Fetal monitoring system and method and computer for determining fetal hemoglobin oxygen saturation level

Abstract

To provide systems for performing trans-abdominal fetal oximetry.SOLUTION: Light beams emitted from one or more light sources may be directed into an abdomen of a pregnant mammal toward a fetus contained therein. Some of the light may be reflected by the pregnant woman and fetus and received at a detector over a first time. A photodetector into an electronic reflected signal, which may be communicated to a computer, may then convert the received light. The electronic reflected signal may then be processed and / or analyzed to isolate a portion of the electronic reflected signal reflected from the fetus. The isolated portion of the electronic reflected signal reflected from the fetus may then be analyzed to determine a fetal hemoglobin oxygen saturation level of the fetus. An indication of the fetal hemoglobin oxygen saturation level may then be provided to an operator by way of, for example, computer display.SELECTED DRAWING: Figure 2E

Description

Detailed Description of the Invention

[0001] [Related Applications] This application is a non-provisional application of and claims priority to U.S. Provisional Patent Application No. 62 / 273,196, entitled "SYSTEMS, DEVICES, AND METHODS FOR DETECTING / DETERMINING FETAL HEMOGLOBIN OXYGEN SATURATION LEVELS," filed December 30, 2015, the entire contents of which are incorporated herein by reference. [Technical Field]

[0002] The present invention relates to the field of medical devices, and more particularly to the field of transperitoneal fetal oximetry and transperitoneal fetal pulse oximetry. [Background technology]

[0003] When a pregnant mammal is in the process of labor and delivery of its fetus, it is common practice to monitor both the fetal heart rate and the uterine tone of the pregnant mammal. The uterine tone of the pregnant mammal, for example, is measured by measuring the pressure exerted by the uterine muscles, providing information about the uterine contractions of the pregnant mammal in pressure units such as millimeters of mercury (mmHg) and / or kilopascals (kPg). One way to provide information about the fetal heart rate and uterine tone to a physician or other healthcare provider is to provide a graph, either on paper or in electronic form, displaying the fetal heart rate and uterine tone over time. In most cases, this information is synchronized so that the fetal heart rate and uterine tone for a particular time can be observed simultaneously. By comparing the fetal heart rate at a particular time with the uterine tone at the same time, a physician may be able to determine whether the fetal heart rate decreases when the pregnant mammal is experiencing uterine contractions.

[0004] FIGS. 1A and 1B provide two examples of fetal heart rate and uterine tone displayed simultaneously for corresponding times. In FIGS. 1A and 1B, graphs 10A and 10B, respectively, display fetal heart rate in beats per minute as a function of time, with each vertical line provided on the grid representing one minute. In FIGS. 1A and 1B, graphs 12A and 12B display uterine tone in mmHg and kPa, respectively, as a function of time. In FIG. 1A, graph 10A shows a fetal heart rate within the normal range of 120 to 180 beats per minute, with no significant fluctuations in fetal heart rate corresponding to changes in uterine tone. Using the information provided in FIG. 1A, a physician can conclude that the fetus is not being adversely affected by uterine contractions and is not in distress. In contrast, graph 10B shows a fetal heart rate that has experienced a significant drop (e.g., from approximately 150 beats per minute before the contraction to less than 90 beats per minute immediately following the contraction) corresponding to a uterine contraction (i.e., an increase in intrauterine pressure). Using the information provided in FIG. 1B, a physician may conclude that the fetus has been adversely affected by the uterine contraction and may be in distress (e.g., suffering from a lack of oxygen that may cause neurological damage). In reaching this conclusion, the physician may determine that the fetus's health is at risk and therefore should be surgically removed from the uterus via an open delivery (cesarean section). However, because there are many other possible causes of a drop in fetal heart rate, fetal heart rate changes of the type shown in FIG. 1B do not always indicate that the fetus is in distress. Thus, a physician may prescribe a cesarean section when one is not required, causing undue harm to the pregnant mammal.

[0005] Oximetry is a method for determining the oxygen saturation of hemoglobin in mammalian blood. Typically, 90% (or more) of adult human hemoglobin is saturated with (i.e., bound to) oxygen, while only 30-60% of fetal blood is saturated with oxygen.

[0006] Pulse oximetry is a type of oximetry that uses changes in arterial blood volume throughout the cardiac cycle to internally calibrate the oxygen saturation measurement of blood oxygen level.

[0007] Current methods for performing fetal oximetry are deficient for a number of reasons. For example, U.S. Pat. Although JP 2004 / 0116789 describes a fetal oximeter using pulse oximetry, this oximeter is deficient for at least three reasons. First, the wavelength of the electromagnetic radiation used by the '789 publication to determine fetal oximetry is short and, as a result, cannot travel the distance through the abdomen of a pregnant mammal to reach the fetus with sufficient intensity. Therefore, the signal reflection signal is too weak to be interpreted. Second, the '789 publication is deficient due to its inherent assumption that it is based on studies using adult hemoglobin, which is fundamentally different from fetal hemoglobin because fetal hemoglobin has a different structure than adult hemoglobin and therefore absorbs and reflects light differently. Finally, the '789 application does not process the received signal to reduce noise.

[0008] Similar to the '789 publication, WO2009 / 032168 describes a fetal oximeter using near-infrared spectroscopy, but does not provide a signal processing algorithm. In addition, WO2009 / 032168 uses assumptions about adult hemoglobin to determine fetal oximetry, which produces inaccurate results due to fetal and adult hemoglobin having different structures and therefore reflecting light differently.

[0009] U.S. Patent Publication No. 2011 / 0218413 describes algorithms for signal processing using maternal electrocardiography (ECG), Doppler, and pulse oximetry. However, for at least the reasons noted above, attempts to obtain fetal oximetry signals using maternal (i.e., adult) pulse oximetry will not work. Furthermore, the '413 publication does not provide any compensation for structural differences in fetal and adult hemoglobin.

[0010] U.S. Patent Publication No. 2011 / 0218413 provides another example in which a pregnant mammal wears a belt that shines a light toward the abdomen and fetus detected on the other side of the abdomen. The distance the light travels is 15 to 30 inches, or 35 to 75 cm, which is technically impossible because the signal received by the detector would be too weak to decipher. The light is quickly reduced in intensity because excessively intense light could, for example, cause burns to the pregnant mammal and retinal damage to the fetus, and there are FDA limits on the intensity of light that can be directed into the abdomen of a pregnant mammal. Summary of the Invention

[0011] Disclosed herein are systems, devices, and methods for performing transperitoneal fetal oximetry and / or transperitoneal fetal pulse oximetry. The systems, devices, and methods may be performed using one or more fetal hemoglobin probes that contact the abdomen of the pregnant mammal (i.e., are attached to the pregnant mammal via adhesives, straps, harnesses, etc.). In some embodiments, all or a portion of the fetal hemoglobin probe may not contact the abdomen of the pregnant mammal, as may be the case when non-contact pulse oximetry measurements and calculations are performed. When using non-contact pulse oximetry measurements and calculations, the fetal hemoglobin probe and / or a portion thereof may be positioned over the abdomen of the pregnant mammal on, for example, a scaffold or cart.

[0012] An exemplary fetal hemoglobin probe disclosed herein may include a housing, multiple light sources, one or more detectors, a transceiver, and a power source. An exemplary system disclosed herein includes one or more fetal hemoglobin probes and a processor or computer that may be coupled to a display device (e.g., a monitor or touch screen). More specifically, the housing of the fetal hemoglobin probe may be configured to house a first light source, a second light source, a detector, a transceiver, and a power source. In some cases, the housing, the first light source, the second light source, the detector, the transceiver, and / or the power source are configured to be disposable after a single use.

[0013] The first light source is adapted to project light of a first wavelength into the abdomen of the pregnant mammal toward the fetus contained therein, and the second light source is adapted to project light of a second wavelength into the abdomen of the pregnant mammal toward the fetus. In some examples, the first and second light sources may be present in a single light container comprised of multiple light sources (e.g., LEDs), while in other examples, the first and second light sources may be individually housed. An exemplary wavelength for light emitted from the first light source may be 700 nm to 740 nm, and an exemplary wavelength for light emitted from the second light source may be 800 to 900 nm.

[0014] The detector may be adapted to detect light reflected from the abdomen and fetus of the pregnant mammal. Exemplary detectors include, but are not limited to, a photodetector, a photosensor, a photodiode, and a camera. When the detector is a photodetector (or the like), the detector may also convert the detected light into an electronic reflection signal and transmit the electronic reflection signal to a transceiver.

[0015] The transceiver may be adapted to receive the electronic return signals from the detector and to transmit the received electronic return signals to a processor or computer. The transceiver may be any device capable of receiving information from the detector and transmitting information from the fetal hemoglobin probe.

[0016] The power source may be electrically coupled to the first light source, the second light source, and the detector, and may be adapted to provide power to the first light source, the second light source, the detector, and the transceiver. Exemplary power sources include, but are not limited to, a battery and a device that couples the fetal hemoglobin probe to a conventional power source (e.g., a wall outlet).

[0017] The processor may be configured to receive the electronic return signals from the detector and isolate a portion of the electronic return signals that is reflected from the fetus. The processor may then analyze the isolated portion of the electronic return signals to determine the fetal hemoglobin oxygen saturation level and provide an indication of the fetal blood oxygen level to a display device, such as a monitor.

[0018] In some embodiments, the system can include an adjustment mechanism coupled to one of the first and second light sources. The adjustment mechanism can be adapted to, for example, adjust the frequency of the light emitted by the respective first and / or second light source, the angle of incidence of the light emitted by the respective first and / or second light source when projected into the abdomen of the pregnant mammal, and focus the light beam projected into the abdomen of the pregnant mammal when emitted from the respective first and / or second light source.

[0019] In one exemplary embodiment, the system further includes an adjusting device, or a portion thereof, coupled to the container, which may be adapted to adjust the frequency of the light emitted by the respective first and / or second light sources, the angle of incidence of the light emitted by the respective first and / or second light sources when projected into the abdomen of the pregnant mammal, and to focus the light beam projected into the abdomen of the pregnant mammal when emitted from the respective first and / or second light sources.

[0020] In some embodiments, the system may include an additional detector, which may be positioned within the container and coupled to the transceiver and power source, adapted to detect light reflected from the abdomen and fetus of the pregnant mammal, convert the detected light into an additional electronic reflection signal, and communicate the additional electronic reflection signal to the transceiver and / or processor or computer.

[0021] In some embodiments, the system and / or fetal hemoglobin probe may include four or more additional light sources housed within the container or housed within separate containers. Each of the additional light sources is coupled to a power source. These embodiments may also include an additional detector. The additional detector may be positioned within the container and coupled to the transceiver and power source, and may be adapted to detect light reflected from the pregnant mammal's abdomen and fetus, convert the detected light into additional electronic reflection signals, and transmit the additional electronic reflection signals to the transceiver and / or processor or computer. In these embodiments, the container may be adapted to extend around a portion of the pregnant mammal's abdomen and have a length of at least 10 cm to direct light to multiple locations (e.g., two or more sides) of the fetus. In these embodiments, the detector may be positioned on a first side of the container, the additional detector may be positioned on a second side of the container, and the light source may be positioned between the first and second sides of the container.

[0022] In some cases, the system may include a temperature probe housed within the enclosure and coupled to the power supply and transceiver. The temperature probe may be adapted to measure the temperature of the pregnant mammal's abdomen and / or skin and transmit the temperature measurement to, for example, the transceiver and / or controller. At times, a temperature measurement above a threshold may indicate that the system is overheating and may cause damage to the pregnant mammal and / or fetus. When this occurs, the controller may shut down one or more components of the system and / or alert an operator of the elevated temperature of the pregnant mammal.

[0023] In another embodiment, the system may include an ultrasound detector housed within the enclosure and coupled to the power supply and the transceiver, the ultrasound detector may be adapted to detect ultrasound emissions of the pregnant mammal's abdomen and fetus caused by transient thermoelastic expansion resulting from interaction of tissue of the pregnant mammal's abdomen and fetus with light emitted from at least one of the first light source and the second light source due to the so-called photoacoustic effect.

[0024] In another embodiment, the system may further include a uterine contraction measurement device contained within the container and coupled to the power supply and the transceiver, processor, and / or computer, wherein the uterine contraction measurement device may be adapted to measure changes in the muscle state of the pregnant mammal's uterus and communicate these measurements to the transceiver, processor, and / or computer.

[0025] An exemplary method described herein can include directing a light beam emitted from the light source into the abdomen of a pregnant mammal toward a fetus contained therein. Light reflected by the pregnant mammal and the fetus can be received over a first time domain with a detector. The detector can then convert the received light into an electronic reflection signal and communicate the electronic reflection signal to a computer / processor.

[0026] The computer may then process the electronic return signals to isolate a portion of the electronic return signals reflected from the fetus and analyze the portion of the electronic return signals reflected from the fetus to determine a fetal hemoglobin oxygen saturation level of the fetus. The computer may then facilitate providing an indication of the fetal hemoglobin oxygen saturation level to an operator, such as a physician or medical technician.

