HK1126641B - Single use pulse oximeter - Google Patents

Description

Single-use pulse oximeter

Technical Field

The present invention relates to oximeters, and more particularly to single use oximeters that are self contained within a patch such as, for example, a self-adhesive bandage. The present invention also relates to a disposable patch oximeter with remote communication capability.

Background

Oximeters are well known. Prior to the present invention, self-contained oximeters come in the form of bulky housings that clip onto the finger of a patient, such as disclosed in U.S. Pat. No. 5,792,052. Another example of a self-contained oximeter is disclosed in U.S. patent 6,654,621, which is assigned to the assignee of the present application. In these prior art self-contained finger oximeters, the electronics are contained within the housing that pivotally grips the patient's finger (the 5792052 patent) or within an opening formed in the housing into which the patient's finger is inserted (the 6654621 patent). Since these finger oximeters are reusable devices, once the oxygen saturation level of the patient is determined, these finger oximeters may be removed from the patient and used on other patients.

There is also a bandage in the market in which the light emitter and sensor of the oximeter are embedded. The electronics for operating the light emitter and sensor and connecting to the bandage are located remotely from the bandage. Such devices are disclosed in us patents 6,735,459, 6,721,585, 6,684,091, 6,519,487, 6,343,224, 6,321,100 and 6,144,868. In this device only the bandage is disposable.

Disclosure of Invention

The present invention is a self-contained, all-disposable, single-use pulse oximeter that is activated when the backing paper used to protect its adhesive is peeled off. All of the components of the oximeter are mounted, integrated or embedded into a multi-layered patch or bandage. In addition to the light or emitter and the sensor or detector, other components of the pulse oximeter are also mounted within the patch; the light emitter or emitters output multi-frequency light to the patient (finger or head); the sensor or detector itself detects light passing through or reflected from the patient to acquire data from the patient, and then calculates the blood oxygen saturation level of the blood from the acquired data (SpO 2). The oximeter includes an oximetry circuit, an optional display, an optional alarm, which may be in the form of a (audible) piezoelectric transducer, and/or an optical indicator and power source on the display (visually). The circuitry may be integrated into an Application Specific Integrated Circuit (ASIC) platform or chip and embedded into a layer of the bandage that is protected by at least two thin barrier layers that are moisture resistant, preventing exposure of the ASIC to the environment. The power source may be a thin universal button cell or fuel cell, which may also be embedded in the same bandage layer as the ASIC chip. The same bandage layer may also contain an optional display and alarm. Alternatively, the display and alarm may be formed on a bandage layer above the ASIC platform layer and below a protective film layer that may include preprinted graphics. Membrane switches may also be provided under the protective membrane to provide the user with the ability to activate a number of functions, such as turning on/off an alarm and/or a display, for example.

The bandage is a sterilized bandage having a release sheet covering its lowermost adhesive layer which allows the bandage to be removably attached to the patient. To provide additional sterility, the bandage may be stored or housed in a sterile package that may have an openable lid.

Depending on the way the patch is used, the light emitter and detector are placed on the patch in a transmissive or reflective manner, wherein in the transmissive mode the patch or bandage is wrapped around the finger or earlobe of the patient; and in a reflective mode the patch is affixed to the forehead or other generally flat surface of the patient.

Remote communication capabilities may also be incorporated into the disposable patch oximeter of the instant invention. For wireless patch oximeters, the transmitter or transceiver is mounted to or embedded within the patch or bandage. The circuitry required for transmitting or transceiving signals to/from the patch oximeter is added or integrated into the ASIC chip, or added as a separate circuit to the electronics layer of the patch.

With the patch oximeter of the instant invention, whether a stand-alone bandage or a wireless bandage, the most convenient way to attach the bandage to the patient is through an adhesive layer, as is commonly done in conventional bandages used to cover wounds on individuals. However, other attachment mechanisms may be used with the patch oximeter or bandage of the instant invention. For example, these attachment mechanisms may include velcro or snaps that securely attach the bandage to the patient. In order to allow the bandage to be removably attached to the patient, it is only necessary that a portion of the lowermost layer of the bandage be provided with an adhesive layer, rather than the entire layer being provided with adhesive.

In addition to being able to communicate wirelessly with the main monitoring system (where the patient's oxygen saturation level SpO2 is monitored remotely), each patch oximeter may also communicate with other similar patch oximeters attached to other parts of the patient, in the inventive wireless form. If at least two oximeters are attached to the patient, the difference in SpO2 may be obtained to allow the patient to be subjected to a hypovolemic shock determination, i.e., to determine that the patient is only bleeding, is about to shock, or has actually been in shock.

