Pulse oximeter

Abstract

A pulse oximeter measuring the SpO2 level of the user's blood having an outer shell, a monitor connected to the outer shell, the outer shell housing a printed circuit board (PCB) connected to and in data communication with a photodiode, a power source, a red emitter, an infrared emitter, and a green emitter, with the pulse oximeter configured to accommodate a patient's finger, and light data received from the red emitter, infrared emitter, and the green emitter, by the photodiode is transmitted to the PCB and an optimal wavelength is determined for the patient based on the patient's skin tone.

Description

PULSE OXIMETERBACKGROUND OF THE INVENTIONTechnical Field

[0001] This invention is related to pulse oximeters. More specifically, this invention is related to pulse oximetry systems, methods, and devices that compensate for differences in skin tone.Background Information

[0002] Pulse oximetry is a non-invasive measurement of blood oxygen saturation used in the preliminary testing of the vitals in hospital, home, and laboratory settings. A pulse oximeter detects the oxygenated hemoglobin (HbO2) and deoxyhemoglobin (RHb) content within the blood, relying on differences in light absorption. In conventional pulse oximeters, the concentration of HbO2 and RHb and their absorption coefficients are measured using infrared and red light, respectively.

[0003] Pulse oximeters are a crucial component of patient care used to monitor a patient's blood oxygen saturation. However, recent studies show inaccurate measurements in people with darker skin tones. This issue has especially come under the spotlight during the COVID- 19 pandemic, where people of color, mainly Africans and Hispanics, have experienced worse patient outcomes than other ethnic groups. On average the SpO2 levels overestimated the SaO2 levels by an average 1.7% among Asian patients, 1.2% among Black patients, and 1.1% among Hispanic patients, (https: / / jamanetwork.com / joumals / jamaintemalmedicine / article- abstract / 2792653)

[0004] Current pulse oximeters may use a light emitting diode (LED) generator that emits one or more light signals. Another common pulse oximeter incorporates red and infrared light. Yet another pulse oximeter may use two green light sources to detect the oxygen saturation level. Each of these existing pulse oximeters is unable to provide reliable measurements for people of all skin tones.

[0005] The current invention addresses the need for a pulse oximeter to better measure oxygen levels in people across a spectrum of light to dark skin tones.SUMMARY OF THE INVENTION

[0006] The present disclosure is directed toward pulse oximetry systems, methods, and devices that compensate for differences in skin tone.

[0007] In one aspect of the present disclosure provided herein, is a pulse oximeter for measuring the SpO2 concentration in blood having an upper section having a hollow interior housing a photodiode connected to a microcontroller and a display. The upper section is hingedly and pivotally connected to an opposable lower section, the lower section having a hollow interior housing a power source, an infrared light emitter, a first light emitter, and a second light emitter, the first light emitter and the second light emitter providing visible light in different wavelengths. The photodiode is positioned on a surface of the upper section facing the lower section, the infrared light emitter, the first light emitter, and the second light emitter positioned on a surface of the lower section facing the upper section, and the power source positioned on a surface of the lower section facing away from the upper section, the upper section and lower section configured to releasably accommodate a finger of a user therebetween and the photodiode configured to receive signals from the infrared light emitter, the first light emitter, and the second light emitter.

[0008] In another aspect of the present disclosure provided herein, is a pulse oximeter for measuring the SpO2 concentration in blood having a body configured for attachment to a finger; a photodiode on a finger-facing surface of the body; an infrared light emitter and a plurality of visible light emitters, each of the visible light emitters configured to transmit visible light at different wavelengths when activated, and the infrared light emitter and the plurality of visible light emitters on a finger-facing surface of the body positioned opposite the photodiode; a microcontroller housed within the body and connected to the photodiode, the infrared light emitter and the plurality of visible light emitters. The microcontroller comprises a processor and a memory, having computer program instructions therein; and where the plurality of visible light emitters emit at least two different wavelengths of light selected by the processor based on computer program instructions determining melanin content of the skin of the finger.

[0009] In another aspect of the present disclosure provided herein, is a method including, providing a pulse oximeter for measuring the SpO2 concentration in blood, including, an upper section having a photodiode connected to a microcontroller and a display; providing an opposable lower section having an infrared light emitter, a first visible light emitter, and a secondvisible light emitter; the photodiode configured to receive signals from the infrared light emitter, the first light emitter, and the second light emitter; transmitting a signal by the first visible light emitter; receiving the signal by the photodiode; determining by the microcontroller the absorbance of the ratio of visible light to infrared light; and determining the proportion of hemoglobin bound to oxygen in the blood of the user.

[0010] In another aspect of the present disclosure provided herein, is a pulse oximeter for measuring the SpO2 concentration in blood having, a body configured for attachment to a finger; a photodiode and an integrated LED on a finger facing surface of the body; at least one lower LED configured to transmit light at a plurality of different wavelengths when activated, the lower LED on a finger-facing surface of the body positioned opposite the photodiode and the integrated LED; a microcontroller housed within the body and connected to the photodiode and the integrated LEDs, the microcontroller having a processor and a memory, having computer program instructions therein; where the at least one lower LED transmits at least two different wavelengths of light, the wavelengths selected by the processor based on computer program instructions determining melanin content of the skin of the finger.

[0011] In another aspect of the present disclosure provided herein, is a method of operation including: initializing a pulse oximeter by the microcontroller, including setting up internal registers, initiating system checks, and establishing interfaces with connected devices; gathering data from a patient by the integrated photodiode sensor; gathering skin color and light absorption rates to determine melanin levels; determining the melanin content of the skin by the microcontroller using data received from the photodiode; activating an infrared light; activating at least a second light of wavelength based on the patient’s skin melanin content; collecting blood oxygen level data by the microcontroller via the photodiode; determining the patient’s SpO2 level; and displaying the SpO2 data on a display.