[0027] In some embodiments, processing the electronic reflection signal to isolate the portion of the electronic reflection signal reflected from the fetus includes receiving a heartbeat signal of the pregnant mammal over a second time domain. The heartbeat signal indicates when the heartbeat of the pregnant mammal occurs over the second time domain. The electronic reflection signal and the heartbeat signal of the pregnant mammal may then be synchronized over the first time domain and the second time domain, and a portion of the electronic received signal corresponding to the heartbeat signal of the pregnant mammal may be determined within the synchronized first and second time domains. The portion of the electronic received signal corresponding to the heartbeat signal of the pregnant mammal from the electronic received signal may then be a subtracted electronic received signal.

[0028] In another embodiment, processing the electronic reflection signals to isolate portions of the electronic reflection signals reflected from the fetus may include receiving a fetal heart rate signal for the fetus over a second time domain. The fetal heart rate signal may indicate when fetal heartbeats occur within the second time domain. The electronic reflection signals and the fetal heart rate signal may then be synchronized over the first and second time domains, and portions of the electronic reflection signals corresponding to individual heartbeats of the fetus as indicated by the received heart rate signal for the fetus within the synchronized first and second time domains may be examined to determine a fetal hemoglobin saturation level for the fetus.

[0029] In a further embodiment, processing the electronic reflection signal to isolate the portion of the electronic reflection signal reflected from the fetus includes receiving a fetal heart rate signal from the fetus over a second time domain, the heart rate signal indicating when the fetal heart rate occurs within the second time domain. The electronic reflection signal and the fetal heart rate signal may then be synchronized over the first time domain and the second time domain. The synchronized electronic reflection signal may then be multiplied by the synchronized fetal heart rate signal. [Brief explanation of the drawings]

[0030] The present invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings, in which:

[0031] [Figure 1A-1B]1 provides an example of fetal heart rate and uterine tone displayed simultaneously for corresponding times. [Figure 2A] Consistent with an embodiment of the present invention, an exemplary system 100 for determining fetal oxygen levels is provided. [Figures 2B-2E] 1 provides a block diagram of an exemplary fetal hemoglobin probe consistent with embodiments of the present invention. [Figures 3A-3D] 1 provides an illustration of how light from a fetal hemoglobin probe may be directed into the abdomen of a pregnant mammal, consistent with an embodiment of the present invention. [Figure 4A] 1 is a flowchart illustrating a process for determining fetal hemoglobin saturation levels, consistent with an embodiment of the present invention. [Figure 4B-4C] 10 is a flowchart illustrating a process for processing electronic return signals to isolate a portion of the electronic return signal from the fetus, consistent with an embodiment of the present invention. [Figure 5A] 1 provides a graph of total electron reflected signal intensity versus time, consistent with an embodiment of the present invention. [Figure 5B] 1 provides a graph of fetal Doppler signal versus time, consistent with an embodiment of the present invention. [Figure 5C] 10 provides a graph showing the product of total electron return signal intensity and Doppler signals synchronized and multiplied together over time, consistent with an embodiment of the present invention. [Figure 5D] 10 provides graphs of the results of multiplying total electronic return signal strength, fetal heart rate / Doppler signal, and time-synchronized total electronic return signal strength and Doppler signal, consistent with embodiments of the present invention. [Figure 6A] 1 provides a graph of fetal Doppler signal versus time, consistent with an embodiment of the present invention. [Figure 6B] 1 provides a graph of electron reflected signal intensity versus time for λ 1 , consistent with an embodiment of the present invention. [Figure 6C]10 provides a graph showing the product of the total electron return signal intensity versus λ1 and the fetal Doppler signal synchronized and multiplied together over time, consistent with an embodiment of the present invention. [Figure 6D] 10 provides a graph showing the time-synchronized co-multiplication product of total electron return signal strength and fetal Doppler signal versus λ averaged over several time periods, consistent with an embodiment of the present invention. [Figure 6E] 10 provides a graph of electron reflected signal intensity versus time for λ 2 , consistent with an embodiment of the present invention. [Figure 6F] 10 provides a graph showing the product of the total electron return signal intensity versus λ and the fetal Doppler signal synchronized and multiplied together over time, consistent with an embodiment of the present invention. [Figure 6G] 10 provides a graph showing the time-synchronized co-multiplication product of total electron return signal intensity and fetal Doppler signal versus λ averaged over several time periods, consistent with an embodiment of the present invention. [Figure 6H] 1 provides a graph showing the relationship between red / infrared wavelength modulation budget and arterial oxygen saturation (%SaO2). [Figure 7A] 1 provides a table of various hemoglobin measurements as a function of wavelength of light shone in adult donor blood and fetal blood obtained by umbilical cord puncture immediately after delivery, consistent with an embodiment of the present invention. [Figure 7B] 1 illustrates a graph showing the difference in absorptivity between oxygenated and deoxygenated states of fetal and maternal hemoglobin at visible wavelengths of light, consistent with an embodiment of the present invention. [Figure 7C] 1 illustrates a graph showing the difference in absorptivity between oxygenated and deoxygenated states of fetal and maternal hemoglobin at wavelengths of near-infrared (NIR) light, consistent with an embodiment of the present invention. [Figure 8A] 1 provides an exemplary display providing fetal hemoglobin oxygen saturation levels along with other information regarding measurements of a pregnant mammal and a fetus, consistent with embodiments of the present invention. [Figure 8B]1 provides an exemplary display of fetal heart rate, fetal hemoglobin oxygen saturation, and uterine tone synchronized to corresponding times, consistent with embodiments of the present invention.

[0032] Throughout the drawings, the same reference numerals and characters, unless otherwise stated, are used to denote like features, elements, components, or portions of the illustrated embodiments. Moreover, while the subject invention will now be described in detail with reference to the drawings, it is done so in connection with the illustrative embodiments. It is contemplated that changes and modifications can be made to the described embodiments without departing from the scope and spirit of the subject invention, as defined by the appended claims. DETAILED DESCRIPTION OF THE INVENTION

[0033] Systems, devices, and methods for transperitoneal and intrauterine fetal oximetry and / or fetal pulse oximetry are described herein. A key output of fetal oximetry and / or fetal pulse oximetry is the level of oxygen saturation of the fetal blood (also referred to as "fetal hemoglobin oxygen saturation level" and "oxygen saturation level"), which may also be understood as the percentage of hemoglobin present in the fetal blood that is bound to oxygen. The fetal blood oxygen saturation level may be used by skilled medical professionals to assess the health of the fetus and the level of pressure the fetus may be subjected to during, for example, the labor and delivery process. Typically, fetal blood oxygen saturation values fall within the range of 30-60%, with values below 30% indicating that the fetus may be in distress.

[0034] For the purposes of the following discussion, the terms "pregnant mammal" or "maternal" or "mother" are used to refer to a female human or animal (e.g., a horse or cow) that is carrying a fetus. In most embodiments, the pregnant individual is a human, although this need not be the case, as the present invention can be used with almost any pregnant mammal. Whether or not the pregnant mammal is the biological mother of the fetus (i.e., the source of the egg from which the fetus develops) is irrelevant to the present invention. What is relevant is that a woman is carrying a fetus.

[0035] A healthy fetus is typically assessed during labor and delivery by looking at the absolute fetal heart rate, measured in beats per minute, and observing how the fetal heart rate changes or responds to uterine contractions. It is generally accepted that a fetal heart rate within the range of 120 to 160 beats per minute is normal and does not indicate fetal distress. However, sudden changes in fetal heart rate, as well as excessively high (e.g., 180 beats per minute) or excessively low (e.g., 100 or 80 beats per minute) fetal heart rates, are cause for concern, especially when such changes occur during a prolonged, difficult, or otherwise complicated labor and delivery process.

[0036] For example, as the uterus contracts to expel a baby from the birth canal, the uterine contractions restrict blood vessels, and therefore blood flow, to and from the placenta, supplying blood to and from the fetus. Restricted fetal blood flow would be expected to slow the fetal heart rate. However, a decrease in fetal heart rate of 150 to 120 beats after each uterine contraction may be an indication of fetal distress and may prompt intervention by a physician or other clinician during the birth process (e.g., cesarean section, medication, etc.).

[0037] However, in some instances, this intervention is not necessarily necessary, as not all declines are caused by fetal compromise. Indeed, a fetus is often healthy even when its heart rate changes—but without further information to help a physician determine whether the fetal heart rate change is normal or pathological. Thus, an indication of fetal hemoglobin oxygen saturation level may be a useful additional indicator of a healthy fetus when determining whether to intervene in the labor and delivery process with surgery or other therapeutic procedures. For example, an indication that the fetal hemoglobin oxygen saturation level remains constant provides a physician with an indication that the fetus is healthy, even if the fetal heart rate decreases or changes. Conversely, a decrease in fetal hemoglobin oxygen saturation level after uterine contractions associated with a decrease in heart rate may be a cause for concern and indicate to a physician that intervention, such as a cesarean section, is necessary.

[0038] Currently, many cesarean sections are performed solely due to fluctuations or slowing of the fetal heart rate, which physicians view as a sign of fetal distress. Two million cesarean sections are performed annually in the United States, and in some areas of the United States, cesarean sections account for nearly half (50%) of all births. In some instances, such cesarean sections may not be necessary because the fetus may not be truly in distress. However, without further information (such as may be provided via fetal pulse oximetry), physicians may overprescribe cesarean sections and other interventions without due caution.

[0039] The present invention provides a more complete picture of fetal health during labor and delivery, and may therefore reduce the number of unnecessary cesarean sections performed when the decision to perform a cesarean section is based solely on fetal heart rate readings. Reducing the number of unnecessary cesarean sections is expected to reduce the overall cost of medical care for pregnant women and newborns, and reduce the number of complications resulting from cesarean sections, which can be very serious. For example, 1 in 1,000 cesarean sections will result in a major complication, such as a blood clot, need for a blood transfusion, or surgical wound infection, and 1 in 10,000 cesarean sections will result in maternal death.

[0040] Fetal hemoglobin has a slightly different structure than adult hemoglobin. More specifically, adult hemoglobin has two alpha and two beta polypeptide chains, while fetal hemoglobin has two alpha and two gamma polypeptide chains. Furthermore, fetal hemoglobin has a stronger oxygen affinity than adult hemoglobin. Due to these factors, fetal hemoglobin absorbs light differently than maternal hemoglobin.

[0041] Furthermore, fetal hemoglobin has a conformation when bound to oxygen that differs from the conformation of fetal hemoglobin when unbound to oxygen. These different hemoglobin conformations absorb light differently and therefore reflect it differently. Therefore, observing the oxygen saturation level of fetal venous hemoglobin may be more clinically useful than the oxygen saturation level of fetal arterial hemoglobin.

[0042] Described herein are systems, devices, and methods for performing noninvasive intrauterine fetal oximetry using near-infrared spectroscopy (NIRS) to determine arterial and / or venous fetal hemoglobin oxygen saturation levels. For example, a physical or other caregiver may then use the determined arterial and / or venous fetal hemoglobin oxygen saturation levels to ascertain information regarding fetal health and / or malconditioning. In some embodiments, the systems, devices, and methods may employ a noninvasive monitor that may be placed on the abdomen of a pregnant mammal to monitor fetal oxygen saturation levels.

[0043] Fetal hemoglobin is too small to be directly observed. However, the reflection of near-infrared light from fetal hemoglobin can be observed. Furthermore, the different intensities for different wavelengths of light reflected by fetal hemoglobin can also be observed. Furthermore, the different intensities for light reflected by fetal oxyhemoglobin compared to fetal deoxyhemoglobin can also be observed. Processing of this observed reflected light can yield a determination of fetal oxygen saturation level.

[0044] 2A provides an exemplary system 100 for determining fetal oxygen levels, and in some examples, for detecting and / or determining fetal hemoglobin oxygen saturation levels. The components of system 100 may be coupled together via wired or wireless communication links. In some examples, wireless communication of one or more components of system 100 may enable the use of short-range wireless communication protocols designed to communicate over relatively short distances (e.g., BLUETOOTH®, near field communication (NFC), radio frequency identification (RFID), and Wi-Fi), for example, with a computer or personal electronic device as described below. In some embodiments, one or more components of system 100 may include one or more devices configured to communicate via one or more short-range communication protocols (e.g., near field communication (NFC), BLUETOOTH®, radio frequency identification (RFID), and Wi-Fi).

[0045] System 100 includes multiple independent sensors / probes designed to monitor various aspects of maternal and / or fetal health and to contact the pregnant mammal. These probes / sensors are fetal hemoglobin probe 115, NIRS adult hemoglobin probe 125, pulse oximetry probe 130, and Doppler and / or ultrasound probe 135. In some embodiments, system 100 may also include an electrocardiography (EKG or ECG) machine (not shown) that can be used to determine the pregnant mammal and / or fetal heart rate, and / or an intrauterine pulse oximetry probe that can be used to determine the fetal heart rate. Doppler and / or ultrasound probe 135 may be configured to be placed on the abdomen of the pregnant mammal and may be approximately the size and shape of a silver dollar. Pulse oximetry probe 130 may be a conventional pulse oximetry probe placed on the hand and / or finger of the pregnant mammal to determine the oxygen saturation of the pregnant mammal. The NIRS adult hemoglobin probe 125 can be placed, for example, on the second digit of the pregnant mammal and configured to calculate the ratio of adult oxyhemoglobin to adult deoxyhemoglobin using, for example, near-infrared spectroscopy. The NIRS adult hemoglobin probe 125 can also be used to determine the heart rate of the pregnant mammal.

