Systems and methods for storing and adjusting an accuracy specification

Abstract

A medical monitoring system that includes a sensor and a monitor. The sensor includes a sensor memory that stores accuracy data. The monitor includes a port to communicatively couple to the sensor to receive the accuracy data, a display, and monitor processing circuitry to determine an accuracy specification based on the accuracy data and instruct presentation of the accuracy specification on the display.

Description

SYSTEMS AND METHODS FOR STORING AND ADJUSTING ANACCURACY SPECIFICATIONCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 622,945, filed January 19, 2024, the entire contents of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The present disclosure generally relates to medical monitoring devices (e.g., sensors) that store an accuracy specification and enable an adjustment (e.g., modification) of the accuracy specification for transmission to a monitor.BACKGROUND

[0002] Various medical monitoring devices may be used to monitor physiological characteristics of an individual. For example, various sensors may be used to measure temperature, pressure, oxygen, and other physiological characteristics of the individual. One such sensor, a pulse oximetry sensor, may be used to measure oxygen saturation levels in blood of the individual by utilizing wavelengths of light. In this manner, the pulse oximetry sensor may provide physiological parameters related to respiratory and circulatory systems of the individual.

[0003] In certain cases, the pulse oximetry sensor may have an accuracy specification with which the pulse oximetry sensor may measure the oxygen saturation levels in the blood. The accuracy specification may indicate how close measured values are to true values of the oxygen saturation levels. For example, the accuracy specification may be expressed as a percentage (e.g., a percent error) meaning that a displayed oxygen saturation level may vary by the percentage (e.g., + / - 1, 1.5, 2, 2.5, 3, 3.5, 4, or more percent). The accuracy specification may be determined via testing processes, and then the accuracy specification may be provided on packaging for the pulse oximetry sensor, an instruction manual for the pulse oximetry sensor, or both.

[0004] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and / or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the presentdisclosure. Accordingly, it may be understood that these statements are to be read in this light, and not as admissions of prior art.SUMMARY

[0005] Certain embodiments commensurate in scope with the originally claimed subject matter are summarized below. These embodiments are not intended to limit the scope of the disclosure. Indeed, the present disclosure may encompass a variety of forms that may be similar to or different from the embodiments set forth below.

[0006] In one embodiment, a medical monitoring system that includes a sensor and a monitor. The sensor includes a sensor memory that stores accuracy data. The monitor includes a port to communicatively couple to the sensor to receive the accuracy data, a display, and monitor processing circuitry to determine an accuracy specification based on the accuracy data and instruct presentation of the accuracy specification on the display.

[0007] In another embodiment, a method of operating a medical monitoring system includes receiving, at a processor and from a memory of a sensor, accuracy data for the sensor, determining, at the processor, an accuracy specification for the sensor based on the accuracy data, and instructing, via the processor, display of the accuracy specification on a display.

[0008] Various refinements of the features noted above may exist in relation to various aspects of the present disclosure. Further features may also be incorporated in these various aspects as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to one or more of the illustrated embodiments may be incorporated into any of the above-described aspects of the present disclosure alone or in any combination. The brief summary presented above is intended only to familiarize the reader with certain aspects and context of embodiments of the present disclosure without limitation to the claimed subject matter.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Advantages of the disclosed techniques may become apparent upon reading the following detailed description and upon reference to the drawings in which:

[0010] FIG. 1 is a perspective view of an embodiment of a medical monitoring system configured to monitor oxygen saturation, in accordance with an aspect of the present disclosure;

[0011] FIG. 2 is a block diagram of the medical monitoring system of FIG. 1, in accordance with an aspect of the present disclosure;

[0012] FIG. 3 is a block diagram illustrating an example technique for adjustment of an accuracy specification of a sensor that may be employed in the medical monitoring system of FIG. 1, in accordance with an aspect of the present disclosure;

[0013] FIG. 4 is an example illustration of a bitstream that may be stored in a memory of a sensor that may be employed in the medical monitoring system of FIG. 1, in accordance with an aspect of the present disclosure;

[0014] FIG. 5 is a flow diagram of a method for adjusting modifier bits based on a change in an accuracy specification of a sensor, in accordance with an aspect of the present disclosure; and

[0015] FIG. 6 is a flow diagram of a method for displaying an adjusted accuracy specification via a monitor, in accordance with an aspect of the present disclosure.DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0016] One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementationspecific decisions must be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0017] When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0018] It is presently recognized that it may be desirable to store an accuracy specification in a memory of a sensor for various reasons, such as to enable transmission of the accuracy specification to a monitor for display on a display screen of the monitor. In this way, a clinician may be aware of the accuracy specification, and the clinician may view both theaccuracy specification and physiological parameters measured by the sensor on the display screen.

[0019] Further, it is presently recognized that certain events, such as recycling of the sensor, remanufacturing of the sensor, or reprocessing of the sensor, may change or adjust the accuracy specification. For example, the recycling and remanufacturing of the sensor may result in the sensor being unable to operate with an original accuracy specification (e.g., an initial accuracy specification; prior to the recycling and remanufacturing) and instead to operate at an adjusted accuracy specification (e.g., after the recycling or remanufacturing). Accordingly, it is also presently recognized that it may be desirable to store the original accuracy specification in the memory of the sensor, as well as to efficiently update the original accuracy specification in the memory of the sensor to thereby store the adjusted accuracy specification in the memory of the sensor.

[0020] Accordingly, the present disclosure generally relates to a sensor that stores an accuracy specification and enables adjustment (e.g., modification, update) of the accuracy specification for transmission to a monitor. The sensor facilitates the adjustment of the accuracy specification, such as from an original accuracy specification to an adjusted accuracy specification, by enabling a rewriting of a portion of a memory of the sensor.

