Systems, devices, and methods for determining fetal-oximetry information and / or an indication of fetal wellness using direct measurements

Abstract

Systems, devices, and methods for configured for directly obtaining fetal oximetry measurements and / or information while a fetus is in utero (negative or 0 station) may be configured to validate that the sensor(s) providing the oximetry information (e.g., optical signals and / or electronic representations of optical signals) correspond to oximetry measurements of fetal, as opposed to maternal, tissue. Additionally, or alternatively, information received via systems, devices, and methods configured for directly obtaining fetal oximetry measurements and / or information while a fetus is in utero may be used to set parameters for the operation of a transabdominal-fetal-oximetry sensor and / or calibrate or adjust data provided by a transabdominal-fetal-oximetry sensor to accurately calculate fetal oximetry information such as fetal hemoglobin and / or tissue oxygen saturation levels.

Description

SYSTEMS, DEVICES, AND METHODS FOR DETERMINING FETAL-OXIMETRY INFORMATION AND / OR AN INDICATION OF FETAL WELLNESS USING DIRECT MEASUREMENTSRelated Application[OOOIJThis patent application is an INTERNATIONAL (PCT) PATENT APPLICATION claiming priority to United States Provisional Patent Application Number 63 / 558,051 , filed on 26 February 2024 and entitled “SYSTEMS, DEVICES, AND METHODS FOR PERFORMING DETERMINING FETAL-OXIMETRYINFORMATION AND / OR AN INDICATION OF FETAL WELLNESS USING DIRECT MEASUREMENTS” and United States Provisional Patent Application Number 63 / 763,236, filed on 25 February 2025 and entitled “SYSTEMS, DEVICES, AND METHODS FOR DETERMINING FETAL-OXIMETRY INFORMATION USING DIRECT MEASUREMENTS” both of which are incorporated by reference herein in their respective entireties.Technical Field

[0002] The present invention is in the field of medical devices and, more particularly, in the field of fetal wellness, fetal oximetry, fetal pulse oximetry, and fetal tissue oxygenation.Background

[0003] Current methods of monitoring fetal health, such as monitoring fetal heartrate, are inefficient and prone to inaccuracies when determining levels of fetal distress and, at times, provide false positive results indicating fetal distress that may result in the unnecessary performance of a Cesarean delivery. One area of interest in improving fetal health monitoring includes the use of transabdominal-fetal-oximetry.

[0004] Oximetry is a method for determining a level of oxygen saturation of a mammal’s tissue, arterial hemoglobin, and / or venous hemoglobin. A mammal’s level of oxygen saturation may provide an indication of health or overall wellness of an individual. Transabdominal-fetal-oximetry is a method of oximetry for a fetus performed by analyzing light projected into a pregnant mammal’s abdomen that reflects off the fetus contained therein and is detected by a photodetector. The optical information detected by the photodetector is analyzed to calculate fetal oximetryvalues that may be used to determine whether or not a fetus is in distress and / or is at risk of developing hypoxemia or hypoxia.Summary

[0005] The systems, devices, and methods disclosed herein may be used to determine whether a direct-measurement-fetal-oximetry device positioned within a uterus of a pregnant mammal is working properly and / or is receiving and / or communicating signals (e.g., optical signals and / or analog and / or digital signals that correspond to detected optical signals) that correspond to light that was incident upon a fetus (as opposed to light that was incident on maternal tissue (e.g., uterine wall or cervix). At times, this may be accomplished by receiving a measurement from a contact sensor of a direct-measurement-fetal-oximetry device positioned within a uterus of a pregnant mammal, determining whether the contact sensor may be in physical or electrical contact with fetal skin (e.g., cheek, a back, a head, an ear, an arm, and / or a chest of the fetus) using the received measurement, and providing an indication (e.g., a message, activation of an indicator light, a tone, etc.) of the determination to a display device.

[0006] The measurement from the contact sensor may be one or more of an impedance measurement, an ECG measurement, and when the direct-measurement- fetal-oximetry device includes an inflatable stabilization device, the measurement may be a force and / or pressure level in an inflation line in communication with the inflatable stabilization device. When the measurement indicates that the contact sensor is not in contact with the fetus, an instruction to further inflate the stabilization device and / or an instruction to adjust a position and / or an orientation of the direct-measurement- fetal-oximetry device may be provided to the display device.

[0007] In some embodiments when the contact sensor is an ECG lead and the information from the contact sensor may be ECG information, maternal ECG information may be received from an external maternal ECG monitor. In these embodiments, determining whether the contact sensor may be in physical or electrical contact with fetal skin may include determining whether the ECG heartrate information from the contact sensor approximately matches the maternal ECG heartrate information and, if not, providing an indication to the display device that the contact sensor may be in electrical contact with fetal skin. If the ECG heartrate information from the contact sensor approximately matches the maternal ECG heartrateinformation, then it may be deduced that the contact sensor is in contact with maternal tissue instead of fetal tissue and an error message may be provided to the display device.

[0008] Additionally, or alternatively, when the contact sensor is an ECG lead and the information from the contact sensor may be ECG information, fetal heartrate information may be received from a fetal heartrate monitor and determining whether he contact sensor is in physical or electrical contact with fetal skin may comprises determining heartrate information from the ECG information from the contact sensor and determining whether the heartrate information from the ECG information from the contact sensor approximately matches the fetal heartrate information from the fetal heartrate monitor and, if so, providing an indication to the display device that the contact sensor is in electrical contact with fetal skin.

[0009] In some embodiments, maternal tissue optical property information may be received from a maternal oximetry monitor and oximetry information may be received from a direct-measurement-fetal-oximetry device positioned within a uterus of a pregnant mammal. Then, it may be determined whether the maternal oximetry approximately matches the oximetry information from the direct-measurement-fetal- oximetry device and, if so, it may be determined that the oximetry information received from a direct-measurement-fetal-oximetry device may be maternal (as opposed to fetal) oximetry information and an error message may be provided to a display device.

[0010] Additionally, or alternatively, directly-measured-fetal-oximetry information may be received from a direct-measurement-fetal-oximetry device in optical contact with a fetus and one or more of a calibration, value, equation, coefficient, or algorithm for evaluating one or more signals received from a transabdominal-fetal-oximetry sensor to determine fetal oximetry information may be determined using to the received directly-measured-fetal-oximetry information. In some embodiments, the one or more signals may be received from the transabdominal-fetal-oximetry sensor and evaluated using the calibration, value, equation, coefficient, or algorithm to determine transabdominally-obtained-fetal- oximetry information. The directly-measured-fetal-oximetry information may be compared with the transabdominally-obtained-fetal-oximetry information and an indication of the transabdominally-obtained-fetal-oximetry information to a display device. Additionally, or alternatively, one or more signals may be received from the transabdominal-fetal-oximetry sensor and evaluated using the calibration, value,equation, coefficient, and / or algorithm to determine transabdominally-obtained-fetal- oximetry information. The directly-measured-fetal-oximetry information and the transabdominally-obtained-fetal-oximetry information may be compared and one or more of the calibration, value, equation, coefficient, or algorithm may be adjusted responsively to the comparison.

[0011] At times, secondary information (e.g., maternal heartrate, fetal heartrate, maternal tissue optical property information, fetal depth, maternal layer thicknesses, geometry, and / or maternal optical properties may be received and used to determine and / or adjust the calibration, value, equation, coefficient, and / or algorithm. For example, the secondary information may be used to calibrate the transabdominally measured fetal oximetry information, filter the transabdominally measured fetal oximetry information, and / or amplify portions of the transabdominally measured fetal oximetry information.

[0012] In some embodiments, the secondary information may be maternal tissue optical property information received from the direct-measurement-fetal- oximetry device via, for example, a set of sensors positioned on the device. In these embodiments, one or more signal(s) corresponding to light (usually at least two wavelengths of light) that was incident on maternal tissue may be received from the direct-measurement-fetal-oximetry device. Exemplary maternal tissue optical properties include, but are not limited to, tissue hemoglobin concentration, scattering coefficient as a function of wavelength (e.g., scattering amplitude and power), absorption coefficient as a function of wavelength, and / or the effective attenuation coefficient (pieff) as a function of wavelength Maternal tissue optical property information may then be determined and / or calculated using the one or more signals and, at times, the maternal tissue optical property information may be used to, for example, isolate a fetal portion of a composite signal (e.g., a transabdominal-oximetry signal that includes contributions from the fetus and pregnant mammal) and / or determine a calibration, value, equation, coefficient, and / or algorithm used to calibrate and / or calculate fetal oximetry information, which may be , for example, a fetal hemoglobin oxygen saturation level and / or a fetal tissue oxygen saturation level.

[0013] In another embodiment, directly-measured-fetal-oximetry information may be received from a direct-measurement-fetal-oximetry device in optical contactwith a fetus and the directly-measured-fetal-oximetry information may be used to determine a directly-measured-fetal oximetry value. Then, one or more signals, corresponding to optical signals emanating from an abdomen of a mammal who is pregnant with the fetus may be received from a transabdominal-fetal-oximetry sensor and a transabdominally-obtained-fetal-oximetry value may be determined using the one or more signals from the transabdominal-fetal-oximetry sensor. The directly- measured-fetal-oximetry value may be compared with the transabdominally-obtained- fetal-oximetry value and the directly-measured-fetal-oximetry value to a display device responsively to a result of the comparison when, for example, a result of the comparison indicates the transabdominally-obtained-fetal-oximetry value and the directly-measured-fetal-oximetry value are sufficiently close to one another (e.g., within 1-20%, 1-15%, 1-10%, 1-5%).

[0014] In some embodiments, a result of the comparison may be used to determine to whether and / or how to calibrate and / or adjust determining a transabdominally-obtained-fetal-oximetry value using the one or more signals from the transabdominal-fetal-oximetry sensor and, if so, the determining the transabdominally-obtained-fetal-oximetry value may be so adjusted / calibrated.

[0015] In some embodiments, secondary information (e.g., the secondary information disclosed herein) may be used to generate one or more transabdominal- fetal-oximetry signals and the one or more transabdominal-fetal signals to determine the transabdominally-obtained-fetal-oximetry value. In some instances, the secondary information may be maternal tissue optical property information received from the direct-measurement-fetal-oximetry device. For example, a signal corresponding to light that was incident on maternal tissue may be received from the direct- measurement-fetal-oximetry device and maternal tissue optical property information may then be determined using the signal corresponding to light that was incident on maternal tissue and, in some cases, determining the calibration, value, equation, coefficient, and / or algorithm may be responsive to the maternal tissue optical property information. Sometimes, the maternal tissue optical property information may include and / or be used to determine maternal optical properties such as scattering and / or absorption coefficients and / or time-of-flight for photons traveling through the maternal tissue, which may be used in some cases to determine fetal depth (e.g., the time-of- flight for photons traveling through maternal tissue overlying the direct-measurement- fetal-oximetry device may be used to calculate the distance the photons travel and thisdistance may be used to calculate the fetal depth, wherein the fetal depth may be approximately equal to a width of the direct-measurement-fetal-oximetry device (e.g., distance between the active side of the direct-measurement-fetal-oximetry device and the set of maternal oximetry sensors) and the width of the maternal tissue determined using photonic time-of-flight. Additionally, or alternatively, the width of maternal tissue may be determined using photoacoustic spectroscopy, wherein maternal and / or fetal tissue may be impinged with light, which causes photonic excitation of the subject tissues, which results in localized micro-heating of the subject tissue that may be detected via ultrasound imaging. Using photoacoustic spectroscopy may provide advantages including, but not limited to, requiring lower time resolution (at the speed of sound instead of the speed of light).

[0016] The direct-measurement-fetal-oximetry devices disclosed herein may include a light source configured to project light into fetal skin, a detector configured to detect light backscattered from fetal tissue and convert the detected light into a signal, and a contact sensor configured to detect contact with fetal skin. The contact sensor may be, for example, an ECG lead, a camera, and / or a closely spaced light source and detector pair. Additionally, or alternatively, the direct-measurement-fetal- oximetry devices disclosed herein an optically-isolating feature configured to optically isolate detector from the light source.

[0017] The direct-measurement-fetal-oximetry device may also include a housing comprising a first side in which the light source and detector are positioned (e.g., an active side) and a stabilization device positioned on a second side of the housing, the second side of the housing opposing the first side of the housing and / or configured to face an internal uterine wall when in situ. The stabilization device may be configured to and / or include a material that is configured to expand into space between the fetus and internal uterine wall, thereby pressing an active side of the direct-measurement-fetal-oximetry device onto and / or into fetal skin and / or holding the active side proximate to the fetal skin.

[0018] A size and / or volume of the stabilization device may be adjustable. For example, the stabilization device may be inflatable and the direct-measurement-fetal- oximetry device and / or a handle thereof may include an inflation line resident in the positioning extension, the inflation line being in communication with the stabilization device and configured to communicate fluid to and / or from the stabilization device, thereby adjusting a size and / or volume of the stabilization device. At times, a degreeof inflation of the stabilization device may be responsive to back pressure and / or force exerted on the inflation line as measured by, for example, a force and / or pressure meter and / or gauge. Additionally, or alternatively, a degree of inflation of the stabilization device may be responsive to an indication of whether the direct- measurement-fetal-oximetry device is in contact (e.g., physical and / or optical) with fetal skin. For example, if a contact sensor indicates that the direct-measurement- fetal-oximetry device is not in contact with fetal skin, an instruction to further inflate the stabilization device may be provided to a display device. Additionally, or alternatively, in some embodiments, the stabilization device may include a material (e.g., foam or hydrogel components) that expands when exposed to amniotic fluid.

[0019] In some embodiments, the direct-measurement-fetal-oximetry device may include a housing in which the light source and detector are positioned and an extension physically coupled to the direct-measurement-fetal-oximetry device and configured to assist with positioning and / or maintaining a position the direct- measurement-fetal-oximetry device proximate to the fetal skin. Additionally, or alternatively, the housing and / or extension may include a reference electrode positioned and configured to contact and / or be electrically coupled with a uterine wall of a mammal who may be pregnant with the fetus.

[0020] Additionally, or alternatively, the housing may include a first side in which the light source and detector are positioned and a set of maternal optical sensors comprising a light source and a detector positioned on a second side of the housing. The set of maternal optical sensors may be sized, positioned, and / or configured to contact maternal tissue and obtain optical information from the maternal tissue including, but not limited to, scattering and / or absorption properties, time-of-flight, and / or tissue oxygen saturation for maternal tissue proximate to the set of maternal oximetry sensors.

[0021] Any of the direct-measurement-fetal-oximetry devices disclosed herein may include a temperature sensor configured to measure a temperature of the fetus and / or a mammal who is pregnant with the fetus and / or a marker configured to be opaque to an imaging technology such as ultrasound or MRI. Additionally, or alternatively, any of the direct-measurement-fetal-oximetry devices disclosed herein may have a portion of an outer surface that is coated and / or treated with a lubricious coating to reduce friction between the device and tissue of mammal pregnant with the fetus. Additionally, or alternatively, any of the direct-measurement-fetal-oximetrydevices disclosed herein may have an optically-isolating feature (e.g., a blinder, an extensions, a recess, a flange, and a gasket) configured to optically isolate detector from the light source. The optically-isolating feature may be positioned around the detector and / or the light source and / or between the detector and / or the light source.

[0022] In some embodiments, the direct-measurement-fetal-oximetry devices disclosed herein may have a set of maternal optical sensors positioned on a portion of a housing not configured for contact with the fetus. The set of maternal optical sensors may include, a light source positioned and configured to project light into a uterine wall of a mammal who is pregnant with the fetus and a detector positioned and configured to detect light backscattered from the uterine wall of the mammal.

[0023] In some embodiments, ECG information may be received from an ECG lead of a direct-measurement-fetal-oximetry device positioned within a uterus of a pregnant mammal and fetal heartrate information may be received from a fetal heartrate monitor. In these embodiments, it may be determined whether the contact sensor is in physical or electrical contact with fetal skin by analyzing the ECG information to determine heartrate information therefrom and then it may be determined whether the heartrate information determined using the ECG information from the contact sensor approximately matches the fetal heartrate information from the fetal heartrate monitor and, if so, it may be determined that the contact sensor is in electrical contact with fetal skin and, therefore an active side of the direct- measurement-fetal-oximetry device is oriented correctly (i.e., pointed toward the fetus). When it is determined that the ECG information from the contact sensor does not approximately match the fetal heartrate information from the fetal heartrate monitor, an error message may be sent to the display device indicating that the direct- measurement-fetal-oximetry device is not oriented correctly.

[0024] In some embodiments, the direct-measurement-fetal-oximetry device may include an inflatable stabilization device and a force and / or pressure measurement from a force and / or pressure gauge in communication with an inflation line that provides inflation media to the inflatable stabilization device may be received and an indication of the force and / or pressure measurement may be provided to the display device. Optionally, an instruction to further inflate the stabilization device may be provided to the display device responsively to a determination that the contact sensor is not in physical or electrical contact with fetal skin. Additionally, or alternatively, an instruction to adjust a position and / or an orientation of the direct-measurement-fetal-oximetry device may be provided to the display device responsively a determination that the contact sensor is not in physical or electrical contact with fetal skin.

[0025] At times, maternal ECG information may be received from an external maternal ECG monitor and determining whether the contact sensor is in physical or electrical contact with fetal skin may comprise determining whether the ECG heartrate information from the contact sensor approximately matches the maternal ECG heartrate information and, if not, providing an indication to the display device that the contact sensor is in electrical contact with fetal skin.

[0026] In some embodiments, directly-measured-fetal-oximetry information may be received from a direct-measurement-fetal-oximetry device in optical contact with a fetus and a parameter for the operation of a transabdominal-fetal-oximetry sensor may be determined using the received directly-measured-fetal-oximetry information. Optionally, the parameter may be communicated to the transabdominal- fetal-oximetry sensor, wherein the transabdominal-fetal-oximetry sensor is configured to adjust its operation responsively to the received parameter.

[0027] In some cases, one or more signals may be received from the transabdominal-fetal-oximetry sensor. The one or more signals may correspond to optical signals emanating from an abdomen of a mammal who is pregnant with the fetus and detected by the transabdominal-fetal-oximetry sensor. Then, transabdominally-obtained-fetal-oximetry information may be determined using the one or more signals received from the transabdominal-fetal-oximetry sensor. The directly-measured-fetal-oximetry information and the transabdominally-obtained-fetal- oximetry information may be compared with one another and an indication of the transabdominally-obtained-fetal-oximetry information to a display device.

