A midwifery system and method for dynamic correction of fetal head position and assessment of birth canal compatibility

Abstract

This invention relates to the field of midwifery technology, specifically to a midwifery system and method for dynamic correction of fetal head position and assessment of birth canal compatibility. The invention determines a scalp adhesion index based on the degree of time lag between the midwifery traction force and the relative displacement of the handle within a pre-defined analysis period before each moment in the traction period; it determines a force-pressure hysteresis coefficient based on the degree of non-coordinated change between the midwifery traction force and the change in negative pressure within the traction period; it corrects the relative displacement of the handle at each moment in the traction period based on the scalp adhesion index and the force-pressure hysteresis coefficient, determines the estimated skull descent, and selects the net bone propulsion value for the traction period; and it assesses the birth canal compatibility status during the traction period based on the force-pressure hysteresis coefficient and the net bone propulsion value. This invention combines the force-pressure hysteresis coefficient, representing the efficiency of midwifery operations, with the net bone propulsion value, representing the actual labor progress, to accurately distinguish the physical causes of labor stagnation and improve the accuracy of birth canal compatibility assessment.

Description

Technical Field

[0001] This invention relates to the field of midwifery technology, specifically to a midwifery system and method for dynamic correction of fetal head position and assessment of compatibility with the birth canal. Background Technology

[0002] During vacuum-assisted obstetric delivery, the fetal scalp edema layer exhibits significant viscoelasticity and rheological properties, resulting in substantial passive stretching deformation (i.e., "skin-bone separation") under traction, fundamentally different from the rigid fetal skull. When traction is applied by the delivery instruments, the relaxed scalp soft tissue preferentially undergoes passive extension or micro-slippage, while the fetal skull may not yet have undergone substantial descent.

[0003] A prior art patent document with publication number CN102789723A discloses a forceps delivery simulation trainer and its operating method. Specifically, it collects the traction and clamping forces acting on the fetal head, and the lower-level computer system generates head-lifting movement control commands based on the force data. However, when the fetus has scalp edema, most of the traction force generated by the delivery instruments is actually consumed by the viscoelastic stretching of soft tissues rather than pushing the skull down. It cannot distinguish between the ineffective stretching deformation of soft tissues and the actual descent displacement of the fetal skull, generating false readings of labor progress. This may lead to blindly increasing the traction force even when bony impaction has already occurred. This not only renders the delivery operation ineffective but also significantly increases the risk of serious mechanical injuries such as fetal scalp avulsion and intracranial hemorrhage. Summary of the Invention

[0004] To address the technical problem of inaccurate assessment of birth canal compatibility due to the inability to distinguish between viscoelastic deformation of the scalp soft tissue and actual displacement of the fetal skull caused by skin-bone separation, this invention aims to provide a midwifery system and method for dynamic correction of fetal head position and assessment of birth canal compatibility. The specific technical solution adopted is as follows:

[0005] In a first aspect, one embodiment of the present invention provides a method for assisted delivery that dynamically corrects fetal head position and assesses compatibility with the birth canal, the method comprising:

[0006] Real-time acquisition of midwifery data at every moment during the midwifery process, including midwifery traction force, handle displacement, and negative pressure value inside the cup;

[0007] Based on the variation characteristics of the traction force during labor, the traction time periods during labor are determined, and the labor data at each moment within the traction time period are benchmarked to obtain the relative displacement of the handle and the change in negative pressure at the corresponding moment.

[0008] Based on the time lag between the traction force and the relative displacement of the handle in the pre-defined analysis period before each moment in the traction period, the scalp adhesion index at the corresponding moment is determined; based on the degree of non-coordinated change between the traction force and the change in negative pressure in the traction period, the force hysteresis coefficient is determined.

[0009] Based on the scalp adhesion index and the force hysteresis coefficient, the relative displacement of the handle at each moment during the traction period is corrected, the estimated skull descent at each moment during the traction period is determined, and the net bone advancement value during the traction period is selected.

[0010] The compatibility of the birth canal during the traction period is evaluated based on the pressure hysteresis coefficient and the net bone propulsion value.

[0011] Furthermore, obtaining the relative displacement of the handle and the change in negative pressure at the corresponding moment includes:

[0012] The handle displacement at the beginning of the traction period is recorded as the reference displacement, and the difference between the handle displacement at each moment during the traction period and the reference displacement is taken as the relative handle displacement at the corresponding moment.

[0013] The average of the negative pressure values ​​inside the cup at all times within a preset reference time period before the start of the traction period is calculated to obtain the reference air pressure value; the difference between the negative pressure value inside the cup at each time during the traction period and the reference air pressure value is taken as the negative pressure change at the corresponding time.

[0014] Further, determining the scalp adhesion index at the corresponding time point includes:

[0015] Select any moment within the traction period as the example moment. Standardize the traction force and relative displacement of the handle at each moment within the preset analysis period before the example moment to obtain the standard traction force and standard relative displacement.

[0016] Arrange the standard traction force and standard relative displacement of all times within the preset analysis period before the example time in chronological order to obtain the standard traction force sequence and standard relative displacement sequence of the example time.

[0017] Calculate the cross-correlation function values ​​of the standard traction force sequence and the standard relative displacement sequence at the example time under different preset time delays, and select the time delay corresponding to the largest cross-correlation function value as the viscous response delay;

[0018] The viscous response delay is normalized to obtain the scalp viscous index at the example time.

[0019] Further, determining the force-pressure hysteresis coefficient includes:

[0020] A two-dimensional space is constructed with the traction force of labor as the horizontal axis and the change in negative pressure as the vertical axis. The traction force and the change in negative pressure at all times during the traction period are mapped onto the two-dimensional space to obtain the coordinate point at each time.

[0021] Connect all coordinate points in the two-dimensional space in chronological order, and add line segments connecting the coordinate points at the start and end times of the traction period to form a closed spatial trajectory.