[0021] As an example, the sensor includes the memory (e.g., an add-only memory, a rewriteable integrated circuit) that stores the original accuracy specification, a constant, and a modifier. More particularly, the memory stores a bitstream (e.g., a binary representation, a number of bits) representative of the original accuracy specification, the constant, and the modifier. The bitstream may include accuracy bits that represent or indicate the original accuracy specification and that may not be updated or rewritten, constant bits that represent or indicate the constant and that may not be updated or rewritten, as well as modifier bits that represent or indicate the modifier and that may be updated or rewritten. In operation, the sensor is coupled to the monitor, the monitor receives and processes the bitstream to determine the accuracy specification, and the accuracy specification is displayed on a display screen of the monitor, such as during use of the sensor to monitor a patient. If the use is an initial use of the sensor, the accuracy specification may be equal to the original accuracy specification.

[0022] After the use, the sensor may be recycled for further utilization (e.g., reuse). Indeed, the sensor may be collected and remanufactured or reprocessed to enable reuse of the sensor on a new patient. As a result of the remanufacturing or reprocessing, the accuracy specification of the sensor may change (e.g., as measured via testing processes), such as froma two percent (e.g., 2%) root-mean-square deviation (RMSD) (e.g., a difference between a predicted value and an observed value) to a three percent (e.g., 3%) RMSD. Thus, a portion (e.g., two bits; the modifier bits) of the bitstream in the memory that is representative of the modifier may be rewritten (e.g., adjusted), such as by changing at least one bit, to enable or indicate a change in a value of the modifier.

[0023] After the remanufacturing or reprocessing, and after updating the modifier bits, the sensor is coupled to the monitor (or another monitor), the monitor (or the another monitor) receives and processes the bitstream to determine the accuracy specification, and the accuracy specification is displayed on the display screen of the monitor (or another display screen of the another monitor), such as during use of the sensor to monitor the new patient. In such cases, the accuracy specification is different than the original accuracy specification and may be referred to as the adjusted accuracy specification.

[0024] As described herein, the monitor may perform certain processing steps to determine the accuracy specification. For example, the sensor transmits accuracy bits (e.g., representative of the original accuracy specification), constant bits (e.g., representative of the constant), and modifier bits (e.g., representative of the modifier) to the monitor. The monitor receives the accuracy bits, the constant bits, and the modifier bits. The monitor determines the original accuracy specification based on the accuracy bits, the constant based on the constant bits, and the modifier based on the modifier bits. Further, the monitor deducts the modifier from the constant to obtain an adjustment value. For example, the constant may be equal to a value of four, and after adjustment in the memory of the sensor, the modifier may be equal to a value of three. Thus, the modifier deducted from the constant is equal to the adjustment value of one. The monitor then adjusts the original accuracy specification by adding the adjustment value to the original accuracy specification to determine an adjusted accuracy specification. As an example, the original accuracy specification may be equal to a value of two (e.g., the 2% RMSD). The original accuracy specification is added to the adjustment value, which results in a value of three (e.g., the 3% RMSD) for the adjusted accuracy specification. The monitor then displays the adjusted accuracy specification. As such, embodiments described herein enable the display of the original accuracy specification, as well as the adjusted accuracy specification that corresponds to the accuracy specification of the remanufactured sensor.

[0025] With the foregoing in mind, FIG. 1 is a perspective view of an embodiment of a medical monitoring system 10 that includes a patient monitor 12 that may be used in conjunction with a medical sensor 14. In the illustrated example, the monitor 12 is a pulseoximetry monitor and the sensor 14 is a pulse oximetry sensor. In such cases, the monitor 12 is configured to process photoplethysmography (PPG) signals to calculate oxygen saturation (SpO2). It should be appreciated that the medical monitoring system 10 may be configured to obtain any of a variety of medical measurements and the techniques described herein may be adapted for use with any variety of monitors and sensors. By way of non-limiting example, in some embodiments, the monitor 12 may include a regional oximeter and the sensor 14 may include a regional saturation sensor. In such cases, the monitor 12 is configured to process the PPG signals to calculate regional oxygen saturation (rSOr). As other non-limiting examples, the sensor 12 may be a thermometer to measure body temperature, an electrocardiography sensor to measure heart rate and other heart parameters, an electroencephalography sensor to measure brain activity, a glucose sensor to monitor glucose, a blood pressure sensor to measure blood pressure, or any other suitable type of sensor, and the monitor 12 may be configured to process the signals received from the sensor 14. Additionally, although the depicted embodiments illustrate the sensor 14 configured for use on a patient’s finger, it should be understood that the sensor 14 may be adapted for use at other tissue locations, such as a forehead, temple, earlobe, toe, foot, heel, ankle, stomach, chest, back, neck, write, thigh, or any other suitable measurement site.

[0026] In FIG. 1, the sensor 14 includes one or more emitters 16 (collectively referred to herein as an emitter for convenience) and one or more detectors 18 (collectively referred to herein as a detector for convenience). The emitter 16 emits wavelengths of light that passes through blood perfused tissue, and the detector 18 detects the light as reflected or transmitted by the tissue. Additional details regarding the emitter 16 and the detector 18 will be described below with respect to FIG. 2.

[0027] The sensor 14 includes a sensor body 20 that may include multiple layers, such as a backing, adhesives, and so on. The sensor body 20 may also include or support a flexible circuit with various components. In certain embodiments, the medical monitoring system 10 may include multiple sensors 14 at multiple locations.