[0046] Optionally, system 100 may include a uterine contraction measurement device 140 configured to measure the intensity and / or timing of uterine contractions of a pregnant mammal. In some embodiments, uterine contractions may be measured over time as a function of pressure (e.g., measured in mmHg) by uterine contraction measurement device 140. In some examples, uterine contraction measurement device 140 is and / or includes a labor transducer, which is an instrument that includes a pressure-sensing region that detects changes in abdominal contour to measure uterine activity, thus observing the frequency and duration of uterine contractions.

[0047] In another embodiment, the uterine contraction measurement device 140 may be configured to pass an electric current through a pregnant mammal and measure the change in the electric current as the uterus contracts. Additionally or alternatively, uterine contractions may also be measured via near-infrared spectroscopy, as uterine contractions are oscillations of the uterine muscle between contracted and relaxed states. The oxygen consumption of the uterine muscle during both of these phases differs, and these differences may be detectable using NIRS.

[0048] Measurements by the NIRS adult hemoglobin probe 125, pulse oximetry probe 130, Doppler and / or ultrasound probe 135, and / or uterine contraction measurement device 140 may be communicated to the computer 150 and transmitted to the receiver 145 for display on the display device 155. In some examples, one or more of the NIRS adult hemoglobin probe 125, pulse oximetry probe 130, Doppler and / or ultrasound probe 135, and uterine contraction measurement device 140 may include a dedicated display that provides measurements to an operator or medical care provider, for example.

[0049] As discussed below, measurements provided by the NIRS adult hemoglobin probe 125, pulse oximetry probe 130, Doppler and / or ultrasound probe 135, and uterine contraction measurement device 140 may be used in conjunction with the fetal hemoglobin probe 115 to isolate the fetal pulse signal and / or fetal heart rate from the maternal pulse signal and / or maternal heart rate.

[0050] It is important to note that not all of these probes may be used in all instances. For example, when a pregnant mammal is using fetal hemoglobin probe 115 in an environment other than a hospital or medical facility (e.g., at home or at work), some of the probes of system 100 (e.g., NIRS adult hemoglobin probe 125, pulse oximetry probe 130, Doppler and / or ultrasound probe 135, uterine contraction measurement device 140) may not be used.

[0051] Receiver 145 may be configured to receive signals and / or data from one or more components of system 100, including, but not limited to, fetal hemoglobin probe 115, NIRS adult hemoglobin probe 125, pulse oximetry probe 130, Doppler and / or ultrasound probe 135, and / or uterine contraction measurement device 140. Communication of receiver 145 with other components of the system may occur using wired or wireless communication.

[0052] In some examples, receiver 145 may be configured to process or pre-process the received signal, such as to generate a signal compatible with computer 150 (e.g., convert an optical signal to an electrical signal), improve the SNR, amplify the received signal, etc. In some examples, receiver 145 may reside within and / or be a component of computer 150. Also, although receiver 145 is illustrated in FIG. 2A as a single receiver, this is not necessarily the case, as any number of suitable receivers (e.g., 2, 3, 4, 5) may be used to receive signals from components of system 100 and convey them to computer 150. In some embodiments, computer 150 may amplify or otherwise condition the received reflected signal, for example, to improve the signal-to-noise ratio.

[0053] Receiver 145 may communicate the received, pre-processed, and / or processed signals to computer 150. Computer 150 may act to process the received signals and facilitate providing the results to display device 155, as discussed in more detail below. Exemplary computers 150 include desktop and laptop computers, servers, tablets, and the like. The display device 155 may include a tablet computer, a personal electronic device, a handheld device (e.g., a smartphone), etc. Exemplary display devices 155 are a computer monitor, a tablet computing device, and a display provided by one or more of the components of system 100. In some examples, display device 155 may reside within receiver 145 and / or computer 150.

[0054] The fetal hemoglobin probe 115 can be used to direct NIR light into the abdomen of the pregnant mammal to reach the fetus and to detect light reflected from the fetus. The NIR light can be emitted by the fetal hemoglobin probe 115, for example, continuously and / or in a pulsed manner. This reflected light can then be processed to determine the amount of light reflected and / or absorbed by fetal oxyhemoglobin and / or deoxyhemoglobin at various wavelengths so that the fetal hemoglobin oxygen saturation level can be determined. This processing will be discussed in more detail below. In some embodiments, the fetal hemoglobin probe 115 can be configured as a single-use or disposable probe that is partially or entirely adhered to the skin of the pregnant mammal, for example, on the abdomen of the pregnant mammal, and in some embodiments, in the suprapubic (bikini) region.

[0055] Exemplary dimensions of the fetal hemoglobin probe 115 include, but are not limited to, a length of 2 to 16 inches and a width of 0.5 to 8 inches. In some examples, the fetal hemoglobin probe 115 can be variously sized to accommodate, for example, different clinical needs, fetal sizes, fetal positions, pregnant mammal sizes, and / or pregnant mammal abdominal sizes.

[0056] The fetal hemoglobin probe 115 may include one or more components as described in more detail below with respect to FIGS. 2B-2E, of which the fetal hemoglobin probes of FIGS. 2B-2D (i.e., 115A, 115B, 115C, and 115D) are transperitoneal fetal hemoglobin probes. The fetal hemoglobin probes 115 described herein may include a housing 102 configured to house one or more components of the fetal hemoglobin probe 115. While the embodiments disclosed herein have all of the components of the fetal hemoglobin probe 115 contained within a single housing 102, this is not necessarily the case, as, for example, two or more components of the fetal hemoglobin probe 115 may be housed within separate housings 102. The housing 102 may be, for example, square, circular, or rectangular in shape and, in some instances, may be designed to be adjustable depending, for example, on the topology of the pregnant mammal's abdomen, the level of skin pigmentation of the pregnant mammal and / or its fetus, etc.

[0057] In some embodiments, the fetal hemoglobin probe 115 and / or the container 102 may be disposable, while in other embodiments, the fetal hemoglobin probe 115 (including and / or the container 102) may be configured for multiple uses (i.e., reusable). In some embodiments (e.g., when the fetal hemoglobin probe is configured to be disposable), the container 102 / fetal hemoglobin probe 115 may include an adhesive (e.g., glue, tape, etc.) designed to be applied to the abdominal skin of the pregnant mammal, configured to apply the container 102 / fetal hemoglobin probe 115 directly to the abdominal skin of the pregnant mammal and hold it in place in a manner similar to a sticker. In some instances, the fetal hemoglobin probe 115 may be applied to the skin of the pregnant mammal via a tape or strap that cooperates with a mechanism (e.g., a snap, loop, etc.) (not shown) provided by the container 102. In some situations, the container 102 may be attached / adjacent to the skin of the pregnant mammal to prevent removal, while in other instances, it may be removable, for example, to achieve a better measurement / reading. In some cases, the container 102 and / or portions thereof may not be adapted to contact the abdomen of the pregnant mammal.

[0058] In some embodiments, the container 102 and / or portions thereof may cooperate with a reusable and / or disposable sleeve (not shown) that fits over the fetal hemoglobin probe 115 so that the fetal hemoglobin probe 115 may be placed within the reusable and / or disposable sleeve of the container 102 so that it may be applied to the skin of a pregnant mammal.

[0059] The fetal hemoglobin probe 115 may be adapted to direct or shine light of one or more wavelengths into the abdomen of the pregnant mammal and to receive signals corresponding to reflections of portions of the light from the tissues and fluids of the pregnant mammal and the fetal tissues and fluids.

[0060] Optionally, fetal hemoglobin probe 115 may include one or more features that allow it to direct the emitted light in a particular direction. Such features include, but are not limited to, a wedge or adhesive material, which may be transparent or nearly transparent. For example, fetal hemoglobin probe 115 may include a wedge positioned on one side that operates to direct light in a particular direction relative to the surface of the pregnant mammal's skin and / or position a detector or transceiver to receive an optimal amount of reflected light.

[0061] In some embodiments, fetal hemoglobin probe 115 may be adapted to be worn by a pregnant mammal for an extended period of time (e.g., several days, weeks, etc.) that does not necessarily coincide with the labor and delivery process, e.g., to monitor the health of the fetus. In some embodiments, one or more components of fetal hemoglobin probe 115 may be positioned external to fetal hemoglobin probe 115 and optically connected thereto, e.g., via one or more fiber optic or Ethernet cable(s).

[0062] The fetal hemoglobin probe 115 may be of any suitable size and, in some circumstances, may be sized to fit the size of the pregnant mammal using an appropriate sizing system (e.g., waist size and / or small, medium, large, etc.). Exemplary lengths for the fetal hemoglobin probe 115 include lengths of 4 cm to 40 cm and widths of 2 cm to 10 cm. In some circumstances, the size and / or configuration of the fetal hemoglobin probe 115, or components thereof, may be responsive to the pigmentation of the skin of the pregnant mammal and / or fetus.

[0063] Although the components of the fetal hemoglobin probe 115 are described herein as being contained within a single probe, it will be understood that this is not necessarily the case, as the components of the fetal hemoglobin probe 115 may be present in two or more different objects / devices applied to the pregnant mammal. In some instances, more than one fetal hemoglobin probe 115 may be used, for example, to improve the accuracy of fetal oxygen saturation measurements. For example, a first fetal hemoglobin probe 115 (or a component thereof) may be positioned on the left side of the pregnant mammal's abdomen, and a second fetal hemoglobin probe 115 (or a component thereof) may be positioned on the right side of the pregnant mammal's abdomen.

[0064] In some embodiments, fetal hemoglobin probe 115 and / or a pregnant mammal wearing fetal hemoglobin probe 115 can be electrically isolated from one or more components of system 100, for example, by electrical isolators 120. Exemplary electrical isolators 120 include circuit breakers, ground fault switches, and fuses.

[0065] 2B-2E, which illustrate different embodiments of exemplary fetal hemoglobin probe 115, labeled 115A, 115B, 115C, and 115D, respectively, intended for transperitoneal use. It will be understood that reference to fetal hemoglobin probe 115 manufactured herein may also refer to and include other embodiments of fetal hemoglobin probes, including fetal hemoglobin probe 115A, fetal hemoglobin probe 115B, fetal hemoglobin probe 115C, and fetal hemoglobin probe 115D. FIG. 2B illustrates exemplary fetal hemoglobin probe 115A, including power supply 160, light source(s) 105, transceiver 107, and detector 114.

[0066] Exemplary power supply 160 includes an internal battery and / or an electrical connection to an external power source. Detector 114 may be adapted to receive optical signals reflected from the pregnant mammal and / or fetus and convert the optical signals into electronic signals that can be transmitted to transceiver 107. Some embodiments of fetal hemoglobin probe 115 may not include transceiver 107, as may be the case when detector 114 communicates directly with computer 150, for example. Exemplary detectors 114 include, but are not limited to, cameras, conventional photomultiplier tubes (PMTs), silicon PMTs, avalanche photodiodes, and silicon photodiodes. In some embodiments, the detector will have relatively low cost (e.g., less than $50), low voltage requirements (e.g., less than 100 volts), and a non-glass (e.g., plastic) formulation. However, these alternatives do not have the same sensitivity as PMTs. In other embodiments, an ultrasensitive camera (e.g., non-contact pulse oximetry) may be deployed to receive light reflected by the abdomen of the pregnant mammal.

[0067] The light source(s) 105 can deliver light at various wavelengths, including near-infrared, to the abdomen of the pregnant mammal. Typically, the light emitted by the light source(s) 105 will be focused or emitted as a narrow beam to reduce light spread upon entry into the abdomen of the pregnant mammal. The light source(s) 105 can be, for example, an LED and / or a laser. In some embodiments, the light source(s) 105 can be an array of two or more light sources 105, as discussed below with respect to FIGS. 2C-2E. Exemplary light sources 105 have a relatively small form factor and high performance to limit heat emitted by the light source(s) 105. In one embodiment, the light source 105 is configured to emit light at 850 nm, an example of which is an LED in a Dragon Dome Package emitting 850 nm light manufactured by Osram Opto Semiconductors (model number SFH4783) having a length of 7.080 mm and a width of 6.080 mm. Another exemplary light source 105 is an LED configured to emit 730 nm light, such as the GF CSHPM1.24-3S4S-1 manufactured by Osram Opto Semiconductors, Inc., having a height of 1.58 mm and a length of 3.1 mm. Exemplary flux ratios of the light source(s) include, but are not limited to, a luminous flux / radiant flux of 175 to 260 mW, a total radiant flux of 300 to 550 mW, and a power rating of 0.6 W to 3.5 W.

[0068] In some embodiments, one or more light sources 105 may be fiber optic cable-transmitted light generated by a separate source (e.g., a laser or a tunable bulb or LED) not present within fetal hemoglobin probe 115. In some examples, light source(s) 105 may be tunable or otherwise user-configurable, while in other examples, one or more of the light sources may be configured to emit light within a predefined range of wavelengths. Additionally or alternatively, one or more filters (not shown) and / or polarizers may filter / polarize the light emitted by light source(s) 105 to consist of one or more preferred wavelengths. These filters / polarizers may also be tunable or user-configurable.