[0022] Obtain the area of ​​the region enclosed by the spatial trajectory, calculate the product of the maximum value of the assisted delivery traction force at all times during the traction period and the preset reference pressure value, and use the ratio of the area to the product as the force hysteresis coefficient of the traction period.

[0023] Furthermore, determining the estimated skull descent at each moment during the traction period includes:

[0024] Based on the scalp adhesion index and the force hysteresis coefficient at each moment during the traction period, the bony coupling weight at the corresponding moment is obtained.

[0025] The difference between the relative displacement of the handle at each moment during the traction period and the adjacent previous moment is taken as the handle displacement increment at each moment.

[0026] The product of the square of the bony coupling weight at each moment during the traction period and the corresponding increment of the handle displacement is calculated as the bony displacement increment at the corresponding moment.

[0027] The sum of the bony displacement increments at each time point during the traction period to the start time is used as the estimated skull drop at each time point during the traction period.

[0028] Furthermore, the assessment of the birth canal compatibility during the traction period based on the force hysteresis coefficient and the net bone propulsion value includes:

[0029] If the force hysteresis coefficient during the traction period is greater than or equal to the preset hysteresis warning threshold, then the scalp overstretching is the condition of the birth canal adaptability during the traction period.

[0030] If the force hysteresis coefficient during the traction period is less than the preset hysteresis warning threshold and the net bone advancement value is less than the preset minimum effective advancement threshold, then the birth canal adaptation status during the traction period is that the skull descent is obstructed.

[0031] If the force hysteresis coefficient during the traction period is less than the preset hysteresis warning threshold and the net bone propulsion value is greater than or equal to the preset minimum effective propulsion threshold, then the birth canal adaptability status during the traction period is effective passage through the birth canal.

[0032] Furthermore, the net bone propulsion value is the maximum value among the estimated skull descent amounts at all times during the traction period.

[0033] Furthermore, both the pressure hysteresis coefficient and the scalp adhesion index are negatively correlated with the bony coupling weight.

[0034] Furthermore, the assisted delivery traction force at the beginning N times during the traction period is greater than the preset traction trigger threshold, and only the assisted delivery traction force at the end time is less than the preset traction end threshold; where N is a preset number.

[0035] Secondly, another embodiment of the present invention provides a midwifery system for dynamic correction of fetal head position and assessment of birth canal compatibility, the system comprising:

[0036] The data acquisition module is used to acquire midwifery data at each moment during the midwifery process in real time. The midwifery data includes midwifery traction force, handle displacement and cup negative pressure value.

[0037] The benchmarking module is used to determine each traction period during the assisted delivery process based on the variation characteristics of the assisted delivery traction force, and to perform benchmarking processing on the assisted delivery data at each moment within the traction period to obtain the relative displacement of the handle and the change in negative pressure at the corresponding moment.

[0038] The feature extraction module is used to determine the scalp adhesion index at each moment based on the time lag between the traction force and the relative displacement of the handle in the pre-defined analysis period before each moment in the traction period; and to determine the force hysteresis coefficient based on the degree of non-coordinated change between the traction force and the change in negative pressure in the traction period.

[0039] The displacement decoupling module is used to correct the relative displacement of the handle at each moment during the traction period based on the scalp adhesion index and the force hysteresis coefficient, determine the estimated skull descent at each moment during the traction period, and select the net bone advancement value during the traction period.

[0040] The birth canal compatibility assessment module is used to assess the birth canal compatibility status during the traction period based on the force hysteresis coefficient and the net bone propulsion value.

[0041] The present invention has the following beneficial effects:

[0042] In this embodiment of the invention, the scheme takes into account the significant viscoelastic characteristics of the edematous scalp soft tissue layer and the rigidity of the fetal skull, which causes scalp displacement to lag behind the traction force and cause disturbances in the air pressure inside the cup, while the skull movement is highly synchronized with the traction force and the gas inside the cup remains essentially unchanged. By analyzing the degree of time delay between the obstetric traction force and the relative displacement of the handle, the viscous deformation of the soft tissue during the current traction operation is reflected, and a scalp viscosity index is obtained. By analyzing the degree of non-coordinated change between the obstetric traction force and the change in negative pressure, the response difference caused by the inelastic deformation of the soft tissue during the current traction operation is quantified, and a force-pressure hysteresis coefficient is obtained, which can identify microscopic slippage or soft tissue rheological phenomena that are difficult to detect by time-domain waveforms alone. By combining the above two indices, the synchronicity of the instrument and bone movement, i.e., the reliability of the displacement, can be analyzed, and the handle displacement can be corrected. This allows for the precise removal of non-bone components originating from scalp stretching and slippage from the aliased displacement signal, thereby restoring the estimated skull descent amount that is only related to the actual movement of the skull. The pressure hysteresis coefficient represents the operational efficiency of the obstetric procedure, while the net bone propulsion value represents the outcome of the procedure. Combining both can accurately distinguish the physical cause of labor stagnation, significantly improve the accuracy of the assessment of the compatibility of the birth canal, and enhance the safety and effectiveness of the obstetric procedure. Attached Figure Description

[0043] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 A flowchart illustrating the steps of an assisted delivery method for dynamic correction of fetal head position and assessment of compatibility with the birth canal, provided in an embodiment of the present invention.

[0045] Figure 2 This is a system structure diagram of a midwifery system for dynamic correction of fetal head position and assessment of birth canal compatibility, provided in an embodiment of the present invention.

[0046] Figure 3 This is a schematic diagram of a computer device for a midwifery device that dynamically corrects fetal head position and assesses compatibility with the birth canal, provided as an embodiment of the present invention. Detailed Implementation

[0047] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a midwifery system and method for dynamic correction of fetal head position and assessment of birth canal compatibility according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0049] The following description, in conjunction with the accompanying drawings, details a specific scheme for a midwifery system and method for dynamic correction of fetal head position and assessment of birth canal compatibility provided by the present invention. Example 1:

[0050] Example 1:

[0051] This invention proposes a method for assisted delivery that dynamically corrects fetal head position and assesses compatibility with the birth canal. Please refer to [link to relevant documentation]. Figure 1 The diagram illustrates a flowchart of a method for dynamic correction of fetal head position and assessment of birth canal compatibility according to an embodiment of the present invention. The method includes:

[0052] Step S1: Acquire labor data at each moment during the labor process in real time. The labor data includes labor traction force, handle displacement and cup negative pressure value.