[0028] The sensor 14 is communicatively coupled to the monitor 12. In the illustrated embodiment, the sensor 14 is coupled to the monitor 12 via a cable 22. The cable 22 may interface directly with the sensor 14 and may include multiple conductors (e.g., wires) to transmit signals and / or receive signals. Additionally or alternatively, the sensor 14 may communicate with the monitor 12 wirelessly (e.g., the sensor 14 and the monitor 12 include wireless transceivers configured to communicate via any suitable wireless protocol). For example, the sensor 14 may include a transceiver that enables wireless signals to betransmited to and / or received from an external device (e.g., the monitor 12). Additionally, the multiple conductors or the transceiver may transmit a raw digitized detector signal, a processed digitized detector signal, or a calculated physiological parameter, as well as any data (e.g., accuracy specification data) that may be stored in the sensor 14.

[0029] In operation, the monitor 12 may receive a signal from the sensor 14, and the monitor 12 may be configured to calculate or measure one or more physiological parameters based on the signal. In particular, the monitor 12 may include a processor configured to execute code (e.g., stored in a memory of the monitor 12 or received from another device) for filtering and processing the signal from the sensor 14 to calculate physiological parameters, such as oxygen saturation. The monitor 12 may additionally or alternatively calculate any variety of physiological parameters, such as arterial blood oxygen saturation, regional or tissue oxygen saturation, pulse rate, respiration rate, blood pressure, blood pressure characteristic measure, autoregulation status, brain activity, temperature, or any other suitable physiological parameter. Further, the monitor 12 may receive the accuracy specification data from the sensor 14 and may calculate an accuracy specification for the sensor 14.

[0030] Additionally, as illustrated in FIG. 1, the monitor 12 includes a display 24 configured to display one or more calculated physiological parameters, such as oxygen saturation. The display 24 may also display other information, such as instructions to charge the sensor 14, alarm indications, setings, the accuracy specification, and so forth. In certain embodiments, the display 24 may be a touch screen display. The monitor 12 may include various input components, such as the touch screen display, knobs, switches, keys and keypads, butons, and so forth, to provide for operation and configuration of the monitor 12. The monitor 12 may also include one or more indicator lights and one or more speakers. The monitor 12 may also include additional slot(s) or wireless interfaces (e.g., channels) to connect to additional devices, such as additional sensors to monitor additional physiological parameters of the patient and / or to monitor physiological parameters of other patients at one time.

[0031] Furthermore, one or more functions of the monitor 12 disclosed herein may also be implemented directly in the sensor 14, or by any other suitable device. For example, in some embodiments, the sensor 14 may include one or more processing components configured to calculate physiological parameters, such as oxygen saturation. Additionally or alternatively, in some embodiments, the sensor 14 may include the one or more processing components configured to calculate the accuracy specification. The sensor 14 may have varying levels of processing power, and may output data in various stages to the monitor 12. For example, insome embodiments, the data output to the monitor 12 may be analog signals, such as detected light signals (e.g., pulse oximetry signals or regional saturation signals), or processed data.

[0032] Further, in some embodiments, the sensor 14 may include a battery to provide power to components of the sensor 14. For example, the sensor 14 may be configured to operate in a wireless mode and, at times, may not receive power from the monitor 12 while operating in the wireless mode. In some embodiments, the battery may be a rechargeable battery such as, for example, a lithium ion, a lithium polymer, a nickel-metal hydride, a nickel-cadmium battery, or any other suitable rechargeable battery. In other embodiments, any suitable power source may be utilized, such as, one or more capacitors or an energy harvesting power supply (e.g., a motion generated energy harvesting device, thermoelectric generated energy harvesting device, or any other suitable energy harvesting power supply).

[0033] Turning to FIG. 2, a simplified block diagram of the medical monitoring system 10 is illustrated in accordance with an embodiment. As described herein, the sensor 14 includes the emitter 16 and the detector 18. The emitter 16 includes two light emitting diodes (LEDs) that are configured to emit at least two wavelengths of light, e.g., a red LED 28 configured to emit wavelengths of light within the red spectrum and an infrared (IR) LED 30 configured to emit wavelengths of light within the infrared or near infrared spectrum. In one embodiment, the LEDs 28, 30 emit light in a range of about 600 nanometers (nm) to about 1000 nm. In one embodiment, the red LED 28 is configured to emit light between approximately 600 nm and 735 nm, and the IR LED 30 is configured to emit light between approximately 800 nm and 1000 nm. It should be noted that the emitter 16 may also transmit 3, 4, or 5 or more wavelengths of light in any suitable application.

[0034] As discussed in more detail herein, a light drive circuitry 31 of the monitor 12 may provide respective drive currents to the LEDs 28, 30 to cause the LEDs 28, 30 to emit respective wavelengths of light. It should be understood that, as used herein, the term "light" may refer to one or more of ultrasound, radio, microwave, millimeter wave, infrared, nearinfrared, visible, ultraviolet, gamma ray or X-ray electromagnetic radiation, and may also include any wavelength within the radio, microwave, infrared, visible, ultraviolet, or X-ray spectra, and that any suitable wavelength of light may be appropriate for use with the present disclosure.

[0035] The emitter 16 emits light that passes through blood perfused tissue, and the detector 18 detects the light as reflected or transmitted by the tissue. The emitter 16 and the detector 18 may be arranged in a transmission configuration or a reflectance configuration with respect to one another. In the transmission configuration, the light enters the detector 18 afterpassing through the tissue of the patient. In the reflectance configuration, the light is reflected by elements in the tissue of the patient to enter the detector 18. In any case, the detector 18 may generate a signal (e.g., PPG signal) indicative of an intensity of the light received at the detector 18, and the detector 18 may send the signal to the monitor 12.

