encasement, only limited information is gathered on the underlying tissue. In instances of internal tissue repair, such as a bone plate, continued direct sensor-driven data collection is not performed. Further, braces and / or sleeves used to support musculoskeletal function do not monitor the functions of the underlying muscles or the movement of the limbs. Outside of direct treatments, common hospital room items such as beds and blankets could be improved by adding capability to monitor patient parameters.

[0008] Therefore, there is a need for improved sensor monitoring, particularly through the use of sensor integrated substrates which can be incorporated into existing treatment regimes. SUMMARY

[0009] A medical monitoring and / or treatment system can include a sensor configured to collect physiological data from a patient. The sensor can include a processing circuitry configured to generate a record including a physiological data value collected from the patient, a data quality value indicative of accuracy of the physiological data value, a timestamp value associated with time of collection of the physiological data value, and a timestamp quality value indicative of accuracy of the timestamp value. The system can include an electronic device with a processing circuitry configured to receive the record transmitted by the sensor; compare at least one of the data quality value or the timestamp quality value to a threshold. The processing circuitry can be configured to, in response to a determination that the at least one of the data quality value or the timestamp quality value satisfies the threshold, process the physiological data value to assess health of the patient. The processing circuitry can be configured to, in response to a determination that the at least one of the data quality value or the timestamp quality value does not satisfy the threshold, perform a remedial action.

[0010] The medical monitoring and / or treatment system of any of the preceding paragraphs and / or any of the medical monitoring and / or treatment systems disclosed herein can include one or more of the following features. Physiological data can include patient activity data. Physiological data can be related to provision of negative pressure wound therapy. The system can include a substrate supporting the at least one sensor and configured to be positioned on the patient.

[0011] The medical monitoring and / or treatment system of any of the preceding paragraphs and / or any of the medical monitoring and / or treatment systems disclosed herein can include one or more of the following features. The remedial action can include causing the sensor to be calibrated to increase accuracy of physiological data collected by the sensor. The electronic device can include another sensor. The remedial action can include causing the sensor to be synchronized with a time value obtained by the electronic device from an external source to increase accuracy of time of collection of physiological data by the sensor. The processing circuitry of the sensor can maintain a clock configured to generate the timestamp value, and causing the sensor to be synchronized can include providing the time value to the sensor to set the clock. The remedial action can include, by the processing circuitry of the electronic device, generating a local time value, and causing the sensor to be synchronized with the local time value.

[0012] The medical monitoring and / or treatment system of any of the preceding paragraphs and / or any of the medical monitoring and / or treatment systems disclosed herein can include one or more of the following features. The remedial action can include determining that a sensitivity of a model configured to process the physiological data value to assess health of the patient satisfies a sensitivity threshold, and, in response to a determination that the sensitivity of the model satisfies the sensitivity threshold, processing the physiological data value to assess health of the patient. The remedial action can include determining an error associated with the physiological data value, from the physiological data value and the error, determining an adjusted physiological data value to compensate for the error, and processing the adjusted physiological data value to assess health of the patient. A data quality value of a first record includes a first physiological data value collected from the patient at a first time can indicate a higher quality than a data quality value of a second record including a second physiological data value collected from the patient at a second time when a duration of time between a time of calibration of the sensor and the second time exceeds a duration of time between the time of calibration of the sensor and the first time.

[0013] A method of operating a medical monitoring and / or treatment system can include, with a sensor, collecting physiological data from a patient and generating a record including a physiological data value collected from the patient, a data quality value indicative of accuracy of the physiological data value, a timestamp value associated with time of collection of the physiological data value, and a timestamp quality value indicative of accuracy of the timestamp value. The method can include, with an electronic processing device, receiving the record transmitted by the sensor. The method can include, with the electronic processing device, comparing at least one of the data quality value or the timestamp quality value to a threshold. The method can include, with the electronic processing device, at a first time, determining that the at least one of the data quality value or the timestamp quality value satisfies the threshold and responsive to determining that the at least one of the data quality value or the timestamp quality value satisfies the threshold, processing the physiological data value to assess health of the patient. The method can include, with the electronic processing device, at a second time, determining that the at least one of the data quality value or the timestamp quality value does not satisfy the threshold and responsive to determining that the at least one of the data quality value or the timestamp quality value does not satisfy the threshold, performing a remedial action.

[0014] The method of operating a medical monitoring and / or treatment system of any of the preceding paragraphs and / or any of the methods disclosed herein can include one or more of the following features. The remedial action can include causing the sensor to be calibrated to increase accuracy of physiological data collected by the sensor. The electronic device can include another sensor. The remedial action can include causing the sensor to be synchronized with a time value obtained by the electronic processing device from an external source to increase accuracy of time of collection of physiological data by the sensor. The method can include, with the sensor, maintaining a clock configured to generate the timestamp value, and with the electronic processing device, causing the sensor to be synchronized by providing the time value to the sensor to set the clock. The remedial action can include, by the electronic processing device, generating a local time value and causing the sensor to be synchronized with the local time value.

[0015] The method of operating a medical monitoring and / or treatment system of any of the preceding paragraphs and / or any of the methods disclosed herein can include one or more of the following features. Performing the remedial action can includes determining that a sensitivity of a model configured to process the physiological data value to assess health of the patient satisfies a sensitivity threshold, and, responsive to determining that the sensitivity of the model satisfies the sensitivity threshold, processing the physiological data value to assess health of the patient. Performing the remedial action can includes determining an error associated with the physiological data value, from the physiological data value and the error, determining an adjusted physiological data value to compensate for the error, and processing the adjusted physiological data value to assess health of the patient. A data quality value of a first record includes a first physiological data value collected from the patient at a first time can indicate a higher quality than a data quality value of a second record including a second physiological data value collected from the patient at a second time when a duration of time between a time of calibration of the sensor and the second time exceeds a duration of time between the time of calibration of the sensor and the first time.

[0016] In some cases, a kit can include the medical monitoring and / or treatment system of any of the preceding paragraphs and / or any of the medical monitoring and / or treatment systems disclosed herein and any of the dressings disclosed herein. Any of the dressings can be sterile. The kit can include a negative pressure wound therapy device configured to supply negative pressure to the wound covered by the dressing. The kit can include a secondary dressing configured to be positioned over the dressing.

[0017] BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Embodiments of the present disclosure will now be described hereinafter, by way of example only, with reference to the accompanying drawings in which:

[0019] FIG. 1 A illustrates a perspective view of a substrate supporting electronic components;

[0020] FIGS. 1B-1C illustrate perspective and top views of a perforated substrate supporting electronic components;

[0021] FIGS. 2A-2B illustrates cross-sections of wound dressings; and

[0022] FIGS. 3A-3B illustrate perspective and top views of a perforated substrate supporting electronic components;

[0023] FIG. 4 illustrates a user activity monitoring system that includes an activity monitoring device;

[0024] FIG. 5 illustrates a schematic of an activity monitoring device;

[0025] FIG. 6 illustrates an activity monitoring device; and

[0026] FIG.7 illustrates a process of using sensor data.

[0027] DETAILED DESCRIPTION

[0028] Embodiments disclosed herein relate to apparatuses and methods of at least one of monitoring or treating biological tissue, for instance, with sensor-enabled substrates. The embodiments disclosed herein are not limited to treatment or monitoring of a particular type of tissue or injury, instead the sensor-enabled technologies disclosed herein are broadly applicable to any type of therapy that may benefit from sensor-enabled substrates. Some implementations utilize sensors and data collection relied upon by health care providers to make both diagnostic and patient management decisions.

[0029] Certain embodiments disclosed herein relate to the use of sensors mounted on or embedded within substrates configured to be used in the treatment of both intact and damaged human or animal tissue. Such sensors may collect information about the surrounding tissue and transmit such information to a computing device or a caregiver to be utilized in further treatment. In certain implementations, such sensors may be attached to the skin anywhere on the body, including areas for monitoring arthritis, temperature, or other areas that may be prone to problems and require monitoring. Sensors disclosed herein may also incorporate markers, such as radiopaque markers, to indicate the presence of the device, for example prior to performing an MRI or other technique.

[0030] The sensor embodiments disclosed herein may be used in combination with clothing. Non-limiting examples of clothing for use with embodiments of the sensors disclosed herein include shirts, pants, trousers, dresses, undergarments, outer-garments, gloves, shoes, hats, and other suitable garments. In certain embodiments, the sensor embodiments disclosed herein may be welded into or laminated into / onto the particular garments. The sensor embodiments may be printed directly onto the garment and / or embedded into the fabric. Breathable and printable materials such as microporous membranes may also be suitable.

[0031] Sensor embodiments disclosed herein may be incorporated into cushioning or bed padding, such as within a hospital bed, to monitor patient characteristics, such as any characteristic disclosed herein. In certain embodiments, a disposable film containing such sensors could be placed over the hospital bedding and removed / replaced as needed.