[0012] These and other objects, features, and advantages of this disclosure will become apparent from the following detailed description of the various aspects of the disclosure taken in conjunction with the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Fig. la, is an isometric view of the fully assembled pulse oximeter;

[0014] Fig. lb, is an isometric view of the fully assembled pulse oximeter of Fig. la when it is partially open;

[0015] Fig. 1c, is a front view of the closed pulse oximeter of Fig. la;

[0016] Fig. Id, is a back view of the closed pulse oximeter of Fig. la;

[0017] Fig. le, is a front view of the partially open pulse oximeter of Fig. la;

[0018] Fig. If, is a right-side view of the pulse oximeter of Fig. la in its neutral position;

[0019] Fig. 1g, is a right-side view of the partially open pulse oximeter of Fig. la;

[0020] Fig. Ih, is an exploded view of the pulse oximeter of Fig. la at an angle;

[0021] Fig. li, is an exploded front view of the pulse oximeter of Fig. la;

[0022] Fig. Ij, is an exploded right-side view of the pulse oximeter of Fig. la;

[0023] Fig. 2a is an isometric top view of the top shell of the pulse oximeter of Fig. la, revealing where the chipset, display monitor, and photodiode are housed, and where the tips of the hairpin springs are attached;

[0024] Fig. 2b is an isometric bottom view of the top shell of Fig. 2a;

[0025] Fig. 2c is a top view of the top shell of Fig. 2a;

[0026] Fig. 2d is a bottom view of the top shell of Fig. 2a;

[0027] Fig. 2e is a front view of the top shell of Fig. 2a;

[0028] Fig. 2f is a back view of the top shell of Fig. 2a of the pulse oximeter of Fig. la;

[0029] Fig. 2g is a right-side view of the top shell of Fig. 2a;

[0030] Fig. 2h is an annotated drawing of the bottom of the top shell of Fig. 2a;

[0031] Fig. 2i is an annotated drawing of the top of the top shell of Fig. 2a;

[0032] Fig. 3a is an isometric top view of the bottom shell of the pulse oximeter of Fig. la, revealing where the emitters of light are housed and where the other end of the hairpin springs are secured;

[0033] Fig. 3b is an isometric bottom view of the bottom shell of Fig. 3a, revealing where the batteries and contact buttons are located;

[0034] Fig. 3c is a top view of the bottom shell of Fig. 3a;

[0035] Fig. 3d is a bottom view of the bottom shell of Fig. 3a;

[0036] Fig. 3e is a front view of the bottom shell of Fig. 3a;

[0037] Fig. 3f is a back view of the bottom shell of Fig. 3a;

[0038] Fig. 3g is a right-side view of the bottom shell of Fig. 3a;

[0039] Fig. 3h is an annotated drawing of the bottom of the bottom shell of Fig. 3a;

[0040] Fig. 3i is an annotated drawing of the top of the bottom shell of Fig. 3a;

[0041] Fig. 3j is an annotated drawing of the hidden edges in the bottom shell of Fig. 3a;

[0042] Fig. 4a is an isometric top view of the part used to pad the finger on the finger-facing surface of the top shell of the pulse oximeter of Fig. la;

[0043] Fig. 4b is an isometric bottom view of the top insert of Fig. 4a;

[0044] Fig. 4c is an annotated drawing of the top insert of Fig. 4a;

[0045] Fig. 5a is an isometric bottom view of the part used to pad the finger on the fingerfacing surface of the bottom shell of the pulse oximeter of Fig. la;

[0046] Fig. 5b is an isometric bottom view of the bottom insert of Fig. 5a;

[0047] Fig. 5c is an annotated drawing of the bottom insert of Fig. 5a;

[0048] Fig. 6a is an isometric top view of the button used to turn on the pulse oximeter of Fig. la;

[0049] Fig. 6b is an isometric bottom view of the button of Fig. 6a;

[0050] Fig. 6c is an annotated drawing of the button of Fig. 6a;

[0051] Fig. 7a is an isometric top view of the top lid that snaps in place to cover the display and chipset of the pulse oximeter of Fig. la;

[0052] Fig. 7b is an isometric bottom view of the top lid of Fig. 7a;

[0053] Fig. 7c is an annotated drawing of the top lid of Fig. 7a;

[0054] Fig. 8a is an isometric top view of the bottom lid that slides into place to cover the power source of the pulse oximeter of Fig. la;

[0055] Fig. 8b is an isometric bottom view of the bottom lid of Fig. 8a;

[0056] Fig. 8c is an annotated drawing of the bottom lid of Fig. 8a;

[0057] Fig. 9 shows a general schematic of the methodology of the present invention; and

[0058] Fig. 10 shows the general circuit diagram of the pulse oximetry system of the present invention.

[0059] Fig. la - Fig. 10 are in accordance with one or more embodiments set forth herein.DETAILED DESCRIPTION OF THE INVENTION

[0060] Aspects of the present disclosure and certain embodiments, features, advantages, and details of the present disclosure, are explained in more detail below with reference to the non-limiting examples illustrated in the accompanying drawings. The detailed description and the specific examples indicate aspects of the disclosure, but arc given for illustration only and arc not for limitation. Various substitutions, modifications, additions, and / or arrangements, within the spirit and / or scope of the underlying inventive concepts will be apparent to those skilled in the art. Certain methods described herein with reference to certain steps that are presented in a certain order, in many instances, these steps may be performed in any order as may be appreciated by one having ordinary skill in the art and the methods are not limited to the particular arrangement of steps disclosed herein.

[0061] Approximating language, as used throughout this disclosure, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about” or “substantially,” is not limited to the precise value specified. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value.

[0062] Terminology used herein is for the purpose of describing particular examples only and is not intended to be limiting. 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. Furthermore, references to “one embodiment” are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, the terms “comprising” (and any form of “comprise,” such as “comprises” and “comprising”), “have” (and any form of “have,” such as “has” and “having”), “include” (and any form of “include,” such as “includes” and “including”), and “contain” (and any form of “contain,” such as “contains” and “containing”) are used as open-ended linking verbs. As a result, any embodiment that “comprises,” “has,” “includes” or “contains” one or more step or element possesses such one or more step or element, but is not limited to possessing only such one or more step or element. As used herein, the terms “may” and “may be” indicate a possibility of an occurrence within a set of circumstances; a possession of a specified property, characteristic or function; and / or qualify another verb by expressing one or more of an ability, capability, or possibility associated with the qualified verb. Accordingly, usage of “may” and “may be” indicates that a modified term is apparently appropriate, capable, or suitable for an indicated capacity, function, or usage, while taking into account that in some circumstances themodified term may sometimes not be appropriate, capable, or suitable. For example, in some circumstances, an event or capacity can be expected, while in other circumstances the event or capacity cannot occur - this distinction is captured by the terms “may” and “may be.”