[0036] A signal representing light intensity versus time or a mathematical manipulation of this signal (e.g., a scaled version thereof, a log taken thereof, a scaled version of a log taken thereof) may be referred to as the PPG signal. Additionally, the term “PPG signal,” as used herein, may also refer to an absorption signal (e.g., representing an amount of light absorbed by the tissue) or any suitable mathematical manipulation thereof. The amount of light detected or absorbed may then be used to calculate any of a number of physiological parameters, including oxygen saturation (e.g., the saturation of oxygen in pulsatile blood, SpO2), an amount of a blood constituent (e.g., oxyhemoglobin), and / or a physiological rate (e.g., pulse rate or respiration rate; when each individual pulse or breath occurs). For SpO2, red and infrared (IR) wavelengths may be used because it has been observed that highly oxygenated blood will absorb relatively less Red light and more IR light than blood with a lower oxygen saturation. By comparing the intensities of two wavelengths at different points in the pulse cycle, it is possible to estimate the blood oxygen saturation of hemoglobin in arterial blood, such as from empirical data that may be indexed by values of a ratio, a lookup table, from curve fitting, or other interpolative techniques.

[0037] As shown, the sensor 14 also includes one or more processors 32 (collectively referred to herein as a processor for convenience) and one or more memory devices 34 (collectively referred to herein as a memory for convenience). The memory 34 may include or be an add-only memory, a rewriteable integrated circuit, or other suitable memory type. The processor 32 may include a processing system or processing circuitry to perform operations and execute instructions stored in the memory 34. Further, at least a portion of the memory 34 is erasable and reprogrammable. For example, the memory 34 may include an erasable programmable read-only memory (EPROM), which is erasable and reprogrammable, and thus enables a user to provide inputs to write data to it. The memory 34 stores information about the sensor 14, such as a type of sensor, an original accuracy specification, a constant, a modifier, calibration information, and so forth. Together, the original accuracy specification, the constant, and the modifier may be considered accuracy specification data and may indicate the accuracy specification for the sensor 14.

[0038] When accessed by the monitor 12, the information about the sensor 14 may enable the monitor 12 to calculate oxygen saturation and / or other physiological parameters using thesignal received from the detector 18. Further, when accessed by the monitor 12, the original accuracy specification, the constant, and the modifier may enable the monitor 12 to determine the accuracy specification for the sensor 14. In certain embodiments, the sensor 14 may include sensing components in addition to, or instead of, the emitter 16 and the detector 18. For example, in one embodiment, the sensor 14 may include one or more actively powered electrodes (e.g., four electrodes) to obtain an electroencephalography signal.

[0039] As described herein, the memory 34 stores the original accuracy specification, the constant, and the modifier. For example, the memory 34 stores a bitstream (including individual bits) representative of the original accuracy specification, the constant, and the modifier. The memory 34 is encrypted to protect data, such as calibration data, of the sensor 14. That is, at least some information stored in the memory 34 is converted into a secure format to prevent unauthorized access (e.g., block access unless provide an encryption key to decode encrypted data). However, a portion of the memory 34, which includes the bits that are representative of the modifier is unencrypted. That is, the portion of the memory 34 is accessible and understandable without decryption (e.g., enable access without an encryption key). In this manner, the portion of the memory 34 including the modifier may be accessed, such as by a user or manufacturer, to be rewritten (e.g., adjusted), while the encrypted portion remains protected. In certain embodiments, the original accuracy specification, the constant, or both may be encrypted and blocked from unauthorized access. However, it should be appreciated that the original accuracy specification, the constant, or both may instead be in the portion of the memory 34 to enable access and adjustment of such accuracy specification data.

[0040] Additionally, the memory 34 may store bits (e.g., 2 bit-values) indicative of numerical values of each of the original accuracy specification, the constant, and the modifier. For example, bits of ‘00’ may be associated with one, ‘01’ may be associated with two, ‘ 10’ may be associated with three, and ‘ 11’ may be associated with four. As described herein, the memory 34 may include or be the add-only memory. Therefore, the portion of the memory 34 may be rewritten to change at least one bit from ‘ 1 ’ to ‘ 0 ’ . However, the at least one bit may not be rewritten from ‘0’ to ‘ 1 ’ . That is, once the bit is set to ‘O’, the bit cannot be reverted to ‘ 1 ’ . Thus, during initial manufacture, the bits for the modifier that are rewritable may be set to ‘ 11 ’ . In this manner, either a first bit of the modifier, a second bit of the modifier, or both, may later be modified to adjust a value of the modifier that is utilized to calculate the accuracy specification (e.g., to adjust the original accuracy specification; to determine the adjusted accuracy specification).

[0041] As shown, the monitor 12 includes one or more processors 40 (collectively referred to herein as a processor for convenience), a memory 42, and the display 24. The processor 40 may include a processing system or processing circuitry to perform operations and execute instructions stored in the memory 42. The processor 40 may process the signal received from the detector 18, such as by performing synchronized demodulation, amplification, and filtering of the signal. The processor 40 may process the signal received from the detector 18 to calculate one or more physiological parameters, such as the oxygen saturation, using various algorithms. Coefficients utilized in the algorithms may be accessed by the processor 40 from the memory 34 or determined by the processor 40 based at on the calibration information of the sensor 14, for example.