Electrodes may also be incorporated into the bandage oximeter of the instant invention to obtain physiological parameters from the patient other than the oxygen saturation level of arterial blood of the patient, such as EEG, ECG, EKG, etc., at the same time as SpO2 of arterial blood of the patient is obtained. To measure additional physiological parameters of the patient, additional electronics need to be integrated within the ASIC circuit so that the patch oximeter can perform additional measurement functions, or mounted to the electronics of the patch as a separate additional circuit.

For wireless patch oximeters, a power source may be used that is not embedded on the patch, but rather is remote from the patch, and will provide power to the patch when the patch is at a predetermined or given distance from the remote power source. For this radio frequency identification (RFId) equipped embodiment, an antenna coil and RF power receiver may be added to the patch oximeter to draw power from a remote power source when the bandage is within communication range of the remote power source. For this embodiment, and other possible wireless embodiments of the inventive patch oximeter, it may not be necessary to mount a display and/or alarm on the patch.

The present invention is therefore a one-piece disposable flexible patch or bandage adapted to be attached to a patient for measuring at least the oxygen saturation level of blood of the patient. The disposable patch has mounted thereon a light emitter and a light detector to detect light emitted from the light emitter that passes through the patient in order to acquire data regarding at least the SpO2 of the patient. Electronic circuitry may also be mounted on the disposable patch to enable efficient operation of the light emitter and light detector and to calculate from the acquired data at least the SpO2 of the patient. An attachment mechanism may also be provided on the patch so that the patch is removably attached to the patient.

The present invention also relates to an oximeter that includes a patch adapted to be attached to a patient. The oximeter includes a light emitter and a light detector each mounted to the patch, respectively, the light detector detecting light emitted from the light emitter that passes through the patient. Electronic circuitry, also mounted to the patch, operates the light emitter and the light detector and calculates from data acquired by the light detector at least the oxygen saturation level of the blood of the patient. A device is provided on the patch such that the patch is removably attachable to the patient.

The invention further relates to a method for preparing a disposable oximeter, comprising the steps of: a) obtaining a flexible patch adapted to be attached to a patient; b) mounting a light emitter and a light detector to a patch; c) ensuring that the light emitter and the light detector are properly arranged on the patch so that they operate in coordination with each other so that the light detector will detect light emitted from the light emitter that passes through or is reflected back from the patient and acquire data from the patient regarding at least the oxygen saturation level of blood; d) mounting electronic circuitry to the patch for operative operation of the light emitter and the light detector and for calculating from the acquired data at least the oxygen saturation level of blood of the patient; and e) providing a device to the patch that causes the patch to be removably attached to the patient.

The wireless one-piece, disposable oximeter of the present invention is a one-piece, disposable patch that is adapted to be attached to a patient to measure the oxygen saturation of arterial blood of the patient. The wireless patch oximeter includes a light emitter mounted to the patch, a light detector mounted to the patch for detecting light emitted from the light emitter that passes through or is reflected back by the patient so that data regarding at least the oxygen saturation level of arterial blood of the patient may be acquired, an electronic circuit mounted to the patch for operatively operating the light emitter and the light detector and for calculating at least the oxygen saturation level of arterial blood of the patient from the acquired data, a transceiver mounted to the patch for transmitting the calculated oxygen saturation level of arterial blood or the acquired patient data to at least a remote device, and an attachment mechanism on the patch for removably attaching the patch to the patient.

The oximeter of the instant invention further comprises a patch adapted to be attached to a patient, a light emitter and a light detector each mounted to the patch, electronic circuitry mounted to the patch for operative operation of the light emitter and the light detector, and for calculating from data acquired by the light detector at least the oxygen saturation level of arterial blood of the patient as the light detector detects by itself light emitted from the light emitter that has passed through the patient, a transceiver mounted to the patch for causing the patch to transmit at least a signal representative of the oxygen saturation level of arterial blood of the patient or data acquired by the light detector to a remote device, and means disposed on the patch for removably attaching the patch to the patient.

The present invention also relates to a method of determining whether a patient is in hypovolemic shock comprising the steps of: a) at least two oximeters are attached to different parts of the patient, each oximeter being a patch adapted to be attached to the patient. Each patch oximeter having mounted thereon a light emitter, a light detector, electronic circuitry for operating the light emitter and the light detector, and data acquired from the light emitted by the light detector from the light emitter passing through the patient to calculate at least the oxygen saturation level of arterial blood of the patient, a transceiver for enabling the patch to communicate the calculated oxygen saturation level of arterial blood of the patient to a remote device or other oximeter attached to the patient, and means for enabling the patch to be removably attached to the patient; b) determining a difference between respective oxygen saturation levels of blood of the patient as measured by each oximeter attached to the patient; and c) comparing the determined difference to a predetermined condition to determine whether the patient is in shock.