[0063] As used herein, the term “portion” is not limited to a single continuous body of material unless otherwise noted. A “portion” may include multiple sub-portions that may be the same or different materials, and / or may include coatings, adhesives, and the like, and may be a separate and distinct component or may be an integral section, segment, or fragment of a larger component. As used herein, the term “coupled” is not limited to a direct coupling of two separate and distinct components. Two “coupled portions” may include indirectly coupled portions or directly coupled portions.

[0064] As used herein, reference to a color shall be understood to refer to wavelength of visible light corresponding to that color. For example, a red LED or a red emitter shall be understood to provide visible light within the red wavelength spectrum. Similarly, references to a light of a particular color shall be understood to correspond to light that has a wavelength within the spectrum of that color (e.g., red light).

[0065] The cunent invention may use two or more light emitters of different wavelengths. While a light emitting diode (LED) may be used with this invention, it is understood that other light emitters may be used as well. In one embodiment, the pulse oximeter may have light emitters that provide light within infrared wavelengths, red wavelengths, and green wavelengths, a design that allows the wavelength to be adjusted to the skin tone of the user, to prevent scattering resulting in higher levels of accuracy. Combining multiple lights to change the frequency used to take data based on skin tone creates a more accurate way to measure oxygen saturation for people of all skin tones. The light two light having visible wavelength may pulse asynchronously.

[0066] In another embodiment of this invention a single emitter may be used and the emitted wavelength may be manipulated by, for example, a diffraction grating. In another embodiment, an infrared emitter and a visible light emitter may be used, with the visible light wavelength being manipulated by a diffraction grating. In still another embodiment, a visible light emitter capable of pulsing at two or more wavelengths may be used.

[0067] The invention herein will be better understood by reference to the figures.

[0068] To address the needs in the art, a pulse oximeter is provided with an additional emitter of visible light used in conjunction with the preprogrammed software to accurately detect the level of oxyhemoglobin (HbO2) in a patient’s blood based on skin tone and produce an accurate oxygen saturation (SpO2) reading. SpO2 is a measure of the amount of oxygen-carrying hemoglobin in the blood relative to the maximum amount of hemoglobin that could carry oxygen.

[0069] The present invention features a pulse oximeter with enhancements that account for skin tone and minimize inaccurate medical diagnoses, such as hypoxia. In an example of a pulse oximeter, a red and infrared light are used. When red and infrared light hits the skin of the patient, melanin in the skin absorbs light that the oximeter would analyze, leading to an overestimation of oxygen saturation levels for people with darker skin tones. Values of 92% oxygen saturation or less are considered sufficiently low to require medical intervention, and values of 88% oxygen saturation or lower are considered medical emergencies.

[0070] In a three emitter embodiment of the present invention, the additional functionality derives from the inclusion of a green light wavelength emitter (green emitter) (e.g., with a preferred wavelength of approximately 522 nm) along with a red light wavelength emitter (red emitter) (e.g., a preferred wavelength of approximately 636 nm) and an infrared light wavelength emitter (infrared emitter) (e.g., a preferred wavelength of approximately 940 nm). The additional green emitter in the model displayed in the detailed drawings accounts for the absorption spectrum of the skin not considered in traditional pulse oximeters that only utilize an infrared light emitter and a red light emitter. Using differences in how much light is reflected at 522 nm and 636 nm, the pulse oximeter can be calibrated for different skin tones using, for example, the Monk Skin Tone Scale (MST), or another standardized scale as a reference. Green light is used with this invention, but those skilled in the art will realize that green light is not the only choice — there may be benefits to including a different number of emitters in the device. In other embodiments, a light wavelength other than green may be used (e.g., white light). In certain other embodiments, emitters of still other visible light wavelengths may be used.

[0071] In one embodiment, the oximeter of the current invention may be a clamshell configuration configured (e.g., shaped and dimensioned) for placement over or clamping onto a finger of the patient and adjustable to accommodate patients having differing finger sizes. A red emitter, a green emitter, and an infrared emitter (e.g., LED) may be mounted in the bottomsection of the pulse oximeter that would go under the bottom part of the finger (i.e., fingerprint side), with the emitters positioned within an opening in the surface of the bottom section, facing the finger and a top section of the pulse oximeter. A photodiode is situated in the top section that would touch the top portion of the finger (i.e., fingernail side), and the photodiode may be positioned within an opening in the surface of the top portion, facing the finger and the bottom part. The two halves of the clamshell configuration may be joined by a spring producing a constant force on the finger on either side. The side placed over the fingernail may also contain a printed circuit board (PCB) 4 (Fig. Ij) within and with a liquid crystal display (LCD) 3 (Fig. Ij) facing the user and informing them of their reading. The bottommost portion may include a compartment for a power source, such as, for example, two rechargeable AAA batteries 14 (Fig. Ij), allowing the user to recharge or replace the power source and easily transport the oximeter.

[0072] The photodiode may have a visible light emitter within the photodiode, or a light emitter integrated with and adjacent to the photodiode. The photodiode light emitter may be a white visible light. Such an emitter may be used to calibrate the photodiode prior to operation of the pulse oximeter. While the photodiode is used in this description, other light sensing devices may be used in place of the photodiode, such as, for example, a spectrophotometer. The photodiode light, in certain other embodiments, may be a visible light of a different wavelength or different color of light.

[0073] The PCB 4 may have a microcontroller, which may be in signal and electrical contact via wires to the photodiode and the light emitters. The circuitry will be described in more detail below.

[0074] In certain embodiments, the PCB may include wireless signaling or communication using, for example, Bluetooth®, NFC, or similar standard mobile phone signaling protocols to provide mobile phone connectivity. Data may be tracked, and trend reports may be generated for users to view at their leisure.Structure and Configuration

[0075] Although the current invention is to be described hereinafter with reference to the above drawings, it should be noted that persons of skill in the appropriate arts may modify the invention here without sacrificing the key objectives of the invention.