[0053] To acquire obstetric data reflecting the mechanical state of the obstetric system, the system is equipped with a microprocessor and a sensor array connected in communication with it. The sensor array includes a tension sensor located at the handle of the obstetric instrument, a displacement measurement unit integrated into the end of the handle, and a high-sensitivity pressure sensor located within the vacuum cup. This sensor captures transient pressure disturbances before pressure stabilization control. The tension sensor measures the axial tension applied by the operator, and the data collected by this sensor is recorded as the obstetric traction force. The displacement measurement unit measures the absolute distance the handle moves along the axis of the birth canal, including the amount of scalp stretching and the actual descent of the skull; the data collected by this measurement unit is recorded as the handle displacement. The pressure sensor monitors the absolute pressure inside the vacuum cup, reflecting the adsorption state and pressure fluctuations caused by volume changes; the data collected by this sensor is recorded as the negative pressure value inside the cup.

[0054] Data from the tension sensor and the pressure sensor of the displacement measurement unit are collected synchronously at a preset sampling frequency to obtain the assisted delivery traction force, handle displacement, and negative pressure value inside the cup at each moment during the assisted delivery process. These are recorded as assisted delivery data, with the units being Newtons, millimeters, and kilopascals, respectively. The sampling frequency is set to 500 Hz, which can be adjusted by the implementer according to specific circumstances. The assisted delivery process refers to the time period from the start of monitoring by the assisted delivery system to the current moment.

[0055] Step S2: Based on the variation characteristics of the traction force during labor, determine the traction period during the labor process, and perform benchmarking processing on the labor data at each moment within the traction period to obtain the relative displacement of the handle and the change in negative pressure at the corresponding moment.

[0056] By precisely extracting independent traction periods containing the complete mechanical action process from the continuous monitoring stream, noise interference during the stationary period is eliminated. Due to initial positional deviations in sensor data and the inherent baseline pressure of the vacuum pump when maintaining negative pressure, directly using the raw readings cannot accurately reflect the relative changes caused by operation. Benchmarking eliminates the cumulative errors between different traction operations and equipment reference drift, ensuring that subsequent dynamic analysis is performed in a unified relative coordinate system.

[0057] Step S3: Based on the time lag between the traction force and the relative displacement of the handle in the pre-defined analysis period before each moment in the traction period, determine the scalp adhesion index at the corresponding moment; based on the degree of non-coordinated change between the traction force and the change in negative pressure in the traction period, determine the force-pressure hysteresis coefficient.

[0058] The edematous layer of scalp soft tissue exhibits significant viscoelastic characteristics, undergoing rheological stretching during traction. This causes the strain response to lag behind stress loading, resulting in a phase lag in handle displacement relative to the traction force. The fetal skull, as a highly rigid entity, moves according to rigid body dynamics, directly converting the traction force into handle displacement. Consequently, the fetal skull displacement and the changes in traction force are highly time-synchronized. Therefore, by analyzing the time delay between the traction force and the relative handle displacement, reflecting the viscous deformation of the soft tissue during the current traction operation, a scalp viscosity index can be obtained, providing a high-temporal-resolution time-domain criterion for distinguishing between skull traction and scalp traction.

[0059] The fetal scalp edema layer, being a viscoelastic soft tissue, undergoes rheological stretching during traction, which encroaches on the internal volume of the vacuum cup. This leads to deformation-related pressure fluctuations within the cup; that is, soft tissue deformation causes slight changes in the vacuum cup volume, resulting in pressure fluctuations. Furthermore, soft tissue exhibits the physical characteristic of non-coincident paths during stretching and retraction. In contrast, the fetal skull, as a near-rigid body, undergoes overall translational motion, without causing changes in the vacuum cup volume or significant pressure hysteresis. Therefore, by analyzing the degree of non-coordinated change in assisted delivery traction force and negative pressure, and quantifying the response differences caused by inelastic soft tissue deformation during current traction operations, a pressure hysteresis coefficient can be obtained. This allows for the identification of microscopic slippage or soft tissue rheological phenomena that are difficult to detect using only time-domain waveforms, compensating for the blind spots of single-time-domain characteristics under complex conditions. It serves as a core basis for evaluating operational efficiency and safety. In one implementation of this invention, the duration of the preset analysis period should be much shorter than the duration of the traction period. The preset analysis period is set as 2000 milliseconds before each moment in the traction period. The implementer can set the duration of the preset analysis period according to the specific circumstances.

[0060] Step S4: Based on the scalp adhesion index and the force hysteresis coefficient, the relative displacement of the handle at each moment during the traction period is corrected, the estimated skull descent at each moment during the traction period is determined, and the net bone advancement value during the traction period is selected.

[0061] Scalp viscosity index characterizes the degree of temporal response lag caused by soft tissue viscosity during instantaneous movement, while the pressure hysteresis coefficient quantifies the degree of inelastic response caused by viscoelastic deformation of scalp soft tissue and microscopic slippage of the instrument throughout the entire cycle. By fusing the instantaneous temporal delay characteristics, i.e., the scalp viscosity index, with the global hysteresis morphology characteristics, i.e., the pressure hysteresis coefficient, the synchronization between instrument and skeletal movement, i.e., displacement reliability, can be analyzed. Further correction of handle displacement allows for the precise removal of non-bone components originating from scalp stretching and slippage from the aliased displacement signals, thus restoring the estimated skull descent amount only related to the actual skull movement. The estimated skull descent amount reflects the real-time positional change of the fetal head within the birth canal, including the propulsion process during traction and the elastic recoil process after unloading. By selecting the net bone propulsion value from the estimated skull descent amounts at all moments within the traction period, the effects of soft tissue rebound and instrument repositioning after the operation can be eliminated. This fundamentally solves the problem of inaccurate displacement caused by skin-bone separation in existing methods, ensuring the physical authenticity of labor data.