Drawings

The invention is described below in conjunction with the appended drawings, and will be clear and understood by reference to the following description.

FIG. 1 is a block diagram of an oximeter patch or bandage of the present invention in which a light emitter and light detector are mounted to the patch and operate in transmission to measure the oxygen saturation level of arterial blood of a patient when the patch is wrapped around the finger or earlobe of the patient;

FIG. 2 is a block diagram of the patch oximeter of the instant invention in which the light emitter and light detector are mounted to the patch in an orientation such that the oximeter is adapted to operate in reflection, wherein the patch is adhered to the forehead or other generally flat surface of the patient;

FIG. 3 is a block diagram of the patch oximeter of the instant invention in which a transmitter or transceiver and appropriate electronics for operating the transmitter or transceiver are added to the patch so that the patch oximeter may communicate wirelessly with a remote device;

FIG. 4 is a block diagram of a wireless patch oximeter in which no power source is provided to the patch, but an antenna and coil are added to the patch to obtain and utilize the power provided by the remote power source;

FIG. 5 is a different embodiment of the wireless patch oximeter of FIG. 4, with the display and alarm except for the respective drivers removed from the patch;

FIG. 6 is a block diagram of a patch oximeter with at least two electrodes added to the patch so that the patch oximeter may acquire at least one physiological parameter other than SpO2 from the patient in a transmission manner;

FIG. 7 is a block diagram of the same patch oximeter as that shown in FIG. 6, but with the light emitter and light detector oriented to operate in reflection;

FIG. 8 is a block diagram illustrating a wireless patch oximeter provided with electrodes for acquiring additional physiological parameters of a patient;

FIG. 9 is a block diagram illustrating a wireless patch oximeter powered by a remote power supply, with the electrodes mounted to the patch;

FIG. 10 is a block diagram of the patch oximeter of FIG. 9, but with the display and alarm removed;

FIG. 11 is a top view of an exemplary patch oximeter of the instant invention;

FIG. 12 is a cross-sectional view of the various layers of the patch or bandage strip of the patch oximeter of the instant invention;

FIG. 13 is an exemplary sterile package for the disposable oximeter of the instant invention, and with the oximeter removed therefrom;

FIG. 14 is a simplified diagram of the patch oximeter of the instant invention, which communicates with a remote monitoring system;

FIG. 15 is a simplified diagram showing the attachment of several patch oximeters of the instant invention to different areas of a patient in order to provide a remote monitoring system with a differential measurement of the patient's SpO2 or perfusion, which may indicate whether the patient is in shock; and

FIG. 16 is a flowchart illustrating a process for determining whether the patient of FIG. 15 is in shock.

Detailed Description

Referring to fig. 1, a flexible patch 2 in the form of a bandage or strip has mounted thereon a light or emitter 4 and a photodetector or sensor 6. As is well known, the light emitter 4 may be formed by a plurality of LEDs, each LED outputting light at a different frequency, which essentially allows the emitter 4 to output a multi-frequency light to a portion of the patient, which may be a finger, the bridge of the nose, an earlobe, the forehead or some other portion of the patient. The photodetector 6 then detects or detects the light passing through the patient itself as data acquired from the patient.

An Application Specific Integrated Circuit (ASIC)8, which may be in the form of a flexible circuit platform or chip, is also mounted on patch 2, with ASIC 8 containing various electronic components to control emitter 4 and sensor 6, and to calculate at least the blood oxygen saturation level of arterial blood (SpO2) and heart rate of the patient from data collected or acquired by sensor 6. As shown in fig. 1, representative electronic components required for the operation of the pulse oximeter are formed or integrated within the ASIC circuit 8, consistent with conventional processes for making ASIC chips. These components include a processor 10, a memory 12, an electronic circuit 14 (specifically designed to perform oximetry functions), a transmitter interface circuit 16, a sensor interface circuit 18, a display driver 20, and an alarm driver 22. For the sake of simplicity, other electronic components which may also be integrated into the ASIC circuit 8 are not shown. For the oximeter embodiments described herein, the ASIC circuitry 8 is assumed to be in the form of a thin chip, which may be flexible, and/or mounted or embedded within a particular layer of the patch, as will be discussed in detail below.