[0076] Descriptions of the physical model of the pulse oximeter refer to Fig. Ij unless otherwise specified. Various views of the body of the pulse oximeter are shown in Figs, la - Ij.With reference to Fig. 1 j, the body includes a hollow top shell 6 and a hollow bottom shell 11 connected by a hinge. In certain embodiments, there may be more than one hinge. In the preferred embodiment, the outer shell (i.e., the top shell 6 and the bottom shell 11) is injection molded with a suitable thermoplastic, such as ABS, PLA, Polyethylene, PolyCarbonate, Polyvinyl Chloride, or Polymethyl Methacrylate. However, the body of the pulse oximeter may be any similar rigid, lightweight material including other plastics or metals.

[0077] The top shell 6 and the bottom shell 11 are opposably and pivotally connected at the hinge. The interior surface of top shell 6 and the interior surface of bottom shell 11 are configured for placement on a patient’s finger. The indent 28 (Fig. 3a) in the front of the bottom shell 11 and the indent 17 (Fig. 2a) in the front of the top shell 6 allow different- sized fingers to be inserted into the device.

[0078] The top shell 6 and the bottom shell 11 are pivotally and opposably connected by two fulcrums 10 on the facing surfaces of the top and bottom shell and may be held together in a closed position with two hairpin springs 8 on the left and right sides of the shells.

[0079] The top shell is visualized in Figs. 2a - 2i and the bottom shell is visualized in Figs. 3a - 3j. Referring now to Fig. 2c and Fig. 3a, respectively, for each springs 8 of Fig. Ij, one end may be inserted into holes 22 (Fig. 2c) in the top shell 6, while the other end is held in place by ledges 27 (Fig. 3a) on the bottom shell 11. Each spring 8 may be further stabilized between shelves 24 (Fig. 3a) and fulcrums 10 (Fig. Ij). This allows the patient’s finger to remain clamped between the top shell 6 and the bottom shell 1 1 with sufficient pressure when inserted, for stable and stationary measuring of blood oxygen saturation.

[0080] Referring to Fig. Ij, the top of the top shell 6 may also contain two screw holes 19 by which PCB 4 may be secured with screws within the hollow top shell 6. The top of the top shell 6 may further contain a small ledge with pegs 23 (Fig. 2c) by which the other end of the PCB 4 may be secured. Through the middle of the top shell 6, a hole 20 (Fig. 2c) through which a photodiode 5 (Fig. Ij) may receive light transmitted by emitters 12 (Fig. Ij) (e.g., LEDs) may be positioned within the bottom shell 11 (Fig. Ij) and emitting light through the top shell facing surface of the bottom shell 11. A rectangular hole 20 (Fig. 2c) may be included through which wires may be run to connect the power source 14 to the PCB 4.

[0081] Referring to Fig. Ij, photodiode 5 may be connected to emitters 12, forming, for example, an integrated photodiode and emitter sensor system. The emitters of the integratedsensor system may emit light into the tissue, and the photodiode may collect data on the reflected light from the patient’s skin. The pulse oximeter may measure the amount of light that is reflected or absorbed by the skin of a user, which can be used to detect variations in blood oxygen levels and melanin presence. The emitters may emit light such that the photodiode may collect the reflected light, which may be used to determine light absorption by the user’s skin. In some embodiments, the wavelength of light from the emitter may be manipulated to minimize the scattering of light. For example, an emitter emitting wavelengths of red visible light may produce a high scattering coefficient when used on skin with darker tones, but produce a lower scattering coefficient when emitting green visible light.

[0082] Referring to Fig. Ij, the bottom of the bottom shell 11 may house batteries 14. In the current embodiment, two AAA batteries are used, but one skilled in the art would understand that the number of batteries, other battery types, and other power sources may be used to provide power for the invention and that this invention may be adapted accordingly. The batteries may sit in two cylindrical cutouts 32 (Fig. 3d) on the bottom of bottom shell 11. The batteries power the PCB 4 through battery contacts 13 that wire to the PCB 4. The battery contacts 13 may sit within cutouts 30 (Fig. 3b) on the bottom of the bottom shell 11, and the wires may be connected to top shell 6 by running through two rectangular holes 33 (Fig. 3d) on the bottom of the bottom shell 11. The bottom of the bottom shell is covered by a battery case 15, which may be freely attached and detached. The battery case may include a joint 40 (Fig. 7b) that may hook into a cavity 29 (Fig. 3b) on the bottom shell 1 1 , which then allows the battery case 15 to connect to the bottom shell 11. The battery case 15 may be further secured by two rectangular extrusions 31 (Fig. 3b) which allow the battery case 15 to slide onto the bottom of bottom shell 11. The underside of the battery case also has two lengthwise, rectangular indents 42 (Fig. 8b) to allow for more space for the two AAA batteries 14 to fit inside the bottom shell. The battery case is visualized further in Figs. 8a - 8c. The battery case 15 has been described for use with AAA batteries 14, however in other embodiments, the battery case 15 may be configured (e.g., shaped and dimensioned) to accommodate different battery types and different numbers of batteries. Furthermore, the battery case 15 may be omitted in place of a different power source (e.g., solar or AC power plug or USB connector) or configured to accommodate the different power source.

[0083] Referring to Fig. Ij, housed on the bottom shell facing side of the top shell 6 is a top insert 7, and housed on the top facing side of the bottom shell 11 is a bottom insert 9. The topinsert 7 is shown in greater detail in Figs. 4a - 4c and the bottom insert 9 is shown in greater detail in Figs. 5a - 5c. The top insert 7 and bottom insert 9 pad the patient’s finger to prevent abrasion. The bottom insert 9 may be secured to the bottom shell 11 by inserting four pegs 25 (Fig. 3a) on the bottom shell 11 into four holes 36 (Fig. 5b) on the bottom of the bottom insert 9. The top insert 7 may be similarly secured to the top shell 6 by inserting four pegs 18 (Fig. 2b) on the top shell 6 into four holes 34 (Fig. 4b) in the bottom of the top insert 7. While the number of pegs used in the example is four, more or fewer pegs may be used to secure the top insert 7 and the bottom insert 9 to the top shell 6 and the bottom shell 11. One skilled in the art would understand that different configurations (e.g., shapes and dimensions) of fasteners, the number of fasteners, and positioning of fasteners may also be used to produce a similar effect. The bottom insert 9 contains a rectangular hole 37 (Fig. 5b) that allows light from the emitters 12 to pass through the bottom insert 9. The top insert 7 contains a rectangular hole 35 (Fig. 4b) that allows the photodiode 5 to receive light from the emitters. The hole through which light from the emitters passes and the hole through which the photodiode 5 receives light from the emitters is depicted as rectangular, however, the hole may be any shape.

