WO2015038852A1

WO2015038852A1 - Unified display of cardiorespiratory parameters

Info

Publication number: WO2015038852A1
Application number: PCT/US2014/055317
Authority: WO
Inventors: Sean COHEN; Richard Melker
Original assignee: Xhale, Inc.
Priority date: 2013-09-13
Filing date: 2014-09-12
Publication date: 2015-03-19

Abstract

Provided according to embodiments of the invention are physiological parameter display systems that include a multicolor display unit that includes a primary emitter unit configured to emit a hue at or between a first predetermined hue and a second predetermined hue; a controller in communication with the multicolor display unit, wherein the controller is configured to direct the primary emitter unit to display the first predetermined hue if a blood oxygen saturation value of an individual is at or above a predefined upper limit and to display the second predetermined hue if the blood oxygen saturation value for the individual is at or below a predefined lower limit.

Description

UNIFIED DISPLAY OF CARDIORESPIRATORY PARAMETERS

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/877,432, filed

September 13, 2013, the contents of which are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates to biological sensors, and in particular, to graphical displays for use with biological sensors.

BACKGROUND OF THE INVENTION

Anesthesiologists and other medical care providers often have a large volume of data available to assess the physiological state of a patient under care. However, this large volume of data may make it difficult to focus on specific parameters and may cognitively overwhelm the care givers, which may lead to human error or missed signs of adverse physiological trends. In addition, monitoring of numerous patient parameters may be time consuming, and thus, detract from other aspects of patient care.

While there has been some research into graphically displaying physiological parameters to facilitate medical care, there remains a need in the art for improved graphical displays of patient physiological data.

SUMMARY OF EMBODIMENTS OF THE INVENTION

Provided according to embodiments of the present invention are physiological parameter display systems that include a multicolor display unit that includes a primary emitter unit that emits a hue at or between a first predetermined hue and a second predetermined hue and a controller in communication with the multicolor display unit. In some embodiments, the controller is configured to direct the primary emitter unit to display the first predetermined hue if a blood oxygen saturation value of an individual is at or above a predefined upper limit (e.g.,

100%) and to display the second predetermined hue if the blood oxygen saturation value for the individual is at or below a predefined lower limit, and the controller directs the primary emitter unit to display a color having a hue between the first predetermined hue and the second predetermined hue if a blood oxygen saturation value is between the predefined upper limit and the predefined lower limit. Furthermore, in some embodiments, the controller directs the primary emitter unit to vary an emission intensity at a heart rate of the individual. In some cases, the controller correlates a blood oxygen saturation value between the predefined upper limit and the predefined lower limit with a hue between the first predetermined hue and the second predetermined hue. In some cases, the controller correlates the hue between the first

predetermined hue and the second predetermined hue based on the proportion of the difference in the blood oxygen saturation between the predefined upper limit and the predefined lower limit.

In some embodiments of the invention, the physiological parameter display systems further include at least one additional emitter unit, wherein the controller directs the at least one additional emitter unit to change emission color and/or intensity based on respiratory parameters of the individual. In some cases, the controller directs the at least one additional emitter unit to vary emission intensity at a respiration rate of the individual. For example, in some

embodiments, the at least one additional emitter unit comprises an array of emitters, and the controller directs a first set of emitters in the array to change intensity and/or color reflecting a first portion of a breath of the individual, and a second set of emitters in the array to change color and/or intensity at a rate reflecting a second portion of the breath of the individual. In some cases, the at least one additional emitter unit may include an array of emitters, and the controller directs at least a portion of the array of emitters to change in color and/or intensity as a function of a respiratory effort of the individual. Furthermore, in some embodiments, the physiological display system includes a diffuser unit that diffuses light from the primary emitter unit at a respiratory rate of the individual.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a representation of the color wheel with the general categories of color hues listed on the outside of the wheel.