[0069] In some embodiments, the fetal hemoglobin probe 115 can direct multiple wavelengths of NIR light (e.g., 7, 6, 5, 4, 3, 2) through the light source 105. In one embodiment, five different wavelengths are used: a first wavelength is used to measure the oxygen saturation level of adult oxyhemoglobin, a second wavelength is used to measure the oxygen saturation level of adult deoxyhemoglobin, a third wavelength is used to measure the oxygen saturation level of fetal oxyhemoglobin, and a fourth wavelength is used to measure the oxygen saturation level of fetal deoxyhemoglobin. A fifth wavelength may be used to remove / improve the signal by helping to detect portions of the reflected signal that may be caused and / or altered by substances other than the pregnant mammal and / or fetal hemoglobin. For example, melanin and bilirubin are known to absorb infrared light. Thus, in instances where the fetus and / or pregnant mammal have darker pigment, or where either or both are jaundiced, the associated melanin and / or bilirubin may distort the reading of the fetal hemoglobin probe 115, resulting in an inaccurate calculation of the oxygen saturation of the fetal and / or pregnant mammal's hemoglobin. The fifth wavelength can be removed from the received signal and serve to test for these variations so that the correct oxygen saturation level can be determined.

[0070] In some embodiments, detector 114 may be a sensitive camera adapted to capture small changes in fetal skin color caused by changes in cardiovascular pressure as the fetal heartbeat. In these embodiments, fetal hemoglobin probe 115 may or may not contact the abdomen of the pregnant mammal, as this embodiment may be used to perform so-called non-contact pulse oximetry. In these embodiments, light source(s) 105 of fetal hemoglobin probe 115 may be adapted to provide light (e.g., in the visible spectrum, near-infrared, etc.) directed toward the abdomen of the pregnant mammal so that detector 114 can receive light reflected by the abdomen and fetus of the pregnant mammal. The reflected light captured by detector 114 in this embodiment may be transmitted via transceiver 107 to computer 150 for processing, e.g., to convert the image into a measurement of fetal hemoglobin oxygen saturation by one or more of the processes described herein.

[0071] In this embodiment, the adjustment mechanism 122 may be adapted to, for example, focus the light source(s) 105, change the frequency of the light emitted by the light source(s) 105, change the distance the light source(s) 105 and / or detector 114 are positioned away from the abdominal surface of the pregnant mammal, and / or change the location of incidence of the emitted light.

[0072] Optionally, fetal hemoglobin probe 115 may also include one or more polarizers (not shown), which may act to polarize one or more of the wavelengths of light prior to emission by fetal hemoglobin probe 115. Polarizing light and imparting a particular orientation to light may function, for example, to aid in signal identification and / or distinguishing desired signals from noise, thereby improving the signal-to-noise ratio (SNR) of the received signal.

[0073] The transceiver 107 may be configured to transmit an electronic signal (corresponding to the reflected optical signal detected by the detector 114) from the detector 114 to a device (e.g., the receiver 145 and / or the computer 150) external to the fetal hemoglobin probe 115, for example, via a fiber optic cable (in the case of an optical signal) and / or a wireless or wired signal (e.g., via an Ethernet port or hardwired connection in the case of an electrical signal). In some examples, the transceiver 107 may be a solid-state transceiver. In some embodiments, the transceiver 107 may be present within and / or part of the detector 114 and configured to detect light and / or photons reflected from the pregnant mammal and fetus and convert the detected light / photons into an electrical signal.

[0074] FIG. 2C shows another exemplary fetal hemoglobin probe 115B, including a power supply 160, light source(s) 105, a transceiver 107, a detector 114, an adjustment mechanism 122, a temperature probe 165, and a control unit 112.

[0075] Temperature probe 165 may be any suitable mechanism for obtaining temperature measurements on a pregnant mammal. Adjustment mechanism 122 may be one or more mechanisms adapted to adjust one or more characteristics of the light emitted by light source(s) 105 and / or the direction / angle of incidence of the light directed into the abdomen of the pregnant mammal. Exemplary adjustment mechanisms include, but are not limited to, filters and polarizers that may be used to adjust the frequency / wavelength of the light emitted by light source(s) 105 and / or the direction of the light. Other exemplary adjustment mechanisms 122 include, for example, lenses adapted to focus or diffuse the light directed into the abdomen of the pregnant mammal. In some examples, the lenses may change the angle of incidence for the light directed into the abdomen of the pregnant mammal. In some embodiments, adjustment mechanism 122 may also include mechanisms capable of moving light source 105 and / or operating lenses, filters, or polarizers. In some embodiments, adjustment mechanism 122 may include a material that is sensitive to electricity and may be capable of being transparent and / or partially opaque when energized. The adjustment mechanism(s) 122 may often receive instructions from a controller 112 that may control (in whole or in part) the operation of the adjustment mechanism 122 .

[0076] Optionally, fetal hemoglobin probe 115 may also include one or more ultrasound detectors 170. Ultrasound detectors 170 may be employed in embodiments of fetal hemoglobin probe 115 configured to perform optoacoustic / photoacoustic and / or thermoacoustic imaging by directing light or radio frequency pulses from light source(s) 105 into the abdomen of pregnant mammal 305. A portion of the incident light may be absorbed by the fetus and pregnant mammal and converted to heat, causing transient thermoelastic expansion that triggers ultrasound emission from the fetus and pregnant mammal. This ultrasound emission may be detected and analyzed by ultrasound detector 170 to determine the level of oxygen saturation for the blood of the fetus and / or pregnant mammal. In some examples, deployment of fetal hemoglobin probe 115 to perform optoacoustic / photoacoustic and / or thermoacoustic imaging may require the use of a laser and / or radio frequency pulse emitter (not shown).

[0077] Controller 112 may be adapted to control one or more components of fetal hemoglobin probe 115 (e.g., adjustment mechanism 122, light source(s) 105, power supply 160, temperature probe 165, detector 114, and / or transceiver 107). In some circumstances, controller 112 may include a processor adapted to receive measurements / information from more than one component of fetal hemoglobin probe 115 (e.g., adjustment mechanism 122, light source(s) 105, power supply 160, temperature probe 165, detector 114, and / or transceiver 107). The processor may be further adapted to process the received measurements, make decisions using them, and communicate instructions based on such decisions and / or measurements to one or more components of fetal hemoglobin probe 115. For example, temperature probe 165 may act to measure the body temperature of the pregnant mammal and provide these measurements to controller 112 and / or the transceiver. In some embodiments, these measurements may be used to determine whether the temperature of the pregnant mammal exceeds a threshold measurement, which in some instances may indicate that the light source(s) 105 and / or fetal hemoglobin probe 115 are delivering too much heat / energy to the pregnant mammal. Upon reaching such a determination, the controller 112 may provide instructions to the light source(s) 105 and / or the adjustment mechanism 122 to correct for this. Exemplary instructions include, but are not limited to, directions for redirecting, blocking, adjusting the frequency of, and adjusting the intensity of one or more of the light sources 105.

[0078] In some examples, the instructions provided by controller 112 may be based on feedback from, for example, detector 114 and / or transceiver 107 regarding, for example, the strength / intensity of the reflected signal, the frequency / wavelength of light received in the reflected signal. For example, if controller 112, transceiver 107, and / or detector 114 determine that the received signal reflected from the abdomen of the pregnant mammal has insufficient strength / intensity, then controller 112 may provide instructions to adjustment mechanism 112 and / or light source(s) 105 to increase the intensity and / or wavelength / frequency of the light incident on the abdomen of the pregnant mammal.

[0079] In another example, temperature probe 165 may act to measure the body temperature of the pregnant mammal and provide these measurements to controller 112 and / or transceiver. In some embodiments, these measurements may be used to determine whether the temperature of the pregnant mammal exceeds a threshold measurement, which in some examples may indicate that light source(s) 105 and / or fetal hemoglobin probe 115 are delivering too much heat / energy to the pregnant mammal. Upon reaching such a determination, controller 112 may provide instructions to light source(s) 105 and / or adjustment mechanism 122 to correct the same. Exemplary instructions include, but are not limited to, directions to redirect, block, adjust the frequency of, and / or adjust the intensity of one or more of light sources 105.

[0080] In some examples, light source(s) 105 may be tunable or otherwise user-configurable, e.g., by a physician or clinician assisting the pregnant mammal during the labor and delivery process. For example, light source 105 may be configured to emit light at multiple frequencies / wavelengths and / or intensities, and light source 105 may be adjusted, e.g., by direct physical manipulation of light source 105 (e.g., via a button on a knob) or by entering commands into, e.g., computer 150 and / or controller 112, regarding the desired frequency / wavelength and / or intensity.

[0081] Adjusting the frequency / wavelength and / or intensity of the light emitted by one or more light sources(s) 105 can be useful in achieving a return signal of sufficient strength or clarity in various situations (e.g., fetal position, fetal size, amount of melanin in the pregnant mammal and / or fetus's skin, size and / or shape of the pregnant mammal, etc.). For example, a relatively higher intensity of light may be desired when the pregnant mammal has a relatively high body mass index (BMI) or body fat positioned in a manner to suppress the strength of the signal reflected from the fetus (i.e., the return signal). In another example, the fetus may be positioned relative to the pregnant mammal's internal organs (i.e., away from the abdominal skin), and a relatively higher intensity and / or different wavelength of light may be desired so that the light reaches the fetus with a sufficiently strong signal so that the return signal can be detected, for example, by detector 114.

[0082] When fetal hemoglobin probe 115 includes more than one light source 105, the light sources 105 may be arranged in an array adapted to maximize the strength of the return signal, such as array 170, as discussed below with respect to FIGS. 2D and 2E. Array 170 may include any suitable number of light sources 105. In some examples, array 170 may include a first row of light sources 105A, 105B-105N of a first type and a second row of light sources 105AA, 105AB-105AN of a second type. The different types of light sources may be configured, for example, to emit light of particular frequencies / wavelengths and / or intensities. For example, light sources 105A, 105B-105N may be configured to emit light having wavelengths in the red spectrum and light sources 105AA, 105AB-105AN may be configured to emit light having wavelengths in the infrared or near-infrared spectrum. Although array 170 has two columns, it will be understood that any number of columns (eg, 3, 4, 5, 6, 7, 8, etc.) may be included in array 170.

[0083] An embodiment of the fetal hemoglobin probe 115 having a relatively long length (e.g., 10 cm to 40 cm) can include an array 170 having a long fetal hemoglobin probe 115 with multiple light source rows, each including, for example, 10, 15, 20, 25, 30, 35, 40, 45, or 50 light sources 105. The fetal hemoglobin probe 115 can also include more than one detector 114, as shown in FIG. 2E, including a first detector 114A and a second detector 114B. In some embodiments, the first detector 114A can be the same as the second detector 114B, while in other embodiments, they can be different. For example, the first detector 114A can be sensitive to a first range of frequencies for reflected light, and the second detector 114B can be sensitive to a second range of frequencies for reflected light. Additionally or alternatively, the first detector 114A can be a different size than the second detector 114B. Any of the fetal hemoglobin probes 115 disclosed herein may include, for example, multiple detectors adapted to direct reflected light to one or more light sources 105 included in an array 170.

[0084] Although shown as a separate component in Figures 2C-2E, one skilled in the art will understand that the adjustment mechanism 122 may be located partially and / or entirely within and / or adjacent to one or more light sources 105.

[0085] The components of system 100 may be applied to the pregnant mammal in any acceptable manner. For example, NIRS adult hemoglobin probe 125 may be placed on the second finger of the pregnant mammal 305, pulse oximetry probe 130 may be placed on the thumb of the pregnant mammal 305, and Doppler and / or ultrasound probe 135 may be placed on the abdomen of the pregnant mammal.

[0086] In some implementations, the uterine contraction measurement device 140 may also be placed on the abdomen of the pregnant mammal. In other implementations, the uterine contraction measurement device 140 may be embodied within the fetal hemoglobin device 115. In some cases, the uterine contraction measurement device 140 may be a pressure sensor configured to detect changes in uterine muscle pressure in pressure units (mmHg and / or kPa).

[0087] In some embodiments, one or more light source(s) 105 and detector(s) 114 may act as an opto-electronic muscle contraction sensor without the need for a separate uterine contraction measurement device 140. In these embodiments, light reflected from the uterus of a pregnant mammal may naturally change when the uterus is in a relaxed state (more scattering) as opposed to a contracted state (less scattering). These changes in light scattering may be detected by one or more detector(s) 114 and processed, for example, by computer 150, to determine changes in the state of the uterine muscle. In some embodiments, one or more light source(s) 105 may direct light of specific frequencies / wavelengths such that measurements of uterine contractions have dedicated beams / frequency of light.

[0088] Preferably, the fetal hemoglobin probe 115 is positioned at or near the bikini / suprapubic region of the pregnant mammal 305. This region is typically just above the pubic hairline. This location is beneficial in the later stages of pregnancy, for example, after 9 months or 36 weeks of gestational progression, because the fetal head is engaged within the cervical birth canal and is therefore in a fairly predictable location within the abdomen of the pregnant mammal. Furthermore, when the fetus is located within the cervical birth canal, the distance between the pregnant mammal and the fetus is minimal; therefore, NIR light passing through the abdomen of the pregnant mammal is more likely to come into contact with the fetus and be reflected back to the fetal hemoglobin probe 115.