The algorithm for performing the SpO2 analysis is described in U.S. patent No. 5,558,096, assigned to the assignee of the present invention. The disclosure of the' 096 patent is incorporated herein by reference. Other algorithms or software necessary to effectively operate the emitter 4 and the sensor 6 in a general manner may also be stored in the memory 12. In addition, software for operating other components or electronics, as will be discussed below, may also be stored in memory 12.

For the oximeter shown in fig. 1, a display 24, an alarm 26 and a power source 28 in the form of a battery are also mounted to patch 2. Display 24 may be a thin film LCD display and alarm 26 may be a piezoelectric transducer that may be integrated as a separate electronic component mounted to patch 2. The power supply 28 suitable for the oximeter of the instant invention may be a conventional thin sheet cell or fuel cell that is self-activating when the patch is removed from its sterile package. The chemical light source may also be self-activating and may be used as an illumination source for the display 24 when the patch is removed from its sterile package, or when the adhesive backing strip of the patch is removed. The use of a chemical illumination source can extend the life of the battery. With self-activation there would be no need to install an "on" switch. In addition, the illumination source may be enabled to automatically detect ambient lighting conditions to determine if the illumination source is needed, thereby conserving battery power when self-illumination is not needed. For the present invention, the duration of the chemiluminescence can be adjusted to reflect the life of the battery.

For illustrative purposes, attachment portions 30 and 32 are also provided on patch 2. Although they are shown as separate parts in the figures, it should be noted that in practice such an attachment part may be an adhesive layer at the surface of the patch which is brought into contact with the patient to adhere the patch to the patient. The attachment portions 30 and 32 may also be made of velcro so that a patch in the form of a bandage may be wrapped around the patient's finger or earlobe. Other types of attachment mechanisms, such as snaps or snaps, may also be used. This is particularly applicable to the embodiment shown in fig. 1, where emitter 4 and sensor 6 are arranged or oriented so that they work in concert in a transmissive manner when the patch oximeter is wrapped around the patient's finger, earlobe or nose bridge, etc. The various layers of the patch oximeter will be discussed in detail below with respect to the discussion of fig. 12.

Fig. 2 has the same components as shown in fig. 1. Like components in fig. 2, as well as those that will be discussed in other figures, are labeled with like reference numerals. One difference between the patch oximeter shown in fig. 2 and that shown in fig. 1 is the placement of the emitter 4 and sensor 6 on the patch. As shown, emitter 4 and sensor 6 are mounted to the patch in a defined proximity to each other so as to enable the patch oximeter to measure the SpO2 of the patient reflectively. Thus, the reflection mode patch oximeter of fig. 2 is best adapted for attachment to the forehead, or other generally flat skin surface, of the patient.

Fig. 3 illustrates another embodiment of the present invention wherein, in addition to including all of the components of the above-described embodiments, the patch oximeter also has mounted thereto electronic components that operate as a wireless patch oximeter. In particular, a transmitter or transceiver 34 is added to the electronics layer of the patch, and an antenna 36 coupled to the transceiver 34 provides a means by which signals may be transmitted and/or transceived to or from the patch oximeter. To provide the additional functionality required to operate the transceiver 34, electronics in the form of a transmission circuit 38 is added to the electronics layer of the patch, either as a separate circuit or integrated into the ASIC circuit 8. The functionality of the transceiver 34 and its corresponding transmission circuitry 38 may be gleaned from assignee's U.S. patent 6,731,962, the disclosure of which is incorporated herein by reference.

Since the patch oximeter is equipped with a transceiver 34, the patch oximeter may not only transmit information to the remote device, but it may also receive information from the remote device. For example, the patch oximeter is normally in a sleep state and may be activated by a signal from a remote device to start monitoring or measuring. By way of further example, the final transmission of the patch oximeter may not be accurately received by the remote device, and thus the remote device may require the patch oximeter to retransmit the data.

While the light emitter 4 and sensor 6 in the wireless patch oximeter embodiment are shown arranged to operate in a transmissive mode, it should be appreciated that it may also operate in a reflective mode simply by rearranging the respective positions of the emitter 4 and sensor 6 (as shown in the fig. 2 embodiment).