[0028] Additionally, or alternatively, one or more signals may be received from the transabdominal-fetal-oximetry sensor and the one or more signals may correspond to optical signals emanating from an abdomen of a mammal who is pregnant with the fetus and detected by the transabdominal-fetal-oximetry sensor. Transabdominally- obtained-fetal-oximetry information may then be determined using the one or more signals from the transabdominal-fetal-oximetry sensor and the directly-measured- fetal-oximetry information and transabdominally-obtained-fetal-oximetry information may be compared with one another and, at times, the parameter may be adjusted responsively to the comparison.

[0029] In some embodiments, secondary information (e.g., a maternal heartrate, a fetal heartrate, a fetal depth, and maternal tissue optical property information) and determining the parameter for the operation of a transabdominal- fetal-oximetry sensor may be responsive to the received secondary information.

[0030] In some instances, the direct-measurement-fetal-oximetry device may include a light source and a plurality of detectors and the parameter may be a selection of a detector of the pair of detectors from which to use a signal to determine fetal oximetry information. For example, in a direct-measurement-fetal-oximetry device that includes four detectors, signals from two of the detectors that are furthest away from the light source may be selected for further analysis to determine fetal oximetry information while signals from the remaining two detectors may be ignored or used to determine one or more properties of maternal tissue.

[0031] In some embodiments, one or more maternal optical characteristic(s) (e.g., tissue thickness and / or composition) may be received and the determining of the parameter for the operation of a transabdominal-fetal-oximetry sensor may be responsive to the maternal optical characteristic(s).Brief Description of the Figures

[0032] The present invention is illustrated byway of example, and not limitation, in the figures of the accompanying drawings in which:

[0033] FIG. 1A is a block diagram of an exemplary system for assessing fetal and / or maternal health and / or detecting and / or determining fetal hemoglobin oxygen saturation levels and / or fetal depth, consistent with some embodiments of the present invention;

[0034] FIG. 1 B is a block diagram of an exemplary set of components that may be included in a transabdominal-fetal-oximetry sensor, in accordance with some embodiments of the present invention;

[0035] FIG. 1C is a block diagram of an exemplary transabdominal-fetal- oximetry sensor, in accordance with some embodiments of the present invention;

[0036] FIG. 1 D is a block diagram of an exemplary set of components that may be included in a direct-measurement-fetal-oximetry sensor, in accordance with some embodiments of the present invention;

[0037] FIG. 2A is a diagram of a top plan view of an exemplary direct- measurement-fetal-oximetry sensor, in accordance with some embodiments of the present invention;

[0038] FIG. 2A1 A provides a schematic diagram of a top view of a first housing, in accordance with some embodiments of the present invention;

[0039] FIG. 2A1 B provides a schematic diagram of a cross-section view of the first housing of FIG. 2A1A, in accordance with some embodiments of the present invention;

[0040] FIG. 2A2A provides a schematic diagram of a top view of a second housing, in accordance with some embodiments of the present invention;

[0041] FIG. 2A2B provides a schematic diagram of a cross-section view of the second housing of FIG. 2A2A, in accordance with some embodiments of the present invention;

[0042] FIG. 2A3A provides a schematic diagram of a top view of a third housing, in accordance with some embodiments of the present invention;

[0043] FIG. 2A3B provides a schematic diagram of a cross-section view of the third housing of FIG. 2A3A, in accordance with some embodiments of the present invention;

[0044] FIG. 2A4 provides a side view of a fourth housing, in accordance with some embodiments of the present invention;

[0045] FIG. 2A5 provides a side, or cut-away, view of a fifth housing, in accordance with some embodiments of the present invention;

[0046] FIG. 2A6 provides a side, or cut-away, view of a sixth housing, in accordance with some embodiments of the present invention;

[0047] FIG. 2A7 provides a side, or cut-away, view of a seventh housing, in accordance with some embodiments of the present invention;

[0048] FIG. 2A8 provides a side, or cut-away, view of an eighth housing, in accordance with some embodiments of the present invention;

[0049] FIG. 2B is a diagram of a side plan view of an exemplary direct- measurement-fetal-oximetry sensor, in accordance with some embodiments of the present invention;

[0050] FIG. 2C is a schematic diagram of a side view of another exemplary direct-measurement-fetal-oximetry sensor, in accordance with some embodiments of the present invention;

[0051] FIG. 2D is a schematic diagram of a side view of a further example of a direct-measurement-fetal-oximetry sensor, in accordance with some embodiments of the present invention;

[0052] FIG. 2E is a schematic diagram of a side view of a further example of a direct-measurement-fetal-oximetry sensor with a light source and detector arranged to detect maternal tissue optical property information, in accordance with some embodiments of the present invention;

[0053] FIG. 2F is a schematic diagram illustrating a cross-section view of a pregnant human woman with the direct-measurement-fetal-oximetry sensor of FIG. 2A positioned within the pregnant woman’s uterus and proximate to the pregnant woman’s fetus, in accordance with some embodiments of the present invention;

[0054] FIG. 2G is a diagram illustrating a cross-section view of a pregnant human woman with the direct-measurement-fetal-oximetry sensor of FIG. 2C positioned within the pregnant woman’s uterus and proximate to the pregnant woman’s fetus, in accordance with some embodiments of the present invention;

[0055] FIG. 2H is a diagram illustrating a cross-section view of a pregnant human woman with the direct-measurement-fetal-oximetry sensor of FIG. 2D positioned within the pregnant woman’s uterus and proximate to the pregnant woman’s fetus, in accordance with some embodiments of the present invention;

[0056] FIG. 2I is a diagram illustrating a cross-section view of a pregnant human woman with the direct-measurement-fetal-oximetry sensor of FIG. 2E positioned within the pregnant woman’s uterus and proximate to the pregnant woman’s fetus, in accordance with some embodiments of the present invention;

[0057] FIG. 3A is a schematic diagram of an exemplary direct-measurement- fetal-oximetry sensor with a retractable cover that includes a light source and a detector in a first state of operation, in accordance with some embodiments of the present invention;

[0058] FIG. 3B is a schematic diagram of the exemplary direct-measurement- fetal-oximetry sensor of FIG. 3A in a second state of operation, in accordance with some embodiments of the present invention;

[0059] FIG. 3C is a schematic diagram of direct-measurement-fetal-oximetry sensor that includes a light source, a detector, and a pair of cooperating cable braces separated by a junction in a first state of operation, in accordance with some embodiments of the present invention;

[0060] FIG. 3D is a schematic diagram of the direct-measurement-fetal- oximetry sensor of FIG. 30 in a second state of operation, in accordance with some embodiments of the present invention;

[0061] FIG. 3E is a schematic diagram of an exemplary direct-measurement- fetal-oximetry sensor that includes a light source, a detector, and two arms in a first state of operation, in accordance with some embodiments of the present invention;

[0062] FIG. 3F is a schematic diagram of the exemplary direct-measurement- fetal-oximetry sensor of FIG. 3E in a second state of operation, in accordance with some embodiments of the present invention;

[0063] FIG. 4A is a top view of an exemplary light source / detector spacer, in accordance with some embodiments of the present invention;

[0064] FIG. 4B is a top view of an exemplary light source / detector spacer with a source and detector arranged thereon, in accordance with some embodiments of the present invention;

[0065] FIG. 4C is a top view of an exemplary light source / detector spacer with a source and detector arranged in a second arrangement thereon, in accordance with some embodiments of the present invention;

[0066] FIG. 5A is a schematic diagram of an exemplary direct-measurement- fetal-oximetry sensor with a retractable cover that includes a light source and two detectors in a first state of operation, in accordance with some embodiments of the present invention;

[0067] FIG. 5B is a schematic diagram of the exemplary direct-measurement- fetal-oximetry sensor of FIG. 5A in a second state of operation, in accordance with some embodiments of the present invention;

[0068] FIG. 5C is a schematic diagram of a direct-measurement-fetal-oximetry sensor that includes a light source, two detectors, and a pair of cooperating cable braces separated by a junction in a first state of operation, in accordance with some embodiments of the present invention;

[0069] FIG. 5D is a schematic diagram of the direct-measurement-fetal- oximetry sensor of FIG. 5C in a second state of operation, in accordance with some embodiments of the present invention;

[0070] FIG. 5E is a schematic diagram of another exemplary direct- measurement-fetal-oximetry sensor that includes a light source, two detectors, andtwo arms in a first state of operation, in accordance with some embodiments of the present invention;

[0071] FIG. 5F is a schematic diagram of the direct-measurement-fetal- oximetry sensor of FIG. 5E in a second state of operation, in accordance with some embodiments of the present invention;

[0072] FIG. 6A is a top view of an exemplary cross-shaped light source / detector spacer, in accordance with some embodiments of the present invention;

[0073] FIG. 6B is a top view of the exemplary cross-shaped light source / detector spacer with a source and two detectors arranged thereon, in accordance with some embodiments of the present invention;

[0074] FIG. 7 is a flowchart showing a process for determining fetal-oximetry information using a direct-measurement-fetal-oximetry sensor, in accordance with some embodiments of the present invention;

[0075] FIG. 8 is a flowchart showing an exemplary process for using both a transabdominal-fetal-oximetry sensor and a direct-measurement-fetal-oximetry sensor to obtain, determine, and / or validate fetal-oximetry information, in accordance with some embodiments of the present invention;

[0076] FIG. 9 is a flowchart showing an exemplary process for adjusting transabdominal-fetal-oximetry sensor, in accordance with some embodiments of the present invention; and

[0077] FIG. 10 is a flowchart showing an exemplary process for calibrating signals received from a transabdominal-fetal-oximetry sensor, in accordance with some embodiments of the present invention; and

[0078] FIG. 11 illustrates an exemplary process for validating transabdominally- obtained-fetal-oximetry information using direct-measurement-fetal-oximetry information, in accordance with some embodiments of the present invention.

[0079] 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, the description is done in connection with the illustrative embodiments. It is intended that changes and modifications can be made to the described embodiments without departing from the true scope and spirit of the subject invention as defined by the appended claims.DESCRIPTION

[0080] There are clinical situations in which obtaining sufficiently accurate transabdominal-fetal-oximetry information is challenging. For example, when a fetus is positioned beneath relatively thick layers of maternal tissue as may occur with a fetus of young gestational age (e.g., 15-25 weeks) and / or when a pregnant mammal has relatively thick layers of adipose tissue positioned between the abdominal epidermis and uterus, it can be difficult to illuminate the fetus with enough light to cause a sufficiently strong, or clear (i.e., not noisy), returning optical signal (i.e., an optical signal that has been diffusely reflected from within the fetal blood-containing tissues) to be reliably analyzed to determine fetal-oximetry information. In addition, it may be difficult to calibrate a transabdominal-fetal-oximetry sensor and / or signals detected by a transabdominal-fetal-oximetry sensor in certain situations due to, for example, fetal skin tone, fetal position within the maternal abdomen, geometrical considerations of an arrangement of the fetus within the maternal abdomen, and / or characteristics / behavior (e.g., scattering and / or absorption) of light as it travels through maternal and / or fetal tissue.

[0081] The systems, devices, and / or methods disclosed herein may be used to, for example, calibrate a transabdominal-fetal-oximetry sensor, directly measure fetal- oximetry information (e.g., optical signals that are incident on fetal skin) via a direct- measurement-fetal-oximetry sensor that is in contact with fetal skin, validate and / or verify fetal-oximetry information determined using a transabdominal-fetal-oximetry sensor. On some occasions, the direct-measurement-fetal-oximetry sensor disclosed herein may be used on a periodic, continuous, and / or as-needed basis during, for example, labor and delivery of a fetus to, for example, directly measure fetal-oximetry information and / or calibrate a transabdominal-fetal-oximetry sensor over time to account for changes in the geometry and / or anatomy of the pregnant mammal’s abdomen and / or a position of the fetus therein during labor and delivery.

[0082] FIG. 1A provides an exemplary system 100 for assessing fetal and / or maternal health, detecting optical signals that may be analyzed to determine fetal- oximetry information, and / or determining fetal-oximetry information and / or indications of fetal distress that may, in some instances, be correlated to deoxygenation. The components of system 100 may be coupled together via wired and / or wireless communication links. In some instances, wireless communication of one or more components of system 100 may be enabled using short-range wirelesscommunication protocols designed to communicate over relatively short distances (e.g., Bluetooth®, near field communication (NFC), radio-frequency identification (RFID), and Wi-Fi) with, for example, a computer and / or processor or personal electronic device (e.g., tablet computer or smart phone) as described below.

[0083] System 100 includes an exemplary fetal-oximetry sensor 115 that houses at least one light source 105 and at least one detector 160 and may be configured for transabdominal, transvaginal, or transcervical use. On some occasions, fetal-oximetry sensor 115 may include additional components as described herein with regard to FIGs. 1 B, 1C, and / or 1 D. Light source 105 may include a single or multiple light sources, and detector 160 may include a single or multiple detectors. Light source 105 may transmit light of one or more wavelengths, including near infrared (NIR), into a pregnant mammal’s abdomen and / or directly into fetal skin. Light source 105 may be, for example, an LED, and / or a LASER that may be coupled to a fiber optic cable. On some occasions, one or more light sources 105 may be one or more fiber optic cables optically coupled to a laser and arranged in an array. In some instances, light source 105 may be tunable or otherwise user configurable, while in other instances light source 105 may be configured to emit light within a pre-defined range of wavelengths. Additionally, or alternatively, one or more filters (not shown) and / or polarizers may filter / polarize the light emitted by light sources 105 to be of one or more preferred wavelengths and / or polarizations. In some cases, these filters / polarizers may also be tunable or user configurable. An exemplary light source 105 may have a relatively small form factor and may operate with high efficiency, which may serve to, for example, conserve space and / or limit heat emitted by the light source 105. In one embodiment, light source 105 is configured to emit light in the range of 500-1100nm, 600-1070nm or 850-1070nm. In some embodiments, light source 105 (or multiple light sources 105) may emit light of at least two different wavelengths (e.g., 735 and 890nm; 760 and 810 nm; or 730 and 850 nm).

[0084] Detector 160 may be one or more components configured to detect light emanating from the pregnant mammal and / or the fetus via, for example, transmission and / or back scattering and convert this light signal into an analog and / or digital, or electronic, signal. The detected signal may be communicated to a computer or processor such as computer and / or processor 150 and / or a receiver such as receiver / interface 145 via, for example, an on-board transceiver and / or a wired communication link. Exemplary detectors 160 include, but are not limited to,photodetectors and cameras. Photodetector technologies that could be employed include PN or PIN photodiodes, avalanche photodiodes, traditional photomultiplier tubes (PMTs), single photon avalanche detectors (SPADs), and / or silicon PMTs.

[0085] System 100 includes a number of optional independent sensors / sensors configured to monitor various aspects of maternal and / or fetal health that may be communicatively coupled to, for example, a timestamping device 185, a receiver / interface 145, and / or computer and / or processor 150. These sensors / sensors include a visible and near infrared spectroscopy (Vis-NIRS) adult hemoglobin sensor 125, a pulse oximetry sensor 130, a Doppler and / or ultrasound sensor 135, a uterine contraction measurement device 140, an electrocardiography (ECG) measurement device 175, and a ventilatory / respiratory signal source 180. ECG measurement device 175 may be used to determine the pregnant mammal’s heartrate, and, in some embodiments, ECG measurement device 175 may be a fetal ECG that may be used to determine the fetus’s heartrate. In some instances, ECG measurement device 175 may be used internally via, for example, placement in the endocervical canal and / or vagina. At times, placement of ECG measurement device 175 in the vagina and / or on fetal skin may be facilitated by inclusion in a direct- measurement-fetal-oximetry sensor as disclosed herein. In some embodiments, a signal from ECG measurement device 175 may be used as a trigger or to create a binarized waveform to perform other actions such as cross-correlation filtering, pulse averaging, and / or synchronous detection and / or filtering of a composite signal to isolate a fetal signal.

[0086] Doppler and / or ultrasound sensor 135 may be configured to be placed on the abdomen of the pregnant mammal and may provide information regarding, for example, fetal depth, tissue layer thicknesses, fetal position, orientation, and / or heartrate. Pulse oximetry sensor 130 may be a conventional pulse oximetry sensor placed on, for example, the pregnant mammal's earlobe and / or finger to measure the pregnant mammal’s hemoglobin oxygen saturation level. Vis-NIRS adult hemoglobin sensor 125 may be placed on, for example, the pregnant mammal’s 2nd finger or earlobe and may be configured to, for example, use visible and near infrared spectroscopy to calculate the ratio of adult oxyhemoglobin to adult deoxyhemoglobin. Vis-NIRS adult hemoglobin sensor 125 may also be used to determine the pregnant mammal’s heartrate. In some embodiments, Vis-NIRS adulthemoglobin sensor 125 may be a blood CO-oximeter, a hemoximeter, or blood gas analyzer.

[0087] Uterine contraction measurement device 140 may be configured to measure the strength and / or timing of the pregnant mammal’s uterine contractions. In some embodiments, uterine contractions may be measured by uterine contraction measurement device 140 as a function of pressure and / or force (e.g., measured in e.g., mmHg and / or pound force (Ibf)) over time. In some instances, uterine contraction measurement device 140 is and / or includes a tocotransducer, which is an instrument that includes a pressure-sensing area that detects changes in the abdominal contour to measure uterine activity and, in this way, monitors frequency and duration of contractions. Additionally, or alternatively, uterine contractions may be measured via visible and / or near infrared spectroscopy using, for example, light received / detected by detector 160 because uterine contractions, which are muscle contractions, are oscillations of the uterine muscle between a contracted state and a relaxed state that may be observed via analysis of an optical signal detected by detector 160 because oxygen consumption of the uterine muscle during both of these stages is different and these differences may be detectable using Vis-NIRS. Additionally, or alternatively, uterine contraction measurement device 140 may employ electromyography (EMG) to measure electrical activity from the uterine muscle to detect one or more characteristics of uterine contractions during a labor and delivery process. Additionally, or alternatively, uterine contraction measurement device 140 may be an intrauterine pressure catheter (IUPC).