[0042] Additionally or alternatively, the processor 40 may receive and process the bitstream that includes the bits of each of the original accuracy specification, the modifier, and the constant. The processor 40 may access a table that associates the bits with the numerical values. For example, as set forth herein, the bits of ‘00’ may be associated with one, ‘01’ may be associated with two, ‘ 10’ may be associated with three, and ‘ 11’ may be associated with four. The processor 40 may access the table from the memory 42 of the monitor 12, receive the table from the memory 34 of the sensor 14, or from any other source. In any case, the processor 40 may use the table to determine respective numerical values for the original accuracy specification, the modifier, and the constant. Then, the processor 40 may use the respective values to determine the accuracy specification (e.g., adjust the original accuracy specification), such as by using various algorithms. In some embodiments, the bitstream may be encoded by the sensor 14 before transmission, and the processor 40 may interpret the received bitstream according to the encoding scheme. For example, the encoding scheme may define accuracy bits that correspond to the original accuracy specification, constant bits that correspond to the constant, and modifier bits that correspond to the modifier within the bitstream.

[0043] In some embodiments, the monitor 12 may already have the constant stored in the memory 42 of the monitor 12. Therefore, the monitor 12 may receive the bits indicative of the original accuracy specification and the modifier from the sensor 14 and may use the constant stored in the memory 42 to determine the accuracy specification. It should be noted that the processor 40 may be embodied wholly or in part as software, hardware, or both.

[0044] As shown, the monitor 12 includes a time processing unit (TPU) 44, which may be controlled by the processor 40 and is configured to provide timing control signals to the light drive circuitry 31 and optionally to other parts of the medical monitoring system 10. Thelight drive circuitry 31 may control when the red LED 28 and the IR LED 30 are illuminated and / or a drive current provided to the red LED 28 and the IR LED 30. It should be appreciated that one or more functions or components of the monitor 12 disclosed herein may also be implemented directly in the sensor 14, or by any other suitable device.

[0045] With the foregoing in mind, FIG. 3 is a block diagram illustrating an example algorithm 50 for adjusting an original accuracy specification 52, in accordance with an aspect of the present disclosure. While the algorithm 50 is described herein as being performed or utilized by the monitor 12 of the medical monitoring system 10 of FIG. 1, it should be noted that the algorithm 50 may be performed or utilized by any other suitable device, such as the sensor 14 employed in the medical monitoring system 10 of FIG. 1.

[0046] In operation, the monitor 12 receives the accuracy bits, the constant bits, and the modifier bits from the sensor 14. The monitor 12 then determines the original accuracy specification 52 based on the accuracy bits, a constant 54 based on the constant bits, and a modifier 56 based on the modifier bits. As an example, each of the bits may represent numerical values. Thus, the monitor 12 may determine the numerical values associated with each of the accuracy bits, the constant bits, and the modifier bits. The monitor 12 obtains (e.g., determines) an adjustment value by performing a subtraction operation 60 (e.g., a deduction) using the constant 54 and the modifier 56. That is, the modifier 56 is subtracted from the constant 54 to obtain the adjustment value.

[0047] After obtaining the adjustment value, the monitor 12 performs an addition operation 62 to add the adjustment value to the original accuracy specification 52. The addition operation 62 of the original accuracy specification 52 and the adjustment value results in an accuracy specification 64. Moreover, the monitor 12 displays the accuracy specification 64 via the display 24. Notably, at manufacturing and for initial use of the sensor 14, the constant 54 and the modifier 56 may be set to provide the adjustment value of zero. Accordingly, when the monitor 12 performs the algorithm 50, the monitor 12 determines that the accuracy specification 64 is equal to the original accuracy specification 52. However, after remanufacturing, the modifier 56 may be changed such that the constant 54 and the modifier 56 provide a non-zero adjustment value (e.g., with a value of one, two, or three).Accordingly, when the monitor 12 performs the algorithm 50, the monitor 12 determines that the accuracy specification 64 is different (e.g., greater) than the original accuracy specification 52. Additional details with regard to determining the accuracy specification 64 will be described below with respect to FIGS. 4-6.

[0048] As described herein, the memory 34 stores the bitstream of the original accuracy specification 52 (e.g., accuracy bits), the constant 54 (e.g., constant bits), and the modifier 56 (e.g., modifier bits). Further, a portion of the memory 34 of the sensor 14, which includes the modifier 56, may be adjusted based on a change detected or identified in a measured accuracy specification (e.g., measured via testing processes) after remanufacture. For example, the change may correspond to an increase in the measured accuracy specification after remanufacture (e.g., less accurate, such as three percent RMSD instead of two percent RMSD). With the foregoing in mind, FIG. 4 is an example illustration of the bitstream that may be stored in the memory 34 of the sensor 14 employed in the medical monitoring system 10 of FIG. 1, in accordance with an aspect of the present disclosure.

[0049] As illustrated in FIG. 4, the memory 34 includes a bitstream 70 (e.g., a binary representation), which includes bits of the original accuracy specification 52 and bits of the modifier 56. The most significant bits (e.g., leftmost bits) of the bitstream 70 are representative of the original accuracy specification 52. Moreover, the least significant bits (e.g., rightmost bits) of the bitstream 70 are representative of the modifier 56. Additionally, as shown in FIG. 4, each of the respective bits of the original accuracy specification 52 and the modifier 56 may be associated with a numerical value. For example, the bits of ‘00’ may be associated with one, ‘01’ may be associated with two, ‘ 10’ may be associated with three, and ‘ 11’ may be associated with four. It should be noted that although the original accuracy specification 52 and the modifier 56 are shown as being represented by two bits, any suitable number of bits may be used to represent the original accuracy specification 52, the constant 54, and the modifier 56.