[0062] Step S5: Based on the force hysteresis coefficient and the net bone propulsion value, assess the compatibility of the birth canal during the traction period.

[0063] The force hysteresis coefficient represents the operational efficiency of the obstetric procedure, reflecting whether the applied traction force is effectively applied to the skeleton or consumed by soft tissue deformation; the net bone propulsion value represents the outcome of the procedure, reflecting whether the fetal head has achieved substantial descent under the current energy input. By jointly analyzing these two indicators, it is possible to accurately distinguish the physical nature of labor stagnation, whether it is due to excessive scalp stretching caused by improper operation, obstructed skull descent due to excessive objective resistance (such as cephalopelvic disproportion), or efficient passage through the birth canal. This multidimensional assessment solves the problem that a single indicator cannot identify occult bony blockage or distinguish the cause of blockage, thereby accurately assessing the physical fit between the fetal head and the birth canal.

[0064] In this embodiment of the invention, the assisted delivery traction force at the beginning N times during the traction period is greater than a preset traction trigger threshold, and only the assisted delivery traction force at the end time is less than a preset traction end threshold; where N is a preset number.

[0065] It should be noted that, during the traction initiation phase, to avoid false triggers due to accidental contact or signal jitter, a valid traction action is only considered to have started when the traction force at N consecutive sampling times is greater than a preset traction trigger threshold. The first of the N sampling times is marked as the start time of the traction period. The traction action is considered terminated when the traction force falls below the preset traction end threshold for the first time after the start time. This mechanism allows for the accurate extraction of independent traction periods containing the complete mechanical action process from the continuous monitoring data stream.

[0066] The preset traction trigger threshold should be higher than the sensor's noise floor level and random fluctuations in a static state, but significantly lower than the minimum force required for effective assisted delivery. Typically, the effective traction force for vacuum assisted delivery is above 50 Newtons, and the preset traction trigger threshold can be set between 5 and 10 Newtons; in this embodiment, it is set to 5 Newtons. The preset traction end threshold should be close to zero but slightly higher than zero, used to determine if the operator has completely released the force. It is usually set lower than the preset traction trigger threshold to create hysteresis and prevent premature interruption of the event due to hand tremors at the end of the operation; in this embodiment, the preset traction end threshold is set to 2 Newtons.

[0067] In one implementation of this invention, the preset quantity is set to 10, which can be set by the implementer according to specific circumstances.

[0068] Preferably, in some possible implementations of the embodiments of the present invention, the method for obtaining the relative displacement of the handle and the change in negative pressure includes: recording the handle displacement at the beginning of the traction period as the reference displacement; taking the difference between the handle displacement at each moment during the traction period and the reference displacement as the relative displacement of the handle at the corresponding moment; averaging the negative pressure values ​​inside the cup at all moments during the preset reference period before the beginning of the traction period to obtain the reference air pressure value; and taking the difference between the negative pressure value inside the cup at each moment during the traction period and the reference air pressure value as the change in negative pressure at the corresponding moment.

[0069] It should be noted that the absolute position of the delivery instruments after entering the birth canal and attaching to the fetal head exhibits significant randomness between different traction operations. To accurately quantify the substantial displacement increment resulting from a single delivery operation, this initial positional difference must be eliminated. By recording the handle displacement at the start of the traction period as the baseline displacement, the subsequent relative handle displacement can directly characterize the axial movement distance of the instruments caused by this traction action. Considering that the vacuum pump has an inherent baseline pressure while maintaining negative pressure, and that this baseline may drift slightly over time, the reference pressure value reflects the baseline pressure of the vacuum pump before this traction. By eliminating the steady-state DC component through the difference between the negative pressure value inside the cup and the reference pressure value, the change in negative pressure retains only the dynamic AC component caused by volumetric deformation.

[0070] In one implementation of this invention, 200 milliseconds before the start of the traction period is used as the preset reference period. The implementer can set the duration of the preset reference period according to the specific circumstances.

[0071] Preferably, in some possible implementations of the embodiments of the present invention, the method for obtaining the scalp adhesion index includes: selecting any moment within the traction period as the example moment; standardizing the traction force and relative displacement of the handle at each moment within a preset analysis period before the example moment to obtain the standard traction force and standard relative displacement in sequence; arranging the standard traction force and standard relative displacement at all moments within the preset analysis period before the example moment in chronological order to obtain the standard traction force sequence and standard relative displacement sequence at the example moment in sequence; calculating the cross-correlation function values ​​of the standard traction force sequence and standard relative displacement sequence at the example moment under preset different time delays, and selecting the time delay corresponding to the largest cross-correlation function value as the viscous response delay; and normalizing the viscous response delay to obtain the scalp adhesion index at the example moment.

[0072] It should be noted that, in order to eliminate the influence of signal amplitude differences, this embodiment uses the minimax normalization method to standardize the assisted delivery traction force and the relative displacement of the handle, so that their values ​​are between 0 and 1. The cross-correlation function value under each time delay reflects the similarity between the assisted delivery traction force waveform and the relative displacement waveform of the handle when that time delay exists; the larger the cross-correlation function value, the greater the likelihood that the time delay is the actual physical transmission delay between the assisted delivery traction force and the relative displacement of the handle. The viscous response delay characterizes the actual time difference between the handle displacement response and the change in traction force.