[0032] In some implementations, the sensor embodiments disclosed herein may incorporate energy harvesting, such that the sensor embodiments are self-sustaining. For example, energy may be harvested from thermal energy sources, kinetic energy sources, chemical gradients, or any suitable energy source.

[0033] The sensor embodiments disclosed herein may be utilized in rehabilitation devices and treatments, including sports medicine. For example, the sensor embodiments disclosed herein may be used in braces, sleeves, wraps, supports, and other suitable items. Similarly, the sensor embodiments disclosed herein may be incorporated into sporting equipment, such as helmets, sleeves, and / or pads. For example, such sensor embodiments may be incorporated into a protective helmet to monitor characteristics such as acceleration, which may be useful in concussion diagnosis.

[0034] The sensor embodiments disclosed herein may be used in coordination with surgical devices, for example, the NAVIO surgical system by Smith & Nephew Inc. In some implementations, the sensor embodiments disclosed herein may be in communication with such surgical devices to guide placement of the surgical devices. In some implementations, the sensor embodiments disclosed herein may monitor blood flow to or away from the potential surgical site or ensure that there is no blood flow to a surgical site. Further surgical data may be collected to aid in the prevention of scarring and monitor areas away from the impacted area.

[0035] To further aid in surgical techniques, the sensors disclosed herein may be incorporated into a surgical drape to provide information regarding tissue under the drape that may not be immediately visible to the naked eye. For example, a sensor embedded flexible drape may have sensors positioned advantageously to provide improved area-focused data collection. In certain implementations, the sensor embodiments disclosed herein may be incorporated into the border or interior of a drape to create fencing to limit / control the surgical theater.

[0036] Sensor embodiments as disclosed herein may also be utilized for pre-surgical assessment. For example, such sensor embodiments may be used to collect information about a potential surgical site, such as by monitoring skin and the underlying tissues for a possible incision site. For example, perfusion levels or other suitable characteristics may be monitored at the surface of the skin and deeper in the tissue to assess whether an individual patient may be at risk for surgical complications. Sensor embodiments such as those disclosed herein may be used to evaluate the presence of microbial infection and provide an indication for the use of antimicrobials. Further, sensor embodiments disclosed herein may collect further information in deeper tissue, such as identifying pressure ulcer or pressure injury damage and / or the fatty tissue levels.

[0037] The sensor embodiments disclosed herein may be utilized in cardiovascular monitoring. For example, such sensor embodiments may be incorporated into a flexible cardiovascular monitor that may be placed against the skin to monitor characteristics of the cardiovascular system and communicate such information to another device and / or a caregiver. For example, such a device may monitor pulse rate, oxygenation of the blood, and / or electrical activity of the heart. Similarly, the sensor embodiments disclosed herein may be utilized for neurophysiological applications, such as monitoring electrical activity of neurons.

[0038] The sensor embodiments disclosed herein may be incorporated into implantable devices, such as implantable orthopedic implants, including flexible implants. Such sensor embodiments may be configured to collect information regarding the implant site and transmit this information to an external source. In some cases, an internal source may also provide power for such an implant. The sensor embodiments disclosed herein may also be utilized for monitoring biochemical activity on the surface of the skin or below the surface of the skin, such as lactose buildup in muscle or sweat production on the surface of the skin. In some cases, other characteristics may be monitored, such as glucose concentration, urine concentration, tissue pressure, skin temperature, skin surface conductivity, skin surface resistivity, skin hydration, skin maceration, and / or skin ripping.

[0039] Sensor embodiments as disclosed herein may be incorporated into Ear, Nose, and Throat (ENT) applications. For example, such sensor embodiments may be utilized to monitor recovery from ENT-related surgery, such as wound monitoring within the sinus passage.

[0040] Sensor embodiments disclosed herein may encompass sensor printing technology with encapsulation, such as encapsulation with a polymer film. Such a film may be constructed using any polymer described herein, such as polyurethane. Encapsulation of the sensor embodiments may provide waterproofing of the electronics and protection from local tissue, local fluids, and other sources of potential damage.

[0041] In certain embodiments, the sensors disclosed herein may be incorporated into an organ protection layer. Such a sensor-embedded organ protection layer may both protect the organ of interest and confirm that the organ protection layer is in position and providing protection. Further, a sensor-embedded organ protection layer may be utilized to monitor the underlying organ, such as by monitoring blood flow, oxygenation, and other suitable markers of organ health. In some cases, a sensor-enabled organ protection layer may be used to monitor a transplanted organ, such as by monitoring the fat and muscle content of the organ. Further, sensor-enabled organ protection layers may be used to monitor an organ during and after transplant, such as during rehabilitation of the organ.

[0042] The sensor embodiments disclosed herein may be incorporated into treatments for wounds (disclosed in greater detail below) or in a variety of other applications. Non-limiting examples of additional applications for the sensor embodiments disclosed herein include: monitoring and treatment of intact skin, cardiovascular applications such as monitoring blood flow, orthopedic applications such as monitoring limb movement and bone repair, neurophysiological applications such as monitoring electrical impulses, and any other tissue, organ, system, or condition that may benefit from improved sensor-enabled monitoring.

[0043] Wound Therapy Some systems and methods disclosed herein relate to wound therapy for a human or animal body. Therefore, any reference to a wound herein can refer to a wound on a human or animal body, and any reference to a body herein can refer to a human or animal body. The disclosed technology embodiments may relate to preventing or minimizing damage to physiological tissue or living tissue, or to the treatment of damaged tissue (for example, a wound as described herein) wound with or without reduced pressure, including for example a source of negative pressure and wound dressing components and apparatuses. The apparatuses and components comprising the wound overlay and packing materials or internal layers, if any, are sometimes collectively referred to herein as dressings. In some cases, the wound dressing can be provided to be utilized without reduced pressure.

[0044] As used herein the expression “wound” may include an injury to living tissue may be caused by a cut, blow, or other impact, typically one in which the skin is cut or broken. A wound may be a chronic or acute injury. Acute wounds occur as a result of surgery or trauma. They move through the stages of healing within a predicted timeframe. Chronic wounds typically begin as acute wounds. The acute wound can become a chronic wound when it does not follow the healing stages resulting in a lengthened recovery. It is believed that the transition from acute to chronic wound can be due to a patient being immuno-compromised.

[0045] Chronic wounds may include for example: venous ulcers (such as those that occur in the legs), which account for the majority of chronic wounds and mostly affect the elderly, diabetic ulcers (for example, foot or ankle ulcers), peripheral arterial disease, pressure ulcers, pressure injury, or epidermolysis bullosa (EB).

[0046] Examples of other wounds include, but are not limited to, abdominal wounds or other large or incisional wounds, either as a result of surgery, trauma, stemiotomies, fasciotomies, or other conditions, dehisced wounds, acute wounds, chronic wounds, subacute and dehisced wounds, traumatic wounds, flaps and skin grafts, lacerations, abrasions, contusions, burns, diabetic ulcers, pressure ulcers, pressure injury, stoma, surgical wounds, trauma and venous ulcers or the like.

[0047] Wounds may also include a deep tissue injury. Deep tissue injury is a term proposed by the National Pressure Ulcer Advisory Panel (NPUAP) to describe a unique form of pressure ulcers. These ulcers have been described by clinicians for many years with terms such as purple pressure ulcers, ulcers that are likely to deteriorate and bruises on bony prominences. Wounds may also include a pressure injury. A pressure injury is localized damage to the skin and / or underlying soft tissue, usually over a bony prominence or related to a medical or other device. The injury can present as intact skin or an open ulcer and may be painful. The injury occurs as a result of intense and / or prolonged pressure or pressure in combination with shear. The tolerance of soft tissue for pressure and shear may also be affected by microclimate, nutrition, perfusion, comorbidities and condition of the soft tissue.

[0048] Wound may also include tissue at risk of becoming a wound as discussed herein. For example, tissue at risk may include tissue over a bony protuberance (at risk of deep tissue injury / insult) or pre-surgical tissue (for example, knee tissue) that may have the potential to be cut (for example, for joint replacement / surgical alteration / reconstruction).

[0049] Some systems and methods disclosed herein relate to methods of treating a wound with the technology disclosed herein in conjunction with one or more of the following: advanced footwear, turning a patient, offloading (such as, offloading diabetic foot ulcers), treatment of infection, systemix, antimicrobial, antibiotics, surgery, removal of tissue, affecting blood flow, physiotherapy, exercise, bathing, nutrition, hydration, nerve stimulation, ultrasound, electrostimulation, oxygen therapy, microwave therapy, active agents ozone, antibiotics, antimicrobials, or the like.

[0050] Alternatively or additionally, a wound may be treated using topical negative pressure (TNP) and / or traditional advanced wound care, which is not aided by the using of applied negative pressure (may also be referred to as non-negative pressure therapy).

[0051] Advanced wound care may include use of an absorbent dressing, an occlusive dressing, use of an antimicrobial and / or debriding agents in a wound dressing or adjunct, a pad (for example, a cushioning or compressive therapy, such as stockings or bandages), or the like.