Figures 2A-2E show multicolor display units according to some embodiments of the invention. Figure 2A shows a primary emitter unit 100 having a round shape. Figure 2B shows a primary emitter unit 100 having a triangular shape. Figure 2C shows a primary emitter unit 110 and additional emitter units 120 having a uniform shape and size. Figure 2D shows a primary emitter unit 110 and additional emitter units 120 with varying sizes. Figure 2E shows a primary emitter unit 110 and additional emitter units 120 wherein the primary emitter unit 110 has a different shape than the additional emitter units 120. Figure 3 shows multicolor display unit 100 having a two dimensional configuration.

Figure 4 is a flow chart showing steps in a method according to an embodiment of the invention for iteratively changing the hue value of an emitter unit based on a calculated blood oxygen saturation value.

Figure 5 is a flow chart showing steps in a method according to an embodiment of the invention for varying the emitter intensity of an emitter unit based on an individual's heart rate.

Figure 6 is a flow chart showing steps in a method according to an embodiment of the invention for varying the emitter intensity and color hue of an emitter unit based on the individual's heart rate and blood oxygen saturation.

Figure 7 shows a multicolor display unit 100 according to an embodiment of the invention wherein the color or intensity of the light in an emitter unit may be varied based on respiratory information from the individual.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. However, this invention should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. It will be understood that when an element is referred to as being "on" or "adjacent" to another element, it can be directly on or directly adjacent to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly adjacent" to another element, there are no intervening elements present. It will also be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present. Like numbers refer to like elements throughout the specification.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first element discussed below could be termed a second element without departing from the teachings of the present invention.

Embodiments of the present invention are described herein with reference to schematic illustrations of idealized embodiments of the present invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected.

Physiological Parameter Display Systems

Provided according to embodiments of the present invention are physiological parameter display systems that include a multicolor display unit and a controller for directing the color and/or intensity of the light emitted from the multicolor display unit based on physiological parameters of an individual. The physiological parameter display systems described herein may provide a readily comprehensible indication of the individual's cardio-respiratory status, which may facilitate patient care, for example, in hospital, medical office and home settings.

The multicolor display unit includes one or more emitters that emit light at multiple wavelengths so that the color of at least some of the emitters may be varied based on

cardiorespiratory parameters. Any suitable type of emitter may be used, but in some

embodiments, the emitter is a light-emitting diode (LED), and in some embodiments, a red- green-blue (RGB) LED. Examples of other types of emitters/display types include Liquid Crystal Displays (LCD), Organic LEDs (OLED), Plasma Displays (PD) and Cathode Ray Tube (CRT) Displays. An emitter unit may also be considered a pixel or group of pixels that form part of a larger display. The multicolor display unit includes a primary emitter unit, and optionally, one or more additional emitter units (e.g., 2, 3, 4, 5, 6, etc.). Each emitter unit may convey information regarding a particular physiological parameter. In some cases, a particular emitter unit may convey information regarding more than one physiological parameter, and in some cases, more than one emitter unit may convey information about a single physiological parameter.

Some emitter units may display a wide variety of hues of one or more colors. In particular embodiments, an emitter unit displays incremental hues along a gradient between a first hue and a second hue. As used herein, the term "hue" is meant to refer to the attribute of colors that permits them to be classified as red, yellow, green, blue, or between any contiguous pair of these colors. A hue is considered between to two colors if it falls between the two hues on a color wheel (e.g., a RYB color wheel or RGB color wheel; example shown in Figure 1, which provides a general order of hues around the wheel). Thus, a secondary hue such as orange is between two primary hues (in this case yellow and red), violet is between red and blue, and green is between yellow and blue. The color hue may be any incremental change in hue between the first hue and the second hue, and thus, a large number of incremental differences in color may be present between two hues.

The emitter units may also display a variety of light intensities. As used herein, the term "intensity" is meant to refer to a perceived increase or decrease in brightness of an emitter, and includes increases and decreases in luminous flux and luminous intensity. A change of intensity also refers to the change from no emission to a state of emission, and vice versa, so that, for example, flashing of an emitter on and off would refer to a change or variation of the intensity of the emitter.