[0084] With reference to Fig. Ij, above the top shell 6 is the top lid 2, visualized further in Figs. 7a - 7c. The top lid 2 may snap onto the top shell 6 using four snap joints 38 (Fig. 7b). The top shell 6 includes four cavities 16 (Fig. 2a) that may house the snap joints 38. In other embodiments, there may be more or less than four snap joints. The top lid further contains a rectangular hole 39 (Fig. 7b) in which a liquid crystal display (LCD) monitor 3 may be housed and the display surface of the monitor 3 may be viewed from the outside of the device for the purpose of displaying the SpO2 readings. The top lid 2 may also contain a smaller rectangular hole 40 (Fig. 7b) next to the LCD monitor 3 on which a power button 1 can be placed. The power button 1 is visualized further in Figs. 6a - 6c.

[0085] While the power button 1 and the PCB 4 are shown within the top shell 6, it is understood that the PCB 4 and the power button 1 may just as easily be housed within the bottom shell 11. It is further understood that in certain other embodiments, the placement of the photodiode 5 and the emitters 12 may be reversed, and the emitters 12 may be within the top shell 6 and the photodiode 5 within the bottom shell 11. While an LCD monitor 3 is used, it is understood that other display monitors may also be used, such as an OLED monitor.Functionality and Operation

[0086] With reference to Fig. 10, a general circuit diagram of an embodiment of the pulse oximeter is shown. The general circuit shows a microcontroller 1, an integrated photodiode and emitter sensor system 2, an LCD monitor 3, a capacitor 8, a power supply 7, a 68Q resistor connected to the anode of a green LED 4, a 4.7kQ resistor connected to a red LED 5, and a 4.7kQ resistor connected to an infrared (IR) LED 6. The microcontroller 1 may contain a processor in communication contact with a memory area and / or various registers, the processor configured to process instructions from a computer program stored in the memory area and / or various registers. The integrated photodiode and emitter sensor system 2 may be a single component from a circuitry integration standpoint, but the photodiode may be a physically separate component from the emitters.

[0087] The integrated photodiode and emitter sensor system 2 is an integrated pulse oximetry sensor, having controlled LED drivers (e.g., red and infrared), a photodetector, an analog -digital (A-D) converter, and at least one signal processing program providing instructions to the processor of the microcontroller. The sensor operates in such a way to serve a dual function, emitting light into a pulsating capillary bed (e.g., via LED drivers) and then measuring the incident light that is not absorbed or scattered (e.g., via the photodetector / photodiode). The analog signals from the photodetector may be converted to digital values (e.g., via the A-D converter), which may be used by the processor of the microcontroller to calculate blood oxygen saturation levels. In certain other types of embodiments, the integrated photodiode and emitter sensor system 2, may also include a heart-rate sensor, with the processor further providing heart rate results. The pulse oximeter and the heart rate monitor may be used in, for example, wearable health devices.

[0088] The LCD display module 3 displays various calculated health data. For example, the LCD display module 3 may display SpO2 results and may be configured to provide high- contrast, high-resolution, and full-color visuals. The operation of the display module is managed by an embedded SSD1306 display controller module which autonomously handles the necessary pixel refresh functions, freeing the primary system microcontroller from these tasks. The display module communicates with the microcontroller via Inter- Integrated Circuit (I2C) / SPI protocol, enabling the display of processed sensor data or system statuses for the user. While an LCD display module is preferred, a lower definition or higher definition display or similar variant of such a display may be used.

[0089] Referring to Fig. 10, herein describes the connections within the PCB. A positive terminal of the power supply 7 is shown connected to the 3.3 V pin of the microcontroller 1 by connection 1101 (e.g., a wire). 1102a and 1102b (e.g., wires) represent the decoupled connections between the power supply 7 and the 0.1 pF capacitor 8 of the present invention. The power supply 7 is connected to the LCD display 3 by connection 1103 (e.g., a wire). This connection 1103 is provided to decouple the power supply. Capacitors (e.g., capacitor 8) in these positions help maintain a smooth voltage supply by attenuating any sudden changes or noise in the power line. This is important for the stable operation of all components, especially the microcontroller 1 and sensor 2, where voltage fluctuations can cause erroneous behavior. The negative terminal of the battery 7 may be connected to the ground (GND) that pervades the system, providing a common reference point for all voltages in the circuit.

[0090] The positive terminal of the battery 7 is connected to the power supply pin of the integrated photodiode and emitter sensor system 2 by power connection 1104 (e.g., a wire). 1201 represents the INT pin connection on the integrated photodiode and emitter sensor 2 to the microcontroller 1. 1301 shows that connecting the LCD display 3 and the microcontroller 1 to a common GND creates a common voltage reference point. 1401 shows that the anode of the green LED is connected to the 68Q resistor 4, with the cathode connected through a series of bridged jumpers (JP9, JP11, and JP12) and connected to the GND of the microcontroller 1. 1402 shows one end of the resistor 6 (4.7kQ) connected to the anode of the infrared LED, the cathode of the infrared LED connected to the 1R_LED+ pin of the integrated photodiode and emitter sensor system 2, and the other end of the resistor 6 connected to 1026. 1403 shows one end of the resistor 5 (4.7kQ) connected to the anode of the red LED, the cathode of the infrared LED connected to the R_LED+ pin of the integrated photodiode and emitter sensor system 2, with the other end of the resistor 5 connected to 1025. 1501 is a jumper diagram used to make connections for communication. Serial data line (SDA) and serial clock line (SCL) pins of both the integrated photodiode and emitter sensor 2 and the microcontroller 1 are connected via 1502 using jumpers for I2C communication, providing communication over the same bus without signal interference. 1503 shows the SDA pin allowing data transmission between devices via I2C communication, using only two wires (they can send and receive data, facilitating their communication). 1504 shows the SCL pins from the display providing for I2C protocol communication between the microcontroller 1 and the display 3.

[0091] The following steps describe one method of operation in the preferred embodiment referenced in Fig. 9.