[0088] Measurements and / or signals from Vis-NIRS adult hemoglobin sensor 125, pulse oximetry sensor 130, Doppler and / or ultrasound sensor 135, and / or uterine contraction measurement device 140 may be communicated directly to computer and / or processor 150 and / or to receiver / interface 145 for communication to computer and / or processor 150 and display on display device 155 and, in some instances, may be considered secondary signals. In some embodiments, measurements provided by Vis-NIRS adult hemoglobin sensor 125, pulse oximetry sensor 130, a Doppler and / or ultrasound sensor 135, uterine contraction measurement device 140, ECG measurement device 175, and / or ventilatory / respiratory signal source 180 may be used in conjunction with fetal-oximetry sensor 115 to isolate a fetal contribution (also referred to herein as a “fetal signal”) to an optical signal detected by detector 160 that may include light that was incident on both the pregnant mammal and fetus.Receiver / interface 145 may be configured to receive signals and / or data from one or more components of system 100 including, but not limited to, fetal-oximetry sensor 115, Vis-NIRS adult hemoglobin sensor 125, pulse oximetry sensor 130, Doppler and / or ultrasound sensor 135, uterine contraction measurement device 140, ECG measurement device 175, and / or ventilatory / respiratory signal source 180. Communication between receiver / interface 145 and / or computer and / or processor 150 and other components of system 100 may be made using wired or wireless communication.

[0089] In some instances, one or more of Vis-NIRS adult hemoglobin sensor 125, pulse oximetry sensor 130, a Doppler and / or ultrasound sensor 135, uterine contraction measurement device 140, ECG measurement device 175, and / or ventilatory / respiratory signal source 180 may include a dedicated display that provides the measurements to, for example, a user or medical treatment provider. It is important to note that not all of these sensors are used in every instance. For example, when the pregnant mammal is using fetal-oximetry sensor 115 in a setting outside of a hospital or treatment facility (e.g., at home or work) then, some of the sensors (e.g., Vis-NIRS adult hemoglobin sensor 125, pulse oximetry sensor 130, a Doppler and / or ultrasound sensor 135, uterine contraction measurement device 140, ECG measurement device 175, and / or ventilatory / respiratory signal source 180) of system 100 may not be used.

[0090] In some instances, receiver / interface 145 may be configured to process or pre-process received signals so as to, for example, make the signals compatible with computer and / or processor 150 (e.g., convert an optical signal to a digital and / or an electrical signal), improve signal to noise ratio (SNR), amplify a received signal, etc. In some instances, receiver / interface 145 may be resident within and / or may be a component of computer and / or processor 150. In some embodiments, computer and / or processor 150 may amplify or otherwise condition the received detected signal so as to, for example, improve the signal-to-noise ratio.

[0091] Receiver / interface 145 may communicate received, pre-processed, and / or processed signals to computer and / or processor 150. Computer and / or processor 150 may act to process the received signals, according to, for example, one or more of the methods disclosed herein, and facilitate provision of the results to display device 155. Exemplary computer and / or processors 150 include desktop and laptop computers, servers, tablet computers, personal electronic devices, mobiledevices (e.g., smart phones), application specific circuits (ASICs), field programmable gate arrays (FPGAs), and the like. Exemplary display devices 155 are computer monitors, tablet computer devices, and displays provided by one or more of the components of system 100. In some instances, display device 155 may be resident in receiver / interface 145 and / or computer and / or processor 150. Computer and / or processor 150 may be communicatively coupled to a database 170, which may be configured to store instructions for executing one or more of the methods disclosed herein and / or information regarding physiological characteristic and / or combinations of physiological characteristic of pregnant mammals and / or their fetuses, impacts of physiological characteristic on light behavior, information regarding the calculation of hemoglobin oxygen saturation levels, calibration factors, and so on.

[0092] In some embodiments, system 100 may include a ventilatory / respiratory signal source 180 that may be configured to monitor the pregnant mammal’s respiratory rate and provide a respiratory signal indicating the pregnant mammal’s respiratory rate to, for example, computer and / or processor 150. In some embodiments, ventilatory / respiratory signal source 180 may be a source of a ventilatory signal obtained via, for example, cooperation with a ventilation machine. Exemplary ventilatory / respiratory signal sources 180 include, but are not limited to, a carbon dioxide measurement device, a stethoscope, electronic acoustic stethoscope, a device that measures chest excursion for the pregnant mammal, and a pulse oximeter. Additionally, or alternatively, a signal from a pulse oximeter (e.g., pulse oximetry sensor 130 and / or Vis-NIRS adult hemoglobin sensor 125) may be analyzed to determine variations in the PPG signal that may correspond to respiration for the pregnant mammal. Additionally, or alternatively, ventilatory / respiratory signal source 180 may provide a respiratory signal that corresponds to a frequency with which gas (e.g., air, anesthetic, etc.) is provided to the pregnant mammal during, for example, a surgical procedure. This respiratory signal may be used to, for example, determine a frequency of respiration for the pregnant mammal, which may correspond to motion artifacts present in a signal detected by detector 160.

[0093] In some embodiments, system 100 may include timestamping device 185 configured to timestamp a signal detected and / or generated by, for example, fetal- oximetry sensor 115, Doppler / ultrasound sensor 135, pulse oximetry sensor 130, Vis- NIRS adult hemoglobin sensor 125, uterine contraction measurement device 140, ECG measurement device 175, and / or ventilatory / respiratory signal source 180 witha timestamp that represents, for example, an event (e.g., time, or t, = 0, 10, 20, etc.) and / or chronological time (e.g., date and time) so that these signals may be synchronized in time using with the timestamp. Timestamping device 185 may timestamp a signal via, for example, introducing a ground, acoustic, and / or optical signal into system 100 that may simultaneously, or nearly simultaneously, interrupt or otherwise introduce a stamp or other indicator into a signal generated by one or more of, for example, fetal-oximetry sensor 115, Doppler / ultrasound sensor 135, pulse oximetry sensor 130, Vis-NIRS adult hemoglobin sensor 125, uterine contraction measurement device 140, ECG measurement device 175, and / or ventilatory / respiratory signal source 180.

[0094] FIG. 1 B is a block diagram of an exemplary set of components that may be included in a transabdominal-fetal-oximetry sensor 115A, such as the transabdominal-fetal-oximetry sensors disclosed herein. Transabdominal-fetal- oximetry sensor 115A may be configured to, for example, project light into a pregnant mammal’s abdomen and detect a resultant (via, for example, reflection and / or back scattering) optical signal. This resultant optical signal may be analyzed to, for example, determine fetal-oximetry information. Transabdominal-fetal-oximetry sensor 115A may include a port(s) 141 , a transceiver 142, a power supply 146, one or more light source(s) 105, a uterine contraction measurement device 148, a controller, processor, and / or memory 172, one or more detectors 160, a signal processing component 154, a calibration component 156, and / or a user interface 64.

[0095] Light source(s) 105 may be configured to emit light of various intensities and / or of various wavelengths (e.g., red and / or infrared). In some embodiments, one or more light source(s) may be tunable and / or adjustable to, for example, facilitate emission of light with desired characteristics. Detector(s) 160 may be any device configured to detect an optical signal and / or photon and communicate same to, for example, computer and / or processor 150, controller, processor, and / or memory 172, transceiver 142, and / or an external device. In some instances, detector 160 may be configured to convert the detected optical signal / photon into a current, voltage, and / or electronic signal.

[0096] Controller, processor, and / or memory 172 may be communicatively coupled to one or more components of transabdominal-fetal-oximetry sensor 115A. For example, controller, processor, and / or memory 172 may be communicatively coupled to detector(s) 160 and may be configured to receive one or more voltagereadings, detected electronic signal(s), and / or composite signals therefrom. Controller, processor, and / or memory 172 may also be communicatively coupled to light source 105 and may be configured to provide instructions thereto. Exemplary instructions include, but are not limited to, turning light source 105 on / off, a duration of time to project light, light modulation instructions, and / or what type (e.g., wavelength or set of wavelengths) and / or intensity of light to emit.

[0097] In some embodiments, controller, processor, and / or memory 172 may be configured to pre-process and / or filter signals received from one or more detectors 160. Exemplary pre-processing includes, but is not limited to, filtering (e.g., bandpass or Kalman filter), synchronous detection / demodulation, and / or noise reduction / cancellation. One or more operations performed by controller, processor, and / or memory 172 may be executed using one or more sets of instructions stored thereon and / or received via, for example, port(s) 141 and / or transceiver 142. At times, these instructions may be updated via communications received via, for example, port(s) 141 , user interface 164, and / or transceiver 142. In addition, controller, processor, and / or memory 172 may be configured to store and / or execute instructions for one or more processes, or process steps, disclosed herein.

[0098] Transceiver 142 may be communicatively coupled to components of transabdominal-fetal-oximetry sensor 115A and / or devices external thereto (e.g., a computer, processor, external equipment or a display devices). In some instances, controller, processor, and / or memory 172, power supply 146, and / or port(s) 141 and may be configured to communicate composite signals, analog signals, optical signals, and / or detected electronic signals to one or more communicatively connected devices such as receiver / interface 145 and / or display device 155. Transceiver 142 may also be configured to receive instructions regarding the operation of transabdominal-fetal- oximetry sensor 115A and provide these instructions to computer and / or processor 150. Transceiver 142 may be configured to operate via wired and / or wireless communications.