The emitters in the multicolor display unit may be arranged in a variety of different configurations, and any suitable configuration may be used. For example, referring to Figure 2, the multicolor display unit 100 may include a primary emitter unit 110 of any shape, such as a round (shown in Fig. 2A) or another shape (e.g., triangular, as shown in Fig. 2B). While the primary emitter unit 110 may include only a single emitter, in some embodiments, more than one emitter (e.g., LED) may form the primary emitter unit 110. As used herein, emitters are considered to be part of the same "emitter unit" if they are close to or adjacent to one another and act in concert (i.e., are substantially the same hue and intensity at substantially the same time).

Referring to Figures 2C-2E, in some embodiments, the multicolor display unit 100 includes the primary emitter unit 110 and at least one additional emitter unit(s) 120. The at least one additional emitter unit(s) 120 may be in any suitable configuration. For example, referring to Fig. 2C, in some cases, the at least one additional emitter unit(s) 120 are of uniform shape and size. However, in other embodiments, as shown in Fig. 2D, the at least one additional emitter unit(s) 120 of the multicolor display unit 100 are of varying sizes. The at least one additional emitter unit(s) 120 may also be of any shape, as shown in Fig. 2E, and the shapes may be the same or different as that in the primary emitter unit 110. Thus, various shapes and sizes may be used for both the primary emitter unit 110 and at least one additional emitter unit(s) 120. While the multicolor display unit 100 may be in a linear (ID) configuration, as shown in Figure 2, the multicolor display unit 100 may also be in a variety of two dimensional (e.g., as shown in Figure 3) or even three dimensional configurations.

The controller in the physiological parameter display systems is in communication with the multicolor display unit. The controller is one or more computers, processors, or other devices that may be used to direct (e.g., electronically signal) the primary emitter unit, and optionally at least one additional emitter unit(s), of the multicolor display unit to display particular hues and/or intensities, and at particular rate(s), based on physiological parameters of an individual. The controller is also in communication with a pulse oximeter and/or a processing device related thereto, so that it can receive photoplethysmography (PPG) signals, data and/or calculated physiological parameters related to the PPG signals. The multicolor display unit, controller and/or pulse oximeter may be one device, or they may be two or more separate devices. The pulse oximeter may be used solely for the blood oxygen saturation measurements or it may be used for determining other physiological parameters such as cardiac and respiratory parameters, as discussed further below. While any suitable pulse oximeter (or PPG sensor) may be used, in some embodiments, the pulse oximeter is a central site pulse oximeter, such as the nasal alar PPG sensors described in Application Serial No. 13/650,310, filed October 10, 2012, entitled "Photoplethysmography Sensors," incorporated by reference herein in its entirety herein. Other physiological sensors may be in communication with the controller including other respiration detectors such as thermistors, thermocouples, RTDs, moisture detectors, capnometers, microphones, pressure sensors, nasal airway flow detectors, such as nasal flow transducers, NAP, and detectors of vibrations in the ear. Examples of other sensors that may be in communication with the controller include oxygen sensors, pH sensors, blood pressure monitors, breath constituent monitors, blood constituent monitors, heart rate monitors, including ECG leads, and depth of anesthesia monitors. The multicolor display unit may also include one or more emitters configured to display data or parameters obtained from the other physiological sensors.

The term "in communication" includes any communication that may be used to convey signals to and from the controller, including via electronic communication via wires and cables or with wireless communication devices. Any suitable wireless communication component may be used, but in some embodiments, Bluetooth®, WiFi, Zigbee and/or infrared technology may be used.