With its wireless functionality, the patch oximeter of fig. 3 may transmit at least the calculated patient SpO2 value to a remote device (e.g., a monitoring system) to display and/or record the patient SpO2 value at the remote device; such as a vital signs monitor of an assignee equipped with a suitable radio communication receiver, such as a radio frequency transmitter equipped with a radio frequency link. After incorporating the transceiver 34 in the patch oximeter, the information or data acquired by the sensor 6 or by the discussed electrodes added to the patch oximeter may be transmitted to a similar wireless patch oximeter, so as to establish a micro radio communication network among a large number of wireless patch oximeters, enabling medical personnel to closely monitor the different physiological parameters of the patient. Such monitoring will be discussed in detail below with reference to fig. 15.

Fig. 4 illustrates another embodiment of the present invention in which the battery power source is removed from the patch oximeter. Instead, the patch oximeter gets power remotely by adding antenna 40 and coil 42. Antenna 40 is optional because coil 42 is the component that allows the patch oximeter to draw power from a remote power source. The electronics required for obtaining remote power functionality are added to the patch by the remote power circuit 44. The manipulation of grabbing remote power resembles the common RFID (radio frequency identification) technology used to identify objects. One example of the use of such RFID technology is in the form of small electronic circuit tags that are placed on items, for example to identify the items when they are sold. If the casual customer does not pay, an alarm will be triggered when the item passes through the cash register or out of the store. The electronic circuitry that operates to trigger the alarm draws power from a remote power source. The same situation may apply to the wireless patch oximeter of fig. 4, and the power required for operating an embodiment, such as the patch oximeter embodiment shown in fig. 4, should be increased by at least a factor of two in order to have a sufficient power level to operate the transmitter 4.

For the embodiment of fig. 4, while the display 24 and alarm 26 remain, it should be appreciated that these components are not necessarily required, particularly when the patient is not required to view the display, such as due to a sleep study involving, for example, sleep apnea being performed on the patient, the patient wears the patch oximeter whereby the patient's data is displayed remotely on a remote monitor. A patch oximeter that does not include a display and alarm assembly and its respective driver is shown in fig. 5. As previously mentioned, for all of the embodiments described, it is assumed that the patch oximeter is operable in both the transmissive mode and the reflective mode, regardless of how the emitter 4 and sensor 6 are shown positioned in the figures.

Another aspect of the invention is illustrated by the block diagram of the strip or bandage shown in fig. 6. As shown, the disposable patch oximeter of fig. 6 has two electrodes 44 and 46 added thereto, and their respective interface circuits 44a and 44b, 44a and 44b may be integrated into ASIC circuit 8, or as additional electronics mounted separately to the electronics layer of patch 2. Additional electronics, represented by electrode circuit 48, may also be integrated into ASIC circuit 8, or mounted as a separate component to the electronics layer of patch 2. The electrodes 44 and 46 are in each case common bioelectric electrodes (not limited to, for example, silver-silver chloride electrodes, possibly pre-frozen electrodes) which, when placed at a distance from one another (or made concentric), can measure further physiological parameters of the patient, such as, for example, EKG, ECG, etc. As is well known, EKG and ECG are physiological parameters associated with electrical stimulation of the heart. The time difference between the patient's ECG QRS complex and its plethysmograph waveform, which is shown to correlate with non-invasive blood pressure (NIBP), can be determined by adding electrodes to measure bioelectrical events.

In addition to the previously mentioned physiological parameters relating to the patient's pulse, heart rate and SpO2, electrodes or sensors in the form of temperature sensors and appropriate electronics may also be added to the patch to measure the patient's body temperature. Thus, the patch oximeter of fig. 6 may continuously monitor or acquire other types of physiological parameters besides SpO2 and heart rate, such as body temperature and blood pressure in the form of non-invasive blood pressure (NIBP).

Fig. 7 shows, in block diagram form, the possible different placement locations of electrodes 44 and 46, and of emitter 4 and sensor 6 on the patch, when SpO2 is desired to be reflectively acquired on the forehead or other generally flat surface of a patient.

Fig. 8 shows a wireless patch oximeter equipped with ECG electrodes 44 and 46, and an electrode circuit 48 for acquiring data measured by the electrodes. For the embodiment of fig. 8, in addition to SpO2 and the data collected by sensor 6 for use in calculating at least SpO2, data collected by electrodes 44 and 46 regarding other physiological parameters of the patient may likewise be transmitted to a remote device, such as the aforementioned vital signs monitor for display and/or recording. It will be appreciated that although separate radio communication circuits 38 and electrode circuits 48 are shown, in practice these circuits may be incorporated into the main electronic circuit 14 of the ASIC circuit 8 mounted to the electronics layer of the patch 2.