[0052] In some cases, a wound dressing comprises one or more absorbent layer(s). The absorbent layer may be a foam or a superabsorbent.

[0053] In some cases, the disclosed technology may be used in conjunction with a nonnegative pressure dressing. A non-negative pressure wound dressing suitable for providing protection at a wound site may comprise an absorbent layer for absorbing wound exudate and an obscuring element for at least partially obscuring a view of wound exudate absorbed by the absorbent layer in use. The obscuring element may be partially translucent. The obscuring element may be a masking layer. In some cases, the non-negative pressure wound dressing as disclosed herein comprises the wound contact layer and the absorbent layer overlies the wound contact layer. The wound contact layer can carry an adhesive portion for forming a substantially fluid tight seal over the wound.

[0054] In some cases, the wound dressing as disclosed herein further comprises layer of a superabsorbent fiber, or a viscose fiber or a polyester fiber.

[0055] In some cases, the wound dressing as disclosed herein further comprises a backing layer. The backing layer may be a transparent or opaque film. Typically the backing layer comprises a polyurethane film (typically a transparent polyurethane film).

[0056] In some cases, the foam may be an open cell foam, or closed cell foam, typically an open cell foam. The foam can be hydrophilic.

[0057] The wound dressing may comprise a transmission layer and the layer can be foam. The transmission layer may be a polyurethane foam laminated to a polyurethane film.

[0058] The non-negative pressure wound dressing may be a compression bandage. Compression bandages are known for use in the treatment of oedema and other venous and lymphatic disorders, e.g., of the lower limbs. The compression bandage in some cases may comprise a bandage system comprising an inner skin facing layer and an elastic outer layer, the inner layer comprising a first ply of foam and a second ply of an absorbent nonwoven web, the inner layer and outer layer being sufficiently elongated so as to be capable of being wound about a patient's limb.

[0059] Negative Pressure Wound Therapy

[0060] In some cases, treatment of wounds can be performed using negative pressure wound therapy. It will be understood that embodiments of the present disclosure are generally applicable to use in TNP systems. Briefly, negative pressure wound therapy assists in the closure and healing of many forms of "hard to heal" wounds by reducing tissue oedema; encouraging blood flow and granular tissue formation; removing excess exudate and may reduce bacterial load (and thus infection risk). In addition, the therapy allows for less disturbance of a wound leading to more rapid healing. TNP therapy systems may also assist on the healing of surgically closed wounds by removing fluid and by helping to stabilize the tissue in the apposed position of closure. A further beneficial use of TNP therapy can be found in grafts and flaps where removal of excess fluid is important and close proximity of the graft to tissue is required in order to ensure tissue viability.

[0061] Negative pressure therapy can be used for the treatment of open or chronic wounds that are too large to spontaneously close or otherwise fail to heal by means of applying negative pressure to the site of the wound. Topical negative pressure (TNP) therapy or negative pressure wound therapy (NPWT) involves placing a cover that is impermeable or semi-permeable to fluids over the wound, using various means to seal the cover to the tissue of the patient surrounding the wound, and connecting a source of negative pressure (such as a vacuum pump) to the cover in a manner so that negative pressure is created and maintained under the cover. In some cases, the source of negative pressure can be supported by a wound dressing positioned in and / or over the wound. It is believed that such negative pressures promote wound healing by facilitating the formation of granulation tissue at the wound site and assisting the body’s normal inflammatory process while simultaneously removing excess fluid, which may contain adverse cytokines or bacteria.

[0062] Some of the dressings used in NPWT can include many different types of materials and layers, for example, gauze, pads, foam pads or multi-layer wound dressings. One example of a multi-layer wound dressing is the PICO dressing, available from Smith & Nephew, includes a wound contact layer and a superabsorbent layer beneath a backing layer to provide a canisterless system for treating a wound with NPWT. The wound dressing may be sealed to a suction port providing connection to a length of tubing, which may be used to pump fluid out of the dressing or to transmit negative pressure from a pump to the wound dressing. Additionally, RENASYS-F, RENASYS-G, RENASYS-AB, and RENASYS-F / AB, available from Smith & Nephew, are additional examples of NPWT wound dressings and systems. Another example of a multi-layer wound dressing is the ALLEVYN Life dressing, available from Smith & Nephew, which includes a moist wound environment dressing that is used to treat the wound without the use of negative pressure.

[0063] As is used herein, reduced or negative pressure levels, such as -X mmHg, represent pressure levels relative to normal ambient atmospheric pressure, which can correspond to 760 mmHg (or 1 atm, 29.93 inHg, 101.325 kPa, 14.696 psi, etc.). Accordingly, a negative pressure value of -X mmHg reflects absolute pressure that is X mmHg below 760 mmHg or, in other words, an absolute pressure of (760-X) mmHg. In addition, negative pressure that is "less" or "smaller" than X mmHg corresponds to pressure that is closer to atmospheric pressure (such as, -40 mmHg is less than -60 mmHg). Negative pressure that is "more" or "greater" than -X mmHg corresponds to pressure that is further from atmospheric pressure (such as, -80 mmHg is more than -60 mmHg). In some cases, local ambient atmospheric pressure is used as a reference point, and such local atmospheric pressure may not necessarily be, for example, 760 mmHg.

[0064] In some cases of wound closure devices described herein, increased wound contraction can lead to increased tissue expansion in the surrounding wound tissue. This effect may be increased by varying the force applied to the tissue, for example by varying the negative pressure applied to the wound over time, possibly in conjunction with increased tensile forces applied to the wound via embodiments of the wound closure devices. In some cases, negative pressure may be varied over time for example using a sinusoidal wave, square wave, or in synchronization with one or more physiological indices (such as, heartbeat).

[0065] Any of the embodiments disclosed herein can be used in combination with any of the features disclosed in one or more of W02010 / 061225, US2016 / 114074, US2006 / 0142560, and US5,703,225, which describe absorbent materials; W02013 / 007973, which describes non-negative pressure wound dressings; GB 1618298.2 (filed on 28 October 2016), GB1621057.7 (filed on 12 December 2016), and GB1709987.0 (filed on 22 June 2017), which describe multi-layered wound dressings; EP2498829 and EP1718257, which describe wound dressings; W02006 / 110527, US 6,759,566, and US2002 / 0099318, which describe compression bandages; US8,235,955 and US7,753,894, which describe wound closure devices; WO2013 / 175306, WO2016 / 174048, US2015 / 0190286, US2011 / 0282309, and US2016 / 0339158, which describe negative pressure wound therapy dressings, wound dressing components, wound treatment apparatuses, and methods. The disclosure of each of these applications is hereby incorporated by reference in its entirety.

[0066] Substrate Supporting Sensors

[0067] A wound dressing that incorporates a number of electronic components, including one or more sensors, can be utilized in order to monitor characteristics of a wound. Collecting and analyzing data from a wound can provide useful insights towards determining whether a wound is on a healing trajectory, selecting proper therapy, determining whether the wound has healed, or the like. In some implementations, a number of sensor technologies can be used in wound dressings or one or more components forming part of an overall wound dressing apparatus. For example, as illustrated in FIGS. 1A-1C, one or more sensors can be incorporated onto or into a substrate (such substrate can be referred to as “sensor integrated substrate”). The substrate illustrated as having a square shape, but it will be appreciated that the substrate may have other shapes such as rectangular, circular, oval, etc. In some cases, a substrate supporting one or more sensors can be provided as an individual material layer that is placed directly or indirectly over or in a wound. The sensor integrated substrate can be part of a larger wound dressing apparatus. In some cases, the sensor integrated substrate is part of a single unit dressing. Additionally or alternatively, the sensor integrated substrate can be placed directly or indirectly over or in the wound and then covered by a secondary wound dressing, which can include one or more of gauze, foam or other wound packing material, a superabsorbent layer, a drape, a fully integrated dressing like the Pico or Allevyn Life dressing manufactured by Smith & Nephew, or the like.

[0068] The sensor integrated substrate can be placed in contact with a wound and can allow fluid to pass through the substrate while causing little to no damage to the tissue in the wound. The substrate can be flexible, elastic, extensible, or stretchable or substantially flexible, elastic, extensible, or stretchable in order to conform to or cover the wound. For example, the substrate can be made from a stretchable or substantially stretchable material, such as one or more of polyurethane, thermoplastic polyurethane (TPU), silicone, polycarbonate, polyethylene, polyimide, polyamide, polyester, polyethelene tetraphthalate (PET), polybutalene tetreaphthalate (PBT), polyethylene naphthalate (PEN), polyetherimide (PEI), along with various fluropolymers (FEP) and copolymers, or another suitable material.

[0069] In some cases, the substrate can include one or more flexible circuit boards, which can be formed of flexible polymers, including polyamide, polyimide (PI), polyester, polyethylene naphthalate (PEN), polyetherimide (PEI), along with various fluropolymers (FEP) and copolymers, or the like. One or more sensors can be incorporated into a two-layer flexible circuit board. In some scenarios, the one or more circuit boards can be a multi-layer flexible circuit board.