[0092] Initialization: The microcontroller 1 may have a set of internal registers that may be used to control operation of the microcontroller 1 as well as handle communications with peripherals. This may include configuring the modes of the general purpose input output (GPIO) pins (input, output, analog, digital, etc.), configuring peripherals, setting up timers and interrupts, etc. Peripherals may include components such as the display screen, buttons, battery, power supply, and communication interfaces like USB or Bluetooth® for data transmission.

[0093] Initiating System Checks: System checks or self-tests are processes where the system verifies its hardware and software components' operational status. This means verifying the integrity of the firmware, checking the state of memory, confirming the availability and responsiveness of external peripherals, etc. This step is used to catch potential issues upon activation and to ensure that no errors are present with the functioning of the pulse oximeter.

[0094] Establishing Interfaces with Connected Devices: The peripherals in the project, such as the integrated photodiode and emitter sensor system 2 and LCD display 3, communicate with the microcontroller 1 using particular protocols or interfaces. These include interfaces like I2C, SPI, UART, etc. During initialization, the microcontroller 1 may start these communication interfaces and set up the necessary data rates, addressing schemes, etc. The microcontroller 1 may staid the I2C interface to communicate with the LCD display 3 and the integrated photodiode and emitter sensor system 2. The initialization and system check steps are normally performed during startup or before collecting information from a patient.

[0095] Data Acquisition: The data acquisition process is the function of gathering data from the photodiode 5 (Fig. Ij) of the integrated photodiode and emitter sensor system 2, processing such data to determine a suitable light to measure the level of oxygen in the blood (pulse oximetry) based on the presence of melanin in the patient. The emitter may emit light into the tissue, with the photodiode gathering light data. The photodiode sends a signal to the processor, and the amount of light that is absorbed is measured. These measurements may be used to detect variations in blood oxygen saturation and melanin presence. It may operate in the red and infrared spectrum bands, however, in other embodiments, other light wavelengths may be used. The gathered information may be sent by the integrated photodiode and emitter sensor system 2 and may be sent to the microcontroller 1 via the I2C interface. The raw data often needs to befurther adjusted by the processor for noise reduction and to derive useful information based on computer program instructions.

[0096] Initial Data Processing: The sensor(s) (e.g., the photodiode) should first gather the necessary biological data. This may be light absorption measures, biometric data, or other relevant metrics. The sensor(s) (e.g., the photodiode) may send this data to the microcontroller 1 via an I2C interface. The microcontroller 1 module receives this data, typically into a register or memory area. At this point, the microcontroller 1 may begin to process this raw data. This may involve removing any noise, carrying out necessary conversions and / or normalizations, applying additional computer program instructions, and / or analyzing the data to provide preliminary findings / measurements based on computer program instructions. If the data contains information that can be used to estimate the melanin level in the patient’s skin, the microcontroller 1 may apply a signal to execute a melanin detection computer program.

[0097] System Data Decision Making: This data is processed by the processor to determine the melanin content of the patient’s skin. If the initial data processing determines that the skin contains almost no melanin, then the program instructs the processor to activate the red and the infrared LED lights. If the initial data processing determines the skin contains some melanin, another program may be executed to provide instructions to the processor to determine if the skin contains a lot of melanin. If it is determined that the skin has a high melanin content, then the processor is instructed to activate the infrared LED and the green LED. The activation of different LEDs is employed to provide indications and to help improve accuracy of the sensor readings under various conditions. If the initial data processing determines that the skin does not contain a high or low amount of melanin (i.e., medium melanin content), then the processor will activate the red LED, the green LED, and the infrared LED to enhance blood oxygen saturation reading accuracy for all users.

[0098] If medium melanin content is determined, the red and infrared and the green and infrared emitters may continue to asynchronously pulse to determine a ratio of light intensities. Depending on the melanin content, a weighting factor may be assigned to each light by the processor based on a threshold of values using a scale, equation, or other method of calibration. The weighting factor assigned to each light may be correlative to the user’s skin tone. The weighting factor may be used to more accurately determine the blood oxygen saturation level of the user.

[0099] Data Transmission: The integrated photodiode and emitter sensor system 2 measure oxygen levels and send the data to the microcontroller 1 for further processing. This transmission of data may be done via the I2C protocol or interface. The I2C interface consists of two main lines, an SDA and an SCL. The SDA is used for moving the data to and from each of the devices. The SDA line changes only when the SCL is low. All data (e.g., reads, writes, and their addresses) are sent serially on this line. The microcontroller 1 may be the master device and controls the SCL. The SCL is used for synchronization and is required for the receiving end to detect and decode the data. In this interface, multiple devices can be connected to these lines, each having their own unique addresses. The processor in the microcontroller 1 initially generates a ‘Start Condition,’ wherein a high-to-low transition on the SDA line occurs while the SCL remains high. The microcontroller 1 then sends out the address of the device it wants to communicate with (e.g., the integrated photodiode and emitter sensor 2). If the correctly addressed sensor is present, it will acknowledge this by pulling the SDA line low. The microcontroller 1 subsequently sends or receives data on the SDA line, controlling the SCL line to ensure proper timing. The data is considered valid only when the SCL line is stable and high. The ESP32 eventually produces a ‘Stop Condition’ (low-to-high transition on the SDA line while SCL is high) to mark the end of transmission. The sensor may acknowledge the reception of each piece of data by pulling the SDA line low for one clock cycle.

[0100] Final Data Processing: The processor of the microcontroller 1 calculates the ratio of the intensities of received red and infrared light.

[0101] Calculation of SpO2: The ratio of the intensities of received red and infrared light, often described as the Red / IR Ratio, is then used to calculate the SpO2 levels. The program providing instructions to the processor may be calibrated based on empirical data, as the relationship may not be simple or linear due to the complex nature and variability of light absorption and the scattering properties of human tissues. However, a common approach is to apply the empirical formula: SpO2 = -45.060 * (Red / IR ratio) * log(Red / IR ratio) + 30.354. This equation approximates the empirical relationship between SpO2 and the Red / IR ratio for a sensor placed on a human fingertip. Empirical data may be stored in the microprocessor memory or in a separate memory accessible by the processor of the microprocessor 1 or in a database. The computer program may provide instructions to the processor to continue calculations that may be more complex. The instructions need to account for various factors such as the LED drivecurrent (which impacts the intensity of emitted light), skin tone (which affects light absorption and scattering), skin thickness, specific place of the sensor (as light penetration and path length can greatly vary between different parts of the body, e.g., fingertip versus earlobe), etc.