[0089] 3A, 3B, and 3C provide illustrations of how light from a fetal hemoglobin probe 115 may be directed into the abdomen of a pregnant mammal 305, and reflected light may be detected by one or more detectors 114 of the fetal hemoglobin probe 115. More specifically, FIG. 3A provides a cross-sectional view of the fetal hemoglobin probe 115 and pregnant mammal 305, divided along a midline extending through the center of the pregnant mammal 305 (i.e., through the center of the face, between the ribs, etc.) when viewed from the front. FIG. 3A illustrates an approximation of a fetus 310 surrounded by amniotic fluid and other tissues 315 present within a uterus 320 of the pregnant mammal 305. The fetal hemoglobin probe 115 is shown in FIG. 2C as being positioned on the lower abdomen of the pregnant mammal 305 at or near the bikini / suprapubic region of the pregnant mammal 305.

[0090] 3A, a light beam 325 (referred to herein as an "incident beam") emitted from one or more light sources 105 is incident on the abdomen of a pregnant mammal 305 and directed toward a fetus 310. The light beam 325 can be any wavelength / frequency or combination of wavelengths / frequencies. In one embodiment, the incident beam 325 can include light in the red and near-infrared spectrum.

[0091] In some embodiments, the incident beam 325 may include two or more beams of light, which may be emitted, for example, from a single light source 105 (emitting two beams of light of the same frequency and / or two beams of light of different frequencies) or two different light sources 105 (e.g., one frequency per light source). When two or more beams are included in the incident beam 325, they may be oriented in slightly different directions to accommodate, for example, differences in the frequencies of the light of the beams, the condition of the pregnant mammal 305 (e.g., skin pigmentation, body mass index, etc.), and / or the condition of the fetus (e.g., size, position, location within the uterus, skin pigmentation, etc.).

[0092] A portion of incident beam 325 may reflect from fetus 310, amniotic fluid and other tissues 315, and uterus 320 as reflected beam 330 and may be received by one or more detectors 114 provided by fetal hemoglobin probe 115. Although reflected beam 330 is shown as a single beam, it may be any number of beams or individual photons. It is expected that not all of the light in incident beam 325 will be contained within reflected beam 330, as some of the light in incident beam 325 may be lost / undetected due to, for example, scattering and / or absorption.

[0093] FIG. 3B provides an image of the fetal hemoglobin probe 115 with the adjusting device 335 positioned between the skin of the abdomen of the pregnant mammal 305 and a portion of the fetal hemoglobin probe 115. In the embodiment of FIG. 3B, the adjusting device 335 is triangular in shape and acts as a wedge to change the orientation / position of the fetal hemoglobin probe 115 (and the opposing orientation / position of the light source(s) 105 and / or detector(s) 114) relative to the abdomen of the pregnant mammal. In some cases, the adjusting device 335 may change the angle of incidence of the incident beam 325 and / or the orientation of one or more detectors 114. In some embodiments, the adjusting device 335 may be transparent to allow the passage of light into and out of the abdomen of the pregnant mammal 305. In other embodiments, the adjusting device 335 may be translucent or opaque to, for example, change the frequency of the incident beam 325 and / or the reflected beam 330.

[0094] The adjusting device 335 may be configured to adjust for physiological conditions of the pregnant mammal 305's abdomen that make it difficult to receive a reflected beam of sufficient intensity. For example, for a pregnant mammal 305 with a high fat content around the abdomen, applying the fetal hemoglobin probe 115 directly to the pregnant mammal's 305's skin may not orient the incident beam 325 in the correct direction and / or may not allow for detection of the reflected beam 330. Additionally or alternatively, the adjusting device 335 may be configured to adjust for physiological conditions of the fetus 310, including the size and / or position of the fetus 310 within the uterus 320. For example, the adjusting device 335 may be deployed to orient the incident beam 325 toward the head of the fetus 310.

[0095] In some embodiments, two or more adjustment mechanisms 335 may be used. The adjustment device 335 may be of any suitable shape and / or configuration, including, but not limited to, triangular, circular, or rectangular, and may be configured to adjust the positioning or movement of some or all of the components of the fetal hemoglobin probe 115. In some examples, the adjustment device 335 may be designed to improve the comfort of the pregnant mammal 305 while wearing the fetal hemoglobin probe 115 and, to that end, may be configured to include a soft and / or flexible material (e.g., foam) designed to conform to the contours of the pregnant mammal's abdomen. In these examples, the adjustment device 335 will be designed to engage the fetal hemoglobin probe 115 in a manner that does not obscure one or more of its components.

[0096] In another embodiment, conditioning device 335 may include optics, filters, or other mechanical and / or electrical components configured to adjust one or more characteristics of incident beam 325 and / or reflected beam 330. In some examples, one or more operations of conditioning device 335 may be performed upon receipt of instructions from, for example, components of fetal hemoglobin probe 115 and / or computer 150.

[0097] 3C provides a front view of the abdomen of pregnant mammal 305 with fetal hemoglobin probe 115 attached. The perspective view is adjusted somewhat relative to FIG. 3C so that incident beam 325 and reflected beam 330 can be seen. In reality, both incident beam 325 and reflected beam 330 are directed into / reflected from the abdomen of pregnant mammal 305 along the Z axis.

[0098] 3D provides a frontal cross-sectional view of the abdomen of pregnant mammal 305 with fetal hemoglobin probe 115 and Doppler / ultrasound probe 135 aligned. As shown in FIG. 3D, Doppler / ultrasound probe 135 transmits a beam into the abdomen of pregnant mammal 305 toward fetus 310 and receives a reflected signal. Doppler / ultrasound probe 135 then uses this reflected signal to determine a fetal heart rate signal and / or to determine the fetal heart rate per minute.

[0099] 3D has two light sources, a first of which, 105A, emits a light beam 325A of a first wavelength (λ1) (labeled 105A, λ1 and 325A, λ1, respectively) and a second of which, 105B, emits a light beam 325B of a second wavelength (λ2) (labeled 105B, λ2 and 325B, λ2, respectively). Portions of incident beams 325A and 325B are reflected by pregnant mammal 305 and fetus 310 and received by detector 114 as reflected beams 330A and 330B (labeled 330A, λ1 and 330B, λ2, respectively).

[0100] 4A illustrates an exemplary process 400 for performing fetal oximetry and / or fetal pulse oximetry transperitoneally and / or in utero to determine fetal hemoglobin oxygen saturation levels. Process 400 may be performed, for example, by system 100 and / or its components.

[0101] Initially, a light beam, such as incident beam 325, may be directed into the abdomen of a pregnant mammal, such as pregnant mammal 305 (step 405), by one or more light sources, such as light source(s) 105 provided by one or more of the abdomens of the pregnant mammal of the fetal hemoglobin mammal, and directed toward the fetus of the pregnant mammal, such as fetus 310 as shown in Figures 3A and 3B discussed above.

[0102] The light beam directed into the abdomen of the pregnant mammal may include any number of light beams and / or frequencies / wavelengths of light, such as those described above with respect to incident beam 325. In some examples, the light beam of step 405 may be multiple light beams emitted from multiple light sources positioned at multiple different locations along the abdomen of the pregnant mammal, such as those shown in Figures 2D and 2E. Additionally or alternatively, the light beam of step 405 may include multiple wavelengths / frequencies emitted by a single light source, which may include multiple LEDs.

[0103] In some embodiments, the light beam of step 405 may include light of first and second wavelengths, the first wavelength being in the red portion of the electromagnetic spectrum (i.e., 620-750 nm) and the second wavelength being in the near-infrared (NIR) portion of the electromagnetic spectrum (e.g., 750 nm-2,500 nm). Because light of wavelengths in the red and near-infrared spectrum is known to travel through and / or be reflected by skin and body tissue, the use of these wavelengths is preferred, though not required. In some embodiments, for example, third, fourth, fifth, or more different wavelengths of light may be directed toward the abdomen of the pregnant mammal. In some circumstances, the use of more than two wavelengths of light may be useful to improve reflected signal strength and / or clarity in various circumstances, including, but not limited to, the distance of the fetus from the external skin or uterine wall of the pregnant mammal (i.e., fetal depth), the level of melanin / pigment within the pregnant mammal and / or fetus, the strength of the fetal pulse signal, the amount the fetus moves within the placenta and / or uterus of the pregnant mammal, etc.

[0104] In some embodiments, the intensity of the light directed into the pregnant mammal in step 405 may be variable and / or different for different wavelengths of light. For example, the intensity of red light directed into the abdomen of the pregnant mammal may be greater than the intensity of near-infrared light due to the transmission / reflection properties of red light versus near-infrared light (i.e., near-infrared light is known to reflect more light than red light when presented within body tissue). However, it is expected that the intensity of the light beam in step 405 will be safe for both the pregnant mammal and its fetus (e.g., will not cause burns to the pregnant mammal's skin and / or damage to the fetus's tissues (e.g., eyes)).

[0105] In step 410, light (e.g., waves and / or photons) reflected by the abdomen of the pregnant mammal (and fetus) may be received by one or more detectors (e.g., light sensors, photodetectors, or photodiodes), such as detector 115 and / or transceiver 107, and converted (step 415) into an electronic signal representing the reflected light (this signal may be referred to herein by the light sensor / photodiode / photodetector as an "electronic reflected signal"). In some examples, light directed into the abdomen of the pregnant mammal may travel a distance of, for example, 3-5 cm to contact the fetus, and once reflected from the fetus, travel another 3-5 cm to be detected by the detector. Thus, the total travel distance for the incident and reflected beam may be as high as 8 or 10 cm. Traveling this distance causes a substantial amount of scattering and other interference in the detection of the reflected signal, and only a small fraction (e.g., 0.5-5%) of the light incident on the abdomen of the pregnant mammal may be reflected by the fetus and received by the detector.

[0106] Optionally, in step 420, it may be determined whether the electronic reflection signal has sufficient strength to detect, for example, the pulse and / or fetal oxygen saturation of the fetus. Exemplary signal strengths that are sufficient are in the range of 30-500 dB with a signal-to-noise (SNR) ratio of 1-8, with a preferred SNR of approximately 3-4.5.

[0107] When the signal does not have sufficient strength, the light source(s) and / or detector(s) may be adjusted automatically (i.e., without operator intervention) and / or may facilitate providing an indication to an operator (e.g., a doctor or nurse) that adjustment of the light source(s) and / or detector(s) may be desirable or required (step 425). Exemplary indications provided in step 425 include, but are not limited to, warnings, messages (e.g., written or video), and advice. Exemplary automatic adjustments include, but are not limited to, adjusting lenses positioned between the pregnant mammal's abdomen and the light source(s) and / or detector(s) to focus light reflected by the light source(s) and / or received by the detector(s), adjusting the amount of power delivered to the light source(s) and / or detector(s), adjusting the intensity and / or frequency of light emitted by one or more of the light sources, etc. In some embodiments, activation of an additional light source to direct light into the abdomen of the pregnant mammal may be responsive to determining that the electronic reflectance signal does not have sufficient intensity.

[0108] In some examples, the adjustment(s) of step 425 may be made and / or facilitated by one or more adjustment mechanisms, such as adjustment mechanism 122, and / or a control device, such as control device 112. Once adjusted, the light beam may again be directed into the abdomen of the pregnant mammal (i.e., step 405 may be repeated), and steps 410-420 may be repeated. When the electronic reflection signal has sufficient strength, or when steps 420 and 425 are not performed, process 400 may proceed to step 430.

[0109] In step 430, the electronic reflectance signal may be processed to isolate the portion of the electronic reflectance signal reflected from the fetus (as opposed to the pregnant mammal or noise). For ease of discussion, the portion of the electronic reflectance signal reflected from the fetus may be referred to herein as the fetal electronic reflectance signal. Examples of how step 430 may be performed are discussed below with respect to FIGS. 5A-5D. Following step 430, the fetal electronic reflectance signal may be analyzed to determine the oxygen saturation level of the hemoglobin contained within the fetal blood, for example, via oximetry and / or pulse oximetry techniques (step 440). Typical values for fetal blood oxygen saturation fall in the range of 30-70%. An exemplary method for determining fetal hemoglobin saturation levels uses a version of the Beer-Lambert law modified to account for the scattering effects of reflected light scattered by tissues within the body, as described in Zourabian, Anna et al., Trans-abdominal Monitoring of Fetal Arterial Blood Oxygenation Using Pulse Oximetry, Journal of Biomedical Optics, 5(4), pp. 391-405 (October 2000), which is incorporated herein by reference. Further details regarding the implementation of step 435 are provided below with respect to Figures 6A-6H.

[0110] Next, in step 440, an indication of the fetal oxygen level may be facilitated to an operator. Exemplary operators include, but are not limited to, physicians, nurses, and other caregivers. Exemplary indicators include a waveform shown on a display device (e.g., a computer monitor), a numerical value provided via a display device, and / or a message (e.g., an SMS text message) such as the fetal hemoglobin oxygen saturation level. The facilitated provision of the indication in step 465 may include providing the indication to a computer, such as computer 150, and / or a display device, such as display device 155. Examples of such displays of fetal hemoglobin oxygen saturation level are provided in FIGS. 8A and 8B and discussed below.