[0070] In some cases, the sensor integrated substrate can incorporate adhesive, such as a wound contact layer as described herein, that adheres to wet or dry tissue. In some cases, one or more sensors, which can be positioned one or more flexible circuit boards, can be incorporated into any layer of the wound dressing. For example, a wound contact layer can have cutouts or slits that allow for one or more sensors to protrude out of the lower surface of the wound contact layer and contact the wound directly. In some situations, one or more sensors can be incorporated into or encapsulated within other components of a wound dressing, such as an absorbent layer.

[0071] As shown in FIG. 1A, a sensor integrated substrate 100 A can support a plurality of electronic components and a plurality of electronic connections interconnecting at least some of the components. The electronic components can be one or more of any electronic components described herein, such as a sensor, amplifier, capacitor, resistor, inductor, controller, processor, or the like. The electronic connections can electrically connect one or more of the electronic components. The electronic connections can be can be tracks printed on the substrate, such as using copper, conductive ink (such as silver ink, graphite ink, etc.), or the like. At least some of the electronic connections can be flexible or stretchable or substantially flexible or stretchable.

[0072] The plurality of electronic components can include one or more impedance or conductivity sensors 110, which can be arranged in an outer 4x4 grid and an inner 4x4 grid as illustrated in FIGS. 1A-1C. Sensors 110 are illustrated as pads configured to measure impedance or conductivity of tissue across any pair of the pads. Two (or more) excitation pads 115 can be arranged as illustrated to provide the excitation signal across the pads, which is conducted by the tissue and responsive to which impedance or conductance of the tissue can be measured across the pads 110. Electrical components, such as one or more amplifiers 120, can be used to measure impedance or conductance of the tissue. Impedance or conductance measurements can be used to identify living and dead tissue, monitor progress of healing, or the like. The arrangement of the pads 110 in the inner and outer grids can be used to measure the impedance or conductance of the wound, perimeter of the wound, or tissue or areas surrounding the wound.

[0073] The plurality of electronic components can include one or more temperature sensors 130 configured to measure temperature of the wound or surrounding tissue. For example, nine temperature sensors arranged around the perimeter of the substrate 100A. One or more temperature sensors can include one or more thermocouples or thermistors. One or more temperature sensors can be calibrated and the data obtained from the one or more sensors can be processed to provide information about the wound environment. In some cases, an ambient sensor measuring ambient air temperature can also be used to assist in eliminating problems associated with environment temperature shifts.

[0074] The plurality of electronic components can include one or more optical sensors 150. One or more optical sensors 150 can be configured to measure wound appearance or image the wound. In some cases, a light source or illumination source that emits light and a light sensor or detector that detects light reflected by the wound are used as one or more optical sensors. The light source can be a light emitting diode (LED), such as one or more of white LED, red, green, blue (RGB) LED, ultraviolet (UV) LED, or the like. The light sensor can be one or more of an RGB sensor configured to detect color, infrared (IR) color sensor, UV sensor, or the like. In some cases, both the light source and detector would be pressed up against the skin, such that light would penetrate into the tissue and take on the spectral features of the tissue itself. In some scenarios, one or more optical sensor can include an imaging device, such as a charge-coupled device (CCD), CMOS image sensor, or the like.

[0075] In some cases, ultra bright LEDs, an RGB sensor, and polyester optical filters can be used as components of the one or more optical sensors to measure through tissue color differentiation. For example, because surface color can be measured from reflected light, a color can be measured from light which has passed through the tissue first for a given geometry. This can include color sensing from diffuse scattered light, from an LED in contact with the skin, or the like. In some cases, an LED can be used with a proximal RGB sensor to detect the light which has diffused through the tissue. The optical sensors can image with diffuse internal light or surface reflected light.

[0076] One or more of the plurality of electronic components can be controlled by a control module. The control module can receive and process one or more measurements obtained by the one or more sensors. An external control module can be connected to at least some of the plurality of electronic components via a connector 140. In some cases, the connector 140 can be positioned at the end of a conductive track portion as illustrated in FIG. IB or attached to the conductive track portion at a position away from the end as illustrated in FIG. 1A or 1C (such as, attached to the top of the track portion with glue). The control module can include one or more controllers or microprocessors, memory, or the like. In some cases, one or more controllers can be positioned on the substrate, and the connector 140 is not used. In some cases, data and commands can be communicated wirelessly, such as by a transceiver positioned on the substrate, and the connector 140 is not used. In some cases, additional or alternative sensors can be positioned on the substrate, such as one or more pH sensors, pressure sensors, perfusion sensors, or the like.

[0077] In some cases, a substrate can be perforated as illustrated in FIGS. 1B-1C. A plurality of perforations 160 can be formed in the substrate 100B, allowing fluid to pass through the substrate. It may be advantageous to use a perforated substrate in conjunction with application of negative pressure wound therapy, during which reduced pressure is applied to the wound covered by a dressing and which causes removal of fluid (such as wound exudate) from the wound. Perforations 160 can be formed around a plurality of electronic components and connections as illustrated in FIGS. 1B-1C. Perforations 160 can be formed as slits or holes. In some cases, perforations 160 can be small enough to help prevent tissue ingrowth while allowing fluid to pass through the substrate.

[0078] In some cases, any of the wound dressings or wound dressing components described herein can be part of a kit that also includes a negative pressure wound therapy device. One or more components of the kit, such as the sensor integrated substrate, secondary dressing, or the negative pressure wound therapy device can be sterile.

[0079] Any of the embodiments disclosed herein can be used with any of the embodiments described in U.S. Patent No. 11717447, titled “SENSOR ENABLED WOUND MONITORING AND THERAPY APPARATUS,” U.S. Patent No. 11883262, titled “COMPONENT STRESS RELIEF FOR SENSOR ENABLED NEGATIVE PRESSURE WOUND THERAPY DRESSINGS,” International Patent Publication No. WO2019 / 020551, titled “SKEWING PADS FOR IMPEDANCE MEASUREMENT,” and U.S. Patent No. 11957545, titled “SENSOR POSITIONING AND OPTICAL SENSING FOR SENSOR ENABLED WOUND THERAPY DRESSINGS AND SYSTEMS,” each of which is incorporated by reference in its entirety.

[0080] Encapsulation and Stress Relief

[0081] In some cases, while it may be desirable for a substrate to be stretchable or substantially stretchable to better conform to or cover the wound, at least some of the electronic components or connections may not be stretchable or flexible. In such instances, undesirable or excessive localized strain or stress may be exerted on the one or more electronic components, such as on the supporting area or mountings of an electronic component, when the substrate is positioned in or over the wound. For example, such stress can be due to patient movement, changes in the shape or size of the wound (such as, due to its healing), or the like. Such stress may cause movement, dislodgment, or malfunction of the one or more electronic components or connections (for example, creation of an open circuit from a pin or another connector becoming disconnected). Alternatively or additionally, it may be desirable to maintain the position of one or more electronic components, such as one or more sensors, in the same or substantially same location or region with respect to the wound (such as, in contact with the wound) so that measurements collected by the one or more electronic components accurately capture changes over time in the same or substantially same location or region of the wound. While the surface of the stretchable substrate may move when, for example, the patient moves, it may be desirable to maintain same or substantially same locations of one or more electronic components relative to the wound.

[0082] To address these problems, in some cases, non-stretchable or substantially non- stretchable coating (such coating can sometimes be referred to as “hard coat”) can be applied to one or more electronic components, one or more electronic connections, or the like. Hard coat can provide one or more of reinforcement or stress relief for one or more electronic components, one or more electronic connections, or the like. Hard coating can be formed from acrylated or modified urethane material. For example, hard coat can be one or more of Dymax 1901-M, Dymax 9001-E, Dymax 20351, Dymax 20558, Henkel Loctite 3211, or another suitable material. Hard coat can have viscosity from about 13,500cP to 50,000cP before being cured or from about 3,600cP to about 6,600cP before being cured. In some cases, hard coat can have viscosity of no more than about 50,000cP. Hard coat can have hardness from about D40 to about D65 and / or linear shrinkage of about 1.5-2.5%.

[0083] In some cases, another coating (or coatings) can be applied to encapsulate or coat one or more of the substrate or components supported by the substrate, such as the electronic connections or the electronic components. Coating can provide biocompatibility, shield or protect the electronics from coming into contact with fluids, provide padding for the electronic components to increase patient comfort, or the like. As used herein, biocompatible can mean being in compliance with one or more applicable standards, such as ISO 10993 or USP Class VI. Such coating can be sometimes referred to as “conformal coat” or “soft coat.” Soft coat can be stretchable or substantially stretchable. Soft coat can be hydrophobic or substantially hydrophobic. Soft coat can be formed from one or more suitable polymers, adhesives, such as 1072- M adhesive (for example, Dymax 1072-M), 1165-M adhesive (such as, Dymax 1165-M), parylene (such as, Parylene C), silicones, epoxies, urethanes, acrylated urethanes, acrylated urethane alternatives (such as, Henkel Loctite 3381), or other suitable biocompatible and substantially stretchable materials. Soft coat can be thin coating, for example, from about 80 microns or less up to several millimeters or more. Soft coat can have hardness lower than about Al 00, A80, A50 or lower. Soft coat can have elongation at break higher than about 100%, 200%, 300% or more. Soft coat can have viscosity of about 8,000-14,500 centipoise (cP). In some cases, coating can have viscosity no less than about 3,000cP. In some cases, coating can have viscosity less than about 3,000cP.