[0099] Uterine contraction measurement device 148 may be a device configured to measure, for example, an intensity, time, and / or duration of uterine contractions. Exemplary uterine contraction measurement devices 148 include, but are not limited to, pressure transducers, force sensors, piezo-resistance elements, piezo-electrical elements, strain gauges, EMG devices, force meters, and / or intrauterine pressure catheters or components thereof.[000100] Power supply 146 may be any power supply configured to provide electrical power to one or more components of transabdominal-fetal-oximetry sensor 115A. In some embodiments, power supply 146 may be a battery (rechargeable or otherwise). Additionally, or alternatively, power supply may be and / or include a coupling to an AC power supply (e.g., wall outlet). Port(s) 141 may be configured to, for example, provide power to and / or act as a communications interface for transabdominal-fetal-oximetry sensor 115A. Exemplary ports 141 include, but are not limited to USB ports, ethernet ports and the like. In some instances, port(s) 141 may include two or more ports.[000101] Signal processing component 154 may be configured to, for example, improve SNR, adjust gain for a detected electronic signal, filter a detected electronic signal, and / or amplify components of a detected electronic signal. Calibration component 156 may be configured to, for example, calibrate light source(s) 105 and / or detector(s) 160.[000102] User interface 164 may be one or more components configured to receive input (e.g., instructions, patient data, etc.) from a user and / or provide information (e.g., error messages, fetal-oximetry information, confirmation of correct placement, etc.) to the user. Exemplary user interfaces 164 include, but are not limited to, screens, keyboards, buttons, and dials.[000103] FIG. 1C is a block diagram of exemplary fetal sensor 115A positioned on a pregnant mammal’s abdomen. The maternal tissue of the pregnant mammal’s abdomen is represented as an abstraction of maternal tissue 214 and a fetus within the pregnant mammal’s abdomen is represented as an abstraction of a fetus 280. [000104] Fetal sensor 115a has one light source 105 and six detectors 160A, 160B, 160C, 160D, 160E, and 160F, each of which have a different position relative to light source 105 with first detector 160A being the closest to source 105 and sixth detector 160F being the furthest away from source 105. A position of a detector 160A-160F relative to source 105 may be referred to herein as a source / detector distance. In some embodiments, detectors 160A-160F may be arranged linearly and may be positioned 0.5-3cm apart from one another. For example, if detectors 160A- 160F are 2cm apart, first detector 160A may be positioned 2cm away from source 105, second detector 160B may be positioned 2cm away from first detector 160A, third detector 160C may be positioned 2cm away from second detector 160B, fourth detector 160D may be positioned 2cm away from third detector 160C, fifth detector160E may be positioned 2cm away from fourth detector 160D, and sixth detector 160F may be positioned 2cm away from fifth detector 160E but this need not always be the case. In some embodiments, a sensor like fetal sensor 115A may have fewer (e.g., 1-5) than six detectors. For example, in some embodiments, fetal sensor 115A may have two or four detectors 160[000105] During use, source 105 may project an optical signal 190 into the pregnant mammal’s abdomen 206 and a resultant optical signal may be detected by one or more of detector(s) 160A-160F. It is expected that the detectors positioned closer to source 105 will detect a portion of the optical signal that has been incident on the pregnant mammal’s abdomen 206 but not fetus 280 and, in some embodiments, first detector 160A and / or second detector 160B may be positioned via, for example, setting of a source / detector distance, so that a majority, if not all, of an optical signal 190A and 190B detected by first and second detectors 160A and 160B, respectively, has only been incident on the pregnant mammal’s abdomen 206 (i.e., is not incident on the fetus). Third-sixth detectors 160C-160F may detect portions of the optical signal 190C, 190D, WOE, and 190F that are incident on the pregnant mammal 214 and fetus 280 as shown in FIG. 1C. In some cases, third detector 160C may be positioned 3-5cm away from the light source and sixth detector 160F may be positioned 6-10cm away from the light source. Additionally, or alternatively, third-sixth detectors 160C-160F may be positioned within 4-10cm of the light source.[000106] As the source / detector distance increases a proportion of the optical signal that corresponds to light that was incident on fetus 280 increases. Thus, optical signal 190F may include a higher proportion of light that was incident on the fetus (as opposed to the pregnant mammal) than, for example, optical signal WOE or 190D.[000107] FIG. 1 D is a block diagram of exemplary components of a direct- measurement-fetal-oximetry sensor 115B configured to be placed on, or proximate to, fetal skin (prior to delivery), often times without intervening layers of maternal tissue. Direct-measurement-fetal-oximetry sensor 115B includes many of the same components of transabdominal-fetal-oximetry sensor 115A and also optionally includes one or more ECG lead(s) 144, a temperature sensor 152, a contact sensor 158 configured to sense contact with fetal and / or maternal tissue, a force / pressure sensor 160, a colorimeter 166, and a camera 168.[000108] ECG lead(s) 144 may be one or more leads and / or sensors configured to detect impedance and / or an electrical signal and / or electrical potential generated by a fetus’ heart and / or detect an electrical current of the fetus. ECG lead 144 may be configured to provide feedback regarding whether or not direct-measurement-fetal- oximetry sensor 115B is in contact with fetal skin because when direct-measurement- fetal-oximetry sensor 115B is decoupled from fetal skin (i.e., an ECG lead 144 is not in contact with fetal skin and is potentially floating in the amniotic fluid) a low impedance path may exist between two ECG leads that is different from the impedance measured between these two leads when the lead is in contact with the fetal skin. This impedance difference can be measured using, for example, ECG leadoff detection circuitry and / or bioimpedance measurement circuitry. In some embodiments, one or more ECG lead(s) 144 may be positioned so that they are in contact with the fetus and additional ECG lead(s) 144 may be positioned so that they may be in contact with, for example, maternal tissue (e.g., skin (e.g., thigh), vaginal wall, and / or uterine wall when direct-measurement-fetal-oximetry sensor is in situ within the pregnant mammal’s body / uterus.[000109] On some occasions, indications of fetal heartrate and / or cardiac activity provided by ECG lead(s) 144 may be a significant improvement (e.g., more accurate) over the current standard of care, which is to measure fetal heartrate via an ultrasound and / or Doppler machine at least because it is a more direct (i.e., in direct contact) signal than the standard ultrasound method, which relies on measuring fetal heartrate by transmitting an acoustic signal through the maternal abdomen to reach the fetus and then analyzing a reflected ultrasonic signal. Additionally, or alternatively, indications of fetal heartrate and / or cardiac activity provided by ECG lead(s) 144 may be a significant improvement over the current standard of care because ECG waveforms (provided by ECG lead(s) 144) may be easier to process than the Doppler signals based upon waveform morphology (e.g., the R-waves are fairly easy to detect in an ECG waveform with good time resolution).[000110] The improved accuracy provided by use of fetal ECG measurements recorded via ECG lead(s) 144 may correspondingly improve analysis of an optical signal detected by detector(s) 160 to determine fetal-oximetry information as disclosed herein.[000111] Force / pressure sensor 162 may be configured to sense pressure and / or force applied to direct-measurement-fetal-oximetry sensor 115B, or a componentthereof. Exemplary force / pressure sensors 162 include force meters (e.g., a strain gauge), force sensitive resistors, and a spring-based pressure switch that may be configured to activate when a minimum magnitude of force is applied. Additionally, or alternatively, force / pressure sensor 162 may be configured to measure pressure within an amniotic space inside the pregnant mammal’s uterus, using, for example, an intrauterine pressure catheter (IUPC). The force / pressure may be applied by a uterus of the pregnant mammal and a force / pressure reading may be used to determine whether or not direct-measurement-fetal-oximetry sensor 115B is pressed up against the fetal skin and / or wedged between the fetal skin and internal uterine wall because, for example, when direct-measurement-fetal-oximetry sensor 115B is floating in amniotic fluid (i.e., not in direct contact with fetal skin) there may be no, or a reduced amount, of pressure exerted thereon. In some embodiments, force / pressure sensor 162 may be configured to determine characteristics of uterine tone (contraction, relaxation, etc.). Additionally, or alternatively, force / pressure sensor 162 may be embodied as a pressure sensor for an inflation line (e.g., inflation line 215 shown in FIGs. 2A and 2B and discussed below) communicatively coupled to a stabilization device (e.g., stabilization device 225, shown in FIG. 2B and discussed below).[000112] Temperature sensor 152 may be configured to measure a temperature of adjacent tissue (e.g., cervix, vaginal wall, fetus), which may be useful in monitoring the pregnant mammal’s and / or fetus’ health and / or body temperature and, in particular, may be used to monitor for infections like chorioamnionitis or endometritis. Camera 168 may be embodied as a camera and / or an optical instrument (e.g., a fiber optic cable) configured to enable visual observation (e.g., photographs, video, color measurements, etc.) of the fetus and / or direct-measurement-fetal-oximetry sensor 115B while in situ and / or while being placed in situ. In some embodiments, information provided by camera 168 may be used to, for example, confirm a position and / or orientation of measurement-fetal-oximetry sensor 115B (e.g., on fetal skin, on uterine tissue, on cervical tissue, floating in amniotic fluid, etc.), determine if meconium is present within the pregnant mammal’s uterus, and / or obtain skin pigmentation and / or colorimetry (e.g., skin tone) information for the fetus. Additionally, or alternatively, skin tone and / or color may be provided by colorimeter 166.[000113] FIG. 2A is a top plan view of an exemplary direct-measurement-fetal- oximetry sensor 200, 201, or 202 and FIG. 2B is a side plan view of an exemplary direct-measurement-fetal-oximetry sensor 200 with a positioning extension 210.Direct-measurement-fetal-oximetry sensor 200 includes a housing 205 sized, shaped, and configured to house one or more components of direct-measurement-fetal- oximetry sensor 115B. As used herein, “housing 205” may refer to any and / or all of the direct-measurement-fetal-oximetry housings disclosed herein including, but not limited to housing 205A, housing 205B, housing 205C, housing 205D, and / or housing 205E. In some embodiments, housing 205 may include one or more optional markers 207 that may be configured, positioned, and / or sized to be easily observable using an imaging technology. For example, marker 207 may be sonically and / or radio opaque so that it clearly shows up in an ultrasound and / or X-ray image, respectively. In some embodiments, marker 207 may be used to determine a fetal depth (e.g., a distance between a fetal and maternal epidermis). In these embodiments, an imaging technology like ultrasound may be used to find marker 207 when in position and a distance between marker 207 and the maternal epidermis may be determined using the ultrasound image and, for example, measuring a distance between marker 207 and the maternal epidermis as shown in one or more ultrasound images.[000114] Additionally, or alternatively, housing 205 and / or a surface thereof including a light source 105 and one or more detectors 160 may have one or more mechanisms or optically-isolating features (e.g., blinders, extensions, recesses, opaque materials, gaskets, etc.) configured to limit or eliminate optical shunting between one or more light source(s) 105 and one or more detector(s) 160. For example, FIG. 2A1A provides a schematic diagram of a top view and FIG. 2A1 B provides a schematic diagram of a cross-section view of a first housing 205A with a first front, or active, surface 230A that includes four detectors 160 optically separated from light source 105 by an optically-isolating feature embodied as a raised rib 282 that stands proud of a surface of first housing 205A (as may be seen in FIG. 2A1 B). Raised rib 282 may be configured to optically isolate detector(s) 160 from light directly emitted by light source 105, thereby preventing optical shunting between them.[000115] Additionally, or alternatively, a housing 205 may include an optically- isolating flange or boarder like those of FIGs. 2A2A and 2A2B; wherein FIG. 2A2A provides a schematic diagram of a top view and FIG. 2A2B provides a schematic diagram of a cross-section view of a second housing 205B with a second front, or active, surface 230B that includes four detectors 160 optically separated from light source 105 by an optically-isolating feature embodied as a raised boarder or flange 284 that surrounds light source 105 (as may be seen in FIG. 2A2A) and stands proudof a surface of second housing 205B as may be seen in FIG. 2A2B. Raised boarder or flange 284 may be configured to optically isolate detector(s) 160 from light directly emitted by light source 105, thereby preventing optical shunting between them. When embodied as a flange, raised boarder or flange 284 may be configured to flare out upon contact with fetal skin in a manner similar to, for example, a suction cup.[000116] Additionally, or alternatively, a housing 205 may include an optically- isolating flange or border like those of FIGs. 2A3A and 2A3B; wherein FIG. 2A3A provides a schematic diagram of a top view and FIG. 2A3B provides a schematic diagram of a cross-section view of a third housing 205C with a third front, or active, surface 230B that includes four detectors 160 optically separated from light source 105 by an optically-isolating feature embodied as a raised boarder or flange 286 that surrounds all four detectors 160 (as may be seen in FIG. 2A3A) and stands proud of a surface of third housing 205B as may be seen in FIG. 2A3B. Raised boarder or flange 246 may be configured to optically isolate detector(s) 160 from light directly emitted by light source 105, thereby preventing optical shunting between them. When embodied as a flange, raised boarder or flange 286 may be configured to flare out upon contact with fetal skin in a manner similar to, for example, a suction cup.[000117] Additionally, or alternatively, a housing 205 may include one or more components that sit proud of an active surface thereof. For example, FIG. 2A4 provides a side view of a fourth housing 205D with a fourth active surface 230D that includes four detectors 160 that sit proud (e.g., 0.5-5mm) of the surface, or exterior, of fourth housing 205D and a light source 105 that sits flush with the exterior surface of fourth housing 205D as shown in the figure. In this embodiment, detectors 160 may be pressed into the fetal skin slightly when the exterior of fourth housing 205D abuts (e.g., is pressed into) the fetal skin and the fetal skin positioned between the proudly placed detectors 160 may act to optically isolate them from source 105.[000118] Additionally, or alternatively, a housing 205 may include a light source 105 that is recessed into the active surface 230 thereof. For example, FIG. 2A5 provides a side, or cut-away, view of a fifth housing 205E with a fifth active surface 230E that includes four detectors 160 that sit proud (e.g., 0.5-5mm above) of the surface, or exterior, of fifth housing 205E and a light source 105 that sits within a recess, or cavity, 288 as shown in the figure. Cavity 288 may be configured to reduce the angular cone of the source illumination and detector light captures. Optionally, an exterior surface of cavity 288 may be coated with and / or comprise a light-absorbingmaterial. Additionally, or alternatively, cavity 288 may be covered with and / or include an aperture and / or one or more lenses configured to reduce the angular cone of the source illumination and detector light captures. In this embodiment, detectors 160 may be pressed into the fetal skin slightly when the exterior surface of fourth housing 205D abuts (e.g., is pressed into) the fetal skin and the fetal skin positioned between the proudly placed detectors 160 may act to optically isolate them from source 105 and light from source 105 may not travel across active surface 230E.[000119] Additionally, or alternatively, a housing 205 may include a light source 105 that is proud of, and / or a plurality of detectors that are flush with active surface 230 thereof. For example, FIG. 2A6 provides a side, or cut-away, view of a fifth housing 205F with a sixth active surface 230F that includes four detectors 160 that flush with active surface 230F and a light source 105 that sits proud e.g., 0.5-5mm above) of sixth active surface 230F. In this embodiment, light source 105 may be configured and arranged within active surface 230F so that it presses into fetal skin during operation and the fetal skin may act to limit optical shunting between detectors 160 and light source 105 by, for example, limiting a direct pathway (e.g., an optical pipeline) between them.[000120] Additionally, or alternatively, a housing 205 may include a one or more detectors that are recessed into the active surface 230 thereof. For example, FIG. 2A7 provides a side, or cut-away, view of a seventh housing 205F with a seventh active surface 230F that includes four detectors 160, each of which are positioned within a recess, or cavity, 298 and a light source 105 that sits proud (e.g., 0.5-5mm above) of the surface, or exterior, of seventh housing 205F as shown in the figure. Cavity 298 may be configured to reduce optical shunting between light source 105 and their respective detector 160 by eliminating a direct pathway for light to travel between the light source 105 and each detector 160. Optionally, an exterior surface of cavity 298 may be coated with and / or comprise a light-reflecting material. In this embodiment, light source 105 may be configured and arranged within active surface 230G so that it presses into fetal skin during operation and the fetal skin may act to limit optical shunting between detectors 160 and light source 105 by, for example, limiting a direct pathway (e.g., an optical pipeline) between them.[000121] FIG. 2A8 provides a side, or cut-away, view of an eighth housing 205H with an eighth active surface 230H that includes four detectors 160, all of which are positioned within a single recess, or cavity, 299 and a light source 105 that sits proud(e.g., 0.5-5mm above) of the surface, or exterior, of seventh housing 205F as shown in the figure. Cavity 299 may be configured to reduce optical shunting between light source 105 and detectors 160 by eliminating a direct pathway for light to travel between the light source 105 and the detectors 160. Optionally, an exterior surface of cavity 299 may be coated with and / or comprise a light-reflecting material. In this embodiment, light source 105 may be configured and arranged within active surface 230H so that it presses into fetal skin during operation and the fetal skin may act to limit optical shunting between detectors 160 and light source 105 by, for example, limiting a direct pathway (e.g., an optical pipeline) between them.[000122] In some embodiments, two or more optically-isolating features like those shown in FIGs. 2A1A, 2A2A, 2A3A, 2A4, 2A5, 2A6, 2A7 and / or 2A8 may be used in combination. For example, raised rib 282 may be incorporated into a housing like second, third, fourth, and / or fifth housings 205B, 205C, 205D, and / or 205E to further optically isolate one or more of the detectors from light emitted by light source 105. In another example, light source 105 may be positioned within a recess like recess 288 of first, second, third, and / or fourth housings 205B, 205C, and / or 205D.[000123] At times, for the sake of brevity, first, second, third, fourth, and / or fifth housings 205A, 205B, 205C, 205D, and / or 205E may be collectively referred to as “housing 205” herein. Housing 205 may be physically coupled (e.g., bonded, affixed, and / or joined) to positioning extension 210. In some cases, a joint between housing 205 and positioning extension 225 may be configured to articulate to, for example, enable insertion and / or proper positioning of housing 205 on fetal skin. Positioning extension 210 may include a cord 220 configured to, for example, provide electricity to direct-measurement-fetal-oximetry sensor 115B and / or enable communication of, for example, light source drive signals, raw detector signals, ECG signals, temperature signals, force, and / or pressure signals between one or more components of direct- measurement-fetal-oximetry sensor 115B and an external device (e.g., a computer and / or display device). Optionally, positioning extension 210 may include a reference electrode 244 configured to be in electrical contact with maternal tissue (e.g., vaginal or uterine tissue). In some instances, cord 220 may be used to extract direct- measurement-fetal-oximetry sensor 200 from a subject’s uterus and / or body.[000124] In some embodiments, positioning extension 210 may also include an inflation line 215 with a lumen therein configured to provide inflating fluid (e.g., saline) or gas (e.g., air) to an optional inflatable stabilization device 225 (as seen in FIG. 2B).Stabilization device 225 may be configured to be positioned between fetal skin and an internal uterine wall and may be inflated and / or adjusted to occupy space therebetween to press a front, or active, surface 230 of direct-measurement-fetal- oximetry sensor 200 and / or housing 205 against the fetal skin and / or assist with maintaining contact between the fetal skin. In some embodiments, a degree to which stabilization device 225 is inflated may be responsive to, for example, a degree of back pressure and / or force exerted on the inflation line (as measured by, for example, a pressure and / or force gauge), a degree of pressure and / or force required to further inflate stabilization device 225, and / or a measurement taken from one or more components of direct-measurement-fetal-oximetry sensor 115B. For example, if an ECG lead 144 and / or contact sensor 158 is no longer responding and / or provides a measurement indicating that contact with fetal skin has been lost and / or a measurement provided by force / pressure sensor 162 indicates that contact with fetal skin has been lost, a message communicating same and / or an instruction to further inflate stabilization device 225 may be communicated (via, e.g., transceiver 142 and / or cord 220) to a device providing the inflating gas and / or liquid.[000125] In some embodiments, a degree of inflation of stabilization device 225 may be responsive to a position of the fetus within the uterus and / or birth canal and may be configured to, for example, deflate as, for example, a labor and delivery process of the fetus transitions from the first to the second stage of labor. Deflation of stabilization device 225 in this manner may assist with reducing an overall size / profile of direct-measurement-fetal-oximetry sensor 200 so that, for example, it does not interfere with the movement of the fetus through the birth canal. In some embodiments, a level of inflation of stabilization device 225 may vary over time (e.g., may periodically inflate and / or deflate) which may assist with labor and delivery of the fetus and / or prevent dystocia.