[0050] In the illustrated example, the bits of the modifier 56 are ‘ 11’. Thus, with reference to the associated numerical values, the modifier 56 is equal to four. In addition, the bits of the constant 54 transmitted to the monitor 12 or otherwise accessed by the monitor 12 may also be equal to four. In this manner, when the monitor 12 receives the original accuracy specification 52, the constant 54, and the modifier 56, and then subtracts the modifier 56 from the constant 54, the adjustment value is zero. Therefore, there would be no adjustment to the original accuracy specification 52. Indeed, the original accuracy specification 52 plus the adjustment value of zero would be equal to the original accuracy specification 52. This may be the bitstream stored at manufacture of the sensor 14.

[0051] However, if after remanufacture, the measured accuracy specification of the sensor 14 increases by one (e.g., 1 RMSD), then the modifier 56 may be adjusted to cause the monitor 12 to determine the adjustment value of one and to result in the accuracy specification 64being an adjusted accuracy specification that is one more than the original accuracy specification 52. The RMSD is a measure of an average deviation between the values predicted by a model or a measurement and actual observed values. For example, when applied to the accuracy specification, the RMSD is used to quantify the overall accuracy or precision of the sensor 14 in measuring values. For example, a smaller RMSD would indicate that readings of the sensor 14 are closer to true values being measured. However, a larger RMSD would indicate that the readings of the sensor 14 deviate more significantly from the true values. Therefore, updating the accuracy specification to accurately reflect the increase in the RMSD is beneficial for manufacturers and for clinicians because assessing accuracy aids in facilitation of evaluation of patients. Further, updating and storing the accuracy specification (e.g., the bitstream 70 that, when processed, provides the accuracy specification 64) on the sensor 12 provide various additional advantages, such as by enabling transmission of the accuracy specification to the monitor 14 for display for visualization by the clinicians.

[0052] The portion of the memory 34 including the modifier 56 may be rewritten by changing at least one bit of modifier bits from a ‘ 1 ’ to a ‘0’ . For example, the second bit of the modifier 56 may be changed or adjusted from a ‘ 1 ’ to a ‘0’ . Thus, the adjusted bits of the modifier 56 are ‘ 10’, which as shown in the table of FIG. 4, is equal to three. The modifier 56 may be rewritten based on any of a variety of inputs. In some embodiments, the modifier 56 may be rewritten automatically by the processor 32 of the sensor 14, after or in response to input of the measured accuracy specification via a testing system. Additionally or alternatively, the modifier 56 may be rewritten via a user input. For example, the user may identify the bit or bits of the modifier to adjust and provide the user input for the identified bit or bits. The input may include toggling a bit (e.g., changing 1 to 0) or setting (e.g., assigning, defining) a specific value (e.g., 0) for the bit.

[0053] After this change to the modifier 56, when the monitor 12 receives the original accuracy specification 52, the constant 54, and the modifier 56, and subtracts the modifier 56 from the constant 54, the adjustment value is one. The adjustment value is then added to the original accuracy specification 52 to account for the increase relative to the original accuracy specification 52 after remanufacture. Therefore, the accuracy specification 64 is the adjusted accuracy specification, which in this case is the original accuracy specification 52 plus one. Accordingly, embodiments described herein enable the sensor 14 to transmit bit values that enable determination and display of the accuracy specification 64, including after the sensor 14 is remanufactured, such as to account for and reflect a change in the measured accuracyspecification. Additionally, embodiments described herein enable a clinician to ensure proper utilization of the sensor 14 and to be informed as to whether the sensor 14 meets specific accuracy specification standards set by regulatory authorities, for example.

[0054] FIG. 5 is a flow diagram of a method 90 for adjusting modifier bits based on a change in an accuracy specification of a sensor, in accordance with an aspect of the present disclosure. The method 90 disclosed herein includes various steps represented by blocks. It should be noted that at least some steps of the method 90 may be performed as an automated procedure by a system, such as the medical monitoring system 10 of FIG. 1. Further, certain steps or portions of the method 90 may be performed by certain devices, such as the sensor 14 (e.g., the processor 32). Although the flow chart illustrates the steps in a certain sequence, it should be understood that the steps may be performed in any suitable order and certain steps may be carried out simultaneously, where appropriate.

[0055] At block 92, a processor of the sensor instructs storage of an original accuracy specification (e.g., a percent error) in accuracy bits in a memory of the sensor. As described herein, the memory also includes a constant in constant bits and a modifier in modifier bits. At block 94, the processor of the sensor instructs adjustment of the modifier bits based on and to reflect a change in the accuracy specification, such as after remanufacture. For example, after remanufacture, the accuracy specification may increase as measured via testing processes. Thus, the processor adjusts the modifier bits to change a numerical value of the modifier. As an example, the modifier bits may include two bits and either a first bit, a second bit, or both, may be changed. In some embodiments, the change in the accuracy specification may be identified by the sensor (e.g., via signals received from a testing system) and the adjustment of the modifier bits may be performed automatically via the processor of the sensor. In other embodiments, a user may provide user inputs to adjust the modifier bits (e.g., via the user inputs to the testing system or other monitor coupled to the sensor; via the user inputs at keys or other input devices of the sensor).

[0056] Further, in some embodiments, the bitstream (e.g., the accuracy bits, the constant bits, and the modifier bits) may be encoded by the processor of the sensor into a format suitable for a communication channel between the sensor and a monitor. At block 96, the processor of the sensor then instructs transmission of the accuracy bits, the constant bits, and the modifier bits (e.g., adjusted modifier bits) to the monitor. For example, the sensor may be coupled to the monitor via a cable, and the processor of the sensor may instruct transmission of the accuracy bits, the constant bits, and the modifier bits via the cable. As anotherexample, the sensor may transmit the accuracy bits, the constant bits, and the modifier bits wirelessly using a wireless transceiver.