Fig. 9 illustrates in block diagram form an embodiment of the wireless patch oximeter of the instant invention where SpO2, heart rate and other physiological parameters of the patient may be measured. The embodiment of fig. 9 is similar to the embodiment of fig. 4 in that the power to operate the patch oximeter is obtained from the remote power source when the patch oximeter is located within a given distance from the remote power source. Thus, with the patch oximeter of fig. 9 and the patch oximeters with the remote power supply as described with respect to fig. 4 and 5, the patch oximeter attached to the patient is not activated until the patient is within a given distance from the remote power supply, in which case the electronic circuitry (e.g., circuit 14) may be awakened to activate the remaining electronic circuitry to perform its corresponding function and provide power to the transmitter 4. The patient may also view her SpO2 and heart rate, as well as the ECG and possibly intensity bar graphs via display 24 if sufficient power is available from the remote power source. A membrane switch (not shown) may be provided on the top layer of the patch to activate or deactivate the alarm 26 and/or display 24.

Fig. 10 shows the patch oximeter of fig. 9 without any display or alarm. Such a wireless oximeter/electrode combination patch may be used in situations where the patient is not required to view any data or hear any alarms, such as the sleep apnea study discussed previously, to measure various physiological parameters that occur while the patient is asleep.

Fig. 11 shows the patch oximeter of the instant invention in the form of a bandage. As shown, the display 24 of the bandage shows the patient's heart rate and SpO 2.

Fig. 12 shows a cross-sectional view of the different layers of the patch of the oximeter of the instant invention. It should be appreciated that the layers shown in fig. 2 are not drawn to scale or to scale with their respective thicknesses. As shown, starting with the release sheet 50, the layer 52 that contacts the patient is an adhesive layer. As already noted above, in practice such adhesive layer may be replaced by suitable attachment means, such as velcro and snaps. In any event, exposure of adhesive layer 52 to the environment is avoided by release sheet or paper 50. On top of adhesive layer 52 is a foam layer 54 that provides comfort to the patient and compensates for patient movement. On top of the foam layer 54 is a barrier layer 56, which may be a plastic sheet or a polyimide sheet that acts as a moisture barrier and electrical insulation layer.

The underside and the upper side of the electronics layer 60 are protected by the barrier layer 56 and the further barrier layer 58, respectively, whereby various electronic components, including ASIC circuits and other previously mentioned circuits, are embedded or mounted in this layer. Electrical interconnections between the various electronic components represented by electronics layer 60 and/or the ASIC circuitry with emitter 4 and sensor 6 are made due to the direct contact of the electrical interconnections. Emitter 4 and sensor 6 are shown extending from electronics layer 60 so as to be flush with adhesive layer 52 or slightly above adhesive layer 52, respectively. Optional electrodes 44 and 46 are also shown extending from electronics layer 60 to adhesive layer 52. Although the surfaces of the electrodes are shown to be flush with adhesive layer 52, in practice the surfaces of the electrodes extend slightly beyond adhesive layer 52 for more efficient operation and may be pre-frozen. In any case, the peel off sheet 50 protects each contact surface of the emitter 4, sensor 6 and electrodes 44, 46.

As noted above, the electron shell 60 is sandwiched between two protective barrier layers 56 and 58. As shown in fig. 12, display 24 extends from electronics layer 60 to be flush with the upper surface of barrier layer 58. Since barrier layer 58 (similar to barrier layer 56) may be a clean moisture-proof and electrically insulating sheet, the display may be viewed from the top of the patch, alternatively, display 24 may be mounted within electronics layer 60. Also shown is optional switch 60 which may be part of barrier layer 58 or embedded within electronic layer 60. A protective film layer 62 covers the barrier layer 58, and the protective film layer 62 may be printed with graphics and appropriate cleaning window areas to facilitate viewing of the display 24, as shown in fig. 11. The protective film layer 62 is printed with appropriate graphics that, if provided with optional switches 60, allow the patient to easily decide which switch to press to activate or deactivate operation of those components that allow caregiver/patient control, such as optional display 24 and/or alarm 26 not shown in the patch layer of fig. 12.