[0084] Any of the hard or soft coats described herein can be applied by one or more of laminating, adhering, welding (for instance, ultrasonic welding), curing by one or more of light, UV, thermal (such as, heat), or the like. Any of the hard or soft coat described herein can be transparent or substantially transparent to facilitate optical sensing. Any of the coatings described herein can retain bond strength when subjected to sterilization, such as EtO sterilization. Any of the coatings described herein can be modified to fluoresce, such as under UV light.

[0085] FIGS. 2A-2B illustrate cross-sections of wound dressings that include sensor integrated substrates. Dressing 200A shown in FIG. 2A can include a sensor integrated substrate 205 supporting a plurality of electronic components (shown as protruding from the substrate) and a plurality of electronic connections, as described herein. The dressing 200A can include hard coat 214, applied to one or more electronic components or connections. In some cases, hard coat can be applied to areas where electronic components are connected to electronic connections. This can reinforce these connections. In some cases, hard coat can be applied to each of the one or more of the electronic components or connections.

[0086] The dressing 200 A can include soft coat 216, which can be applied to the entire wound facing side of the substrate. Soft coat 216 can be applied to an entire or substantially entire area of the wound facing side of the substrate to encapsulate the substrate, electronic components, and connections. In some cases, soft coat 216 can be applied to certain regions of the substrate, such as those regions supporting one or more of electronic components or connections. The dressing 200A can include a wound contact layer 218. The wound contact layer 218 can include adhesive material configured to adhere the substrate to the wound, which can facilitate maintaining contact of one or more sensors with the wound. The wound contact layer 218 can be formed from silicone. The silicone material can be low tac (or tack) silicone. The wound contact layer 218 can include silicone adhesive mounted on a film. In some cases, the wound contact layer 218 can be similar to the material used in Allevyn Life Non-Bordered dressing manufactured by Smith & Nephew.

[0087] The wound contact layer 218 can be applied to entire or substantially entire area of the wound facing side of the substrate. In some cases, the wound contact layer 218 can be applied to certain regions of the substrate, such as those regions supporting one or more of electronic components or connections.

[0088] As illustrated in FIG. 2A, a plurality of perforations 230 can be formed through one or more of the substrate, hard coat, soft coat, and wound contact layer. As described herein, perforations can be made in regions or areas of the substrate that do not support electronic components or connections.

[0089] The dressing 200A can include a protective layer 220 applied to the wound contact layer 218. The protective layer 220 can be made of paper, such as laminated paper. The protective layer 220 can protect the wound contact layer 218 prior to use and facilitate easy application for a user. The protective layer 218 can include a plurality (such as two) handles. The handles can be applied in a folded configuration, in which a slit separating the handles is covered by one of handles folded over the slit. In some cases, the protective layer 218 can be similar to the protective layer used in the Allevyn Life Non-Bordered dressing.

[0090] As illustrated, a wi eking layer 212 can be positioned over an opposite, non-wound facing side of the substrate. The wicking layer 212 can facilitate passage of fluid through the layers below the wicking layer. For example, the wicking layer can transport (or “wick”) fluid away from the lower layers, such as from the substrate, toward one or more upper layers positioned over the wicking layer 212. Such one or more upper layers can include one or more absorbent materials as described herein. In some cases, the wicking layer 212 is formed from foam, such as foam similar to that used in the Allevyn Life Non-Bordered dressing. The wicking layer can be extensible or substantially extensible.

[0091] As illustrated in the dressing 200B of FIG. 2B, additional layer of soft coat 210 can be positioned over the non-wound facing side of the substrate between the substrate and the wicking layer 212. For example, soft coat 210 can protect the non-wound facing side of the substrate from fluid if the substrate is formed from material that is not impermeable to fluid. In such case, soft coat 210 can be hydrophobic or substantially hydrophobic. Soft coat 210 can be made of same or different material than soft coat 218. Soft coat 210 can be perforated as illustrated and described. In some cases, soft coat can encapsulate the entire substrate, including both the wound facing and non-wound facing sides.

[0092] FIGS. 3A-3B illustrate coated sensor integrated substrates 300. The substrates 300 are illustrated with non-wound facing side 216 up. The substrates 300 can be similar to any of the substrates described herein.

[0093] Any of the embodiments disclosed herein can be used with any of the embodiments described in U.S. PatentNo. 11638664, titled “BIOCOMPATIBLE ENCAPSULATION AND COMPONENT STRESS RELIEF FOR SENSOR ENABLED NEGATIVE PRESSURE WOUND THERAPY DRESSINGS,” which is incorporated by reference in its entirety.

[0094] User Activity Monitoring

[0095] Activities of a user may be desirably monitored by an activity monitoring device for a variety of reasons including wound prevention and monitoring. In one example, the activities of a user can be monitored when the user may be prone to or already have a pressure ulcer. Information gathered by the activity monitoring device about the activities of the user can be helpful for assisting with prevention or treatment of the pressure ulcer. In addition, information gathered by the activity monitoring device about the activities can be useful for checking compliance with a treatment regimen.

[0096] FIG. 4 illustrates a user activity monitoring system 1100 including an activity monitoring device 1120 attached to a body part 1110. The activity monitoring device 1120 can be attached to the body part 1110 using a strap, adhesive, or other coupling mechanism and may be worn on or supported by the body. In some implementations, multiple activity monitoring devices 1120 can be attached to the same body part 1110 or to multiple body parts 1110.

[0097] The body part 1110 can be a leg of a user that includes a knee 1112 and a foot 1114. As illustrated, in some embodiments, the activity monitoring device 1120 can be supported by the body part 1110 at a position between the knee 1112 and the foot 1114, such as proximate to the foot 1114. In other embodiments, the activity monitoring device 1120 can be supported by another part of the body part 1110. The activity monitoring device 1120 can monitor and record activities (for instance, walking, jumping, sitting, laying down, running, squatting, or standing) of the body part 1110, such as from a position, movement, or orientation of the activity monitoring device 1120 or one or more other sensors of the activity monitoring device 1120. The activity monitoring device 1120 can, for example, be used for loading monitoring of loading of the foot 1114. In certain implementations, multiple body parts can be monitored by the activity monitoring device 1120, and different sensors can be used for monitoring different body parts.

[0098] The body part 1110 is shown wearing and partly covered by an orthopedic device 1130. The orthopedic device 1130 can support the body part 1110 and reduce a pressure on the foot 1114 when the user may be standing or engaging in other activities. A compliance monitoring device 1132 can be attached to the orthopedic device 1130. The compliance monitoring device 1132 can be the same as or different from the activity monitoring device 1120 and supported by the orthopedic device 1130 using a strap, adhesive, or other coupling mechanism. The compliance monitoring device 1132 can be attached to an inner surface of the orthopedic device 1130 such that the compliance monitoring device 1132 is disposed between the orthopedic device 1130 and the skin of the patient. The compliance monitoring device 1132 can be attached to an outer surface of the orthopedic device 1130 such that a portion of the orthopedic device 1130 is disposed between the compliance monitoring device 1132 and the skin of the patient. Although not shown in FIG. 4, the compliance monitoring device 1132 can be attached to an orthopedic device 1130 that is not worn by the patient (for example, a cane, a walker).

[0099] Although not illustrated in FIG. 4, the user activity monitoring system 1100 can additionally or alternatively include one or more of the activity monitoring device 1120 or the compliance monitoring device 1132 at other positions, such as at a position supported by the orthopedic device 1130 or another part of the body part 1110. For example, multiple activity monitoring devices 1120 or compliance monitoring devices 1132 can be positioned above and below a joint. These one or more additional or alternative of the activity monitoring device 1120 or the compliance monitoring device 1132 can be the same as or similar to the activity monitoring device 1120 may monitor and record activities of the orthopedic device 1130 or the another part of the body part 1110. FIG. 5 illustrates a schematic 1200 of an activity monitoring device, such as the activity monitoring device 1120. The activity monitoring device and a data processing device can together configure a communication channel with one another to permit transfer of device or transfer of one or more commands from the data processing device to the activity monitoring device, among other possibilities. The data processing device can, for example, be a smart phone or a tablet computer.

[0100] As illustrated by the schematic 1200 in FIG. 5, the activity monitoring device can include a controller 1202, a memory device 1204, a user interface 1206, a power source 1208, one or more sensors 1210, and a communication interface 1212 that are configured to electrically communicate with one another. The power source 1208 can provide power to one or more components of the activity monitoring device. The components of the activity monitoring device can be contained in or supported by a housing of the activity monitoring device as discussed in more detail below.