[0111] One way to process the signal to isolate the portion of the electronic return signal reflected from the fetus from the total electronic return signal is to multiply the total electronic return signal by a signal representing the beating of the fetal heart (i.e., performing step 430), as may be provided by a Doppler and / or ultrasound probe, such as Doppler / ultrasound probe 135. The signal (i.e., the product of the total electronic return signal multiplied by the fetal heartbeat signal) may approximate the portion of the total electronic return signal reflected by the fetus. To improve this approximation, signal readings may be averaged over multiple periods to provide a more accurate approximation of the portion of the total electronic return signal reflected by the fetus. An example of this process is provided in FIGS. 5A-5D, in which FIG. 5A provides a graph 500 of total electronic return signal strength versus time, representing light reflected by the abdomen of the pregnant mammal detected in step 410. FIG. 5B provides a graph 501 of a Doppler signal versus time, representing light reflected by the abdomen of the pregnant mammal detected in step 410. The Doppler signal represents the fetal heartbeat. This signal may be received, for example, from the Doppler / ultrasound probe 135. Figure 5C provides a graph 502 showing the product of multiplying the total electronic return signal intensity (from Figure 2A) and the Doppler signal (from Figure 2B) together, synchronized over time so that the signal intensity of the total electronic return signal at a particular time is multiplied by the Doppler signal intensity at that same particular time. The resulting signal shown in Figure 5C approximates a portion of the total electronic return signal reflected from the fetus. This signal may then be analyzed to determine the fetal oxygen saturation level, for example, using oximetry or pulse oximetry techniques.

[0112] In some embodiments, the accuracy of the approximation of the total electronic reflection signal reflected from the fetus may be improved by averaging many signal intensities over a long period of time (e.g., many periods of time), as shown in FIG. 5D , which provides a graph 503 of the total electronic reflection signal intensity, the fetal heartbeat / Doppler signal, and the result of multiplying the total electronic reflection signal intensity and the Doppler signal synchronized over time (referred to as the “fetal reflection signal” on graph 503).

[0113] Another method of processing the electronic reflection signal to isolate the portion of the electronic reflection signal reflected from the fetus from the total electronic reflection signal is to multiply the total electronic reflection signal by a signal representing the fetal heart provided by FIG. 4B showing sub-process 401 (i.e., performing step 430).

[0114] In step 445 of sub-process 401, a cardiac signal of the pregnant mammal is received, for example, from a pulse oximetry probe, such as pulse oximetry probe 130, and / or an adult hemoglobin probe, such as NIRS adult hemoglobin probe 125. The received cardiac signal of the pregnant mammal may then be synchronized in the time domain with the electronic reflectance signal (step 450). A correlation may then be established between the cardiac signal of the pregnant mammal and changes in the electronic reflectance signal to determine the portion of the electronic reflectance signal reflected by the pregnant mammal (step 455). Next, in step 460, the portion of the portion of the electronic reflectance signal reflected by the pregnant mammal is subtracted from the electronic reflectance signal, thereby isolating the portion of the electronic reflectance signal reflected by the fetus.

[0115] Another method of processing the signal to isolate the portion of the electronic return signal reflected from the fetus from the total electronic return signal is to multiply the total electronic return signal by the signal representing the fetal heart provided by FIG. 4C showing sub-process 402 (i.e., performing step 430).

[0116] In step 465 of sub-process 465, a fetal heartbeat signal may be received from an ultrasound device and / or a Doppler device, such as Doppler / ultrasound probe 135. The received fetal heartbeat signal may then be synchronized in the time domain with the electronic reflection signals (step 470). Portions of the electronic reflection signals corresponding to individual heartbeats in the time domain may then be examined. In this manner, the entire electronic reflection signal does not need to be processed / analyzed, but only the portion of the electronic reflection signal where the fetal heartbeat or pulse occurs is examined. This saves processing time and resources, as the entire signal does not need to be processed.

[0117] In some embodiments, the processing of step 430 and / or the analysis of step 435 may include processing the electronic reflectance signal to identify signals corresponding to absorption / reflection of NIR light by fetal oxygenated and deoxygenated hemoglobin. This information may be used to determine the level (or percentage) of fetal hemoglobin oxygen saturation (step 435).

[0118] Because fetal hemoglobin is structurally different from adult hemoglobin, it absorbs light differently, and the signal reflected from fetal hemoglobin at various wavelengths will have different magnitudes when compared to the magnitude of the signal at those same wavelengths reflected by a pregnant woman. Thus, measuring the amount of light reflected from the pregnant woman's and fetal hemoglobin at various wavelengths will provide an indication of the amount of light at a particular wavelength absorbed by the fetal hemoglobin and the maternal hemoglobin. Viewing the ratio of light reflected at various wavelengths will provide a measure that correlates to a particular fetal blood oxygen level. In some instances, the variation in wavelength absorption of fetal hemoglobin compared to maternal hemoglobin may not be sufficient to provide a sufficiently strong or clear signal indicative of fetal hemoglobin oxygen saturation level for clinical and / or diagnostic purposes. Therefore, as discussed in detail below, one or more signal processing techniques may be applied to the signal received by the fetal hemoglobin probe 115 to determine fetal hemoglobin oxygen saturation.

[0119] In an exemplary signal processing technique, a signal received from a pulse oximetry probe (e.g., pulse oximetry probe 130) of a pregnant woman can be used to determine the pregnant woman's arterial blood oxygen saturation level, which corresponds to the oxygenation state of the maternal hemoglobin. This determination is made using a pulse oximetry probe because the depth of a human finger is 1-2 cm, allowing a measurable amount of light to pass through the fingertip, and there is no interference from fetal blood flow or fetal hemoglobin circulating at the tip of the maternal finger. Therefore, the reading from pulse oximetry probe 130 will directly correspond to the amount of light absorbed and / or reflected at various wavelengths by the maternal adult hemoglobin. This information can be used to understand the amount of light interacting with maternal hemoglobin near the fetus, and this information can be subtracted from the signal received by fetal hemoglobin probe 115 to determine the amount of light absorbed and / or reflected at various wavelengths by fetal hemoglobin.

[0120] Additionally or alternatively, the signal received by fetal hemoglobin probe 115 may be processed using the fetal and / or maternal heart rate. The timing of the maternal heart rate correlates with the timing for various levels of maternal blood oxygen saturation. This correlation may be used to detect a signal corresponding to the maternal blood oxygen saturation level in the signal received by fetal hemoglobin probe 115. The detected signal corresponding to the maternal blood oxygen saturation level may then be subtracted or otherwise filtered from the signal received by fetal hemoglobin probe 115 to determine the fetal oxygen saturation level.

[0121] Additionally or alternatively, the fetal heart rate may be correlated with timing for various levels of fetal blood oxygen saturation. This correlation may then be used to detect a signal corresponding to the level of fetal blood oxygen saturation in the signal received by the fetal hemoglobin probe 115. For example, the Doppler / ultrasound probe 135 and / or ultrasound device may indicate that the fetal heart rate is in the range of 120-160 beats per minute, and this fetal heart rate may be used to gate and / or correlate the NIR signals from the fetus.

[0122] In the rare situation where the fetal and maternal heart rates are similar (fetal bradycardia and maternal tachycardia), the two heartbeats can be distinguished from one another using the known fact that there is a slight pause in the heartbeat during breathing. Thus, by observing the heartbeat signal (e.g., via pulse oximetry probe 130), one may observe a brief drop in the maternal heart rate when the maternal takes a deep breath. This drop will only be present in the signal providing the maternal heartbeat because the fetus is not breathing in utero. In this way, the two heartbeats can be distinguished from one another.

[0123] In some embodiments, the signal from the NIRS adult hemoglobin probe 125 may be processed to determine the ratio of adult oxyhemoglobin to adult deoxyhemoglobin. This ratio may then be used to isolate and analyze the signal due to the fetal blood flow, e.g., subtracting the reading from the maternal blood flow to determine the level of fetal hemoglobin oxygen saturation.

[0124] In other embodiments, processing of signals received by fetal hemoglobin probe 115 may include oscillation between time domain and frequency domain analysis. This oscillation may allow for distinguishing signals that have cyclic (periodic) components as opposed to signals that are random or non-periodic (acyclic / aperiodic). Random or aperiodic signals are likely to be noise, and examining the received signal against random or aperiodic signals will help determine the noise level of the signal as well as portions of the signal that can be filtered or removed.

[0125] In some embodiments, process 400 may include constructing a series of correlations between the intensity of light reflected / absorbed at certain wavelengths by fetal oxyhemoglobin and deoxyhemoglobin and the oxygen saturation levels of fetal oxyhemoglobin and deoxyhemoglobin. This series of correlations may be performed prior to execution of process 400 for a particular pregnant mammal during the fetal labor and delivery process and may be stored, for example, in computer 150. An exemplary correlation may be the reflection of light of wavelength A with intensity X and the reflection of light of wavelength B with intensity 0.8X for a fetal oxygen saturation level of 50% for fetal hemoglobin bound to oxygen. Another exemplary correlation may be the reflection of light of wavelength A with intensity X and the reflection of light of wavelength B with intensity 0.5X for a fetal oxygen saturation level of 25% for fetal hemoglobin bound to oxygen.

[0126] (illustrated in the figures as 105A, λ1 and 325A, λ1, respectively) and a second one of them, 105B, emits a light beam 325B of a second wavelength (λ2) (illustrated in the figures as 105B, λ2 and 325B, λ2, respectively). Portions of incident beams 325A and 325B are reflected by pregnant mammal 305 and fetus 310 and received by detector 114 as reflected beams 330A and 330B, respectively (illustrated in the figures as 330A, λ1 and 330B, λ2).

[0127] 6A-6H provide information in graph form regarding one example of how to analyze electronic reflection signals to determine fetal hemoglobin oxygen saturation level. Sometimes, fetal hemoglobin oxygen saturation level may also be referred to as fetal arterial oxygen saturation level, which may be abbreviated herein as (%SaO2). More specifically, FIG. 6A provides a graph 601 of a Doppler signal versus time. The Doppler signal corresponds to a fetal heartbeat signal. The Doppler signal in FIG. 6A is similar to the Doppler signal in FIG. 5B.

[0128] FIG. 6B provides a graph 602 of electronic return signal strength versus time for λ1. This graph may correspond to return signal 330A, λ1. Any of the processes discussed above may be used to isolate the portion of the signal reflected by the fetus from the electronic return signal for λ1. In the example provided, the total electronic return signal strength for λ1 and the fetal Doppler signal are synchronized and multiplied together over time to provide a product of the total electronic return signal strength and the Doppler signal for λ1 synchronized and multiplied together over time, as shown in graph 603 of FIG.

[0129] 6D provides a graph 604 showing the product of the total electronic reflection signal intensity and the fetal Doppler signal for λ 1 multiplied together, synchronized over time and averaged over several periods of time. This graph (or the data used to generate the graph) is analyzed to determine the intensity of the systolic value for a first wavelength λ 1610 corresponding to the peak (i.e., highest value) of the curve, and the intensity of the diastolic value for a first wavelength λ 1615 corresponding to the base (i.e., lowest / minimum value) of the curve.

[0130] 6E provides a graph 605 of electronic return signal strength versus time for λ2. Any of the processes discussed above may be used to isolate the portion of the signal reflected by the fetus from the electronic return signal strength for λ2. In the example provided, the total electronic return signal strength for λ2 and the fetal Doppler signal are synchronized and multiplied together over time to provide a product of the total electronic return signal strength and the Doppler signal for λ2 synchronized and multiplied together over time, as shown in graph 606 of FIG.

[0131] 6G provides a graph 607 showing the product of the total electronic reflection signal intensity for λ2 and the fetal Doppler signal multiplied together, synchronized over time and averaged over several periods of time. This graph (or the data used to generate the graph) is analyzed to determine the intensity of the systolic value for the second wavelength λ2620 corresponding to the peak (i.e., highest value) of the curve, and the intensity of the diastolic value for the second wavelength λ2625 corresponding to the base (i.e., lowest / minimum value) of the curve.

[0132] The modulation ratio (R) between the reflected intensities of the two wavelengths of light can be calculated as follows:

number

[0133] The modulation ratio R can then be used to determine the level of arterial oxygen saturation (%SaO2) in one of at least two forms. If the relationship between the modulation ratio R and arterial oxygen saturation for a pair of wavelengths (i.e., λ1 and λ2) is known (e.g., by experimentally determined values), the value of R can be used to look up the corresponding arterial oxygen saturation level. 1 provides an exemplary graph plotting the known relationship between values for R (where λ1 is the red spectrum and λ2 is the infrared spectrum) and arterial oxygen saturation values. 1Source of Figure 6H: Paul D. et al., Wavelength Selection for Low-Saturation Pulse Oximetry, IEEE Transactions on Biomedical Engineering, Vol. 44, No. 3, March 1997, p. 149.

[0134] After completing the above example (with appropriate reference numbers for the intensity values inserted from graphs 604 and 607), the following calculations for Equation 1 will result:

number

[0135] The ratio R calculated by this equation can then be used to find the corresponding arterial oxygen saturation level of the fetus (ie, fetal hemoglobin oxygen saturation level).