[0073] A preset upper limit for the soft tissue relaxation time constant is introduced as a normalization benchmark. This upper limit is determined based on the average viscoelastic response characteristics of edematous scalp tissue in full-term fetuses after stress and clinical experience data. In this embodiment, it is set to 150 mm, representing the maximum reasonable time scale for the passive stretching response of soft tissue. The normalization method in this embodiment is as follows: calculate the ratio of the absolute value of the viscous response delay at the example time to the preset upper limit for soft tissue relaxation time, and select the minimum value between this ratio and the constant as the scalp viscous delay at the example time. The larger this value, the higher the proportion of spurious displacement component caused by passive stretching of scalp soft tissue in the current handle displacement, and the lower the proportion of rigid displacement component caused by actual skull movement.

[0074] In one implementation of this invention, the method for obtaining the preset time delay includes: starting from the lower limit of a preset physiological delay range, traversing the physiological delay range according to a preset step size to obtain multiple time delays. The preset step size is set to one sampling period, i.e., 2 milliseconds; the preset physiological delay range is set based on the biomechanical relaxation characteristics of fetal scalp tissue, and in this embodiment, it is set to 0 to 150 milliseconds, which can effectively cover the response hysteresis range caused by soft tissue viscoelasticity, while filtering out pseudo-long delays caused by noise or irrelevant actions.

[0075] It is important to note that the scalp adhesion index is obtained using the same method for all moments within the traction period and the example moment. For the initial stage of the traction period (i.e., moments when the current moment is less than the preset analysis period length), data from the preset baseline period prior to the start of the traction period are used as the data for the preset analysis period prior to that moment to complete the data. When the variance of the midwifery traction force at all moments within the preset analysis period prior to the example moment is zero, it means that the traction force is constant and the cross-correlation is meaningless; in this case, the scalp adhesion index from the previous moment is used for the example moment.

[0076] Preferably, in some possible implementations of the embodiments of the present invention, the method for obtaining the force-pressure hysteresis coefficient includes: constructing a two-dimensional space with the assisted delivery traction force as the horizontal axis and the negative pressure change as the vertical axis; mapping the assisted delivery traction force and negative pressure change at all times during the traction period onto the two-dimensional space to obtain the coordinate point at each time; connecting all coordinate points in the two-dimensional space in chronological order, and adding a line segment connecting the coordinate points at the start and end times of the traction period to form a closed spatial trajectory; obtaining the area of ​​the region enclosed by the spatial trajectory; calculating the product of the maximum value of the assisted delivery traction force at all times during the traction period and a preset reference pressure value; and using the ratio of the area to the product as the force-pressure hysteresis coefficient of the traction period.

[0077] It should be noted that, because the stretching and retraction paths of soft tissue usually do not coincide, and due to the viscoelastic hysteresis effect of the scalp soft tissue and the response delay of the vacuum pump, the state at the end of the traction action (i.e., the change in traction force and negative pressure) cannot return to the state at the beginning. Therefore, a line segment needs to be added between the endpoint (the coordinate point at the end) and the starting point (the coordinate point at the beginning) of the trajectory to construct a closed force-pressure hysteresis loop, i.e., a spatial trajectory. The area enclosed by the spatial trajectory represents the degree of consumption by soft tissue deformation during this traction action. The larger this value, the more the soft tissue deformation consumes the traction action, i.e., the greater the degree of ineffective work. The area enclosed by the spatial trajectory is calculated using the Discrete Green's formula.

[0078] To eliminate the influence of different operating forces and baseline negative pressure settings on the evaluation indicators, the area of ​​the spatial trajectory is divided by the product of the maximum assisted delivery traction force and the preset reference pressure value during the traction period, and then normalized to obtain the force-pressure hysteresis coefficient. The area enclosed by the spatial trajectory is expressed in Newtons per pascal (N·Pa); the preset reference pressure value represents the rated working negative pressure of the vacuum cup, which can be set to 60 kPa. A larger force-pressure hysteresis coefficient indicates a higher proportion of the traction action being converted into ineffective soft tissue deformation work.

[0079] Preferably, in some possible implementations of the embodiments of the present invention, the method for obtaining the estimated skull descent includes: using a force-pressure hysteresis coefficient to weight the scalp adhesion index at each moment during the traction period to obtain the bony coupling weight at the corresponding moment; taking the difference between the relative displacement of the handle at each moment during the traction period and the adjacent previous moment as the handle displacement increment at each moment; calculating the product of the square of the bony coupling weight at each moment during the traction period and the handle displacement increment at the corresponding moment as the bony displacement increment at the corresponding moment; and summing the bony displacement increments at all moments from each moment during the traction period to the starting moment as the estimated skull descent at each moment during the traction period.

[0080] In one specific implementation of this invention, the skeletal coupling weight is expressed by the formula:

[0081] ;

[0082] In the formula, The weight of the bony coupling at time k within the traction period; The scalp adhesion index at time k within the traction period; The force hysteresis coefficient during the traction period; is the preset hysteresis sensitivity coefficient; exp is an exponential function with the natural constant e as the base. It should be noted that the scalp viscosity index assesses the loss of input mechanical work during traction from the perspective of overall energy conversion efficiency. A larger value indicates lower efficiency of the energy transmission path, a smaller proportion of net work used to push the skull, and a lower probability that the handle displacement at time k originates from actual bony movement. The force-pressure hysteresis coefficient assesses the immediacy of the handle displacement response following changes in traction force from the perspective of instantaneous synchronization between displacement and force. A larger value indicates a higher probability that the handle displacement is due to scalp soft tissue rheology rather than instantaneous rigid displacement of the skull, and a lower probability that the handle displacement at time k originates from actual bony movement. Therefore, both the force-pressure hysteresis coefficient and the scalp viscosity index are negatively correlated with the bony coupling weight. Since single time-domain waveform analysis may fail in complex rheological conditions, the force-pressure hysteresis coefficient must be introduced as a safety constraint. The monotonically decaying characteristic of the exponential function means that as the force-pressure hysteresis coefficient increases, It rapidly approaches zero, thus imposing a severe penalty on the skeletal coupling weight.