[0101] The controller 1202 can control operations of one or more other components of the activity monitoring device according at least to instructions stored in the memory device 1204. The controller 1202 can, for instance, control monitoring of loading of the body part 1110 with a weight of the body or positioning of the body part 1110 and record data indicative of loading of the body part 1110 or positioning of the body part 1110 to the memory device 1204.

[0102] The controller 1202 can generate an enable signal to prevent a brownout condition, as described herein. A load can include one or more of the various sensors 1210 of the monitoring device, the user interface 1206, or the communication interface 1212.

[0103] The user interface 1206 can include one or more output elements, such as indicators (for example, light emitting diodes) or speakers, that provide user outputs to a user. The one or more output elements can convey status information to the user like whether the activity monitoring device is successfully functioning or has successfully configured communication with the data processing device. The user interface 1206 can further include one or more input elements, such as buttons, switches, dials, or touch screens, for receiving user inputs for configuring the activity monitoring device. In some embodiments, the user interface 1206 may have no more than one user input element, such as a button, for receiving user inputs to activate and deactivate the activity monitoring device or performing one or more other functions.

[0104] The one or more sensors 1210 can be used to detect and monitor a motion of the activity monitoring device. The one or more sensors 1210 can be used to detect and monitor activities of the user of the activity monitoring device that include, for instance, a loading or positioning of the body part 1110. The one or more sensors 1210 can include one or more accelerometers, gyroscopes, magnetometers, pressure sensors, impedance sensors, thermistors, or optical sensors, among other types of sensors. The one or more sensors 1210 can be positioned proximate to the body part 1110 or may be remote from the body part 1110 yet usable to monitor characteristics of the body part 1110.

[0105] The communication interface 1212 can be used to communicate with the data processing device, such as via radio waves and according to a Bluetooth™ protocol like Bluetooth™ Low Energy or another protocol. The communication interface 1212 can, for example, transmit device usage data like alarms, monitored loading or positioning, or changes to a monitoring or therapy program performed by the activity monitoring device to the data processing device. The communication interface 1212 can be used to receive data, including commands, from the data processing device.

[0106] FIG. 6 illustrates an activity monitoring device, such as the activity monitoring device 1120. The housing 1300 can be arranged to enclose a printed circuit board assembly (PCBA) 1310. The housing 1300 can have a cap portion 1302 and a base portion 1304. The cap portion 1302 and the base portion 1304 can be joined together to form an enclosed space within the housing 1300. The enclosed space can be sized to at least accommodate the PCBA 1310. In the embodiment shown in FIG. 6, the cap portion 1302 has an inner rim 1306 that nests inside an outer sidewall 1308 disposed on the base portion 1304 to form the enclosed space within the housing 1300. The orientation of the inner rim 1306 and the outer sidewall 1308 can be reversed, in some implementations, such that the inner rim 1306 is disposed on the base portion 1304 and the outer sidewall 1308 is disposed on the cap portion 1302.

[0107] The PCBA 1310 can include one or more of the components of the activity monitoring device 1120 such as the controller 1202, the memory device 1204, the user interface 1206, the power source 1208, the sensor(s) 1210, and the communication interface 1212. In some embodiments, one or more of the components of the activity monitoring device 1120 can be mounted to a portion of the activity monitoring device 1120 other than the PCBA 1310, such as the housing 1300. As shown in FIG. 6, the PCBA 1310 can include a microswitch 1302. The PCBA 1310 can include more than one microswitch 1302. The microswitch 1302 can include a push button 1304. The microswitch 1302 can be activated by applying a compressive force to the push button 1304.

[0108] The housing 1300 can be arranged such that a targeted or intended compression of the housing 1300 within a particular vicinity of the microswitch 1302 activates the microswitch 1302. The housing 1300 can include features that cause the push button 1304 to be pressed when a targeted compression is applied to the housing 1300 in the vicinity of the microswitch 1302. The housing 1300 can be arranged such that an untargeted or unintentional compression of the housing 1300 outside a particular vicinity of the microswitch 1302 does not activate the microswitch 1302. The housing 1300 can be arranged such that the housing 1300 shields the PCBA 1310 from compressive forces that are applied to the housing 1300.

[0109] Sensor Data Collection and Formatting

[0110] Physiological data collected by one or more sensors or sensor-enabled devices described herein, such as by a negative pressure wound therapy device, sensor-integrated substrate, activity monitoring device, or compliance monitoring device, can suffer from lack of accuracy. Such lack of accuracy can be related to poor quality of physiological data, for instance, due to inaccurate calibration of a sensor with which data is obtained. As another example, such lack of accuracy can be related to incorrect timing of collection of the data, for instance, due to lack of synchronization between multiple sensors or between timing of multiple collections of data by a single sensor. Further processing of physiological data (for instance, by one or more data processing devices), may be only as good as the quality of physiological data that serves as input to such processing. Such further processing can include one or more of a decision, model (such as, machine learning model), or artificial intelligence (Al) process. Among others, further processing can assess the health of a patient, identify one or more physiological conditions, provide recommendations, or the like. The quality of data input into further processing can be critical and errors can be of many forms such as accuracy, precision or applicability of either the data values itself, of the time at which the data was collected or measured, or of the confidence that the right element has been recorded.

[0111] Timestamps can be assigned to data either at point of generation, at point of processing, or at point of acquisition by a collecting device (such as, a sensor) in addition or in place of a sample or sequency number. Timestamps can be in the form of an Epoch time (such as, an arbitrary value, which may be the time on of the device) or a real time clock (RTC). The ability of a device to maintain a true time depends on a number of factors, including one or more of accuracy of the oscillator of a clock circuitry or the ability of the clock circuitry to compensate for operating conditions, such as temperature. Accuracy of time kept by a clock circuitry can be maintained using one of more of the following approaches. In some instances, RTC maintained by a clock circuitry of each sensor- enabled device can be updated with RTC value from a central node (such as, a smart phone, tablet, or another computing device) or another sensor-enabled device every time communication with a particular sensor-enabled device occurs or at periodic time intervals. In certain cases, at the point of download of data from a sensor-enabled device, “true time” maintained by a control module is appended to the downloaded data.

[0112] However, as described herein, time kept by a clock circuitry can become inaccurate as physiological data is being collected by a sensor. Additionally or alternatively, accuracy of physiological data being collected can be degraded over time. The approaches described herein can efficiently and effectively improve accuracy and precision of storage and transmission of physiological data, which can in turn lead to the development of more accurate further processing techniques and, among others, more accurate assessment of the health of a patient, more accurate identification of one or more physiological conditions, and provision of more accurate recommendations. When different sensors obtain data measurements simultaneously, it may be more important to ensure that the clock circuitry of the sensors is synchronized to a common relative reference time rather than a precise absolute time (such as, UTC or GPS). Thus, precision of a reference time provided by a central node may not be as important to ensure accurate temporal attribution of sensor measurements.

[0113] In some instances, physiological data collected by one or more digital sensors may be transferred for further processing through a communication channel, such as the communication interface 1212, which can be configured to transfer digital data. For instance, such communication channel can be I2C or I3C bus. Sensor identifier can be appended to physiological data transferred over such communication channel. The identifier can be a unique identifier, which may include information (sensor type, sensor model, sensor location, etc.) related to the specific attributes of the sensor. In certain implementations, physiological data collected by one or more analog sensors may be converted into digital data utilizing an Analog to Digital Converter (ADC). Once converted, data can be transferred for further processing using similar approaches.

[0114] A data format for storage or transmission can include one or more of the following fields or elements:

[0115] Type code: Vector or scalar value. • Data value: Data obtained by one or more sensors of a sensor-enabled device or another type of data.

[0116] • Quality code: One or more codes to identify the accuracy and precision of the data.

[0117] • Timestamp: Epoch time or RTC.

[0118] • Time quality code: One or more codes to identify the accuracy and precision of the timestamp.

[0119] Data format can be a data set or a record. Data value may represent physiological data obtained by one or more sensors. The data value can be raw sensor data or can be a processed value. An example of a type code may be related to movement of a particular patient, or a limb attached to the patient, as previously described. The movement may be identified by an acceleration and represented in the type code of the data element as a vector (such as, accelerometer vector) or scalar value. One or more quality codes can indicate the accuracy and precision of the data value. The one or more quality codes can be inversely proportional to the duration of time since the last calibration or update. For example, the one or more quality codes can be a grade that is adjusted to reflect lower quality as the duration of time since the last calibration or update increases. In some instances, the one or more quality codes can indicate a potential or true drift of data. A sensor can drift due to temperature or time of use and such drift can be referred to as a potential drift. Other potential drift trends may be identified by generation of a value that is not expected (such as, a negative value being determined by a sensor that should only measure positive values). When a sensor is recalibrated, the identified error can be used to give a true drift value, which can be utilized to interpolate the error that has occurred between the calibration events.

[0120] As another example, data that is more difficult to validate can be assigned a lower quality code than data that is easier to validate. For instance, patient-reported outcomes measure (PROMs) may be assigned a low grade as compared to data captured by one or more sensors as PROMs is subjective and difficult to validate.