In some embodiments of the invention, the controller may direct a primary emitter unit to display a particular color hue as an indication of the blood oxygen saturation (e.g., arterial blood oxygen saturation) of the individual. In some embodiments, the controller may also direct the primary emitter unit to vary the intensity of the emitted light at rate reflective of the individual's heart rate. With respect to the change in hue based on blood oxygen saturation, the controller may correlate a first hue with a blood oxygen saturation of 100% (or another predefined upper limit if desired), and a second hue with a predefined lower limit (e.g., 70%, 75%, 80%, 85%, 90%, etc.). The controller may then correlate a certain number of color hues between the first hue and the second hue and with blood oxygen saturation levels between the predefined upper limit (100% in this example) and the predefined lower limit. Thus, as the blood oxygen saturation of an individual decreases from 100%, the controller directs the primary emitter unit to emit light slightly varying from the first predetermined hue (that for 100% blood oxygen saturation) to reflect this decrease in saturation. The controller then correlates further decreases in blood oxygen saturation to a different hue, or a series of different hues, each incrementally closer to the predetermined second hue. When the predefined lower limit of the blood oxygen saturation is reached, then hue emitted has then transitioned fully to the second predetermined hue. The process may be iterative as shown in Figure 4. The controller may calculate the blood oxygen saturation level (Sp0₂) for the individual (400), the controller may then correlate the calculated Sp0₂ value with a hue (hue "x") at or between a first predetermined hue and a second predetermined hue (410). Then, the controller may send a signal to the primary emitter unit to emit hue x (420). The primary emitter unit may then emit light at the correlated hue value x (430). The process of calculating the Sp02, correlating the hue value and directing the emitter to emit light at the correlated hue value may be iterated continuously, or at preselected intervals, to provide an updated status on the blood oxygen saturation of the patient.

As a particular example, in some embodiments, the first predetermined hue is a true red hue, and the controller correlates this hue to 100% blood oxygen saturation. In this example, the second predetermined hue is a true blue hue, and the controller correlates this hue to a predefined lower limit, for example, 85% blood oxygen saturation. Thus, if the individual using the physiological parameter display has a 100% blood oxygen saturation, the controller will direct the primary emitter unit to emit light at the true red hue. If the individual's blood oxygen saturation level decreases, the controller will then direct the primary emitter unit to emit light that is less a true red, but having more violet undertones. As the blood oxygen saturation decreases further, the controller may direct the primary emitter unit to emit violet light. As desaturation continues, controller directs the emission of indigo light. When the blood oxygen saturation reaches the predefined limit (85%), the controller directs the emitter to emit light that is the predefined true blue. Thus, a medical care provider may be able to visually assess the blood oxygen saturation based on the color hue between red (fully oxygenated blood) and blue (predefined lower limit) at a glance. As described above with respect to Figure 4, this process may be performed iteratively to provide continuous monitoring and graphic visualization of the patient's blood oxygen saturation status.

In another particular example, the first predetermined hue may be green, and correlate with 100% (or other upper limit) blood oxygen saturation, and the second predetermined hue is red, which correlates to a predefined lower limit of blood oxygen saturation, and so the hue may transition from green to yellow to orange to red as blood oxygen saturation decreases. In some cases, particular intermediate hues may not be shown. For example, in some embodiments, the emitter may vary between green to yellow to red, without emission of any orange hue. As the primary emitter unit changes hue based on the blood oxygen saturation, at least some of the emitted light may also change intensity (e.g., flash) at a rate corresponding to the individual's heart rate. The heart rate information may be obtained by any physiological monitor, but in some embodiments, the heart rate is also obtained from the pulse oximeter/PPG sensor. For example, in some embodiments, the controller directs the primary emitter unit to vary emission intensity of the light based on heart rate obtained by a raw, isolated or processed photoplethysmography waveform generated by the pulse oximeter unit. For example, referring to Figure 5, the pulse oximeter may obtain a PPG waveform (500), the controller may correlate peaks (or other features) in the signal to the pulse or heart rate of the individual (510). Thus, when the controller receives a signal from the pulse oximeter indicative of the pulse, it directs the primary emitter unit to change/vary intensity to reflect the heart beat (520). The primary emitter unit then varies the intensity accordingly (530). The position in the cardiac cycle as determined by the portion of the PPG waveform may also be used, so that if, for example, when the PPG waveform is sampled, no maximium has been measured, the controller directs the primary emitter unit to hold the emission, but when a maximum in the signal is obtained (i.e., the heart beats), the controller directs the primary emitter unit to emit light (at the appropriate hue based on the blood oxygen saturation). This process may be iterated continuously, or at preselected intervals, and allow for visual monitoring of the individual's heart rate. Ideally, the light emitted from the primary emitter unit varies intensity instantaneously or in real-time to the individual's heart beat, but in some cases, a delay between a heartbeat and the emission intensity change may be present.