[0083] The handle displacement increment represents the actual distance the handle is pulled during the current sampling period. Squaring the bony coupling weights serves as nonlinear suppression, i.e., a more severe penalty is imposed on low-confidence handle displacement increments, ensuring that the scaled handle displacement increment represents a high-purity bony component, thus obtaining the bony displacement increment. By integrating all instantaneous bony displacement increments from time k to the start time, the true cumulative descent distance of the fetal skull at time k is reconstructed, yielding the estimated skull descent. A larger value indicates a lower fetal head position and more significant labor progress.

[0084] In one implementation of this invention, the hysteresis sensitivity coefficient is a calibration parameter used to adjust the decay rate of the bony coupling weight as a function of the compressive hysteresis coefficient. Its value is set based on the following principle: when the compressive hysteresis coefficient reaches a preset warning threshold (e.g., 0.4), the calculated bony coupling weight is adjusted to a preset low confidence level (e.g., 0.1) through this coefficient adjustment, thereby forcibly suppressing displacement readings when significant soft tissue rheology is detected. In this embodiment, the hysteresis sensitivity coefficient is set to 5.

[0085] In this embodiment of the invention, the net bone advance value is the maximum value among the estimated skull descents at all times during the traction period. It should be noted that the estimated skull descent reflects the real-time positional change of the fetal head within the birth canal, including the advance process during traction and the elastic recoil process after force release. By selecting the maximum value of the estimated skull descent at all times during the traction period, the irreversible physical displacement limit achieved by overcoming birth canal resistance in a single assisted delivery operation can be quantified. This value eliminates the influence of soft tissue rebound and instrument repositioning after the operation, representing the true and effective contribution of this operation to the progress of labor, and providing a definitive quantitative basis for clinical assessment of whether the fetal head has truly descended.

[0086] Preferably, in some possible implementations of the embodiments of the present invention, the method for evaluating the compatibility of the birth canal includes: if the force hysteresis coefficient during the traction period is greater than or equal to a preset hysteresis warning threshold, then the compatibility of the birth canal during the traction period is scalp overstretching; if the force hysteresis coefficient during the traction period is less than the preset hysteresis warning threshold and the net bone propulsion value is less than a preset minimum effective propulsion threshold, then the compatibility of the birth canal during the traction period is obstructed skull descent; if the force hysteresis coefficient during the traction period is less than the preset hysteresis warning threshold and the net bone propulsion value is greater than or equal to a preset minimum effective propulsion threshold, then the compatibility of the birth canal during the traction period is effective passage of the birth canal.

[0087] It should be noted that if the pressure hysteresis coefficient is greater than or equal to the preset hysteresis warning threshold, and the traction operation stroke during the traction period is occupied by the plastic deformation of the scalp edema layer or the slippage of the vacuum cup, it means that the vacuum cup adsorption position is located in the scalp relaxation area or that there is an angle between the traction direction and the birth canal axis. This indicates a risk of ineffective traction or connection failure, and the failure to form an effective bony traction fulcrum. In this case, the birth canal adaptation state is scalp overstretching. An axis correction command needs to be output to prompt the operator to check the airtightness of the vacuum cup and adjust the traction axis direction to coincide with the pelvic outlet axis to reduce ineffective soft tissue shear deformation.

[0088] If the force hysteresis coefficient is less than the preset hysteresis warning threshold and the net bone propulsion value is less than the preset minimum effective propulsion threshold, the mechanical transmission efficiency of the traction operation during the traction period is high. This means that the vacuum cup and the fetal head are tightly coupled, with no significant slippage or excessive deformation, and the energy transmission efficiency is high. However, the generated efficient force transmission has not been converted into substantial bony displacement, indicating that the fetal head has encountered insurmountable rigid resistance, and there is a risk of cephalopelvic disproportion or bony structure impaction. In this case, the birth canal compatibility status is obstructed skull descent. A stop-operation command should be issued to indicate to the operator that there is a risk of bony impaction. It is recommended to immediately stop the current obstetric attempt to prevent fetal skull fracture or intracranial hemorrhage due to blindly increasing the traction force, and to reassess the indications for cesarean section.

[0089] If the force hysteresis coefficient is less than the preset hysteresis warning threshold and the net bone propulsion value is greater than or equal to the preset minimum effective propulsion threshold, the mechanical transmission efficiency of the traction operation during the traction period is high, and the resistance of the birth canal is successfully overcome. The mechanical work is converted into the physical descent of the fetal head along the birth canal axis, indicating good compatibility between the fetal head and the birth canal. In this case, the compatibility status is considered effective passage through the birth canal. A labor progress record instruction needs to be output, adding the net bone propulsion value of the current traction period to the total labor progress record, and prompting the operator to maintain the current force angle and rhythm.

[0090] In one implementation of this invention, during clinical digital rectal examination, obstetricians typically perceive a minimum fetal head descent of approximately 5 to 10 millimeters. Displacements below this value are often considered minor movements within the range of tissue elastic recoil and cannot be considered substantial progress in labor. A preset minimum effective advancement threshold of 5 millimeters is set, and a preset delay warning threshold of 0.4 millimeters is set. These thresholds can be dynamically adjusted based on clinical statistical data and specific obstetric safety guidelines.

[0091] This invention is now complete.

[0092] Example 2:

[0093] This invention proposes a midwifery system for dynamic correction of fetal head position and assessment of birth canal compatibility. Please refer to [link to relevant documentation]. Figure 2 The diagram illustrates a system structure of a midwifery system for dynamic correction of fetal head position and assessment of birth canal compatibility, according to an embodiment of the present invention. The system includes:

[0094] The data acquisition module 610 is used to acquire data on labor at each moment during the labor process in real time. The labor data includes labor traction force, handle displacement and cup negative pressure value.

[0095] The benchmarking module 620 is used to determine each traction period during the assisted delivery process based on the variation characteristics of the traction force during assisted delivery, and to perform benchmarking processing on the assisted delivery data at each moment within the traction period to obtain the relative displacement of the handle and the change in negative pressure at the corresponding moment.