Fig. 13 shows the packaging of the patch oximeter of the instant invention. Patch 2 may be housed or stored in a package 63 that includes a clear upper wrapper 64 and a lower wrapper 66. The lower wrapper 66 may be the peel away sheet 50 shown in fig. 12, which has the additional function of activating the battery 28 when peeled off if the battery 28 is a fuel cell that operates using zinc/air chemistry. Such batteries are inactive when stored in a sealed environment. But once the peel-off sheet, e.g. 50, is peeled away from the patch, the battery is activated due to exposure of the battery to air. This feature is advantageous since it allows for extended shelf life of the patch oximeter. The battery should have sufficient power to operate the oximeter for a suitable length of time, for example 8-10 hours. The battery 28 may also be a photovoltaic type battery that supplies electrical power when the battery is exposed to light. When a photovoltaic cell is used, the placement of the cell on the patch allows light to reach the photovoltaic cell through a clear window provided in the film layer 62. The chemical light source mentioned above may also be activated by peeling the release sheet 50 from the adhesive layer, which substantially begins its chemical reaction when exposed to air or light.

Fig. 14 illustrates the radio communication functionality of the wireless embodiment of the patch oximeter of the instant invention. When the patch oximeter 2 is within a given distance from the remote power supply 68, it draws power from the remote power supply 68 (for non-self-powered wireless patch oximeters) and transmits the data collected from the patient and/or the calculated SpO2 to the monitoring system 70 via the receiver 72 of the monitoring system 70. The operation of transmitting data from the patch oximeter 2 to the monitoring system is similar to that given in the above-incorporated reference' 962 patent, which discloses the use of a radio frequency link to transmit data packets from the oximeter to the monitoring system 70, and to unpack the data packets by the monitoring system 70.

Fig. 15 illustrates the use of a number of patch oximeters of the present invention in a wireless format to communicate information to a remote device to inform medical personnel whether the patient is in shock. As shown, patch oximeter 2 is attached to the forehead of patient 74. Another patch oximeter 2 'is attached to an extremity, such as a patient's finger. Because each patch oximeter measures the SpO2 of the patient at its respective location, the respective blood perfusion rates on the forehead and the extremities of the patient are also measured, and the difference between the measurements is determined. This is important because when a patient is about to shock, for example hypovolemic shock, the patient's extremities will shut off blood perfusion before the brain. Thus, by comparing the difference in blood perfusion between the extremities and the forehead of the patient, it can be determined whether the patient is about to go into shock or is in shock due to potential bleeding. With the patch oximeter of the instant invention, septic shock or systolic shock may also be measured if appropriate electrodes adapted to measure the temperature or other physiological parameters of the patient are added. As is well known, blood perfusion is generally represented by an index, which is calculated as the ratio of the peak-to-peak value of the red transmission signal to the peak-to-peak value of the infrared transmission signal. See, for example, U.S. patent publication 2003/0236452, the disclosure of which is incorporated herein by reference.

FIG. 16 provides a flow chart of a method of determining whether a patient is in shock or is about to shock. Specifically, a determination is made as to whether the patient is in shock, beginning with the attachment of a number of patch oximeters of the instant invention to the patient, via step 76. A measurement of blood perfusion is obtained from the oximeter, via step 78. It is determined by step 80 whether there is a difference between the blood perfusion measurements, for example, of the forehead and the extremities of the patient. If there is a difference, the difference is compared to a predetermined range of conditions, e.g., 1-10, which is calibrated in advance to determine whether the patient is in good condition, is about to shock, or has been in shock. For the exemplary 1-10 scale, assume that 1-4 corresponds to normal, 5-8 corresponds to likely imminent shock, and 9-10 corresponds to the patient being in shock. The difference between the measured blood perfusion values is compared to a predetermined range in decision steps 84 and 86. If the difference in the measured blood perfusion values is within the shock range, a shock status is signaled by step 88. On the other hand, if the measured discrepancy is within the range that the patient is about to shock, then a status of limbus is signaled by step 90. If the patient exhibits normal, unshock, the process returns to the monitoring phase where the difference in measurements between the patient site(s) (at least two sites) to which the patch oximeter of the instant invention is attached is continuously monitored and calculated. With respect to the various patch oximeter embodiments of the instant invention, the patch oximeter may be discarded once it is used.

Claims (26)

1. A one-piece, self-contained, multi-layer disposable patch adapted to be attached to a patient for measuring at least the oxygen saturation level of blood of the patient, comprising:

a light emitter mounted to the patch;

a light detector mounted to the patch for detecting light emitted from the light emitter that passes through or reflects from the patient to thereby acquire data at least regarding the oxygen saturation level of blood of the patient;

electronic circuitry mounted to the electronics layer of the patch for operatively operating the light emitter and the light detector and calculating from the acquired data at least a blood oxygen saturation level of the patient;

a power supply mounted to the patch for providing electrical power to the electronic circuitry and the light emitter; and

an attachment mechanism is provided at the patch that enables the patch to be attached to a patient.