[0102] Data Display: Once the data is processed and prepared for display, it needs to be transmitted to the OLED display 3 by the processor. This transmission is handled using the I2C interface. I2C is a communication protocol commonly used for connecting low-speed peripherals to a microcontroller 1. Transmitting data via I2C involves setting a device address and sending and / or receiving data bytes. To display text or graphics on the LCD display 3, the processor of the microcontroller 1 may send a specific series of commands and data over I2C to set the cursor position, select the font or graphic pattern, and send the character or pixel data. The microcontroller 1 platforms have libraries available to simplify the task of writing to the LCD display 3. The processed data, once prepared into the necessary format, is sent via the I2C connection from the microcontroller 1 to the LCD display 3. Upon receiving this data, the LCD display 3 will then update to show the new information.

[0103] Data acquisition, initial data processing, data transmission, and final data processing may be repeated, allowing for continuous real-time monitoring of the SpO2 levels of the user.

[0104] The following is a method of operation steps of an embodiment of the current invention. Initializing the pulse oximeter by the microcontroller 1, including setting up internal registers, initiating system checks, and establishing interfaces with connected devices. Gathering data from a patient by the integrated photodiode sensor 2. Gathering skin color and light absorption rates to determine melanin levels. Determining the melanin skin content by the microcontroller 1 using data received from the photodiode. Activating an infrared light. Activating at least a second light of wavelength based on the patient’s skin melanin content. Collecting blood oxygen level data by the microcontroller 1 via the photodiode. Determining the patient’s SpO2 level. Displaying the SpO2 data on an LCD display 3.

[0105] A method including, providing a pulse oximeter for measuring the SpO2 concentration in the blood of the user having an upper section having a photodiode connected to a microcontroller and a display. Providing an opposable lower section having an infrared light emitter, a first light emitter, and a second light emitter connected to the microcontroller and the first and the second light emitter emitting visible light of different wavelengths, with the photodiode configured to receive signals from the infrared light emitter, the first light emitter,and the second light emitter. Receiving the signal by the photodiode. Determining by the microcontroller the absorbance of the ratio of visible light to infrared light. Determining the proportion of hemoglobin bound to oxygen in the blood of a user. Further including a computer program stored in the memory and providing instructions to the processor of the microcontroller, where determining by instructions provided to the processor, the oxygen saturation of hemoglobin. Receiving by the photodiode wavelength data from the infrared light emitter, the first light emitter, and the second light emitter; determining the ratio of visible light to infrared light; and transmitting the absorbance ratio to the processor for interpreting. Analyzing by the processor, the interpreted signal, and determining the wavelength of visible light to provide for the measurement of SpO2 concentration in the user’s blood based on skin tone. Determining the wavelength of visible light corresponding to the user’s skin tone includes determining the smallest scattering coefficient. Creating a thresholds-based skin tone scale test that minimizes light scattering, promoting reading accuracy of SpO2 levels, and determining an optimized wavelength. Transmitting continuous real-time data to a display means by continued pulsing of the infrared light emitter, the first light emitter, and the second light emitter. Continuing continuous real-time data updates until the wavelength data received by the processor drops a predetermined amount during a predetermined time interval.

[0106] Determining that the melanin levels are low, and activating the first light emitter having a wavelength of red light. This method is used to determine whether the melanin levels are not low, whether the melanin levels are high, and activating the at least a second light having a wavelength of green light. Whether the melanin levels are not low and determining that the melanin levels are not high, and activating a second light having a wavelength of green light and a third light having a wavelength of red. Repeating the method steps until a predetermined condition is reached, including a time threshold, device removal, and powering off the device.

[0107] It will be understood that skin tone determination may be applied and used in transmissive and reflective pulse oximeters. In some embodiments, the skin tone may be determined when white visible light from the photodiode is emitted and reflected from the skin, the reflection data collected by the photodiode for skin tone determination. After skin tone is determined, the visible light emitter or emitters selected by the microcontroller to determine SpO2 levels may be selected and weighting assigned to calculations based on light transmission from each of the visible light emitters. In other embodiments, skin tone may be determined bylight reflections after light is transmitted by the red, green, and infrared LEDs and received by the photodiode.

[0108] The configuration described is for the photodiode and the emitters to be on opposite sides of a clamshell style pulse oximeter. Such a configuration may be suitable for transmissive type pulse oximeters. However, the structure described may be modified for a reflective type pulse oximeter, where the photodiode and the emitters are adjacent to each other and on the same side of a clamshell configuration. In certain other embodiments, a configuration other than a clamshell may be used, with the emitters and photodiode positioned adjacent to each other on, for example, a skin-facing surface of a watch, bracelet, or health monitor.

[0109] While several aspects of the present invention have been described and depicted herein, alternative aspects may be affected by those skilled in the art to accomplish the same objectives. Accordingly, it is intended by the appended claims to cover all such alternative aspects as fall within the true spirit and scope of the invention.

Claims

CLAIMSWhat is claimed is:

1. A pulse oximeter for measuring the SpO2 concentration in blood comprising: an upper section comprising: a hollow interior housing a photodiode connected to a microcontroller and a display; the upper section hingedly and pivotally connected to an opposable lower section, the lower section comprising: a hollow interior housing an infrared light emitter, a first light emitter, and a second light emitter, the first light emitter and the second light emitter providing visible light in different wavelengths; the photodiode positioned on a surface of the upper section facing the lower section, and the infrared light emitter, the first light emitter, and the second light emitter positioned on a surface of the lower section facing the upper section, the upper section and lower section configured to releasably accommodate a finger of a user therebetween and the photodiode configured to receive signals from the infrared light emitter, the first light emitter, and the second light emitter.

2. The pulse oximeter of claim 1 wherein the display is positioned on an exterior surface of the upper section and visible by a user when the finger is in the pulse oximeter, the display providing a current measure of the user’s SpO2 concentration.

3. The pulse oximeter of claim 1 wherein the microcontroller comprises a processor and a memory having computer program instructions, the computer program instructions providing instructions to interpret wavelength signals gathered by the photodiode and convert the signals into a readable output of the SpO2 concentration of the user on the display.