[0096] The feature extraction module 630 is used to determine the scalp adhesion index at each moment based on the time lag between the traction force and the relative displacement of the handle in the pre-preset analysis period before each moment in the traction period; and to determine the force hysteresis coefficient based on the degree of non-coordinated change between the traction force and the change in negative pressure in the traction period.

[0097] The displacement decoupling module 640 is used to correct the relative displacement of the handle at each moment during the traction period based on the scalp adhesion index and the force pressure hysteresis coefficient, determine the estimated skull descent at each moment during the traction period, and select the net bone advancement value during the traction period.

[0098] The birth canal compatibility assessment module 650 is used to assess the birth canal compatibility status during the traction period based on the force hysteresis coefficient and the net bone propulsion value.

[0099] It should be noted that the devices provided in the above embodiments are only illustrative examples of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the computer device can be divided into different functional modules to complete all or part of the functions described above. Furthermore, the obstetric system for dynamic correction of fetal head position and assessment of birth canal compatibility provided in the above embodiments and the obstetric method for dynamic correction of fetal head position and assessment of birth canal compatibility provided in the above embodiments belong to the same concept. The specific implementation process is detailed in the method embodiments and will not be repeated here.

[0100] Example 3:

[0101] Figure 3 This is a schematic diagram of a computer device for a midwifery apparatus that dynamically corrects fetal head position and assesses compatibility with the birth canal, according to an embodiment of the present invention. For example,... Figure 3 As shown, the computer device includes: a memory 701, a processor 702, and a computer program 703 stored in the memory 701 and running on the processor 702, wherein when the processor 702 executes the computer program 703, the computer device can perform any of the aforementioned methods for assisting childbirth by dynamically correcting the fetal head position and assessing the compatibility of the birth canal.

[0102] Furthermore, embodiments of this application also protect an apparatus that may include a memory and a processor, wherein the memory stores executable program code, and the processor is used to call and execute the executable program code to perform a method for assisting childbirth by dynamically correcting fetal head position and assessing compatibility with the birth canal provided in embodiments of this application.

[0103] This embodiment can divide the device into functional modules based on the above method example. For example, each module can correspond to a separate function, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0104] It should be understood that the device provided in this embodiment is used to perform the above-described method for dynamic correction of fetal head position and assessment of birth canal compatibility, and therefore can achieve the same effect as the above-described method.

[0105] When using integrated units, the device may include a processing module and a storage module. When applied to a workpiece, the processing module can be used to control and manage the workpiece's operations. The storage module can be used to support the execution of program code by the workpiece.

[0106] The processing module may be a processor or a controller, which can implement or execute various exemplary logic blocks, modules, and circuits contained in conjunction with the disclosure of this application. The processor may also be a combination of functions that implement computing capabilities, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and microprocessors, etc., and the storage module may be a memory.

[0107] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0108] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0109] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for assisted delivery based on dynamic correction of fetal head position and assessment of compatibility with the birth canal, characterized in that, The method includes: Real-time acquisition of midwifery data at every moment during the midwifery process, including midwifery traction force, handle displacement, and negative pressure value inside the cup; Based on the variation characteristics of the traction force during labor, the traction time periods during labor are determined, and the labor data at each moment within the traction time period are benchmarked to obtain the relative displacement of the handle and the change in negative pressure at the corresponding moment. Based on the time lag between the traction force and the relative displacement of the handle in the pre-defined analysis period before each moment in the traction period, the scalp adhesion index at the corresponding moment is determined; based on the degree of non-coordinated change between the traction force and the change in negative pressure in the traction period, the force hysteresis coefficient is determined. Based on the scalp adhesion index and the force hysteresis coefficient, the relative displacement of the handle at each moment during the traction period is corrected, the estimated skull descent at each moment during the traction period is determined, and the net bone advancement value during the traction period is selected. Based on the force hysteresis coefficient and the net bone propulsion value, the compatibility status of the birth canal during the traction period is evaluated. The determination of the scalp adhesion index at the corresponding time point includes: Select any moment within the traction period as the example moment. Standardize the traction force and relative displacement of the handle at each moment within the preset analysis period before the example moment to obtain the standard traction force and standard relative displacement. Arrange the standard traction force and standard relative displacement of all times within the preset analysis period before the example time in chronological order to obtain the standard traction force sequence and standard relative displacement sequence of the example time. Calculate the cross-correlation function values ​​of the standard traction force sequence and the standard relative displacement sequence at the example time under different preset time delays, and select the time delay corresponding to the largest cross-correlation function value as the viscous response delay; The viscous response delay is normalized to obtain the scalp viscous index at the example time. The determination of the force-pressure hysteresis coefficient includes: A two-dimensional space is constructed with the traction force of labor as the horizontal axis and the change in negative pressure as the vertical axis. The traction force and the change in negative pressure at all times during the traction period are mapped onto the two-dimensional space to obtain the coordinate point at each time. Connect all coordinate points in the two-dimensional space in chronological order, and add line segments connecting the coordinate points at the start and end times of the traction period to form a closed spatial trajectory. Obtain the area of ​​the region enclosed by the spatial trajectory, calculate the product of the maximum value of the assisted delivery traction force at all times during the traction period and the preset reference pressure value, and use the ratio of the area to the product as the force pressure hysteresis coefficient during the traction period. The determination of the estimated skull descent at each moment during the traction period includes: Based on the scalp adhesion index and the force hysteresis coefficient at each moment during the traction period, the bony coupling weight at the corresponding moment is obtained. The difference between the relative displacement of the handle at each moment during the traction period and the adjacent previous moment is taken as the handle displacement increment at each moment. The product of the square of the bony coupling weight at each moment during the traction period and the corresponding increment of the handle displacement is calculated as the bony displacement increment at the corresponding moment. The sum of the bony displacement increments at each time point during the traction period to the start time is used as the estimated skull drop at each time point during the traction period. The assessment of the birth canal compatibility during the traction period based on the force hysteresis coefficient and the net bone propulsion value includes: If the force hysteresis coefficient during the traction period is greater than or equal to the preset hysteresis warning threshold, then the scalp overstretching is the condition of the birth canal adaptability during the traction period. If the force hysteresis coefficient during the traction period is less than the preset hysteresis warning threshold and the net bone advancement value is less than the preset minimum effective advancement threshold, then the birth canal adaptation status during the traction period is that the skull descent is obstructed. If the force hysteresis coefficient during the traction period is less than the preset hysteresis warning threshold and the net bone propulsion value is greater than or equal to the preset minimum effective propulsion threshold, then the birth canal adaptability status during the traction period is effective passage through the birth canal.