[0121] Timestamp data may be used for synchronization with one or more of another sensing device or a data processing device. Synchronization may include periodic time updates with respect one or more of another sensing device or processing device. One or more time quality codes can reflect a measure of time variation or drift for the timestamp data. The one or more time quality codes can be represented as an absolute value or a class code (such as, letter or numerical grade). The one or more time quality codes can be inversely proportional to the duration of time since the last synchronization or correction. For example, the one or more time quality codes can be a grade that is adjusted to reflect lower quality as the duration of time since the last synchronization or correction increases. In some instances, the time of one or more quality codes can indicate a potential or true drift of the timestamp, as explained herein. The one or more time quality codes can incorporate a measure of the degree of separation from a high-accuracy time source (or node). For instance, such separation can be similar to the distance from a primary reference clock source (such as, Stratum 0) in the NTP stratum hierarchy.

[0122] A processing device may determine how to process a data value based on one or more quality codes or one or more time quality codes associated with the data value. For instance, the processing device can move to lower fidelity backup approaches responsive to one or more quality codes or one or more time quality codes failing below a respective quality threshold. Such approaches (which can be referred to as remedial actions) can include a direct communication between devices to gain an accurate timestamp, generation of an arbitrary shared local time value (such as, timestamp) for comparison-only purposes (for instance, when out of communication with a Stratum 0 or Stratum 1), or a request for an absolute or relative calibration action. An example of comparison-only approach can be used during sensing of a joint movement with sensors placed above and below the joint. The angle, movement, range of motion, etc. can be accurately identified if the sensors utilize a common relative reference time, even if that time is incorrect. On of the sensors can generate a time value to which the sensor and other sensor(s) synchronize their clock circuitries. In some cases, data measured with comparison-only approach could be used to generate information that does not require accurate time, but should not be used to generate data that requires accurate time. For instance, if the data is to be used as training data for a walking machine learning model, then it could be used if the confirmation of walking time is generated or inputted on a device with a common clock, but should not be combined with a “true-time” GPS unit trace as the same event (unless a corroborating alignment of timestamps can be achieved). Absolute calibration of an activity monitoring device can include placing the device stationary with respect to gravity and relative calibration can include moving the device or causing an impact. Calibration can be performed a periodic time intervals.

[0123] Data values acquired by one or more sensor devices may serve as an input for a machine learning model based on the one or more quality codes or one or more time quality codes meeting a respective threshold, which can be adjustable. Data values whose quality or timestamp quality codes do not meet the respective threshold (which may be referred to as lower quality data) may not be used by the processing device. This can advantageously improve the quality of further processing, such as, determination of one or more physiological conditions or assessing the health of a patient.

[0124] In some cases, lower quality data may be used as generative data to train or test a machine learning model. For example, lower quality data can be input into the machine learning model to train or test at a first bound and a second bound opposite the first bound. Outputs of the machine learning model for first and second bounds can be compared to identify the sensitivity of the machine learning model. In addition to or alternatively to testing behavior at bounds, lower quality data can be used to train or test at one or more nominal levels, intermediate levels, or random variations around a nominal level and outputs can be compared. If all variants have the same effect on test data (which can be separate from training data), then the machine learning model may be deemed not to be overly sensitive to the fluctuations and the use of lower quality data for processing may be acceptable.

[0125] In situations when calibration or synchronization occurs on a periodic basis (for instance, via external calibration or a timestamp update), there may be two layers of inaccuracy. First, there can be a drift over time in a particular direction. Second, there can be shorter term variations due to external factors, such as, oscillator frequency or speed changes due to temperature variations. When the former (or in some cases the latter or both the former and latter) can be calculated, a data value can be adjusted to compensate for the inaccuracy. A revised and more accurate quality or time quality metric may be assigned to the data value that has been adjusted to compensate for the drift or variations. In this case, one or more values (such as, data elements) can be added or appended to the data format to indicate that compensation had been performed. While both uncompensated and compensated data formats may be stored, care may need to be taken to ensure that further processing uses a single instance of such data set in order to avoid the possibility of using multiples of the same data set and skewing the behavior of the output.

[0126] Data format for storage or transmission can include one or more of the following additional or alternative fields or elements, which can be appended to the data value or be part of a header of a data set:

[0127] • Sensor identification (ID): Unique identification of each sensor-enabled device.

[0128] • Device type / generation code: Type or revisions of sensor-enabled device.

[0129] • Use code: Additional value identifying the specific use or position of the sensor- enabled device (such as, above or below a knee, above or below a wrist, upstream or downstream of a particular location, etc.).

[0130] • Geo-tag / location code: Location data.

[0131] • Source time ID: Unique ID of the time source against which the sensor-enabled device was synchronized.

[0132] • Time drift scale: Drift between synchronizations.

[0133] • Data record ID: Unique data record ID to avoid duplication of data.

[0134] Sensor ID can be unique information identifying a sensor-enabled device. Sensor ID may include information, such as, sensor type, sensor model, sensor location, etc., related to the specific attributes of a sensor that provided the data. A data processing device that receives data from multiple sensor-enabled devices can use sensor identifiers to distinguish between different such devices and different patients. For example, the data processing device may process data related to a particular patient based on a sensor identifier corresponding to a particular sensor-enabled device that monitors the particular patient.

[0135] Device type / generation code can indicate a type or revisions of a sensor-enabled device. This information can allow for inclusion or exclusion of data value from specific types and variants if later information identifies that they are particularly useful or flawed.

[0136] Use code can identify specific placement and position of a sensor-enabled device. An example of the use code may identify if the sensor-enabled device is located on an orthopedic device 1130 or a knee 1112 and a foot 1114 of a patient as illustrated in FIG. 4.

[0137] Geo-tag or location code can identify the location of a sensor-enabled device. This information can allow comparison of behavior at a specific locale or against particular environmental conditions. This information may be appended to the data value or as a header to the data set or a sub-set thereof. In some instances, a location code for a base location would be against the full or partial data and a more detailed location code would be against a smaller sub-set or individual values. This may be particularly applicable in cases where geo-tags utilize different location mechanisms (such as, Wi-Fi location, GPS location, or cellular location). It may be appropriate to amalgamate all data, for instance, if range of motion measurements are made in a hospital as part of a rehab assessment during which some sensor- enabled devices may be able to identify a very accurate location but others, with different antennas, may only be able to identify a location to within a mile or more. If the hospital is the only place within such wider zone that will typically perform the exact range of motion test, then measured data may be inferred, based on the geo-tags, to have come from within the hospital and can be compared.

[0138] Source time ID can indicate a unique ID of the time source against which a sensor- enabled device was synchronized. This can allow for comparison of data that was obtained in the same session (such as, from multiple sensor-enabled devices monitoring the same patient at the same time).

[0139] Time drift state can be used for identifying the drift between synchronizations when a sensor-enabled device is synchronized from a central (or intermediate) time source. When the drift is consistent across multiple synchronizations, time drift state can reflect the underlying drift value. This drift value can be used to compensate for the inaccuracy as described herein.

[0140] Data record ID can be a unique value that avoids duplication of data. For instance, be a combination of sensor ID and source time ID can be utilized.

[0141] FIG. 7 illustrates a process 700 of using data collected by a sensor-enabled device, such as such as by a negative pressure wound therapy device, sensor-integrated substrate, activity monitoring device, or compliance monitoring device. The process 700 can be implemented by the sensor-enabled device alone or in combination with a data processing device. The process 700 can start in block 702 where a data set described herein is generated by the sensor-enabled device. The data set can include a physiological data value related to condition of a patient, quality code, timestamp, and time quality code. In block 704, the process 700 can determine whether one or more of quality code or timestamp quality code satisfy a respective threshold. If yes, the process 700 can transition to block 706 where the record is processed to assess the patient’s health. If not, the process 700 can transition to block 708 where one or more remedial actions are performed. As described herein, such one or more remedial actions can include one or more of calibration, synchronization, verifying sensitivity, or compensation.

[0142] Approaches described herein can allow data comparison and analysis, such as by a machine learning model, with the ability to utilize only data that is of a known quality. It can be used to eliminate or reduce the development of aberrant data processing techniques based on randomly correlating data and can allow for the testing of the limits of the capabilities of the data processing techniques.

[0143] Other Variations

[0144] In some cases, one or more electronic components can be positioned on the side of a substrate opposite the side that faces the wound. Systems and methods described herein are equally applicable to such wound contact layers. Although certain embodiments described herein relate to wound dressings, systems and methods disclosed herein are not limited to wound dressings or medical applications. Systems and methods disclosed herein are generally applicable to electronic devices in general, such as electronic devices that can be worn by or applied to a user.