[000126] Additionally, or alternatively, in some embodiments, a degree of inflation of stabilization device 225 may be responsive to uterine contractions as measured by, for example, uterine contraction measurement device 148 and / or force / pressure sensor 162. In these embodiments, stabilization device 225 may be configured to deflate as the uterus contracts and may inflate as the uterus relaxes to, for example, fill a space between the uterine wall and fetal skin. In this way, contact of direct- measurement-fetal-oximetry sensor 200 and / or housing 205 with fetal skin may be maintained through fluctuations of uterine contractions over time.[000127] In some embodiments, stabilization device 225 may be configured to expand and / or fill space until an external pressure is exerted thereon. In these embodiments, stabilization device 225 may comprise a material (e.g., foam) configured to expand upon contact with water or amniotic fluid and fill a space between fetal skin and an inner uterine wall. Additionally, or alternatively, stabilization device 225 may comprise a deformable material (e.g., gel and / or memory foam) configured to deform and / or mold to fill a space between fetal skin and an inner uterine wall.[000128] In some embodiments, a surface of an outer surface 240 of direct- measurement-fetal-oximetry sensor 200 may be coated and / or treated with a lubricious coating to, for example, facilitate movement of outer surface 240 along an interior wall of the uterus, cervix, and / or vagina as the fetus is pushed out of the uterus. Additionally, or alternatively, active surface 230 may be manufactured to have a friction-inducing surface that, for example, assists with holding active surface 230 against the fetal skin and / or prevents sliding or movement of active surface 230 when positioned on the fetal skin.[000129] In many embodiments, direct-measurement-fetal-oximetry sensor 200 may be configured so that light source(s) 105 and / or detector(s) 160 are positioned proximate to and / or abut active surface 230 and all, or a portion of, active surface 230 is transparent, or semi-transparent, so that light emitted by light source(s) 105 may pass through active surface 230 into the fetal skin and backscattered light may be detected by detector(s) 160.[000130] FIG. 2C is a schematic diagram of a side view of another exemplary direct-measurement-fetal-oximetry sensor 201 , which is similar to direct- measurement-fetal-oximetry sensor 200 with except that it does not include inflation line 215 and stabilizing device 225 and, instead includes a curved extension 270 sized, shaped, and configured to assist with the positioning and / or maintaining a position of direct-measurement-fetal-oximetry sensor 201 , and / or active side 230, against fetal skin by, for example, exerting a force on the uterine wall that acts to push active surface 230 in the opposite direction (i.e., toward fetal skin) and, in this way, may help with keeping active surface 230 correctly in contact with fetal skin. In some embodiments, curved extension 270 may be flexible and / or configured to apply a controlled range of force the uterine wall, which is translated into pressing into the fetal skin and / or fetal cheek.[000131] FIG. 2D is a schematic diagram of a side view of another exemplary direct-measurement-fetal-oximetry sensor 202, which is similar to direct- measurement-fetal-oximetry sensor 201 with except that it does not include curved extension 270 and instead includes an extension 275 that sits proud from a back (i.e., side opposite to active side 230) side of housing 205. Extension 275 may be any shape (e.g., rectangle, square, circle, oval, etc.) and may be made from any appropriate material including, but not limited to, silicone, foam, memory foam, plastic, and, on some occasions, may be deformable via, for example, a membrane enclosing a fluid (e.g., air, saline, gel, etc.). Extension 275 may be sized, shaped, and configured to assist with the positioning and / or maintaining a position of direct-measurement- fetal-oximetry sensor 202, and / or active side 230, against fetal skin by, for example, exerting a force on the uterine wall that acts to push active surface 230 in the opposite direction (i.e., toward fetal skin) and, in this way, may help with keeping active surface 230 correctly in contact with fetal skin. In some embodiments, extension 275 may be flexible, compressible, and / or configured to adapt to a shape of the uterus, adapt to a shape between the fetus and uterine wall, and / or apply a controlled range of force the uterine wall, which is translated into pressing into the fetal skin and / or fetal cheek.[000132] FIG. 2E is a schematic diagram of a side view of a further example of a direct-measurement-fetal-oximetry configured to detect fetal and maternal tissue optical property information. Direct-measurement-fetal-oximetry sensor 204 includes a housing 205 with active side 230 that may be configured as one or more of the active sides 230 disclosed herein. Direct-measurement-fetal-oximetry sensor 204 also includes a maternal optical sensor side 232 that provides / houses a set of a set of maternal optical and / or oximetry sensors. The set of maternal optical and / or oximetry sensors may include a light source 105 and one or more detector(s) 160 (in the case of FIG. 2E, there are two detectors 160 but, this need not always be the case) and may be sized, configured, and / or positioned to project light into maternal tissue (e.g., uterus and other abdominal tissue (e.g., adipose and skin) and receive light backscattered by the maternal tissue, which may be sent to, for example, a processor and / or computer (e.g., computer and / or processor) and used by the processor and / or computer to determine maternal tissue optical property information (e.g., tissue oxygen saturation) or other optical characteristics (e.g., scattering and / or absorption) of the maternal tissue positioned between direct-measurement-fetal-oximetry sensor 204 and a fetus within the pregnant mammal’s abdomen. In some embodiments, aside of housing 205 including the set of maternal optical sensors may also include one or more contact sensors, contact electrodes, and / or pressure sensors to provide information that may be used to determine whether housing 205 and the set of maternal optical sensors are in adequate contact with maternal tissue.[000133] FIG. 2F is a schematic diagram illustrating a cross-section view of a pregnant human woman with direct-measurement-fetal-oximetry sensor 200 positioned within her uterus as defined by uterine wall 260 when her cervix 267 is partially (e.g., 1-10cm) dilated. As may be seen in FIG. 2F, active side 230 of direct- measurement-fetal-oximetry sensor 200 is in contact with a scalp of a fetus 280 and stabilization device 225 is inflated to occupy space in the uterus between the fetal scalp and uterine wall 260, thereby holding active side 230 in place relative to the fetal cheek by, for example, wedging direct-measurement-fetal-oximetry sensor 200 between the fetal cheek and uterine wall 260. Inflation of stabilization device 225 in the manner shown in FIG. 2F may assist with establishing, and maintaining, contact between active side 230 of direct-measurement-fetal-oximetry sensor 200 even during the labor and delivery process when the uterus is contracting and relaxing (e.g., a distance between the uterine wall and the fetal cheek is dynamic and stabilization device 225 may be configured (e.g., made of flexible silicone or vinyl) to adjust its size and / or where inflation media (e.g., air or saline) is positioned according to the dynamic geometry between fetus 280 and uterine wall 260).[000134] FIG. 2G is a schematic diagram illustrating a cross-section view of a pregnant human woman with direct-measurement-fetal-oximetry sensor 201 positioned within her uterus against fetus’s 280 scalp proximate to the fetus’ ear, when her cervix 267 is, for example, 1-10cm dilated. As may be seen in FIG. 2H, extension 275 is positioned between uterine wall 260 and the fetal scalp so it may occupy space between the fetal scalp and uterine wall as shown to assist with establishing, and maintaining, contact between active side 230 of direct- measurement-fetal-oximetry sensor 201 and the fetal scalp even during the labor and delivery process when the uterus is contracting and relaxing and the fetus is descending through the cervix (e.g., a distance between the uterine wall and the fetal cheek is dynamic).[000135] FIG. 2H is a schematic diagram illustrating a cross-section view of a pregnant human woman with direct-measurement-fetal-oximetry sensor 202 positioned within her uterus against fetus’s 210 scalp proximate to the fetus’ ear, whenher cervix 267 is, for example, 1-10cm dilated. As may be seen in FIG. 2H, extension 275 is positioned between uterine wall 260 and the fetal scalp so that it may occupy space between the fetal scalp and uterine wall as shown to, for example, assist with establishing, and maintaining, contact between active side 230 of direct- measurement-fetal-oximetry sensor 202 and the fetal scalp even during the labor and delivery process when the uterus is contracting and relaxing and the fetus is descending through the cervix (e.g., a distance between the uterine wall and the fetal cheek is dynamic).[000136] FIG. 2I is a schematic diagram illustrating a cross-section view of a pregnant human woman with direct-measurement-fetal-oximetry sensor 204 positioned within her uterus as defined by uterine wall 260 when her cervix 267 is partially (e.g., 1-10cm) dilated. As may be seen in FIG. 2I, active side 230 of direct- measurement-fetal-oximetry sensor 204 is in contact with a scalp of a fetus 280 and maternal optical sensor side 232 (in this case, the side opposing active side 230) of direct-measurement-fetal-oximetry sensor 204 including the set of maternal optical sensors is positioned proximate to (e.g., touching and / or in optical contact with) maternal tissue, in this case an interior surface of uterine wall 260. When in position as, for example, shown in FIG. 2I, the set of maternal optical sensors maternal optical sensor side 232 may obtain maternal optical and / or oximetry information by, for example emitting light (via, for example, light source 205) into uterine wall 260 and detecting (via, for example, one or more detectors 160) resulting light that is backscattered from the maternal tissue.[000137] FIGs. 3A and 3B are illustrations of a direct-measurement-fetal-oximetry sensor 301 that includes one or more light source(s) 105, a light source cable 345, a handle 330A, a detector 160, a detector cable 340, and a retractable cover 335. Additionally, or alternatively, handle 330A may be similar to handles 221 and / or 230. Handle 330A may be configured to facilitate the handling of direct-measurement-fetal- oximetry sensor 301 and / or the insertion of same into the vagina of a pregnant mammal. In some cases, handle 330A may be flexible.[000138] In particular, FIG. 3A shows retractable cover 335 in a first orientation where retractable cover 335 is positioned over light source 105, light source cable 345, detector 160, and detector cable 340 and FIG. 3B shows retractable cover 335 in a second orientation where retractable cover 335 is in a retracted state thereby exposing light source 105, light source cable 345, detector 160, and detector cable 340.Retractable cover 335 may be a closed state (as shown in FIG. 3A) when, for example, moving direct-measurement-fetal-oximetry sensor 301 into, out of, and / or within the vagina, cervical canal, and / or bladder of a pregnant mammal. In this position, retractable cover 335 may serve to protect light source 105, light source cable 345, detector 160, and / or detector cable 340 while direct-measurement-fetal-oximetry sensor 301 while not in use and / or is moving within the pregnant mammal and / or not. [000139] Retractable cover 335 may be retracted into a retracted position as shown in FIG. 3B when direct-measurement-fetal-oximetry sensor 301 is in use. Upon retracting retractable cover 335, light source 105, light source cable 345, detector 160, and detector cable 340 may be exposed so that they may be positioned within the vagina, cervical canal, and / or bladder of a pregnant mammal. In some embodiments, light source 105 may be placed in one position and detector 160 and a distance between them (labeled as a source / detector distance 322A) may be known. Light source cable 345 and / or detector cable 340 may be flexible (e.g., an insulated optic or electrical cable), semi-rigid, and / or rigid.[000140] Retraction of retractable cover 335 may, in some instances, activate a horizontal movement between source 105 and detector 160 so that they spread apart in a horizontal direction and have a source / detector distance 322A as shown in FIG. 3B. At times this horizontal movement may be facilitated via a motorized component such as a motor (not shown) and / or a spring-like device (e.g., compressible / expandable foam or plastic). In some cases, light source cable 345 and / or detector cable 340 may include a memory material (e.g., plastic or metal) such that each of light source cable 345 and / or detector cable 340 may have a shape memory that is realized when retractable cover 335 is retracted and source cable 345 and / or detector cable 340 are free to move / return to a “remembered” shape.[000141] FIGs. 3C and 3D provide illustrations of a direct-measurement-fetal- oximetry sensor 302 that includes light source 105, light source cable 345, a handle 330B, detector 160, detector cable 340, and a pair of cooperating cable braces 320A and 320B separated by a junction 325. With direct-measurement-fetal-oximetry sensor 302, light source cable 345 is folded over an end of handle 330B so that source 105 is positioned along a right-hand side of handle 330B and detector cable 345 is folded over an end of handle 330B so that detector 160 is positioned along a left-hand side of handle 330B. Detector cable 340, detector 160, light source 105 and light source cable 345 are held in this position by cooperating cable braces 320A and 320Bwhen the two cable braces meet at junction 325, thereby making a closed loop around light source cable 345 and detector cable 340 as shown in FIG. 3C. The arrangement shown in FIG. 3C may be applicable when direct-measurement-fetal-oximetry sensor 302 is being stored and / or inserted into a vagina of a pregnant mammal. Once inserted and oriented in a desired position, cable braces 320A and 320B may open at junction 325 so that light source cable 345 and detector cable 340 are able to move into a position (e.g., source / detector distance 322B) when light source 105 and detector 160 may abut maternal tissue and obtain oximetry measurements as shown in FIG. 3D.[000142] FIGs. 3E and 3F provide two views of another exemplary direct- measurement-fetal-oximetry sensor 303 that includes light source 105, light source cable 345, a handle 330C, detector 160, detector cable 340, a light source arm 347, and a detector arm 342. Light source arm 347 and detector arm 342 are configured to articulate so that light source 105 and detector 160 may be moved apart to, for example, a source / detector distance 322C (as shown in FIG. 3F) and moved back together as shown in FIG. 3E.[000143] FIG. 4A is a top view of an exemplary light source / detector spacer 410 (also referred to herein as a “spacer”). Spacer 410 includes five attachment mechanisms 405A, 405B, 405C, 405D, and 405E for attaching to a light source like light source 105 and / or a detector like detector 160. Attachment mechanisms 405A- 405E may be any suitable mechanism for attaching to light source 105 and / or detector 160 including, but not limited to, a chemical bonding agent (e.g., glue) that, in some cases may have a cooperating chemical bonding agent on an exterior surface of light source 105 and / or detector 160, a mechanical attachment mechanism such as a hole configured to accept a corresponding attachment mechanism positioned on an exterior surface of light source 105 and / or detector 160 that is inserted into the hole and / or a snapping component that may be configured to cooperate with a corresponding snapping component on the light source 105 and / or detector 160 or combinations thereof. A distance between each attachment mechanism 405A, 405B, 405C, 405D, and 405E is known so, if a position of light source 105 is known and a position of detector 160 is known then a source / detector distance 322 may be deduced therefrom.[000144] FIG. 4B provides a diagram of spacer 410 in use with light source 105 and detector 160 and a portion of a direct-measurement-fetal-oximetry sensor likedirect-measurement-fetal-oximetry sensor 301 , 302, or 303, wherein light source 105 is attached to fourth attachment mechanism 405D and detector is attached to second attachment mechanism 405B so that a source / detector distance 322’ is known to be a distance between the second and fourth attachment mechanisms 405B and 405D.[000145] FIG. 4C provides a diagram of spacer 410 in use with light source 105 and detector 160 and a portion of a direct-measurement-fetal-oximetry sensor like direct-measurement-fetal-oximetry sensor 301 , 302, or 303, wherein light source 105 is attached to fifth attachment mechanism 405E and detector 160 is attached to second attachment mechanism 405B so that a source / detector distance 322’ is known to be a distance between the second and fifth attachment mechanisms 405B and 405E, respectively. Although only two arrangements of light source 105 and detector 160 are shown in the figures, it will be understood by those of skill in the art that any arrangement of light source 105 and detector 160 with spacer 410 may be made.[000146] FIGs. 5A and 5B provide illustrations of an exemplary direct- measurement-fetal-oximetry sensor 501 that includes detector 160 (in this embodiment, first detector 160), detector cable 340 (in this embodiment, first detector cable 340), a second detector 560, a second detector cable 565, light source 105, light source cable 345, a retractable cover 535, and a handle 530A. Direct-measurement- fetal-oximetry sensor 501 is similar to direct-measurement-fetal-oximetry sensor 301 except that direct-measurement-fetal-oximetry sensor 501 includes second detector 560 and second detector cable 565 and the retractable cover 535 is configured (enlarged) to cover, and retract over, first detector 160, first detector cable 340, second detector 560, second detector cable 565, light source 105, light source cable 345. Handle 530A may be similar to handle 330A except that it is configured to cooperate with retractable cover 535. FIG. 5A shows direct-measurement-fetal-oximetry sensor 501 in a closed state with retractable cover 535 covering first detector 160, first detector cable 340, second detector 560, second detector cable 565, light source 105, and light source cable 345.[000147] When retractable cover 535 is retracted to expose first detector 160, first detector cable 340, second detector 560, second detector cable 565, light source 105, and light source cable 345, the components may spread apart from one another in, for example, a triangular-like pattern as shown in FIG. 5B with a first source / detector distance 522A being between first detector 160 and light source 105 and a second source / detector distance 522B being between second detector 560 and light source105. First and second source / detector distances 522A and 522B may be responsive to maternal physiological and / or geometrical characteristics. In some cases, first and second source / detector distances 522A and 522B may be similar and, in other cases, first and second source / detector distances 522A and 522B may be different.[000148] FIGs. 5C and 5D provide illustrations of an exemplary direct- measurement-fetal-oximetry sensor 502 that includes detector 160 (in this embodiment, first detector 160), detector cable 340 (in this embodiment, first detector cable 340), second detector 560 (not shown in FIG. 5C), second detector cable 565, light source 105, light source cable 345, pair of cooperating cable braces 320A and 320B, which are separated by junction 325, and handle 530B. Direct-measurement- fetal-oximetry sensor 502 is similar to direct-measurement-fetal-oximetry sensor 302 except that direct-measurement-fetal-oximetry sensor 502 includes second detector 560 and second detector cable 565. In addition, the pair of cooperating cable braces 320A and 320B may be larger and / or configured to hold detector cable 340 and first and second detector cables 345 and 565 in place as shown in FIG. 5C. When cooperating cable braces 320A and 320B open detector cable 340 and first and second detector cables 345 and 565 may be released into, for example, a triangular- like pattern as shown in FIG. 5C with a first source / detector distance 522C being between first detector 160 and light source 105 and a second source / detector distance 522D being between second detector 560 and light source 105 as shown in FIG. 5D. [000149] FIGs. 5E and 5F provide two views of another exemplary direct- measurement-fetal-oximetry sensor 503 that includes light source 105, light source cable 345, a handle 330C, first detector 160, detector cable 340, second detector 560, second detector cable 565, light source arm 347, and first detector arm 342, and a second detector arm 547. Direct-measurement-fetal-oximetry sensor 503 is similar to direct-measurement-fetal-oximetry sensor 303 but direct-measurement-fetal- oximetry sensor 303 includes second detector arm 547, second detector 560, and second detector cable 565. Light source arm 347, first detector arm 342, and a second detector arm 547 are configured to articulate so that light source 105, first detector arm 342, and a second detector arm 547 may be move apart to, for example, a fifth source / detector distance 522E and a second source / detector distance 522F as shown in FIG. 3F when in use to obtain fetal -oximetry information and moved back together as shown in FIG. 3E.[000150] FIG. 6A is a top view of an exemplary cross-shaped light source / detector spacer 601 that includes a first strip 610 and a second strip 611. First and second strips 610 and 611 are substantially similar to spacer 410 arranged in a cross shape. First strip 610 includes five attachment mechanisms 605A, 605B, 605C, 605D, and 605E and second strip 611 includes four more attachment mechanisms 605F, 605G, 605H, and 605I. Attachment mechanisms 605A, 605B, 605C, 605D, 605E, 605F, 605G, 605H, and 605I may be similar to 405A, 405B, 405C, 405D, and 405E discussed above with regard to FIGs. 4A-4C. The attachment mechanisms 605 of first and second strips 610 and 611 may be arranged so that a source / detector distance between a light source and detector may be known when they are deployed as shown in, for example, FIGs. 5B, 5D, and / or 5E.[000151] FIG. 6B provides a diagram of spacer 601 in use with light source 105, first detector 160, and second detector 560 as may be arranged following deployment from a direct-measurement-fetal-oximetry sensor like direct-measurement-fetal- oximetry sensor 301 , 302, or 303, wherein light source 105 is attached to fourth attachment mechanism 405D, first detector 160 is attached to second attachment mechanism 605B so that a source / detector distance 622A is known to be a distance between the second and fourth attachment mechanisms 605B and 605D. FIG. 6B also shows second detector 560 is attached to sixth attachment mechanism 605F so that a source / detector distance 622B is known to be a distance between the sixth and fourth attachment mechanisms 605F and 605D.[000152] Additional embodiments of a spacer include a flat sheet with a plurality of holes or openings arranged in, for example, a grid pattern or irregular pattern.[000153] FIG. 7 is a flowchart illustrating a process 700 for determining fetal- oximetry information (e.g., fetal tissue oxygenation and / or a level of oxygen saturation for fetal hemoglobin) using a direct-measurement-fetal-oximetry sensor such as direct- measurement-fetal-oximetry sensors disclosed herein (e.g., direct-measurement- fetal-oximetry sensor 115B, 200, 201 , 202, 204, 301 , 302, 303, 501 , 502, or 503). Process 700 may be performed by, for example, any of the system(s) disclosed herein. [000154] Optionally, in step 705, information (e.g., a measurement) may be received from a contact sensor. The information received in step 705 may be received from, for example, the direct-measurement-fetal-oximetry sensor and / or a component thereof such as an ECG lead like ECG lead 144, a contact sensor like contact sensor 158, and / or a force / pressure sensor like force / pressure sensor 162.