The light emission changes of the primary emitter unit due to the blood oxygen saturation and the heart rate may part of the same iterative loop or different iterative loops. Figure 6 provides an example wherein the hue and intensity of the light emitter are updated concurrently. Referring to Figure 6, the Sp0₂ and the position in cardiac cycle (e.g., as determined using the PPG or an ECG waveform) may be determined by a processor or the controller itself (600). The Sp0₂ value may then be correlated with a particular hue value x and the position in the cardiac cycle correlated with a particular emission intensity y (610). Then, the controller may direct the primary emitter unit to emit light at the correlated hue value x with an intensity y (620), and the primary unit may then emit light at hue value x with intensity y (630). In some embodiments of the invention, the controller may also direct at least one additional emitter unit to change color and/or intensity based on at least one additional physiological parameter. In particular embodiments, the controller directs at least one additional emitter unit to change color and/or intensity based on respiratory parameters such as respiration rate and/or respiratory effort.

As an example, referring to Figure 7, which shows the multicolor display unit from

Figure 2C, the primary emitter unit 110 may emit light having a color hue based on the blood oxygen saturation of the individual and may change intensity at a rate reflecting the individual's heart rate. At the same time, the at least one additional emitter unit(s) 120 may emit light to convey information regarding the respiration rate of the individual. For example, in some cases, each of the emitters in the array of the at least one additional emitter unit(s) 120 may change color and/or intensity at a rate reflective of the individual's respiration rate. In such cases, the controller may receive information from the pulse oximeter/PPG sensor related to the inspiration, expiration or respiratory rate of the individual. Then, the controller may direct the at least one additional unit(s) 120, including emitters 700, 710, 720, 730and 740, to emit light at a rate reflective of the respiration rate, or of particular points in the inspiration and/or expiration cycle.

In particular embodiments, all of the at least one additional emitter units 120 emit light at a calculated respiration rate of the individual. In such an embodiment, although the particular emitters may emit different colors or intensities of light, the emitters flash or change intensity and/or color at the same rate. In other embodiments, the at least one additional emitter unit(s) 120 form an array and may emit light at slightly different rates to reflect different portions of the individual's breath. For example, a first additional emitter 700 may change light color or intensity correlated to a first portion of an inspiratory breath, a second additional emitter 710 may change light color or intensity correlated to a second portion of the inspiratory breath, a third additional emitter 720 may change light color or intensity correlated to a third portion of the inspiratory breath, a fourth additional emitter 730 may change light color or intensity correlated to a fourth portion of the inspiratory breath, and a fifth additional emitter 740 may change light color or intensity correlated to a fifth portion of the inspiratory breath. Conversely, the fifth additional emitter 740, the fourth additional emitter 730, the third additional emitter 720, the second additional emitter 710 and the first additional emitter 700 may change color and/or intensity sequentially to reflect the different stages of the expiratory breath as well. Fewer or more emitter units may be used to depict the inspiration and/or expiration of the individual, and any portion of the breath cycle could be reflected with the at least one additional emitter unit(s) 120.

In some embodiments, the controller may direct the at least one additional emitter unit 120 to change color and/or intensity in response to the respiratory effort of the individual. Thus, for example, one or more emitter units could increase in intensity and/or change to a different color/hue to reflect an increase in respiratory effort.