[0136] Fetal oxygen saturation levels may also be calculated using the following equation (Equation 2):

number

number

number

[0137] Further details regarding calculations using Equations 1, 2, 3, and 4 and methods for determining fetal hemoglobin oxygen saturation levels are provided by Mannheimer, Paul D. et al., Wavelength Selection for Low-Saturation Pulse Oximetry, IEEE Transactions on Biomedical Engineering, Vol. 44, No. 3, March 1997, pp. 148-158, and Zourabian, Anna et al., Trans-abdominal Monitoring of Fetal Arterial Blood Oxygenation Using Pulse Oximetry, Journal of Biomedical Optics, 5(4), pp. 391-405 (October 2000), both of which are incorporated herein by reference.

[0138] Figure 7A shows the birth 2 Table 700 provides various hemoglobin measurements as a function of wavelength of light shone in adult donor blood and fetal blood obtained by immediate umbilical cord puncture. The values in columns 2-8 of the table are millimolar absorptivity (L*mmol -1 *cm -1 ) is measured More specifically, the first column of table 700 provides a list of wavelengths measured in nanometers (nm) ranging from 450 nm to 1000 nm, the second column of table 700 provides fetal hemoglobin (HbF) measurements in the deoxyhemoglobin state (Hb), the third column of table 700 provides adult hemoglobin (HbA) measured in the deoxyhemoglobin state (Hb), the fourth column of table 700 provides fetal hemoglobin in the oxyhemoglobin state (HbO), and the fifth column of table 700 provides oxyhemoglobin (HbO). 7B and 7C. The data from table 700 is used to generate the graphs shown in FIGS. 7B and 7C. The data from table 700 is used to generate the graphs shown in FIGS. 7B and 7C. 2 Experimental results are provided in Zijistra, WG et al.: Absorption Spectra of Human Fetal and Adult Oxyhemoglobin, De-Oxyhemoglobin, Carboxyhemoglobin, and Methemoglobin, Clin. Chem. Vol. 39 / 9, pp. 1633-1638 (1991).

[0139] FIG. 7B illustrates a graph 701 showing the oxygenated (oxy) and deoxygenated (deoxy) states of fetal and maternal hemoglobin at visible wavelengths of light from 450 nm to 700 nm, where the dashed green line represents the difference in absorptivity between the oxygenated and deoxygenated states of fetal hemoglobin as a function of wavelength and the dashed red line represents the difference in absorptivity between the oxygenated and deoxygenated states of maternal fetal hemoglobin as a function of wavelength.

[0140] FIG. 7C illustrates a graph 702 showing the difference in absorptance between oxygenated and deoxygenated states of fetal and maternal hemoglobin at wavelengths of near-infrared (NIR) light between 700 nm and 1000 nm, where the green dashed line represents the difference in absorptance between oxygenated and deoxygenated states of fetal hemoglobin as a function of wavelength and the red dashed line represents the difference in absorptance between oxygenated and deoxygenated states of maternal fetal hemoglobin as a function of wavelength.

[0141] 7A-7C, the greatest difference in absorptivity between fetuses and pregnant women occurs in the wavelength ranges of approximately 700-750 nm and 950-1000 nm. Therefore, emission of infrared light within these wavelength ranges by fetal hemoglobin probe 115 is preferred to achieve optimal differences between signals from maternal and fetal hemoglobin.

[0142] All of the signal processing and analysis techniques described herein may employ one or more noise reduction techniques, including, but not limited to, canceling out ambient noise that may arise from lights in the room the pregnant mammal is located in and the operation of electrical equipment near the pregnant mammal. Noise cancellation techniques may also include searching for non-periodic modulations in the electronic reflectance signal and canceling such modulations from the signal, as non-periodic contributions to the signal are unlikely to be indicative of blood flow in either the pregnant mammal or the fetus.

[0143] Additionally or alternatively, one or more of the signal processing and analysis techniques described herein may be combined with one another, for example, processes 401 and 402 may be used to process the electronic return signal to isolate the portion of the electronic return signal reflected by the fetus.

[0144] 8A provides an exemplary display 800 that provides the level of fetal hemoglobin oxygen saturation along with other information regarding measurements of the pregnant mammal and fetus. Display 800 provides fetal hemoglobin oxygen saturation level 805, expressed, for example, as a percentage of 100, a continuous waveform (i.e., plethysmogram) 810 representing the fetal heart rate over time, and a numerical value 815 representing the fetal heart rate expressed in beats per minute. Display 800 also provides the hemoglobin oxygen saturation level 820 of the pregnant mammal, expressed, for example, as a percentage of 100, a continuous waveform 825 representing the pregnant mammal's heart rate over time, and a numerical value 830 representing the pregnant mammal's heart rate expressed in beats per minute. Display 800 further provides a graph 835 showing the fetal heart rate over time as measured over several hours, and an indication of the uterine tone or pressure produced by uterine contractions measured over time as measured in mmHg versus minute is provided as a numerical value 845. The graph 835 of fetal heart rate over time allows a visual assessment of how the fetal heart rate changes during a contraction and to determine how well the fetus is enduring the labor and delivery process. The contraction number 845 is a number between 0 and 50 calculated by the pressure sensor and allows an assessment of how long a contraction lasts, the strength of the contraction, and the frequency of the contraction.

[0145] 8B provides an exemplary display 801 of fetal heart rate, fetal hemoglobin oxygen saturation, and uterine tone synchronized to corresponding times. Display 801 is provided on a paper tape having a Cartesian grid printed thereon, with vertical lines representing the passage of time (e.g., each vertical line representing one minute) and horizontal lines indicating the measurement scale. Paper tapes of this type are not printed with a specific time scale, as these tapes are typically used continuously throughout an observation period that may last many hours, with the time scale starting at 1 and progressing to 2, 3, 4, etc., and are not relevant to the information provided to a physician treating a pregnant mammal.

[0146] The top graph of display 801 provides a graph 860 of fetal heart rate as measured in beats per minute over time. The second graph of display 801 provides a graph 865 of fetal hemoglobin oxygen concentration (for simplicity, referred to on the graph as "fetal oxygen") over time. The third graph of display 801 provides a graph 870 of uterine tone (for simplicity, referred to on the graph as "contractions"). All three graphs 860, 865, and 870 are synchronized in the time domain so that measurements of fetal heart rate during specific times correspond to fetal hemoglobin oxygen concentration levels and uterine tone at such specific times. In this manner, a treating physician (or other medical professional) can simultaneously monitor the uterine tone, fetal heart rate, and fetal hemoglobin oxygen concentration levels of a pregnant mammal, for example, during the labor and delivery process, to assess the health of the fetus.

[0147] Thus, disclosed herein are systems, devices, and methods for determining fetal oxygen levels. In some embodiments, use of the systems, devices, and methods described herein can be particularly useful during labor and delivery of the fetus (e.g., during the first and / or second stage of labor) due to the difficulty of assessing fetal health during the labor and delivery process. Examples of the present invention are as follows: However, the present invention is not limited to these. [Example 1] 1. A system comprising: a housing configured to house the first light source, the second light source, the detector, the transceiver, and the power source; a first light source adapted to project light at a first wavelength into the abdomen of the pregnant mammal toward a fetus contained therein; a second light source adapted to project light at a second wavelength into the abdomen of the pregnant mammal toward the fetus; the detector adapted to detect light reflected from the abdomen of the pregnant mammal and the fetus, convert the detected light into an electronic reflection signal, and transmit the electronic reflection signal to the transceiver; the transceiver adapted to receive the electron return signal from the detector and to communicate the received electron return signal to a processor; the power source electrically coupled to the first light source, the second light source, and the detector, the power source adapted to provide power to the first light source, the second light source, the detector, and the transceiver; the processor configured to receive the electronic reflection signal from the detector, isolate a portion of the electronic reflection signal that is reflected from the fetus, analyze the isolated portion of the electronic reflection signal to determine a fetal hemoglobin oxygen saturation level of the fetus, and provide an indication of the fetal hemoglobin oxygen saturation level of fetal blood to a display device. [Example 2] The system of Example 1 further comprises an adjustment mechanism coupled to at least one of the first and second light sources, the adjustment mechanism being adapted to adjust at least one of the frequency of the light emitted by the respective first and second light sources, the angle of incidence of the light emitted by the respective first and second light sources when projected into the abdomen of the pregnant mammal, and to concentrate the light beam projected into the abdomen of the pregnant mammal when emitted from the respective first and second light sources. [Example 3] The system described in Example 1 further comprises an adjusting device coupled to the container adapted to adjust at least one of the frequency of the light emitted by the respective first and second light sources when projected into the abdomen of the pregnant mammal, the angle of incidence of the light emitted by the respective first and second light sources, and to concentrate the light beams projected into the abdomen of the pregnant mammal when emitted from the respective first and second light sources. [Example 4] 2. The system of example 1, wherein the container, first light source, second light source, detector, transceiver, and power source are configured to be disposable after their single use. [Example 5] The system of Example 1 further comprises an additional detector positioned within the container and coupled to the transceiver and the power source, the additional detector adapted to detect light reflected from the abdomen of the pregnant mammal and the fetus, convert the detected light into an additional electronic reflection signal, and transmit the additional electronic reflection signal to the transceiver. [Example 6] four additional light sources housed within the housing, each of the additional light sources coupled to the power source; an additional detector positioned within the enclosure and coupled to the transceiver and the power source, the additional detector detecting light reflected from the abdomen of the pregnant mammal and the fetus, converting the detected light into an additional electronic reflectance signal, and converting the additional electronic reflectance signal into an additional electronic reflectance signal; an additional detector adapted to transmit a signal to the transceiver; The system described in Example 1, wherein the container is adapted to extend around a portion of the pregnant mammal's abdomen and have a length of at least 10 cm to direct light to two sides of the fetus, and further wherein the detector is positioned on a first side of the container, the additional detector is positioned on a second side of the container, and the light source is positioned between the first and second sides of the container. [Example 7] 2. The system of claim 1, wherein the first light source emits light at a wavelength of 700 nm to 740 nm, and the second light source emits light at a wavelength of 800 to 900 nm. [Example 8] The system of Example 1 further comprises a temperature probe housed within the container and connected to the power source and transceiver, the temperature probe adapted to measure the abdominal temperature of the pregnant mammal and transmit the temperature measurement to the transceiver. [Example 9] The system of Example 1 further comprises an ultrasound detector housed within the enclosure and coupled to the power source and transceiver, the ultrasound detector adapted to detect ultrasound emissions from the abdomen and fetus of the pregnant mammal resulting from transient thermoelastic expansion resulting from interaction of tissue of the abdomen and fetus with light emitted from at least one of the first light source and the second light source. [Example 10] The system of Example 1 further comprises a uterine contraction measurement device housed within the container and coupled to the power source and transceiver, the uterine contraction measurement device adapted to measure changes in the muscle state of the uterus of the pregnant mammal and to transmit these measurements to the transceiver. [Example 11] directing a light beam emitted from the light source into the abdomen of the pregnant mammal toward the fetus contained therein; receiving light reflected by the pregnant mammal and the fetus at a detector over a first time region; converting the received light into an electronic reflection signal by the detector; transmitting the electron return signal by the detector to a computer; processing the electronic return signals by a computer to isolate a portion of the electronic return signals reflected from the fetus; analyzing, by the computer, the portion of the electronic reflection signal reflected from the fetus to determine a fetal hemoglobin oxygen saturation level of the fetus; and facilitating, by said computer, providing an indication of said fetal hemoglobin oxygen saturation level to an operator. [Example 12] processing the electronic return signals to isolate a portion of the electronic return signals reflected from the fetus; receiving a heartbeat signal of the pregnant mammal over a second time domain, the heartbeat signal indicating when a heartbeat of the pregnant mammal occurred within the second time domain; synchronizing the electrical reflection signals and the cardiac signal of the pregnant mammal across the first time domain and the second time domain; determining a portion of the received electronic signal corresponding to the heartbeat signal of the pregnant mammal within the synchronized first and second time domains; and subtracting from the electronic received signal the portion of the electronic received signal corresponding to the heartbeat signal of the pregnant mammal. [Example 13] processing the electronic return signals to isolate a portion of the electronic return signals reflected from the fetus; receiving a fetal heart rate signal from the fetus over a second time domain, the fetal heart rate signal indicating when a fetal heart rate occurs within the second time domain; synchronizing the electrical reflection signals and the fetal heart rate signals across the first time domain and the second time domain; and examining, within the synchronized first and second time domains, portions of the electronic reflection signals corresponding to individual heartbeats of the fetus as indicated by the received heartbeat signal of the fetus. [Example 14] processing the electronic return signals to isolate a portion of the electronic return signals reflected from the fetus; receiving a fetal heart rate signal of the fetus over a second time domain, the heart rate signal indicating when a fetal heart rate occurs within the second time domain; synchronizing the electroreflectance signals and the fetal heart rate signal across the first time domain and the second time domain; multiplying the synchronized electrical reflection signal by the synchronized fetal heart rate signal. [Example 15] 12. The method of example 11, wherein the light directed into the abdomen of the pregnant woman has multiple wavelengths. [Example 16] 1. A fetal hemoglobin probe comprising: a housing configured to house the first light source, the second light source, the detector, the transceiver, and the power source; a first light source adapted to project light at a first wavelength into the abdomen of the pregnant mammal toward a fetus contained therein; a second light source adapted to project light at a second wavelength into the abdomen of the pregnant mammal toward the fetus; the detector adapted to detect light reflected from the abdomen of the pregnant mammal and the fetus, convert the detected light into an electronic reflection signal, and transmit the electronic reflection signal to the transceiver; the transceiver adapted to receive the electron return signal from the detector and to communicate the received electron return signal to a processor; the power source electrically coupled to the first light source, the second light source, and the detector, the power source adapted to provide power to the first light source, the second light source, the detector, and the transceiver; an adjustment mechanism coupled to at least one of the first and second light sources, the adjustment mechanism adapted to adjust at least one of a frequency of light emitted by the respective first and second light sources when projected into the abdomen of the pregnant mammal, an angle of incidence of the light emitted by the respective first and second light sources, and to concentrate a light beam projected into the abdomen of the pregnant mammal when emitted from the respective first and second light sources. [Example 17] Example 16. The method of claim 16, further comprising: an adjusting device coupled to the container, the adjusting device adapted to adjust at least one of a frequency of light emitted by the respective first and second light sources, an angle of incidence of light emitted by the respective first and second light sources when projected into the abdomen of the pregnant mammal, and to concentrate light beams projected into the abdomen of the pregnant mammal when emitted from the respective first and second light sources. The fetal hemoglobin probe described. [Example 18] 17. The fetal hemoglobin probe of Example 16, wherein the container, first light source, second light source, detector, transceiver, and power source are configured to be disposable after a single use. [Example 19] The fetal hemoglobin probe of Example 16, further comprising an additional detector positioned within the container and coupled to the transceiver and the power source, the additional detector adapted to detect light reflected from the abdomen of the pregnant mammal and the fetus, convert the detected light into an additional electronic reflection signal, and transmit the additional electronic reflection signal to the transceiver. [Example 20] four additional light sources housed within the housing, each of the additional light sources coupled to the power source; an additional detector positioned within the container and coupled to the transceiver and the power source, the additional detector adapted to detect light reflected from the abdomen of the pregnant mammal and the fetus, convert the detected light into an additional electronic reflection signal, and transmit the additional electronic reflection signal to the transceiver; A fetal hemoglobin probe as described in Example 16, wherein the container is adapted to extend around a portion of the abdomen of the pregnant mammal and have a length of at least 10 cm so as to direct light to two sides of the fetus, and further wherein the detector is positioned on a first side of the container, the additional detector is positioned on a second side of the container, and the light source is positioned between the first and second sides of the container. [Example 21] 17. The fetal hemoglobin probe according to Example 16, wherein the first light source emits light having a wavelength of 700 nm to 740 nm, and the second light source emits light having a wavelength of 800 nm to 900 nm. [Example 22] The fetal hemoglobin probe of Example 16, further comprising a temperature probe housed within the container and connected to the power source and transceiver, the temperature probe adapted to measure the abdominal temperature of the pregnant mammal and transmit the temperature measurement to the transceiver. [Example 23] The fetal hemoglobin probe of Example 16 further comprises an ultrasound detector housed within the housing and coupled to the power source and transceiver, the ultrasound detector adapted to detect ultrasound emissions from the abdomen and fetus of the pregnant mammal resulting from transient thermoelastic expansion resulting from interaction of tissue of the abdomen and fetus with light emitted from at least one of the first light source and the second light source. [Example 24] The fetal hemoglobin probe of Example 16 further comprises a uterine contraction measurement device housed within the housing and coupled to the power source and transceiver, the uterine contraction measurement device adapted to measure changes in the muscle state of the uterus of the pregnant mammal and transmit these measurements to the transceiver.