[000155] In step 710, it may be determined whether the information received in step 705 indicates that the direct-measurement-fetal-oximetry sensor, or an active surface thereof (e.g., active surface 230), is in, for example, physical, optical, and / or electrical contact with tissue (fetal or maternal) within the uterus of a pregnant mammal and, if not, an error message and / or a message instructing the user to, for example, adjust a position of direct-measurement-fetal-oximetry sensor to reestablish contact with fetal skin may be communicated to the user (step 745) via, for example, providing the error message to a display device like display device 155. When a result of the determination of step 710 indicates the direct-measurement-fetal-oximetry sensor, or the active surface thereof is in, for example, physical, optical, and / or electrical contact with tissue, process 700 proceeds to step 715.[000156] In some embodiments, the information received in step 705 is an impedance measurement (which may be measured by an ECG lead like ECG lead 144) and the determination of step 710 may include determining if a value of the impedance measurement is consistent with, for example, contact with fetal tissue, contact with maternal tissue, and / or contact with fluid, such as amniotic fluid. If the impedance measurement is consistent with contact with fetal tissue (e.g., 1 ,900- 15,800 Ohms), process 700 may proceed to step 715. Alternatively, if the impedance measurement is consistent with contact with maternal tissue and / or fluid, process 700 may proceed to step 745. Additionally, or alternatively, when the contact sensor is embodied as a camera, execution of step 710 may include analysis of one or more image(s) generated by the camera to determine optical properties of the tissue of the image(s) to see if they are consistent with maternal (e.g., uterine) optical properties or fetal optical properties.[000157] Additionally, or alternatively, information and / or signals received from the source(s) and / or detector(s) of the direct-measurement-fetal-oximetry sensor may be used to sense whether a surface of the direct-measurement-fetal-oximetry sensor is in contact with maternal and / or fetal tissue. For example, one or more signal(s) from two or more of the detector(s) on active side 230 and / or maternal optical sensor side 232 may be used to determine an effective attenuation coefficient of the tissue being interrogated by light from the light source and detected by the detectors. It may then be determined whether or not the effective attenuation coefficient is consistent with maternal tissue (e.g., uterine wall) or fetai tissue (e.g., fetal skin). In some cases, an effective attenuation coefficient may be determined for tissue interrogated by the lightsource and detectors of both active side 230 and maternal optical sensor side 232. The two effective attenuation coefficients may then be compared with one another to, for example, determine differences therebetween and / or assess which side of the housing is facing fetal skin and which side of housing 205 is facing maternal tissue.[000158] Additionally, or alternatively, the information received in step 705 may be an image or video of the area in which the direct-measurement -fetal-oximetry sensor is positioned. In these embodiments, execution of step 710 may include evaluation of the image, or video, to see if it is consistent with contact with the fetus. In some embodiments, this evaluation may include color analysis to determine whether the image includes colors consistent with fetal skin, vernix, or maternal tissue (e.g., uterine wall or cervix).[000159] Additionally, or alternatively, the information received in step 705 may be a pressure and / or force measurement corresponding to pressure and / or force within an inflation line (e.g., inflation line 215) for an inflatable stabilization device (e.g., stabilization device 225) of a direct-measurement -fetal-oximetry sensor. A relatively high (e.g., 0.5-1 .5 Ibf) pressure and / or force measurement may indicate that the stabilization device is experiencing back pressure and / or force from being wedged between the fetus and the pregnant mammal and, in these instances, process 700 may proceed to step 715. Alternatively, a relatively low pressure and / or force measurement a may indicate that the stabilization device is not experiencing back pressure from being wedged between the fetus and the pregnant mammal and, in these instances, it may be deduced that the direct-measurement -fetal-oximetry sensor is not in contact with fetal skin (e.g., is floating in the amniotic fluid) and process 700 may proceed to step 745. On some occasions, execution of step 745 may include providing an instruction to further inflate the stabilization device to the display device. [000160] In step 715, one or more signals may be received from the direct- measurement-fetal-oximetry sensor and / or a component thereof, such as one or more detectors like detector 160. The received signals may be responsive to light (e.g., between 600 and 1000nm) projected into the fetal skin by a light source of the direct- measurement-fetal-oximetry sensor such as one or more light source(s) 105 and may be, for example, an optical signal, an analog signal, and / or an electronic signal corresponding to light detected by the detector.[000161] In some embodiments, the one or more received signals may be used to determine oximetry information (step 720) such as pulse oximetry information, fetalhemoglobin oxygen concentration, DC oxygen saturation levels, AC oxygen saturation levels, and / or tissue oxygen saturation levels. At times, execution of step 720 may include performing one or more calibrations using the one or more received signals. For example, information received in step 705 may be used to determine a skin tone and / or level of scattering and / or absorption by tissue and this / these determinations may be used to calibrate a determination of oximetry information as, for example, described herein.[000162] In some embodiments, the oximetry information may be determined in step 715 using, for example, the modified Beer-Lambert law, which is presented as Equation 1 below, for each wavelength of light included in the received signal(s) (step 710) under study.where:Apa(A) = the change in the absorption coefficient for a given wavelength A over a defined time period; r = a distance between the light source and detector;DPF = the differential path length factor for the given wavelength A;Io = the intensity of emitted light of the given wavelength A (e.g., the number of photons emitted by the light source) and time (t) = 0; andA / (A) = the change in the measured light intensity of detected light (e.g., the number of photons detected by the detector) for the given wavelength A over the defined time period.A value for Io for each wavelength of light in an incident optical signal corresponding to a received signal under study may be, for example, an intensity of light of the particular wavelength projected into the skin.[000163] Once the absorption coefficient is determined via Equation 1 , oximetry information (e.g., an indication of hemoglobin oxygen saturation) may be determined via, for example, calculations using Equation 2, provided below:Apa(X)= AcHbO*sHbO(A)+AcHb*sHb (X) Equation 2 where:Apa(A) = the change in the absorption coefficient for a given wavelength A over a defined time period;AcHbo = a change in the concentration of oxygenated hemoglobin (HbO) over the defined time period;AcHb = a change in the concentration of deoxygenated hemoglobin (Hb) over the defined time period;SHbo(A) = the extinction coefficient for oxygenated hemoglobin (HbO) for the given wavelength; andSHb(X) = the extinction coefficient for deoxygenated hemoglobin (Hb) for the given wavelength.[000164] Equation 1 may be solved for two or more wavelength pairs by inputting the change in intensity I, as a function of wavelength X. From this, changes in absorption coefficients, Apa, may be determined using Equation 2 by inputting known extinction coefficients, sHbO(A) and sHb (A) for a particular wavelength, which may be, for example, looked up in, for example, a look-up table stored on, for example, computer and / or processor 150 to determine, for example, a level of oxygen saturation for the blood. Additionally, or alternatively, the oxygen saturation may be determined by creating a linear or higher-order calibration curve of SaO2 vs. R (where “R” is the ratio-of-ratios, or approximately (ACM / DC AI) / ( ACA2 / DC \2), as derived from the received optical information for the two wavelengths), and then using measured values of R to estimate SpO2 values. The wavelength pairs used to perform the calculations of Equation 2 may be any pair of wavelengths included in the spectrum of wavelengths of the optical signal incident upon the skin. In some embodiments, the calculation of Equation 2 may be performed many times (e.g., 10s, 100s, or 1000s), in different combinations of wavelengths, in order to arrive at multiple values for AcHbO and AcHb which may be weighted and / or averaged according to one or more criteria to arrive at robust values (e.g., statistically valid and / or with an acceptable level of confidence and error rate) for AcHbO and AcHb for the fetus. Additionally, or alternatively, the calculation of Equation 2 may be performed many times (e.g., 10s, 100s, or 1000s), to fit a plurality of wavelengths at the same time to the equation.[000165] The values for AcHbO and AcHb generated via Equation 2 may be relative values, not absolute values, for the concentrations of oxygenated anddeoxygenated hemoglobin in the fetus’s blood, which may be useful in monitoring changes in the hemoglobin oxygen saturation levels of the fetus over time as, for example, a determination of oximetry information. In some embodiments, the determination of step 715 may also include determining an overall oxygen saturation for the fetus’s hemoglobin by determining a ratio of the change in concentration of oxygenated hemoglobin to the change in concentration of total functional hemoglobin, which may be the sum of oxygenated and deoxygenated hemoglobin.[000166] In situations where the direct-measurement-fetal-oximetry sensor includes multiple detectors, each detector providing a signal received in step 710 may have a different source / detector distance and each detector may be associated with a different detector identifier (e.g., a code). These different detectors may each contribute a different signal to the signals received in step 710 and each of these signals may be associated with a respective detector identifier so that, for example, the source / detector distance for a particular received signal within a group or set of received signals may be determined and / or factored into the determination of the oximetry information of step 715.[000167] In some embodiments, the optical signal corresponding to one or more of the received signals, or a portion thereof, may be of a set, or known, wavelength that may be at an isosbestic point (e.g., 808 nm) for light directed into human tissue to determine a ratio of oxygenated and de-oxygenated hemoglobin for the human’s blood. Light at this wavelength is reflected from oxygenated and de-oxygenated hemoglobin in the same way and may be used to, for example, determine a skin tone of the fetus and / or level of absorption and / or scattering caused by the fetal skin / tissue using, for example, Equations 1 or 2 as explained herein.[000168] Optionally, in step 725, secondary information may be received from, for example, one or more components of system 100. For example, maternal pulse oximetry information, maternal tissue oximetry information, maternal heartrate, maternal ECG information, fetal heartrate, and / or a pressure and / or force within an inflation line (e.g., inflation line 215) may be received from one or more components of a system like system 100 and / or a direct-measurement-fetal-oximetry device like the direct-measurement-fetal-oximetry devices disclosed herein. In step 730, the secondary information may be compared with the direct-measurement oximetry information to determine whether, or not, the direct-measurement oximetry information is fetal-oximetry information (or maternal-oximetry information) and, if not, step 745may be executed. Execution of step 745 may include, for example, providing an error message, providing an instruction to further inflate a stabilization device of the direct- measurement-fetal-oximetry device to the display device, and / or providing an instruction to adjust a position and / or an orientation of the direct-measurement-fetal- oximetry device responsively to the indication of the determination. Following step 745, process 700 may end.[000169] In some embodiments, information from the contact sensor received in step 705 may include ECG information, and the secondary information received in step 725 may be maternal ECG information from an external maternal ECG monitor (e.g., ECG 175). In these embodiments, execution of step 735 may include comparing, or otherwise evaluating, the maternal ECG information and the ECG information from the contact sensor to determine whether the ECG information from the contact sensor approximately matches the maternal ECG information in terms of heartrate and, if not, it may be deduced that the ECG information from the contact sensor indicates that the contact sensor (and therefore the active side of the direct- measurement-fetal-oximetry device) is in contact with fetal skin. If the ECG information from the contact sensor matches the maternal ECG information, it may indicate that the contact sensor is contact with maternal (as opposed to fetal) tissue and process 700 may proceed to step 745.[000170] Additionally, or alternatively, information from the contact sensor received in step 705 may include ECG information and the secondary information received in step 725 may be fetal heartrate information from fetal heartrate monitor (e.g., Doppler / ultrasound sensor 135). In these embodiments, execution of step 735 may include determining heartrate information from the ECG information from the contact sensor and determining whether the heartrate information indicated by the ECG information from the contact sensor approximately matches the fetal heartrate information from the fetal heartrate monitor and, if so, it may be deduced that the ECG information from the contact sensor indicates that the contact sensor (and therefore the active side of the direct-measurement-fetal-oximetry device) is in contact with fetal skin. If the ECG / heartrate information from the contact sensor does not approximately match the fetal ECG information, it may indicate that the contact sensor is contact with maternal (as opposed to fetal) tissue and process 700 may proceed to step 745. If the ECG / heartrate information from the contact sensor does approximately match thefetal ECG information, it may indicate that the contact sensor is contact with fetal (as opposed to maternal) tissue and process 700 may proceed to step 740.[000171] Additionally, or alternatively, maternal tissue optical property information may be received from a maternal oximetry monitor (e.g., pulse oximetry sensor 130) during execution of step 725 and, in step 735 the maternal tissue optical property information may be compared with the signals (or oximetry information determined therefrom) from the direct-measurement-fetal-oximetry sensor. If the maternal oximetry approximately matches (e.g., within 1-20%) the oximetry information from the direct-measurement-fetal-oximetry device and it may be deduced that the oximetry information provided by the direct-measurement-fetal-oximetry device is maternal (and not fetal) oximetry information and process 700 may proceed to step 745. If the oximetry information from the direct-measurement-fetal-oximetry device does not approximately match the maternal tissue optical property information, it may indicate that the contact sensor is contact with fetal (as opposed to maternal) tissue and process 700 may proceed to step 740. Additionally, or alternatively, the maternal tissue optical property information may be used to calculate, or determine, maternal heartrate. This maternal heartrate may be compared a fetal ECG measurement and / or a fetal heartrate derived from a fetal SpO2 measurement and, if the optically-derived maternal heartrate information approximately matches the fetal ECG information and / or fetal heartrate derived from the fetal SpO2 measurement, it may indicate that the contact sensor is contact with maternal (as opposed to fetal) tissue and process 700 may proceed to step 745. If the optically-derived maternal heartrate information does not approximately match the fetal ECG information and / or fetal heartrate derived from the fetal SpO2 measurement, it may indicate that the contact sensor is contact with fetal (as opposed to maternal) tissue and process 700 may proceed to step 740.[000172] When the determination of step 735 indicates that the directly-measured oximetry information is fetal-oximetry information, process 700 may continue to step 740. In step 740, the fetal-oximetry information may be provided to a user via, for example, a display device (e.g., display device 155) and / or a user interface like user interface 164 as, for example, a fetal hemoglobin oxygen saturation level or percentage, an AC fetal hemoglobin oxygen saturation level or percentage, a DC fetal hemoglobin oxygen saturation level or percentage, a fetal tissue oxygen saturation level or percentage, a binary value indicating whether or not the fetus is in distress(e.g., 1 for no distress and 2 for distress), and a scale (e.g., 1-10) indicating whether or not the fetus is in distress (e.g., 1 for no distress and 10 for extreme distress). In some embodiments, execution of step 740 may include providing an indication to the display device that the contact sensor is in electrical contact with fetal skin. At times, the directly-measured-fetal-oximetry information may be averaged over a period of time (e.g., 5, 10, 15, 20, 30, 40, 45, or 60 minutes) and when the directly-measured- fetal-oximetry information and / or a value indicating same falls below a threshold amount, a prediction that the fetus is in distress may be made and / or an alert may be provided to the display device.[000173] Optionally, in some embodiments, process 700 may be executed on multiple occasions over a period of time (e.g., minutes or hours) and over this period of time, it may optionally be determined and / or verified that the direct-measurement- fetal-oximetry sensor is still in contact with fetal skin (step 725). This determination / verification may be made using, for example, information received from an ECG lead like ECG lead 144, a contact sensor like contact sensor 158, and / or a force / pressure sensor like force / pressure sensor 162. Additionally, or alternatively, this determination / verification may be made by evaluating signal strength, wherein a direct-measurement-fetal-oximetry sensor may provide a weak signal when not in contact with the fetal skin. When direct-measurement-fetal-oximetry sensor is in contact with fetal skin, process 700 may proceed to step 710. When direct- measurement-fetal-oximetry sensor is not in contact with fetal skin, an error message and / or a message instructing the user to, for example, adjust a position of direct- measurement-fetal-oximetry sensor to reestablish contact with fetal skin may be communicated to the user (step 730). Additionally, or alternatively, execution of step 730 may include providing an instruction to the direct-measurement-fetal-oximetry sensor to take action to reestablish contact with the fetal skin by, for example, inflating a stabilizing device like stabilizing device 225.[000174] FIG. 8 illustrates an exemplary process 800 for using both a transabdominal-fetal-oximetry sensor and a direct-measurement-fetal-oximetry sensor to obtain, determine, and / or validate transabdominally-obtained-fetal-oximetry information using direct-measurement-fetal-oximetry information. Process 800 may be performed by, for example, any of the system(s) disclosed herein.[000175] In step 805, one or more signals (e.g., analog, digital, and / or electronic signals) corresponding to one or more respective optical signals emanating from apregnant mammal and / or her fetus that have been detected by a detector like detector 160 may be received by, for example, a processor or computer and / or processor like computer and / or processor 150. The signals may be received from a transabdominal- fetal-oximetry sensor such as transabdominal-fetal-oximetry sensor 115A. Optionally, in step 810, secondary information such as one or more characteristics of the maternal tissue and / or the pregnant mammal’s fetus may be received from, for example, one or more components of system 100. Exemplary characteristics include, but are not limited to, a fetal depth (i.e., a width of tissue and / or amniotic fluid positioned between a detector of the transabdominal-fetal-oximetry sensor and the fetus), maternal tissue layer thicknesses, maternal heartrate, a maternal heartbeat signal, maternal pulse oximetry information, maternal DC oximetry information, a noise signal and / or a fetal heartbeat signal.[000176] Optionally, in step 815, the received signal(s) may be processed to isolate a portion thereof that was incident on the fetus that may be referred to herein as a “fetal signal.” Step 815 may be executed using any appropriate method of isolating a fetal signal from a corresponding received signal and / or set of received signals including, but not limited to, reducing noise in the signal(s) via, for example, application of filtering, noise cancellation, or amplification techniques, determining a portion of the first detected electronic signal that is contributed by the pregnant mammal and then subtracting, or otherwise removing, that portion of the first detected electronic signal from the received first detected electronic signals and / or receiving information regarding a fetal heartrate and using that information to lock in (via, for example, a lock-in amplifier) on a portion of the received first detected electronic signals generated by the fetus. In some embodiments, the direct-measurement-fetal- oximetry sensor may provide directly-measured-fetal-ECG information and / or a directly-measured-fetal-ECG signal and this ECG information / signal may be used to isolate the one or more fetal signals by, for example, providing assistance when selecting portions of the one or more signals received in step 805 to further analyze and / or filtering portions of the one or more signals received in step 805 to remove portions that do not correspond to a fetal heartrate.[000177] Optionally, execution of step 815 may include pre-processing of the detected electronic signal in order to, for example, remove noise from the signal and / or confounding effects of the pregnant mammal’s anatomy or physiological signals (e.g., a respiratory signal) from the detected electronic signals. Execution of the pre-processing may include, but is not limited to, application of filtering techniques to the received signal(s), application of amplification techniques to the received signal(s), utilization of a lock-in amplifier on the received signal(s), and so on. In some embodiments, the pre-processing may include application of a filter (e.g., bandpass or Kalman) to the received signal(s) to reduce noise or hum in the received signal(s) that may be caused by, for example, electronic noise generated by equipment generating and / or detecting the received signal(s) and / or environmental equipment (e.g., a ventilator) that may, in some instances, be proximate and / or coupled to the pregnant mammal.