The respiratory information discussed above with reference to Figure 7 may be obtained from a pulse oximeter/PPG sensor or may be obtained from one or more additional respiration sensor such as thermistors, thermocouples, RTDs, moisture detectors, capnometers,

microphones, pressure sensors, nasal airway flow detectors, such as nasal flow transducers, NAP, and detectors of vibrations in the ear. Additionally, the respiration rate or respiratory effort may be obtained by analysis of two or more respiration sensors. For example, the pulse oximeter and a thermistor may both obtain respiratory rate and/or respiratory effort, and the controller may use information from both sources to direct the emitter units in the physiological parameter display system.

In some embodiments of the invention, the respiratory information of the individual may be displayed by using a variable diffuser over the primary emitter unit. In some cases, the variable diffuser may diffuse light from the primary emitter unit at a rate corresponding to the respiratory rate of the individual. The intensity or diameter of the diffusing portion of the diffuser may also be varied to display additional information, for example, information regarding the respiratory effort of the individual.

Such systems and devices may be used with any suitable individual, including humans and animals, and may be used to monitor patients in a wide variety of settings including hospital, medical offices and home/personal care settings. In some embodiments of the invention the physiological parameter display devices and systems are portable, and could be manufactured as hand-held devices, badges or other wearable displays. In the drawings and specification, there have been disclosed embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for puiposes of limitation, the scope of the invention being set forth in the following claims.

Claims

We claim:

1. A physiological parameter display system comprising

a multicolor display unit comprising a primary emitter unit that emits a hue at or between a first predetermined hue and a second predetermined hue;

a controller in communication with the multicolor display unit,

wherein the controller is configured to direct the primary emitter unit to display the first predetermined hue if a blood oxygen saturation value of an individual is at or above a predefined upper limit and to display the second predetermined hue if the blood oxygen saturation value for the individual is at or below a predefined lower limit, and wherein the controller directs the primary emitter unit to display a color having a hue between the first predetermined hue and the second predetermined hue if a blood oxygen saturation value is between the predefined upper limit and the predefined lower limit, and

wherein the controller directs the primary emitter unit to vary an emission intensity at a heart rate of the individual.

2. The physiological parameter display system of claim 1, wherein the predefined upper limit is 100%.

3. The physiological parameter display system of claim 1, wherein the controller correlates a blood oxygen saturation value between the predefined upper limit and the predefined lower limit with a hue between the first predetermined hue and the second predetermined hue.

4. The physiological parameter display system of claim 3, wherein the controller correlates the hue between the first predetermined hue and the second predetermined hue based on the proportion of the difference in the blood oxygen saturation between the predefined upper limit and the predefined lower limit.

5. The physiological parameter display system of claim 1, wherein the first predetermined hue is red and the second predetermined hue is blue.

6. The physiological parameter display system of claim 1, wherein the primary emitter unit comprises a red-green-blue (RGB) light emitting diode (LED).

7. The physiological parameter display system of claim 1, wherein the primary emitter unit comprises an LCD display.

8. The physiological parameter display system of claim 1, further comprising at least one additional emitter unit, wherein the controller directs the at least one additional emitter unit to change emission color and/or intensity based on respiratory parameters of the individual.

9. The physiological parameter display system of claim 8, wherein the controller directs the at least one additional emitter unit to vary emission intensity at a respiration rate of the individual.

10. The physiological parameter display system of claim 8, wherein the at least one additional emitter unit comprises an array of emitters, and the controller directs a first set of emitters in the array to change intensity and/or color reflecting a first portion of a breath of the individual, and a second set of emitters in the array to change color and/or intensity at a rate reflecting a second portion of the breath of the individual.

11. The physiological parameter display system of claim 10, wherein the controller directs a third set of emitters in the array to change intensity and/or color reflecting a third portion of the breath of the individual.

12. The physiological parameter display system of claim 8, wherein the at least one additional emitter unit comprises an array of emitters, and wherein the controller directs at least a portion of the array of emitters to change in color and/or intensity as a function of a respiratory effort of the individual.

13. The physiological parameter display system of claim 1, further comprising a diffuser unit that diffuses light from the primary emitter unit at a respiratory rate of the individual.