[0057] FIG. 6 is a flow diagram of a method for displaying an accuracy specification, such as an adjusted accuracy specification, via a monitor, in accordance with an aspect of the present disclosure. The method 110 disclosed herein includes various steps represented by blocks. It should be noted that at least some steps of the method 90 may be performed as an automated procedure by a system, such as the medical monitoring system 10 of FIG. 1. Further, certain steps or portions of the method 110 may be performed by certain devices, such as the monitor 12 (e.g., the processor 40) and / or the sensor 14 (e.g., the processor 32). Although the flow chart illustrates the steps in a certain sequence, it should be understood that the steps may be performed in any suitable order and certain steps may be carried out simultaneously, where appropriate.

[0058] At block 112, the processor of the monitor receives the accuracy bits, the constant bits, and the modifier bits from the sensor. In some embodiments, if the bitstream was encoded by a transmitting device (e.g., the sensor), the processor of the monitor may decode the bitstream by reversing the encoding to obtain the original bit data. At block 114, the processor of the monitor determines an original accuracy specification based on the accuracy bits. Further, at block 116, the processor of the monitor determines a constant based on the constant bits. Moreover, at block 118, the processor of the monitor determines a modifier based on the modifier bits. At block 120, the processor of the monitor deducts the modifier from the constant to obtain an adjustment value.

[0059] At block 122, the processor of the monitor adjusts the original accuracy specification by adding the adjustment value to the original accuracy specification to determine the accuracy specification, which in this example is an adjusted accuracy specification. In this manner, the adjusted accuracy specification accurately corresponds to the accuracy specification of the remanufactured sensor. At block 124, the processor of the monitor displays (e.g., presents) the adjusted accuracy specification. As an example, the processor of the monitor may render a numerical percentage associated with the adjusted accuracy specification on the display of the monitor.

[0060] It should be noted that although the method 110 is described as being performed by the monitor, in some embodiments, certain steps or portions of the method 110 may be performed by the sensor. For example, the sensor may perform blocks 112-122 and then transmit the adjusted accuracy specification to the monitor for the monitor to display at block 124. Indeed, the memory of the sensor may store instructions to process the bitstream withthe adjusted modifier. The processor of the sensor may be configured to execute such instructions. For example, the processor of the sensor may execute instructions to determine the original accuracy specification based on accuracy bits, determine the constant based on constant bits, and determine the modifier based on modifier bits. The processor of the sensor deducts the modifier from the constant to obtain an adjustment value. Further, the processor of the sensor adjusts the original accuracy specification to determine an adjusted accuracy specification. The processor of the sensor may then transmit the adjusted accuracy specification to the monitor for display by the monitor.

[0061] Accordingly, embodiments described herein enable a portion of the memory of the sensor, which includes the modifier, to be adjusted to enable the monitor to determine the accuracy specification of the sensor even after remanufacturing of the sensor. Further, architecture of the memory may limit or block adjustment of certain data, such as the calibration data, the original accuracy specification, and so forth. Moreover, the architecture of the memory and algorithms utilized to determine the accuracy specification may limit or block certain changes, such as by limiting a number of times the portion of the memory or the modifier bits can be changed (e.g., via blocking change from “0” to “1”), blocking an increase to the original accuracy specification (e.g., by limiting numerical values available for the modifier, and then by subtracting the modifier from the constant to determine the adjustment value), and so forth.

[0062] As described herein, the sensor transmits the bitstream representative of the accuracy specification for the sensor (e.g., as measured via testing processes), including the accuracy specification of the remanufactured sensor (e.g., the adjusted accuracy specification that varies from the original accuracy specification) to the monitor. The monitor may process the bitstream to determine the accuracy specification, and the monitor may display the accuracy specification. Additionally, embodiments described herein enable the clinician to view the accuracy specification, which may allow the clinician to verify proper utilization of the sensor, make informed decisions about the patient’s therapy or overall medical condition, and be informed as to whether the sensor meets specific accuracy specification standards, for example.

[0063] While the disclosure may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the embodiments provided herein are not intended to be limited to the particular forms disclosed. Rather, thevarious embodiments may cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as defined by the following appended claims.

[0064] The following examples are illustrative of the techniques described herein.

[0065] Example 1. A medical monitoring system, comprising: a sensor comprising a sensor memory that stores accuracy data; and a monitor comprising: a port to communicatively couple to the sensor to receive the accuracy data; a display; and monitor processing circuitry to determine an accuracy specification based on the accuracy data and instruct presentation of the accuracy specification on the display.

[0066] Example 2. The medical monitoring system of Example 1, wherein the sensor comprises sensor processing circuitry to adjust the accuracy data to adjusted accuracy data based on a reprocessing of the sensor.

[0067] Example 3. The medical monitoring system of Example 2, comprising the monitor processing circuitry to determine an adjusted accuracy specification based on the adjusted accuracy data and instruct presentation of the adjusted accuracy specification on the display.

[0068] Example 4. The medical monitoring system of Example 1, wherein the accuracy data comprises an original accuracy specification, a constant, and a modifier.

[0069] Example 5. The medical monitoring system of Example 4, comprising the monitor processing circuitry to deduct the modifier from the constant to obtain an adjustment value, and to add the adjustment value to the original accuracy specification to determine the accuracy specification.

[0070] Example 6. The medical monitoring system of Example 1, comprising the monitor processing circuitry to determine a physiological parameter and instruct presentation of the physiological parameter with the accuracy specification on the display.

[0071] Example 7. The medical monitoring system of Example 1, wherein the sensor memory comprises an erasable programmable read-only memory (EPROM).