[000178] The fetal signal may then be used to determine transabdominally- obtained-fetal-oximetry information using, for example, Equations 1 and 2, described above (step 820). Next, steps 705, 710, and / or 715 of process 700 may be executed to determine fetal-oximetry information using one or more signals from a direct- measurement-fetal-oximetry sensor. Then, the transabdominally-obtained fetal- oximetry information (step 820) and the fetal-oximetry information determined using one or more signals from a direct-measurement-fetal-oximetry sensor (step 715) may be compared with one another or otherwise processed (step 825) to determine one or more differences therebetween. Then, in step 830, it may be determined whether the comparison results are within a specified range of values. Execution of step 830 may include, for example, determining whether the determined transabdominally-obtained- fetal-oximetry information and the direct-measurement-fetal-oximetry information (or values corresponding thereto) fall within a standard of deviation (e.g., + / - 1%, 3%, 5%, or 10%) or acceptable range of error when compared with one another. When the transabdominally-obtained-fetal-oximetry information and the direct-measurement- fetal-oximetry information are not within a specified range of values (e.g., are too different from one another), the results of the comparison may be analyzed to, for example, detect errors, determine a source of errors, or otherwise trouble shoot the determinations of the transabdominally-obtained-fetal-oximetry information and the direct-measurement-fetal-oximetry information (step 835). Additionally, or alternatively, execution of step 835 may include requesting and / or initiating a repeated execution of step(s) 805-820 and / or 705, 710, and / or 715 to determine subsequent transabdominally-obtained-fetal-oximetry information and / or direct-measurement- fetal-oximetry information. When the transabdominally-obtained-fetal-oximetry information and the direct-measurement-fetal-oximetry information values are within aspecified range of values (i.e., not too different (e.g., within 1-10%) from one another), an indication of the fetal-oximetry information may be communicated to a display device for display or provision to a user (step 840).[000179] In some embodiments, data gathered from a direct-measurement-fetal- oximetry sensor may be used to set and / or adjust one or more hardware (e.g., beam focus, wavelengths and / or intensity of light used, selection of one or more detectors from a plurality of detectors to be used, etc.) and / or software (e.g., timing, multiplexing, duration of light beam projection, etc.) settings of a transabdominal-fetal-oximetry sensor on, for example, a one-time, periodic, as-needed (e.g., as a spot check) and / or continuous basis by, for example, executing some, or all, of process 900 as shown in FIG. 9, which may be executed by any of the systems, devices, and / or components thereof disclosed herein. Additionally, or alternatively, process 900, or a portion thereof, may be executed to calibrate and / or mathematically adjust one or more signals received from a transabdominal-fetal-oximetry sensor and / or the analysis of those signals. Execution process 900 may begin with performance of step(s) 705, 710, and / or 715.[000180] Optionally, in step 905, one or more settings and / or parameters for a transabdominal-fetal-oximetry sensor and / or a component thereof may be determined using, for example, the one or more directly-measured-fetal-oximetry signals received in step 710 and / or fetal-oximetry information determined in step 715. Exemplary settings and / or parameters for the transabdominal-fetal-oximetry sensor include, but are not limited to one or more wavelengths emitted by a light source of the transabdominal-fetal-oximetry sensor (e.g., light source 105), an intensity, focus, and / or incident angle of light projected into the pregnant mammal’s abdomen by a light source of the transabdominal-fetal-oximetry sensor, an optical multiplexing routine performed by the transabdominal-fetal-oximetry sensor or a component thereof, and a duty cycle (turning on and / or off) of one or more light sources and / or detectors included in the transabdominal-fetal-oximetry sensor. Additionally, or alternatively, a setting or parameter received and / or determined in step 905 may select one or more detectors (e.g., detector 160) from which to receive a signal, tune a sensitivity of a detector of the transabdominal-fetal-oximetry sensor to preferentially detect light of one or more wavelengths, selection or determination of a parameter for processing (e.g., noise reduction, filtration, and / or amplification) one or more signals generated by and / or transmitted from the transabdominal-fetal-oximetry sensor.[000181] In some embodiments, execution of step 905 may include processing the one or more directly-measured-fetal-oximetry signals received in step 710 and / or fetal-oximetry information determined in step 715 to determine optical scattering and / or absorption characteristics for the fetus, optimize a manner in which to project light (e.g., wavelength(s), intensity, multiplexing protocols, duty cycles, etc.) into the maternal abdomen, and / or optimize a manner in which to detect light reflected by the fetus (e.g., duty cycles, detector sensitivity, power draw, etc.) by a transabdominal- fetal-oximetry sensor.[000182] Additionally, or alternatively, in some embodiments, step 920 (receiving secondary information) may be executed prior to step 905 and, in these embodiments, execution of step 905 may include analysis of the secondary information to determine the one or more parameters and / or settings for the transabdominal-fetal-oximetry sensor. For example, secondary information in the form of one or more optical, anatomical, and / or geometrical properties of the fetus and / or pregnant mammal that may be received from, for example, Doppler / ultrasound sensor 165, ECG 175, and / or database 170 and / or determined using the one or more directly-measured-fetal- oximetry signals received in step 710 and / or fetal-oximetry information determined in step 715 may be used to set and / or adjust a parameter and / or setting for the transabdominal-fetal-oximetry sensor. For example, an intensity of light projected by a light source of the transabdominal-fetal-oximetry sensor may be adjusted responsively to a fetal depth (e.g., a distance between the pregnant mammals epidermis and the fetus’ epidermis) and / or a multiplexing routine (e.g., emitting light of different wavelengths at different times) performed by the transabdominal-fetal- oximetry sensor may be adjusted responsively to a fetal depth, a presence of meconium in the amniotic fluid, and / or skin color.[000183] When step 905 is performed, in step 910, the transabdominal-fetal- oximetry sensor and / or an operation thereof may be adjusted according to one or more determinations of step 905.[000184] In step 915, one or more signals corresponding to one or more respective optical signals emanating from a pregnant mammal and / or her fetus may be received by, for example, a processor or computer and / or processor like computer and / or processor 150. The one or more signals may be received from a transabdominal-fetal-oximetry sensor such as transabdominal-fetal-oximetry sensor 115A that, in some embodiments, may be adjusted via execution of step 910.[000185] Optionally, in step 920, secondary information such as the secondary information described above with regard to execution of step 810, may be received. Optionally, in step 925, the received signal(s) of step 915 may be processed to isolate a portion thereof that was incident on the fetus, thereby generating one or more adjusted fetal signal(s). In some embodiments, execution of step 925 may be similar to execution of step 815, described above with the exception that the transabdominal- fetal-oximetry sensor providing the one or more signals of step 915 may be adjusted in, for example, steps 910 and / or 915. Additionally, or alternatively, the one or more signals received from the direct-measurement-fetal-oximetry sensor may be used, in a manner similar to that described above with regard to step 815, to isolate and / or generate the fetal signal during execution of step 925.[000186] In step 930, transabdominally-obtained-fetal-oximetry information may be determined using the fetal signals of step 925 as, for example, described herein (e.g., using, for example, Equations 1 or 2 as explained herein). Then, in step 935, the transabdominally-obtained-fetal-oximetry information from step 930 and the direct- measurement-fetal-oximetry information of step 715 may be compared with one another or otherwise processed to determine one or more differences therebetween. Then, in step 940, it may be determined whether the comparison results are within a specified range of values (e.g., within a standard of deviation or within 5-20%, 1-10%, 5-10%, 1-5%, 1-20% of each other). In some embodiments, execution of step 940 may be similar to execution of step 830, described above. When the adjusted transabdominally-obtained-fetal-oximetry information and the direct-measurement- fetal-oximetry information values are within the specified range of values, an indication of the transabdominally-obtained-fetal-oximetry information may be communicated to, for example, a display device for display or provision to a user (step 950).[000187] In some embodiments, the secondary information received in step 920 may be maternal tissue optical property information received from a set of maternal optical sensors like the set of maternal optical sensors of direct-measurement-fetal- oximetry sensor 204. The maternal tissue optical property information received from the set of maternal optical sensors may include, for example, tissue oximetry information for maternal tissue positioned between a direct-measurement-fetal- oximetry sensor like the direct-measurement-fetal-oximetry sensors disclosed herein, optical characteristics (e.g., scattering and / or absorption) of the maternal tissue positioned proximate to the direct-measurement-fetal-oximetry sensor overlying thefetus, and / or a thickness of maternal tissue proximate to direct-measurement-fetal- oximetry sensor by, for example, measuring a time of flight for light (i.e., photons) from when they are emitted by a light source (e.g., source 105) and detected by a detector (e.g., detector 160). Additionally, or alternatively, secondary information received in step 920 may be a fetal depth that is measured and / or deduced using one or more images (e.g., ultrasound images) of a maternal abdomen. For example, when the direct-measurement-fetal-oximetry sensor providing the signals of step 715 includes a marker like marker 207, a fetal depth may be determined using ultrasound images of the maternal abdomen and, for example, measuring a distance between marker 207 and the maternal epidermis as shown in one or more ultrasound images.[000188] When maternal tissue optical property information is received from the set of maternal optical sensors in step 920, the maternal tissue optical property information may be used during execution of step 925 to generate the one or more fetal signal(s) and / or isolate maternal and fetal contributions to one or more signals from a transabdominal-fetal-oximetry sensor like the transabdominal-fetal-oximetry sensors disclosed herein. Additionally, or alternatively, when maternal tissue optical property information is received from the set of maternal optical sensors in step 920, execution of step 930 to determine fetal oximetry information may be executed by, for example, calibrating the fetal oximetry calculations to include and / or account for maternal optical characteristics and / or tissue oxygenation proximate to the fetus.[000189] Additionally, or alternatively, when fetal depth information (or images from which fetal depth may be determined) are received in step 920, the fetal depth information may be used during execution of step 925 to generate the one or more fetal signal(s) and / or isolate maternal and fetal contributions to one or more signals from a transabdominal-fetal-oximetry sensor like the transabdominal-fetal-oximetry sensors disclosed herein. Additionally, or alternatively, when fetal depth information is received in step 920, execution of step 930 to determine fetal oximetry information may be executed by, for example, calibrating the fetal oximetry calculations to include and / or account for the fetal depth.[000190] In some embodiments, information received in step 920 may include fetal depth, maternal tissue composition, and / or maternal tissue layer thicknesses and / or the parameters determined in step 905 may be responsive to fetal depth, maternal tissue composition, and / or maternal tissue layer thicknesses. When the transabdominal-fetal-oximetry sensor has multiple light sources and / or multipledetectors, execution of step 910 and / or 925 may include selecting (using, for example, the fetal depth, maternal tissue composition, and / or maternal tissue layer thicknesses) one or more light source and detector pair(s) for signal extraction and / or analysis to generate the fetal signals. For example, if the transabdominal-fetal-oximetry sensor has once light source and six detectors like transabdominal-fetal-oximetry sensor 115A, each source detector pair may generate a signal and the fetal depth may be used to select which of these signals to generate the fetal signal. Continuing with the example of transabdominal-fetal-oximetry sensor 115A only the signals from detectors 160C, 160D, 160E, and 160F would be selected for further processing and / or generation of the fetal signal because the signals from detectors 160A and 160B do not penetrate the abdominal tissue to the fetal depth (i.e., are not incident on the fetus). Additionally, or alternatively, fetal depth, maternal tissue composition, and / or maternal tissue layer thicknesses may be used to select one or more wavelengths of light projected by the light source into the maternal abdomen. Additionally, or alternatively, maternal optical properties may be received in step 920 and these maternal optical properties may be used to adjust[000191] Additionally, or alternatively, execution of process 900 (e.g., step 905, 910, 925, and / or 930) may include adjusting fetal oximetry calculations to incorporate measured maternal layer optical properties (e.g., peff) depending on, for example, fetal depth and / or maternal layer thicknesses.[000192] When the transabdominally-obtained and direct-measurement-fetal- oximetry information are not within a specified range of values (step 940), the results of the comparison may be analyzed to, for example, detect errors, determine a source of errors, or otherwise trouble shoot the determinations of the transabdominally- obtained-fetal-oximetry information to determine how to adjust the transabdominal- fetal-oximetry sensor (step 945) and some, or all of, step(s) 905-945 may be repeated. [000193] FIG. 10 illustrates a process 1000 for calibrating one or more signals received from a transabdominal-fetal-oximetry sensor, which may be executed by any of the systems, devices, and / or components thereof disclosed herein. Execution process 1000 may begin with performance of step(s) 705, 710, and 715.[000194] In step 1005, one or more signals (e.g., digital and / or analog) corresponding to one or more respective optical signals emanating from a pregnant mammal and / or her fetus may be received by, for example, a processor or computer and / or processor like computer and / or processor 150. The one or more signals maybe received from a transabdominal-fetal-oximetry sensor such as transabdominal- fetal-oximetry sensor 115A that, in some embodiments, may be adjusted via, for example, execution of process 900 and / or a detector like detector 160.[000195] In step 1010, one or more calibrations, values, equations, coefficients, and / or algorithms, (at times collectively referred to as “calibrations” herein) to be applied to the signal(s) received in step 1005 may be determined and / or selected. These calibrations, values, equations, coefficients, and / or algorithms, correct, adjust, and / or pertain to scattering and / or absorption of maternal and / or fetal tissue, known errors or fluctuations in equipment performance (e.g., hum or distortion) that may impact one or more aspects of a signal, maternal and / or fetal geometry, anatomy, physiology, and / or tissue composition, and / or environmental factors that may impact the signal such as ambient light and / or electrical interference. In some embodiments, execution of step 1010 may incorporate determining one or more calibrations, values, equations, coefficients, and / or algorithms using information from a set of maternal optical sensors like the set of maternal optical sensors of direct-measurement-fetal- oximetry device 204.[000196] In step 1015, the one or more signal(s) received in step 1005 may be calibrated, or otherwise adjusted, using, for example, and / or one or more calibrations, values, equations, coefficients, and / or algorithms determined and / or selected in step 1010. Optionally, in step 1020, secondary information such as the secondary information described above with regard to execution of step 810 and 920, may be received.[000197] In some embodiments, step 1020 may be performed prior to performance of step 1010 and, in these embodiments, the determination and / or selection of the calibrations, values, equations, coefficients, and / or algorithms may be responsive to the secondary information. For example, if a maternal skin tone is received as secondary information, the maternal skin tone may be used, in step 1015 to calibrate, or otherwise adjust, the received signal(s) for optical properties (e.g., scattering and / or absorption) associated with the maternal skin tone.[000198] Then, in step 1025, the calibrated signal(s) of step 1015 may be processed using, for example, the secondary information of step 1020, to isolate a portion thereof that was incident on the fetus, thereby generating one or more calibrated fetal signal(s). Execution of step 1025 may be similar to execution of step 815 and / or 925, described above with the exception that the one or more signals maybe calibrated in, for example, step 1015. Additionally, or alternatively, the one or more signals received from the direct-measurement-fetal-oximetry sensor may be used to isolate and / or generate the fetal signal during execution of step 1025.[000199] In step 1030, calibrated transabdominally-obtained-fetal-oximetry information may be determined using the calibrated signal(s) of step 1015 and / or the calibrated fetal signal(s) of step 1025 using one or more processes for determining fetal oximetry information described herein. In some embodiments, execution of step(s) 1020, 1025, and / or 1030 may be similar to and / or incorporate execution of some of the processes and / or steps of execution of step(s) 920, 925, and / or 930, respectively.[000200] In step 1035, the calibrated transabdominally-obtained-fetal-oximetry information from step 1030 and the direct-measurement-fetal-oximetry information of step 715 from process 700 may be compared with one another or otherwise processed to determine one or more differences therebetween. Next, in step 1040, it may be determined whether the comparison results are within a specified range of values (e.g., within a standard of deviation or within 5-20% of each other). In some embodiments, execution of step 1040 may be similar to execution of step 830 and / or 940, described above. When the calibrated transabdominally-obtained-fetal-oximetry information and the direct-measurement-fetal-oximetry information values are within a specified range of values (e.g., within a standard of deviation or within 5-20%, 1-10%, 5-10%, 1-5%, 1-20% of each other) and an indication of the calibrated transabdominally-obtained-fetal-oximetry information may be communicated to, for example, a display device for display or provision to a user (step 1050).[000201] When the calibrated transabdominally-obtained and direct- measurement-fetal-oximetry information are not within a specified range of values (step 1040), the results of the comparison may be analyzed to, for example, detect errors, determine a source of errors, or otherwise trouble shoot the determinations of the calibrated transabdominally-obtained-fetal-oximetry information to determine how to calibrate the transabdominally-obtained-fetal-oximetry signals (step 1045) and, in some instances, some, or all of, step(s) 1005-1045 may be repeated.[000202] FIG. 11 illustrates an exemplary process 1100 for validating transabdominally-obtained-fetal-oximetry information using direct-measurement-fetal- oximetry information. Process 1100 may be performed by, for example, any of the system(s) disclosed herein.[000203] In step 1105, direct-measurement-fetal-oximetry information, such as the direct-measurement-fetal-oximetry information determined in step 715 may be received and in step 1110, one or more signals corresponding to one or more respective optical signals emanating from a pregnant mammal and / or her fetus may be received by, for example, a processor or computer and / or processor like computer and / or processor 150. The one or more signals may be received from a transabdominal-fetal-oximetry sensor such as transabdominal-fetal-oximetry sensor 115A.[000204] Optionally, in step 1115, secondary information such as the secondary information described above with regard to, for example, execution of step(s) 810 and / or 920, may be received. Optionally, in step 1120, the signal(s) in step 1110 may be processed to isolate a portion thereof that was incident on the fetus, thereby generating one or more fetal signal(s). Execution of step(s) 1115 may be similar to, for example, execution of step(s) 920 and / or 1020. Additionally, or alternatively, execution of step(s) 1120 may be similar to, for example, execution of step(s) 815, 925, and / or 1025.[000205] In step 1125, transabdominally-obtained-fetal-oximetry information may be determined using the one or more signals received in step 1110 and / or the transabdominal fetal signals of step 1120. On some occasions, execution of step 1125 may resemble execution of step 930.[000206] Then, in step 1130, the transabdominally-obtained-fetal-oximetry information and the direct-measurement-fetal-oximetry information received in step 1105 may be compared with one another or otherwise processed (step 1130) to determine one or more differences therebetween. Then, in step 1135, it may be determined whether the comparison results are within a specified range of values (e.g., within a standard of deviation or within 5-20%, 1-10%, 5-10%, 1-5%, 1-20% of each other). Execution of step 1135 may be similar to execution of step 830, 940, and / or 1040, described above. When the transabdominally-obtained-fetal-oximetry information and the direct-measurement-fetal-oximetry information values are within a specified range of values, an indication of the transabdominally-obtained-fetal- oximetry information may be communicated to a display device for display or provision to a user (step 1145).[000207] When the calibrated transabdominally-obtained and direct- measurement-fetal-oximetry information are not within a specified range of values(step 1135), the results of t e comparison may be analyzed to, for example, detect errors, determine a source of errors, or otherwise trouble shoot the determinations of the transabdominally-obtained-fetal-oximetry information and the direct- measurement-fetal-oximetry information to determine how to recalibrate the transabdominal-fetal-oximetry sensor, the signals received from the transabdominal- fetal-oximetry sensor, and / or calculations made using one or more signals received from the transabdominal-fetal-oximetry sensor (step 1140) so that step 1110, 1120, and / or 1125 may be repeated to accordingly recalibrate signals received from the transabdominal-fetal-oximetry sensor, the transabdominal fetal signals, and / or the determination of transabdominally-obtained-fetal oximetry information to, for example, more closely match the direct-measurement-fetal-oximetry information received in step 1105.[000208] Hence, systems, devices, and methods for determining fetal-oximetry information have been herein disclosed. In some embodiments, use of the systems, devices, and methods described herein may be particularly useful during the labor and delivery of the fetus (e.g., during the first and / or second stage of labor) because it is difficult to assess fetal wellness and / or oxygenation status during the labor and delivery process.