Claims

1. In fetal monitoring systems, a detector adapted to detect light reflected from the abdomen of the pregnant mammal and the fetus contained therein, the reflected light corresponding to incident light projected into the abdomen of the pregnant mammal and the fetus by a light source, the detector further adapted to convert the detected light into an electronic reflection signal and communicate the electronic reflection signal to a processor; a processor in communication with the detector, (1) receiving the electron return signal from the detector; (2) receiving a heartbeat signal from the pregnant mammal; (3) using the cardiac signal of the pregnant mammal to isolate a portion of the electronic reflection signal corresponding to light reflected from the fetus; (4) analyzing the isolated portion of the electronic reflectance signal to determine the fetal hemoglobin oxygen saturation level; (5) a processor configured to communicate an indication of the hemoglobin oxygen saturation level of the fetus to a display device; the processor is further configured to synchronize the electronic reflection signals with a cardiac signal of the pregnant mammal before determining the portion of the electronic reflection signals that corresponds to the cardiac signal of the pregnant mammal. Fetal monitoring system.

2. 10. The system of claim 1, wherein the light source is configured to project light into the abdomen of the pregnant mammal and toward the fetus contained within the abdomen.

3. 3. The system of claim 2, further comprising an adjustment mechanism coupled to the light source, the adjustment mechanism configured to adjust at least one of: (1) a frequency of light emitted by the light source; (2) an angle of incidence of the light emitted by the light source; and (3) a focus of the beam of light.

4. 3. The system of claim 2, further comprising an additional light source configured to project light into the abdomen of the pregnant mammal and toward the fetus contained therein.

5. The system of claim 2 , wherein the light source emits light at a wavelength in the range of 620 nm to 900 nm.

6. 10. The system of claim 1, further comprising an additional detector configured to (1) detect light reflected from the abdomen of the pregnant mammal, (2) convert the detected light into an additional electronic reflectance signal, and (3) communicate the additional electronic reflectance signal to the processor.

7. 10. The system of claim 1, further comprising a temperature probe configured to measure abdominal temperature of the pregnant mammal and communicate the temperature measurement to the processor, the processor further configured to provide an indication of the measured temperature to the display device.

8. 10. The system of claim 1, further comprising an ultrasound detector configured to detect ultrasound emissions from the abdomen of the pregnant mammal and the fetus and to communicate signals corresponding to the detected ultrasound emissions to the processor.

9. 10. The system of claim 1, further comprising an ultrasound detector adapted to detect ultrasound emissions from the abdomen of the pregnant mammal and the fetus caused by transient thermoelastic expansion resulting from interaction of the abdominal tissue of the pregnant mammal and the fetus with light emitted from the light source, and to transmit signals corresponding to the detected ultrasound emissions to the processor.

10. 10. The system of claim 1, further comprising a uterine contraction measurement device adapted to measure changes in muscular state of the uterus of the pregnant mammal and communicate the measured changes to the processor, the processor further configured to provide an indication of the measured changes to the display device.

11. 10. The system of claim 1, further comprising a transceiver communicatively coupled to at least one of the detector and the processor, the transceiver configured to receive the electron return signal from the detector and to communicate the received electron return signal to the processor.

12. 10. The system of claim 1, further comprising a receiver communicatively coupled to the detector, a source of cardiac signals of the pregnant mammal, and the processor, the receiver configured to receive cardiac signals of the pregnant mammal from the source of cardiac signals of the pregnant mammal and the electronic reflection signals from the detector, and to communicate the received cardiac signals of the pregnant mammal and the electronic reflection signals to the processor.

13. 10. The system of claim 1, wherein the processor further receives an indication of a hemoglobin oxygen saturation level of the pregnant mammal, and the processor is further configured to analyze the indication of the hemoglobin oxygen saturation level of the pregnant mammal to determine a heart rate signal of the pregnant mammal.

14. 1. A method for determining fetal hemoglobin oxygen saturation level, comprising: receiving, by a processor, a heart rate signal of the pregnant mammal from a monitor communicatively coupled to said processor; receiving, by the processor, an electronic reflection signal from a detector communicatively coupled to the processor, the electronic reflection signal corresponding to light reflected from an abdomen of a pregnant mammal and a fetus contained therein, the reflected light being a portion of light projected into the abdomen of the pregnant mammal and a fetus contained therein by a light source, the reflected light being converted into the electronic reflection signal by the detector; isolating, by the processor, a portion of the electronic reflection signal corresponding to light reflected from the fetus using the cardiac signal of the pregnant mammal; analyzing, by the processor, the isolated portion of the electronic return signal to determine a fetal hemoglobin oxygen saturation level of the fetus; transmitting, by the processor, an indication of the fetal hemoglobin oxygen saturation level to a display device; The method further comprising the step of synchronizing, by the processor, the electronic reflection signals with a cardiac signal of the pregnant mammal before determining a portion of the electronic reflection signals that corresponds to the cardiac signal of the pregnant mammal.

15. 15. The method of claim 14, further comprising projecting the light with the light source into the abdomen of the pregnant mammal.

16. The method described in claim 15, further comprising the step of adjusting at least one of (1) the frequency of the light, (2) the angle of incidence of the light, and (3) the focus of the beam of light by an adjustment mechanism controlled by the processor.

17. The method of claim 16, further comprising: determining, by the processor, whether the electron reflection signal has sufficient intensity; 16. The method of claim 15, further comprising adjusting, by an adjustment mechanism controlled by the processor, the light source in response to determining that the electronic reflection signal does not have sufficient strength.

18. The method of claim 17, further comprising: determining, by the processor, whether the electron reflection signal has sufficient intensity; 16. The method of claim 15, further comprising adjusting the detector in response to determining, by the processor, that the electron return signal does not have sufficient intensity.

19. receiving a heartbeat signal from the pregnant mammal, receiving, by the processor, a pulse oxygen signal of the pregnant mammal from a pulse oxygen monitor in communication with the processor, the pulse oxygen signal of the pregnant mammal including information regarding the heart rate of the pregnant mammal and the hemoglobin oxygen saturation level of the pregnant mammal; and deriving, by the processor, a heart rate signal of the pregnant mammal from the hemoglobin oxygen saturation level of the pregnant mammal.

20. The step of isolating a portion of the electron return signal comprises: receiving, by the processor, an indication of a hemoglobin oxygen saturation level of the pregnant mammal; 15. The method of claim 14, further comprising determining, by the processor, how hemoglobin of the pregnant mammal interacts with the electronic reflectance signal, wherein subtraction is responsive to the determination of how hemoglobin of the pregnant mammal interacts with the electronic reflectance signal.

21. 15. The method of claim 14, further comprising receiving, by the processor, from an ultrasound detector in communication with the processor, signals indicative of ultrasound emissions from the abdomen of the pregnant mammal and the fetus, wherein the ultrasound emissions from the abdomen of the pregnant mammal and the fetus are caused by transient thermoelastic expansion resulting from interaction of tissues of the abdomen of the pregnant mammal and the fetus with light emitted from the light source.

22. processing, by the processor, the electronic reflection signals to determine a muscular state of the uterus of the pregnant mammal; and transmitting, by the processor, an indication of the muscular status of the uterus of the pregnant mammal to the display device.

23. 1. A computer for determining fetal hemoglobin oxygen saturation level, the computer comprising a processor, the processor comprising: receiving a heart rate signal of the pregnant mammal from a monitor communicatively coupled to the processor; receiving an electronic reflection signal from a detector communicatively coupled to the processor, the electronic reflection signal corresponding to light reflected from an abdomen of a pregnant mammal and a fetus contained therein, the reflected light being a portion of light projected into the abdomen of the pregnant mammal and a fetus contained therein by a light source, the reflected light being converted into the electronic reflection signal by the detector; using the cardiac signal of the pregnant mammal to isolate a portion of the electronic reflection signal corresponding to light reflected from the fetus; analyzing the isolated portion of the electronic reflection signal to determine a fetal hemoglobin oxygen saturation level of the fetus; and transmitting an indication of the fetal hemoglobin oxygen saturation level to a display device; The computer, wherein the processor is further configured to synchronize the electronic reflection signals with a cardiac signal of the pregnant mammal before determining a portion of the electronic reflection signals that corresponds to a cardiac signal of the pregnant mammal.

24. the processor: receiving a pulse oxygen signal of the pregnant mammal from a pulse oxygen monitor in communication with the processor, the pulse oxygen signal of the pregnant mammal comprising information regarding the heart rate of the pregnant mammal and the hemoglobin oxygen saturation level of the pregnant mammal; 24. The computer of claim 23, further configured to derive a heart rate signal of the pregnant mammal from a hemoglobin oxygen saturation level of the pregnant mammal.

25. the processor: receiving an indication of a hemoglobin oxygen saturation level of the pregnant mammal; 24. The computer of claim 23, further configured to isolate a portion of the electronic reflectance signal by determining how hemoglobin of the pregnant mammal interacts with the electronic reflectance signal, the subtraction being responsive to the determination of how hemoglobin of the pregnant mammal interacts with the electronic reflectance signal.

26. the processor:

24. The computer of claim 23, further configured to receive, from an ultrasound detector in communication with the processor, signals indicative of ultrasound emissions from the abdomen of the pregnant mammal and the fetus, wherein the ultrasound emissions from the abdomen of the pregnant mammal and the fetus are caused by transient thermoelastic expansion resulting from interaction of tissue of the abdomen of the pregnant mammal and the fetus with light emitted from the light source.

27. the processor: processing the electronic reflectance signals to determine a muscular state of the uterus of the pregnant mammal; 24. The computer of claim 23, further configured to communicate to the display device an indication of a muscular state of the uterus of the pregnant mammal.

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