[0072] Example 8. The medical monitoring system of Example 1, wherein a first portion of the sensor memory is encrypted and a second portion of the sensor memory is unencrypted.

[0073] Example 9. The medical monitoring system of Example 8, wherein the second portion of the sensor memory comprises a modifier bit that represents a modifier to adjust an original accuracy specification of the sensor based on a reprocessing of the sensor.

[0074] Example 10. The medical monitoring system of Example 9, wherein the sensor comprises sensor processing circuitry to adjust the modifier bit by a toggle of the modifier bit or by an assignment of a value for the modifier bit.

[0075] Example 11. The medical monitoring system of Example 1, wherein the accuracy specification indicates a root-mean-square deviation between a measured value of a physiological parameter measured by the sensor and a true value of the physiological parameter.

[0076] Example 12. The medical monitoring system of Example 1, wherein the sensor comprises a pulse oximetry sensor.

[0077] Example 13. A method of operating a medical monitoring system, comprising: receiving, at a processor and from a memory of a sensor, accuracy data for the sensor; determining, at the processor, an accuracy specification for the sensor based on the accuracy data; and instructing, via the processor, display of the accuracy specification on a display.

[0078] Example 14. The method of Example 13, comprising: receiving, at the processor or at another processor and from the memory of the sensor, adjusted accuracy data for the sensor after a reprocessing of the sensor; determining, at the processor or the another processor, an adjusted accuracy specification for the sensor based on the adjusted accuracy data; and instructing, via the processor or via the another processor, display of the adjusted accuracy specification on the display.

[0079] Example 15. The method of Example 14, wherein receiving the adjusted accuracy data for the sensor after the reprocessing of the sensor comprises receiving an accuracy bit indicative of an original accuracy specification of the sensor and a modifier bit indicative of a modifier to adjust the original accuracy specification of the sensor based on the reprocessing of the sensor.

Claims

CLAIMSWhat is claimed is:

1. A medical monitoring system (10), comprising: a sensor (14) comprising a sensor memory (34) that stores accuracy data; and a monitor (12) comprising: a port to communicatively couple to the sensor (14) to receive the accuracy data; a display (24); and monitor processing circuitry (40) to determine an accuracy specification (64) based on the accuracy data and instruct presentation of the accuracy specification (64) on the display (24).

2. The medical monitoring system (10) of claim 1, wherein the sensor (14) comprises sensor processing circuitry (32) to adjust the accuracy data to adjusted accuracy data based on a reprocessing of the sensor (14).

3. The medical monitoring system (10) of any of claims 1 or 2, comprising the monitor processing circuitry (40) to determine an adjusted accuracy specification based on the adjusted accuracy data and instruct presentation of the adjusted accuracy specification on the display (24).

4. The medical monitoring system (10) of any of claims 1 to 3, wherein the accuracy data comprises an original accuracy specification (52), a constant (54), and a modifier (56).

5. The medical monitoring system (10) of claim 4, comprising the monitor processing circuitry (40) to deduct the modifier (56) from the constant (54) to obtain an adjustment value, and to add the adjustment value to the original accuracy specification (52) to determine the accuracy specification (64).

6. The medical monitoring system (10) of any of claims 1 to 5, comprising the monitor processing circuitry (40) to determine a physiological parameter and instruct presentation of the physiological parameter with the accuracy specification on the display (24).

7. The medical monitoring system (10) of any of claims 1 to 6, wherein the sensor memory (34) comprises an erasable programmable read-only memory (EPROM).

8. The medical monitoring system (10) of any of claims 1 to 7, wherein a first portion of the sensor memory (34) is encrypted and a second portion of the sensor memory (34) is unencrypted.

9. The medical monitoring system (10) of claim 8, wherein the second portion of the sensor memory (34) comprises a modifier bit that represents a modifier (56) to adjust an original accuracy specification (52) of the sensor (14) based on a reprocessing of the sensor (14).

10. The medical monitoring system (10) of any of claims 1 to 9, wherein the sensor (14) comprises sensor processing circuitry (32) to adjust the modifier bit by a toggle of the modifier bit or by an assignment of a value for the modifier bit.

11. The medical monitoring system (10) of any of claims 1 to 10, wherein the accuracy specification (64) indicates a root-mean-square deviation between a measured value of a physiological parameter measured by the sensor (14) and a true value of the physiological parameter.

12. The medical monitoring system (10) of any of claims 1 to 11, wherein the sensor (14) comprises a pulse oximetry sensor.

13. A method of operating a medical monitoring system (10), comprising: receiving, at a processor (40) and from a memory (34) of a sensor (14), accuracy data for the sensor (14); determining, at the processor (40), an accuracy specification (64) for the sensor (14) based on the accuracy data; and instructing, via the processor (40), display of the accuracy specification (64) on a display (24).

14. The method of claim 13, comprising: receiving, at the processor (40) or at another processor and from the memory (34) of the sensor (14), adjusted accuracy data for the sensor (14) after a reprocessing of the sensor (14); determining, at the processor (40) or the another processor, an adjusted accuracy specification for the sensor (14) based on the adjusted accuracy data; and instructing, via the processor (40) or via the another processor, display of the adjusted accuracy specification on the display (24).

15. The method of any of claims 13 or 14, wherein receiving the adjusted accuracy data for the sensor (14) after the reprocessing of the sensor (14) comprises receiving an accuracy bit indicative of an original accuracy specification (52) of the sensor (14) and a modifier bit indicative of a modifier (56) to adjust the original accuracy specification (52) of the sensor (14) based on the reprocessing of the sensor (14).

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