Claims

CLAIMSWe claim:1 . A method comprising: receiving, by a processor, ECG information from an ECG lead of a direct- measurement-fetal-oximetry device positioned within a uterus of a pregnant mammal; receiving, by the processor, fetal heartrate information from a fetal heartrate monitor; and determining, by the processor, whether the contact sensor is in physical or electrical contact with fetal skin by: determining, by the processor, heartrate information from the ECG information received from the ECG lead of the direct-measurement-fetal-oximetry device; and determining, by the processor, whether the heartrate information from the ECG information from the contact sensor approximately matches the fetal heartrate information from the fetal heartrate monitor and, if so, providing an indication to a display device that the contact sensor is in electrical contact with fetal skin.

2. The method of claim 1 , further comprising: sending, by the processor, an error message to the display device responsively to a determination that the ECG information from the contact sensor does not approximately match the fetal heartrate information from the fetal heartrate monitor.

3. The method of claim 1 or 2, wherein the direct-measurement-fetal-oximetry device includes an inflatable stabilization device, the method further comprising: receiving, by the processor, a force and / or pressure measurement from a force and / or pressure gauge in communication with an inflation line that provides inflation media to the inflatable stabilization device; and providing, by the processor, an indication of the force and / or pressure measurement to the display device.

4. The method of claim 3, further comprising:providing, by the processor, an instruction to further inflate the stabilization device to the display device responsively to a determination that the contact sensor is not in physical or electrical contact with fetal skin.

5. The method of any of claims 1-4, further comprising: providing, by the processor, an instruction to adjust a position and / or an orientation of the direct-measurement-fetal-oximetry device responsively a determination that the contact sensor is not in physical or electrical contact with fetal skin.

6. The method of claim 1-5, wherein the direct-measurement-fetal-oximetry device includes a marker configured to be opaque to an imaging technology, the method further comprising: receiving, by the processor, an image of an abdomen of the pregnant mammal; and determining, by the processor, a position of the marker by analyzing the image.

7. A method comprising: receiving, by a processor, maternal tissue optical property information from a maternal oximetry monitor; receiving, by the processor, oximetry information from a direct-measurement- fetal-oximetry device positioned within a uterus of a pregnant mammal; and determining, by the processor, whether the maternal oximetry approximately matches the oximetry information from the direct-measurement-fetal-oximetry device and, if so, providing an error message to the display device.

8. The method of any of claims 7, further comprising: providing, by the processor, an instruction to adjust a position and / or an orientation of the direct-measurement-fetal-oximetry device responsively a determination that the maternal oximetry approximately matches the oximetry information from the direct-measurement-fetal-oximetry device.

9. A method comprising:receiving, by a processor, directly-measured-fetal-oximetry information from a direct-measurement-fetal-oximetry device in optical contact with a fetus; and determining, by the processor, at least one of a calibration, value, equation, coefficient, or algorithm for evaluating one or more signals received from a transabdominal-fetal-oximetry sensor to determine fetal oximetry information responsively to the received directly-measured-fetal-oximetry information.

10. The method of claim 9, further comprising: receiving, by the processor, one or more signals from the transabdominal-fetal- oximetry sensor; evaluating, by the processor, the one or more signals received from the transabdominal-fetal-oximetry sensor using the at least one calibration, value, equation, coefficient, or algorithm to determine transabdominally-obtained-fetal- oximetry information; comparing, by the processor, the directly-measured-fetal-oximetry information and the transabdominally-obtained-fetal-oximetry information; and providing, by the processor, an indication of the transabdominally-obtained-fetal- oximetry information to the display device.

11. The method of claim 9, further comprising: receiving, by the processor, one or more signals from the transabdominal-fetal- oximetry sensor; evaluating, by the processor, the one or more signals received from the transabdominal-fetal-oximetry sensor using the at least one at least one of a calibration, value, equation, coefficient, or algorithm to determine transabdominally- obtained-fetal-oximetry information; comparing, by the processor, the directly-measured-fetal-oximetry information and the transabdominally-obtained-fetal-oximetry information; and adjusting, by the processor, the at least one of calibration, value, equation, coefficient, or algorithm responsively to the comparison.

12. The method of any of claims 9-11 , further comprising:receiving, by the processor, secondary information, wherein determining the at least one calibration, value, equation, coefficient, or algorithm is responsive to the received secondary information.

13. The method of claim 12, wherein the secondary information is used to calibrate the transabdominally measured fetal oximetry information, filter the transabdominally measured fetal oximetry information, and / or amplify portions of the transabdominally measured fetal oximetry information.

14. The method of claim 12 or 13, wherein the secondary information is at least one of a maternal heartrate, a fetal heartrate, a fetal depth, and maternal tissue optical property information.

15. The method of claim 12 or 13, wherein the secondary information is maternal tissue optical property information received from the direct-measurement-fetal- oximetry device.

16. The method of any of claims claim 1-11 , further comprising: receiving, by the processor, a signal corresponding to light that was incident on maternal tissue from the direct-measurement-fetal-oximetry device; determining, by the processor, maternal tissue optical property information using the signal corresponding to light that was incident on maternal tissue, wherein determining the at least one calibration, value, equation, coefficient, or algorithm is responsive to the maternal tissue optical property information.

17. The method of any claims 9-14, wherein the fetal oximetry information is at least one of a fetal hemoglobin oxygen saturation level and a fetal tissue oxygen saturation level.

18. A method comprising: receiving, by a processor, directly-measured-fetal-oximetry information from a direct-measurement-fetal-oximetry device in optical contact with a fetus; determining, by the processor, a directly-measured-fetal oximetry value using the received directly-measured-fetal-oximetry information;receiving, by the processor, one or more signals from the transabdominal-fetal- oximetry sensor, the one or more signals corresponding to optical signals emanating from an abdomen of a mammal who is pregnant with the fetus and detected by the transabdominal-fetal-oximetry sensor; determining, by the processor, a transabdominally-obtained-fetal-oximetry value using the one or more signals from the transabdominal-fetal-oximetry sensor; comparing, by the processor, the directly-measured-fetal-oximetry value and the transabdominally-obtained-fetal-oximetry value; and providing, by the processor, the transabdominally-obtained-fetal-oximetry value to a display device responsively to a result of the comparison.

19. The method of claim 18, wherein the determining of the transabdominally- obtained-fetal-oximetry value comprises: receiving, by the processor, secondary information; generating, by the processor, one or more transabdominal-fetal-oximetry signals by processing the one or more signals from the transabdominal-fetal-oximetry sensor using the received secondary information; and using, by the processor, the one or more transabdominal-fetal-oximetry signals to determine the transabdominally-obtained-fetal-oximetry value.

20. The method of claim 19, wherein the secondary information is maternal tissue optical property information received from the direct-measurement-fetal-oximetry device.

21. The method of any of claims claim 18-20, further comprising: receiving, by the processor, a signal corresponding to light that was incident on maternal tissue from the direct-measurement-fetal-oximetry device; determining, by the processor, maternal tissue optical property information using the signal corresponding to light that was incident on maternal tissue, wherein determining the at least one calibration, value, equation, coefficient, or algorithm is responsive to the maternal tissue optical property information.

22. The method of claim 18, further comprising:determining whether a result of the comparison is within a range of values, wherein the transabdominally-obtained-fetal-oximetry value is provided to the display device only when the result of the comparison is within a range of values.

23. The method of claim 18, further comprising: determining whether a result of the comparison is within a range of values, wherein an error message is sent to the display device when the result of the comparison is not within a range of values.

24. The method of any of claims 18-23, further comprising: determining, by the processor, whether the determining a transabdominally- obtained-fetal-oximetry value using the one or more signals from the transabdominal-fetal-oximetry sensor should be calibrated or adjusted responsively to a result of the comparison.

25. The method of claim 18, further comprising: determining, by the processor, whether the determining a transabdominally- obtained-fetal-oximetry value using the one or more signals from the transabdominal-fetal-oximetry sensor should be calibrated or adjusted responsively to a result of the comparison; and calibrating, or adjusting, by the processor, the determination of the transabdominally-obtained-fetal-oximetry value responsively to a determination that the determining a transabdominally-obtained-fetal-oximetry value using the one or more signals from the transabdominal-fetal-oximetry sensor should be calibrated or adjusted.

26. A direct-measurement-fetal-oximetry device comprising: a light source configured to project light into fetal skin; a detector configured to detect light backscattered from fetal tissue and convert the detected light into a signal; and a contact sensor configured to detect contact with fetal skin.

27. The direct-measurement-fetal-oximetry device of claim 26, wherein the contact sensor is at least one of an ECG lead and a camera.

28. The direct-measurement-fetal-oximetry device of claim 26 or 27, further comprising: a housing comprising a first side in which the light source and detector are positioned; and a stabilization device positioned on a second of the housing, the second side of the housing opposing the first side of the housing.

29. The direct-measurement-fetal-oximetry device of claim 28, wherein the stabilization device is configured to face an internal uterine wall when in situ.

30. The direct-measurement-fetal-oximetry device of claim 29 or 29, wherein a size and / or volume of the stabilization device is adjustable.

31. The direct-measurement-fetal-oximetry device of claim 28, 29, or 30, wherein the stabilization device is inflatable, the direct-measurement-fetal-oximetry device further comprising: an inflation line resident in the positioning extension, the inflation line being in communication with the stabilization device and configured to communicate fluid to and / or from the stabilization device, thereby adjusting a size and / or volume of the stabilization device.

32. The direct-measurement-fetal-oximetry device of claim 31 , wherein a degree of inflation of the stabilization device is responsive to back pressure and / or force exerted on the inflation line.

33. The direct-measurement-fetal-oximetry device of claim 31 , wherein a degree of inflation of the stabilization device is responsive to an indication of whether the direct-measurement-fetal-oximetry device is in contact with fetal skin.

34. The direct-measurement-fetal-oximetry device of any of claims 26-33, wherein the stabilization device comprises a material that expands when exposed to amniotic fluid.

35. The direct-measurement-fetal-oximetry device of any of claims 26-34, wherein the stabilization device comprises a material that expands into space between the fetus and internal uterine wall.

36. The direct-measurement-fetal-oximetry device of any of claims 26-35, wherein the stabilization device is configured to occupy space between the fetus and internal uterine wall and assist with maintaining contact between the fetal skin and the ECG lead.

37. The direct-measurement-fetal-oximetry device of any of claims 26-36, further comprising: a housing comprising; and an extension physically coupled to the housing, the extension being configured to assist with positioning and / or maintaining a position the direct-measurement-fetal- oximetry device proximate to the fetal skin.

38. The direct-measurement-fetal-oximetry device of any of claims 26-37, further comprising: a housing comprising a first side in which the light source and detector are positioned; and a reference electrode positioned on a second side of the housing, the reference electrode being positioned and configured to contact and / or be electrically coupled with a uterine wall of a mammal who is pregnant with the fetus.

39. The direct-measurement-fetal-oximetry device of any of claims 26-38, further comprising: a housing comprising a first side in which the light source and detector are positioned; and a set of maternal optical sensors comprising a light source and a detector positioned on a second side of the housing, the set of maternal optical sensors being configured and positioned to contact maternal tissue.

40. The direct-measurement-fetal-oximetry device of any of claims 26-39, wherein the skin is at least one of a cheek, a back, a head, an arm, and a chest of the fetus.41 .The direct-measurement-fetal-oximetry device of any of claims 26-40, further comprising: a temperature sensor configured to measure a temperature of the fetus and / or a mammal who is pregnant with the fetus.

42. The direct-measurement-fetal-oximetry device of any of claims 26-41 , further comprising: a marker configured to be opaque to an imaging technology.

43. The direct-measurement-fetal-oximetry device of any of claims 26-42, wherein an outer surface of a portion is coated and / or treated with a lubricious coating to reduce friction between the device and tissue of a mammal who is pregnant with the fetus.

44. The direct-measurement-fetal-oximetry device of any of claims 26-43, further comprising: an optically-isolating feature configured to optically isolate detector from the light source.

45. The direct-measurement-fetal-oximetry device of claim 44, wherein the optically- isolating feature is one of a blinder, an extensions, a recess, a flange, and a gasket.

46. The direct-measurement-fetal-oximetry device of claim 44 or 45, wherein the optically-isolating feature is positioned around the detector and / or the light source.

47. The direct-measurement-fetal-oximetry device of any of claims 26-46, wherein the light source is a first light source and the detector is a first detector, the device further comprising: a housing comprising an active side in which the light source and detector are positioned; a second light source positioned on a second side of the housing, the second light source being positioned and configured to project light into a uterine wall of a mammal who is pregnant with the fetus; anda second detector positioned on the second side of the housing, the second detector being positioned and configured to detect light backscattered from the uterine wall of the mammal who is pregnant with the fetus.

48. A method comprising using the direct-measurement-fetal-oximetry device of any of claims 26-47 to obtain fetal oximetry information or data used to determine fetal oximetry information.

49. A direct-measurement-fetal-oximetry device comprising: a light source configured to project light into fetal skin; a detector configured to detect light backscattered from fetal tissue and convert the detected light into a signal; and an optically-isolating feature configured to optically isolate detector from the light source.

50. The direct-measurement-fetal-oximetry device of claim 49, further comprising: a housing comprising a first side in which the light source and detector are positioned; and a stabilization device positioned on a second of the housing, the second side of the housing opposing the first side of the housing.

51. The direct-measurement-fetal-oximetry device of claim 50, wherein the stabilization device is configured to face an internal uterine wall when in situ.

52. The direct-measurement-fetal-oximetry device of claim 50 or 51 , wherein a size and / or volume of the stabilization device is adjustable.

53. The direct-measurement-fetal-oximetry device of claim 50, 51 , or 52, wherein the stabilization device is inflatable: an inflation line resident in the positioning extension, the inflation line being in communication with the stabilization device and configured to communicate fluid to and / or from the stabilization device, thereby adjusting a size and / or volume of the stabilization device.

54. The direct-measurement-fetal-oximetry device of claim 53, wherein a degree of inflation of the stabilization device is responsive to back pressure and / or force exerted on the inflation line.

55. The direct-measurement-fetal-oximetry device of claim 53 or 54, wherein a degree of inflation of the stabilization device is responsive to an indication of whether the direct-measurement-fetal-oximetry device is in contact with fetal skin.

56. The direct-measurement-fetal-oximetry device of any of claims 50-55, wherein the stabilization device comprises a material that expands when exposed to amniotic fluid.

57. The direct-measurement-fetal-oximetry device of any of claims 50-56, wherein the stabilization device comprises a material that expands into space between the fetus and internal uterine wall.

58. The direct-measurement-fetal-oximetry device of any of claims 50-57, wherein the stabilization device is configured to occupy space between the fetus and internal uterine wall and assist with maintaining contact between the fetal skin and the ECG lead.

59. The direct-measurement-fetal-oximetry device of any of claims 49-58, further comprising: a housing comprising an active side in which the light source and detector are positioned; and an extension positioned on a surface of the housing opposing the active side of the housing, the extension being configured to assist with positioning and / or maintaining a position the direct-measurement-fetal-oximetry device proximate to the fetal skin.

60. The direct-measurement-fetal-oximetry device of any of claims 49-59, further comprising: a housing comprising a first side in which the light source and detector are positioned; anda reference electrode positioned on a second side of the housing, the reference electrode being positioned and configured to contact and / or be electrically coupled with a uterine wall of a mammal who is pregnant with the fetus.61 .The direct-measurement-fetal-oximetry device of any of claims 49-60, wherein the skin is at least one of a cheek, a back, a head, an arm, and a chest of the fetus.

62. The direct-measurement-fetal-oximetry device of any of claims 49-61 , further comprising: a temperature sensor configured to measure a temperature of the fetus and / or a mammal who is pregnant with the fetus.

63. The direct-measurement-fetal-oximetry device of any of claims 49-62, further comprising: a marker configured to be opaque to an imaging technology.

64. The direct-measurement-fetal-oximetry device of any of claims 49-63, wherein an outer surface of a portion is coated and / or treated with a lubricious coating to reduce friction between the device and tissue of a mammal who is pregnant with the fetus.

65. The direct-measurement-fetal-oximetry device of any of claims 49-64, wherein the light source is a first light source and the detector is a second detector, the device further comprising: a housing comprising an active side in which the light source and detector are positioned; a second light source positioned on a second side of the housing, the second light source being positioned and configured to project light into a uterine wall of a mammal who is pregnant with the fetus; and a second detector positioned on the second side of the housing, the second detector being positioned and configured to detect light backscattered from the uterine wall of the mammal who is pregnant with the fetus.

66. A method comprising using the direct-measurement-fetal-oximetry device of any of claims 49-66 to obtain fetal oximetry information or data used to determine fetal oximetry information.

67. A method comprising: receiving, by a processor, directly-measured-fetal-oximetry information from a direct-measurement-fetal-oximetry device in optical contact with a fetus; and determining, by the processor, a parameter for the operation of a transabdominal- fetal-oximetry sensor using the received directly-measured-fetal-oximetry information.

68. The method of claim 67, further comprising: communicating, by the processor, the parameter to the transabdominal-fetal- oximetry sensor, wherein the transabdominal-fetal-oximetry sensor is configured to adjust its operation responsively to the received parameter.

69. The method of claim 67 or 68, further comprising: receiving, by the processor, one or more signals from the transabdominal-fetal- oximetry sensor, the one or more signals corresponding to optical signals emanating from an abdomen of a mammal who is pregnant with the fetus and detected by the transabdominal-fetal-oximetry sensor; determining, by the processor, transabdominally-obtained-fetal-oximetry information using the one or more signals received from the transabdominal-fetal- oximetry sensor; comparing, by the processor, the directly-measured-fetal-oximetry information and the transabdominally-obtained-fetal-oximetry information; and providing, by the processor, an indication of the transabdominally-obtained-fetal- oximetry information to a display device responsively to the comparison.

70. The method of claim 67 or 68, further comprising: receiving, by the processor, one or more signals from the transabdominal-fetal- oximetry sensor, the one or more signals corresponding to optical signals emanating from an abdomen of a mammal who is pregnant with the fetus and detected by the transabdominal-fetal-oximetry sensor;determ ining , by the processor, transabdominally-obtained-fetal-oximetry information using the one or more signals from the transabdominal-fetal-oximetry sensor; comparing, by the processor, the directly-measured-fetal-oximetry information and the transabdominally-obtained-fetal-oximetry information; and adjusting, by the processor, the parameter responsively to the comparison.

71. The method of any of the claims 67-70, further comprising: receiving, by the processor, secondary information, wherein determining the parameter for the operation of a transabdominal-fetal-oximetry sensor is further responsive to the received secondary information.

72. The method of claim 71, wherein the secondary information is at least one of a maternal heartrate, a fetal heartrate, a fetal depth, and maternal tissue optical property information.

73. The method of any of claims 67-72, wherein the fetal oximetry information is at least one of a fetal hemoglobin oxygen saturation level and a fetal tissue oxygen saturation level.

74. The method of any of claims 67-73, wherein the d i rect- measu rem ent-feta I - oximetry device includes a light source and a plurality of detectors and the parameter is a selection of a detector of the pair of detectors from which to use a signal to determine fetal oximetry information.

75. The method of any of claims 67-74, further comprising: receiving, by the processor, a maternal optical characteristic, wherein the determining of the parameter for the operation of a transabdominal-fetal-oximetry sensor is responsive to the maternal optical characteristic.

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