[0145] Although some embodiments describe negative pressure wound therapy, the systems, devices, and / or methods disclosed herein can be applied to other types of therapies usable standalone or in addition to TNP therapy. Systems, devices, and / or methods disclosed herein can be extended to any medical device, and in particular any wound monitoring and / or treatment device. For example, systems, devices, and / or methods disclosed herein can be used with devices that provide one or more of ultrasound therapy, oxygen therapy, neurostimulation, microwave therapy, active agents, antibiotics, antimicrobials, or the like. Such devices can in addition provide TNP therapy. As another example, systems, devices, and / or methods disclosed herein can be used with a wound debridement system, patient monitoring system, or the like.

[0146] Any of storage or transmission of data described herein can be performed securely. For example, one or more of encryption, https protocol, secure VPN connection, error checking, confirmation of delivery, or the like can be utilized.

[0147] Any value of a threshold, limit, duration, etc. provided herein is not intended to be absolute and, thereby, can be approximate. In addition, any threshold, limit, duration, etc. provided herein can be fixed or varied either automatically or by a user. Furthermore, as is used herein relative terminology such as exceeds, greater than, less than, etc. in relation to a reference value is intended to also encompass being equal to the reference value. For example, exceeding a reference value that is positive can encompass being equal to or greater than the reference value. In addition, as is used herein relative terminology such as exceeds, greater than, less than, etc. in relation to a reference value is intended to also encompass an inverse of the disclosed relationship, such as below, less than, greater than, etc. in relations to the reference value. Moreover, although blocks of the various processes may be described in terms of determining whether a value meets or does not meet a particular threshold, the blocks can be similarly understood, for example, in terms of a value (i) being below or above a threshold or (ii) satisfying or not satisfying a threshold.

[0148] Features, materials, characteristics, or groups described in conjunction with a particular aspect, embodiment, or example are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features or steps are mutually exclusive. The protection is not restricted to the details of any foregoing embodiments. The protection extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0149] While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of protection. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made. Those skilled in the art will appreciate that in some cases, the actual steps taken in the processes illustrated or disclosed may differ from those shown in the figures. Depending on the embodiment, certain of the steps described above may be removed, others may be added. For example, the actual steps or order of steps taken in the disclosed processes may differ from those shown in the figure. Various components illustrated in the figures or described herein may be implemented as software or firmware on a processor, controller, ASIC, FPGA, or dedicated hardware. The software or firmware can include instructions stored in a non-transitory computer-readable memory. The instructions can be executed by a processor, controller, ASIC, FPGA, or dedicated hardware. Hardware components, such as controllers, processors, ASICs, FPGAs, and the like, can include logic circuitry. Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure.

[0150] Although the present disclosure includes certain embodiments, examples and applications, it will be understood by those skilled in the art that the present disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments or uses and obvious modifications and equivalents thereof, including embodiments which do not provide all of the features and advantages set forth herein. Accordingly, the scope of the present disclosure is not intended to be limited by the specific disclosures of preferred embodiments herein, and may be defined by claims as presented herein or as presented in the future.

[0151] Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, or steps. Thus, such conditional language is not generally intended to imply that features, elements, or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, or steps are included or are to be performed in any particular embodiment. The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list. Further, the term “each,” as used herein, in addition to having its ordinary meaning, can mean any subset of a set of elements to which the term “each” is applied.

[0152] Conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require the presence of at least one of X, at least one of Y, and at least one of Z. Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount.

[0153] The scope of the present disclosure is not intended to be limited by the specific disclosures of preferred embodiments in this section or elsewhere in this specification, and may be defined by claims as presented in this section or elsewhere in this specification or as presented in the future. The language of the claims is to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive.

Claims

WHAT IS CLAIMED IS:

1. A medical monitoring and / or treatment system comprising: a sensor configured to collect physiological data from a patient, the sensor comprising a processing circuitry configured to generate a record comprising a physiological data value collected from the patient, a data quality value indicative of accuracy of the physiological data value, a timestamp value associated with time of collection of the physiological data value, and a timestamp quality value indicative of accuracy of the timestamp value; and an electronic device comprising a processing circuitry configured to: receive the record transmitted by the sensor; compare at least one of the data quality value or the timestamp quality value to a threshold; in response to a determination that the at least one of the data quality value or the timestamp quality value satisfies the threshold, process the physiological data value to assess health of the patient; and in response to a determination that the at least one of the data quality value or the timestamp quality value does not satisfy the threshold, perform a remedial action.

2. The medical monitoring and / or treatment system of claim 1 , wherein physiological data comprises patient activity data.

3. The medical monitoring and / or treatment system of claim 1 , wherein physiological data is related to provision of negative pressure wound therapy.

4. The medical monitoring and / or treatment system of claim 1, wherein the system comprises a substrate supporting the at least one sensor and configured to be positioned on the patient.

5. The medical monitoring and / or treatment system of any one of the preceding claims, wherein the remedial action comprises causing the sensor to be calibrated to increase accuracy of physiological data collected by the sensor.

6. The medical monitoring and / or treatment system of any one of the preceding claims, wherein the electronic device comprises another sensor.

7. The medical monitoring and / or treatment system of any one of the preceding claims, wherein the remedial action comprises causing the sensor to be synchronized with a time value obtained by the electronic device from an external source to increase accuracy of time of collection of physiological data by the sensor.

8. The medical monitoring and / or treatment system of claim 7, wherein: the processing circuitry of the sensor maintains a clock configured to generate the timestamp value; and causing the sensor to be synchronized comprises providing the time value to the sensor to set the clock.

9. The medical monitoring and / or treatment system of any one of the preceding claims, wherein the remedial action comprises: by the processing circuitry of the electronic device, generating a local time value; and causing the sensor to be synchronized with the local time value.

10. The medical monitoring and / or treatment system of any one of the preceding claims, wherein the remedial action comprises: determining that a sensitivity of a model configured to process the physiological data value to assess health of the patient satisfies a sensitivity threshold; and in response to a determination that the sensitivity of the model satisfies the sensitivity threshold, processing the physiological data value to assess health of the patient.

11. The medical monitoring and / or treatment system of any one of the preceding claims, wherein the remedial action comprises: determining an error associated with the physiological data value; from the physiological data value and the error, determining an adjusted physiological data value to compensate for the error; and processing the adjusted physiological data value to assess health of the patient.

12. The medical monitoring and / or treatment system of any one of the preceding claims, wherein a data quality value of a first record comprises a first physiological data value collected from the patient at a first time indicates a higher quality than a data quality value of a second record comprising a second physiological data value collected from the patient at a second time when a duration of time between a time of calibration of the sensor and the second time exceeds a duration of time between the time of calibration of the sensor and the first time.

13. A method of operating a medical monitoring and / or treatment system, the method comprising: with a sensor, collecting physiological data from a patient and generating a record comprising a physiological data value collected from the patient, a data quality value indicative of accuracy of the physiological data value, a timestamp value associated with time of collection of the physiological data value, and a timestamp quality value indicative of accuracy of the timestamp value; and with an electronic processing device: receiving the record transmitted by the sensor; comparing at least one of the data quality value or the timestamp quality value to a threshold; at a first time, determining that the at least one of the data quality value or the timestamp quality value satisfies the threshold and responsive to determining that the at least one of the data quality value or the timestamp quality value satisfies the threshold, processing the physiological data value to assess health of the patient; and at a second time, determining that the at least one of the data quality value or the timestamp quality value does not satisfy the threshold and responsive to determining that the at least one of the data quality value or the timestamp quality value does not satisfy the threshold, performing a remedial action.

14. The method of claim 13, wherein the remedial action comprises causing the sensor to be calibrated to increase accuracy of physiological data collected by the sensor.

15. The method of any of claims 13 to 14, wherein the electronic processing device comprises another sensor.

16. The method of any one of claims 13 to 15, wherein the remedial action comprises causing the sensor to be synchronized with a time value obtained by the electronic processing device from an external source to increase accuracy of time of collection of physiological data by the sensor.

17. The method of claim 16, further comprising: with the sensor, maintaining a clock configured to generate the timestamp value; and with the electronic processing device, causing the sensor to be synchronized by providing the time value to the sensor to set the clock.

18. The method of any one of claims 13 to 17, wherein the remedial action comprises: by the electronic processing device, generating a local time value; and causing the sensor to be synchronized with the local time value.

19. The method of any one of claims 13 to 18, wherein performing the remedial action comprises: determining that a sensitivity of a model configured to process the physiological data value to assess health of the patient satisfies a sensitivity threshold; and responsive to determining that the sensitivity of the model satisfies the sensitivity threshold, processing the physiological data value to assess health of the patient.

20. The method of any one of claims 13 to 19, wherein performing the remedial action comprises: determining an error associated with the physiological data value; from the physiological data value and the error, determining an adjusted physiological data value to compensate for the error; and processing the adjusted physiological data value to assess health of the patient.

21. The method of any one of claims 13 to 20, wherein a data quality value of a first record comprises a first physiological data value collected from the patient at a first time indicates a higher quality than a data quality value of a second record comprising a second physiological data value collected from the patient at a second time when a duration of time between a time of calibration of the sensor and the second time exceeds a duration of time between the time of calibration of the sensor and the first time.

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