4. The pulse oximeter of claim 1 wherein the infrared emitter emits light at a wavelength with respect to oxyhemoglobin and deoxyhemoglobin of 800-940 nm and has a peak wavelength of 940 nm.

5. The pulse oximeter of claim 4 wherein the first light emitter emits light at a wavelength of 600-700 nm and provides a peak wavelength of 660 nm.SUBSTITUTE SHEET RULE 266. The pulse oximeter of claim 5 wherein the at the second light emitter emits light at a wavelength of 400-640 nm and provides a peak wavelength of 522 nm.

7. The pulse oximeter of claim 6 wherein the photodiode is positioned to receive signals from the infrared light emitter, the first light emitter, and the second light emitter that is not absorbed by the skin.

8. The pulse oximeter according to claim 4 wherein the first light emitter and the second light emitter are correlated to the skin tone of the user.

9. A pulse oximeter for measuring the SpO2 concentration in blood comprising: a body configured for attachment to a finger; a photodiode on a finger-facing surface of the body; an infrared light emitter and a plurality of visible light emitters, each of the visible light emitters configured to transmit visible light at different wavelengths when activated, the infrared light emitter and the plurality of visible light emitters on a finger facing surface of the body positioned opposite the photodiode; a microcontroller connected to a power source and housed within the body, the microcontroller and the power source connected to the photodiode, the infrared light emitter and the plurality of visible light emitters, the microcontroller comprising: a processor and a memory having computer program instructions therein; wherein the plurality of visible light emitters emit at least two different wavelengths of light selected by the processor based on computer program instructions determining melanin content of the skin of the finger.

10. The pulse oximeter of claim 9, wherein the plurality of visible light emitters is a first LED emitting light of a red wavelength, and a second LED emitting light of a green wavelength.

11. A method comprising: providing a pulse oximeter for measuring the SpO2 concentration in blood comprising: an upper section having a photodiode connected to a microcontroller and a display; providing an opposable lower section having an infrared light emitter, a first visible light emitter, and a second visible light emitter; the photodiode configured to receive signals from the infrared light emitter, the first light emitter, and the second light emitter; transmitting a signal by the first visible light emitter; receiving the signal by the photodiode;SUBSTITUTE SHEET RULE 26determining by the microcontroller the absorbance of the ratio of visible light to infrared light; determining the proportion of hemoglobin bound to oxygen in the blood of the user.

12. The method of claim 11, further including a computer program stored on the memory and providing instructions to the processor of the microcontroller, wherein determining by instructions provided to the processor, the oxygen saturation of hemoglobin.

13. The method of claim 12 further including transmitting a signal by the first visible light emitter; receiving the signal by the photodiode; determining by the microcontroller an absorbance of the ratio of visible light to infrared light; determining the proportion of hemoglobin bound to oxygen in the blood of the user.

14. The method of claim 13 further including transmitting a signal by the second visible light emitter; receiving the signal by the photodiode; determining by the microcontroller an absorbance of the ratio of visible light to infrared light; determining the proportion of hemoglobin bound to oxygen in the blood of the user.

15. The method of claim 14 further including analyzing by the processor, the absorbance of the ratio of visible light to infrared light of the first visible light emitter and absorbance of the ratio of visible light to infrared light of the second visible light emitter; comparing the absorbance ratio of the ratio; and determining the wavelength of visible light to provide for the measurement of SpO2 concentration in the user’s blood based on skin tone.

16. The method of claim 15 wherein determining the wavelength of visible light corresponding to the user’s skin tone includes determining a smallest scattering coefficient.

17. The method of claim 16 wherein creating thresholds based skin tone scale tests that minimizes light scattering; promoting reading accuracy of an SpO2 level; and determining an optimized wavelength.SUBSTITUTE SHEET RULE 2618 The method of claim 17 wherein the at least one of the first visible light emitter or the second visible light emitters continue to pulse, resulting in continuous real-time data being transmitted to the display means.

19. The method of claim 17 wherein the first visible light emitter and the second visible light emitters continue to pulse, resulting in continuous real-time data being transmitted to the display means.

20. The method of claim 19 stopping once the wavelength signal strength received by the processor changes drastically.

21. The method of claim 20 stopping once a predetermined time interval has passed.

22. A pulse oximeter for measuring the SpO2 concentration in blood comprising: a body configured for attachment to a finger; a photodiode and an integrated LED on a finger facing surface of the body; at least one lower LED configured to transmit light at a plurality of different wavelengths when activated, the lower LED on a finger facing surface of the body positioned opposite the photodiode and the integrated LED; a microcontroller housed within the body and connected to the photodiode and the integrated LED, and the lower LED, the microcontroller comprising: a processor and a memory having computer program instructions therein; wherein the at least one lower LED transmits at least two different wavelengths of light, the wavelengths selected by the processor based on computer program instructions determining melanin content of the skin of the finger.

23. A method of operation comprising: initializing a pulse oximeter by the microcontroller, comprising: setting up internal registers, initiating system checks, and establishing interfaces with connected devices; gathering data from a patient by the photodiode sensor; gathering skin color and light absorption rates to determine melanin levels; determining the melanin skin content by the microcontroller using data received from the photodiode; activating an infrared light;SUBSTITUTE SHEET RULE 26activating at least one second light of a wavelength based on the patient’s skin melanin content; collecting blood oxygen level data by the microcontroller via the photodiode; determining the patient’s SpO2 level; displaying the SpO2 data on display.

24. A method of using a pulse oximeter to determine use SpO2 levels based on skin melanin content comprising: initializing a pulse oximeter by the microcontroller, comprising: setting up internal registers, initiating system checks, and establishing interfaces with connected devices; gathering data from a patient by the photodiode sensor; gathering skin color and light absorption rates to determine melanin levels; calibrating the microcontroller to select at least one light emitter; calibrating the microcontroller by assigning a weighting factor to light absorption from the at least one light source; activating an infrared light; activating at least one visible light of a wavelength based on the patient’s skin melanin content; collecting blood oxygen level data by the microcontroller via the photodiode; determining the patient’s SpO2 level; displaying the SpO2 data on display.SUBSTITUTE SHEET RULE 26

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