2. The patch of claim 1, further comprising a display mounted thereon for displaying at least the calculated oxygen saturation level of blood of the patient.

3. The patch of claim 1, wherein the electronic circuit comprises an ASIC circuit integrally mounted to the electronics layer of the patch.

4. The patch of claim 1, wherein the patch comprises a bandage adapted to wrap at least a finger or an earlobe of a patient.

5. The patch of claim 1, wherein the patch includes a bandage adapted to adhere to the forehead or other generally flat surface of a patient.

6. The patch of claim 1, further comprising at least two electrodes mounted to the patch and additional electronics mounted to the electronics layer of the patch or integrated into the electronic circuitry to cause the electrodes to operate effectively to measure at least one other physiological parameter of a patient.

7. The patch of claim 2, further comprising a chemical light source that is activatable for illuminating the display.

8. The patch of claim 1, wherein the power supply comprises a battery.

9. The patch of claim 1, wherein the power supply comprises electronics to draw power from a remote power source.

10. An oximeter, comprising:

a multi-layer patch adapted to be attached to a patient,

a light emitter and a light detector both mounted to the patch, the light detector detecting light emitted from the light emitter that passes through or reflects from the patient and acquiring data at least regarding the oxygen saturation level of blood of the patient,

electronic circuitry mounted to the electronics layer of the patch for operative operation of the light emitter and the light detector, and for calculating from the acquired data at least a blood oxygen saturation level of the patient,

a power supply device mounted to the patch for providing electrical power to the electronic circuit and the light emitter, an

Means provided at the patch to enable the patch to be removably attached to the patient.

11. The oximeter of claim 10, further comprising a display mounted thereon for displaying at least the calculated oxygen saturation level of blood of the patient.

12. The oximeter of claim 10, wherein said electronic circuit comprises an ASIC circuit integrally mounted to said electronic layer of said patch.

13. The oximeter of claim 10, wherein said patch comprises a bandage adapted to wrap around at least a finger or an earlobe of a patient.

14. The oximeter of claim 10, wherein said patch comprises a bandage adapted to adhere to the forehead or other substantially flat surface of the patient.

15. The oximeter of claim 10, further comprising at least two electrodes mounted to said patch and additional electronics mounted to said electronics layer of said patch or integrated to said electronic circuitry for enabling said electrodes to function effectively to measure at least one other physiological parameter of the patient.

16. The oximeter of claim 10, further comprising an alarm mounted to said patch, said alarm emitting an alarm signal when oxygen saturation is deemed not to be within an acceptable range.

17. The oximeter of claim 11, further comprising a chemical light source that is activatable for illuminating the display.

18. The oximeter of claim 10, wherein said power supply comprises a battery.

19. The oximeter of claim 10, wherein said power supply comprises electronics to draw power from a remote power source.

20. A method for manufacturing a multi-layer disposable oximeter, comprising the steps of:

a) obtaining a flexible patch adapted to be attached to a patient;

b) mounting a light emitter and a light detector to the patch;

c) ensuring that the light emitter and the light detector are disposed on the patch so that they operate in concert with one another, such that the light detector detects light emitted from the light emitter that passes through or is reflected by the patient and acquires data relating to at least the oxygen saturation level of blood of the patient;

d) mounting electronic circuitry to an electronics layer of the patch effective to operate the light emitter and the light detector and to calculate from the acquired data at least a blood oxygen saturation level of the patient;

e) mounting a power supply to the patch to provide electrical power to the electronic circuitry and the light emitter; and

f) a device is provided to the patch that enables the patch to be removably attached to the patient.

21. The method of claim 20, wherein the patch is a bandage, and wherein the step c further comprises the steps of:

the light emitter and light detector are arranged on the bandage to operate in transmission when the bandage is wrapped around a finger or earlobe of a patient.

22. The method of claim 20, wherein said step c further comprises the steps of:

the light emitter and light detector are arranged on the patch to operate in reflection when the patch is attached to the forehead or other generally flat surface of a patient.

23. The method of claim 20, wherein said oximeter is made operative to measure additional physiological parameters of the patient by:

adding at least two electrodes to the patch; and

additional electronics are added to the patch or the electronic circuit to cause the electrodes to operate to measure at least one other physiological parameter of the patient.

24. The method of claim 20, further comprising the steps of:

a display is mounted on the patch to display at least the calculated oxygen saturation level of blood of the patient.

25. The method of claim 24, further comprising the steps of:

a chemical light source is provided to illuminate the display.

26. The method of claim 20, further comprising the steps of:

using electronics included in the power supply device to draw power from a remote power source.