2. The method for assisted delivery based on dynamic correction of fetal head position and assessment of compatibility with the birth canal according to claim 1, characterized in that, The process of obtaining the relative displacement of the handle and the change in negative pressure at the corresponding moment includes: The handle displacement at the start of the traction period is recorded as the reference displacement, and the difference between the handle displacement at each moment during the traction period and the reference displacement is taken as the relative handle displacement at the corresponding moment. The average of the negative pressure values ​​inside the cup at all times within a preset reference time period before the start of the traction period is used to obtain the reference air pressure value. The difference between the negative pressure value inside the cup at each time during the traction period and the reference air pressure value is used as the negative pressure change at the corresponding time.

3. The method for assisted delivery based on dynamic correction of fetal head position and assessment of compatibility with the birth canal according to claim 1, characterized in that, The net bone advance value is the maximum value among the estimated skull descent amounts at all times during the traction period.

4. The method for assisted delivery based on dynamic correction of fetal head position and assessment of compatibility with the birth canal according to claim 1, characterized in that, The pressure hysteresis coefficient and the scalp adhesion index are both negatively correlated with the bony coupling weight.

5. The method for assisted delivery based on dynamic correction of fetal head position and assessment of compatibility with the birth canal according to claim 1, characterized in that, During the traction period, the assisted delivery traction force at the beginning N times is greater than the preset traction trigger threshold, and only at the end time is the assisted delivery traction force less than the preset traction end threshold; where N is a preset number.

6. A midwifery system for dynamic correction of fetal head position and assessment of compatibility with the birth canal, characterized in that, The system includes: The data acquisition module is used to acquire midwifery data at each moment during the midwifery process in real time. The midwifery data includes midwifery traction force, handle displacement and cup negative pressure value. The benchmarking module is used to determine each traction period during the assisted delivery process based on the variation characteristics of the assisted delivery traction force, and to perform benchmarking processing on the assisted delivery data at each moment within the traction period to obtain the relative displacement of the handle and the change in negative pressure at the corresponding moment. The feature extraction module is used to determine the scalp adhesion index at each moment based on the time lag between the traction force and the relative displacement of the handle in the pre-defined analysis period before each moment in the traction period; and to determine the force hysteresis coefficient based on the degree of non-coordinated change between the traction force and the change in negative pressure in the traction period. The displacement decoupling module is used to correct the relative displacement of the handle at each moment during the traction period based on the scalp adhesion index and the force hysteresis coefficient, determine the estimated skull descent at each moment during the traction period, and select the net bone advancement value during the traction period. The birth canal compatibility assessment module is used to assess the birth canal compatibility status during the traction period based on the force hysteresis coefficient and the net bone propulsion value. The determination of the scalp adhesion index at the corresponding time point includes: Select any moment within the traction period as the example moment. Standardize the traction force and relative displacement of the handle at each moment within the preset analysis period before the example moment to obtain the standard traction force and standard relative displacement. Arrange the standard traction force and standard relative displacement of all times within the preset analysis period before the example time in chronological order to obtain the standard traction force sequence and standard relative displacement sequence of the example time. Calculate the cross-correlation function values ​​of the standard traction force sequence and the standard relative displacement sequence at the example time under different preset time delays, and select the time delay corresponding to the largest cross-correlation function value as the viscous response delay; The viscous response delay is normalized to obtain the scalp viscous index at the example time. The determination of the force-pressure hysteresis coefficient includes: A two-dimensional space is constructed with the traction force of labor as the horizontal axis and the change in negative pressure as the vertical axis. The traction force and the change in negative pressure at all times during the traction period are mapped onto the two-dimensional space to obtain the coordinate point at each time. Connect all coordinate points in the two-dimensional space in chronological order, and add line segments connecting the coordinate points at the start and end times of the traction period to form a closed spatial trajectory. Obtain the area of ​​the region enclosed by the spatial trajectory, calculate the product of the maximum value of the assisted delivery traction force at all times during the traction period and the preset reference pressure value, and use the ratio of the area to the product as the force pressure hysteresis coefficient during the traction period. The determination of the estimated skull descent at each moment during the traction period includes: Based on the scalp adhesion index and the force hysteresis coefficient at each moment during the traction period, the bony coupling weight at the corresponding moment is obtained. The difference between the relative displacement of the handle at each moment during the traction period and the adjacent previous moment is taken as the handle displacement increment at each moment. The product of the square of the bony coupling weight at each moment during the traction period and the corresponding increment of the handle displacement is calculated as the bony displacement increment at the corresponding moment. The sum of the bony displacement increments at each time point during the traction period to the start time is used as the estimated skull drop at each time point during the traction period. The assessment of the birth canal compatibility during the traction period based on the force hysteresis coefficient and the net bone propulsion value includes: If the force hysteresis coefficient during the traction period is greater than or equal to the preset hysteresis warning threshold, then the scalp overstretching is the condition of the birth canal adaptability during the traction period. If the force hysteresis coefficient during the traction period is less than the preset hysteresis warning threshold and the net bone advancement value is less than the preset minimum effective advancement threshold, then the birth canal adaptation status during the traction period is that the skull descent is obstructed. If the force hysteresis coefficient during the traction period is less than the preset hysteresis warning threshold and the net bone propulsion value is greater than or equal to the preset minimum effective propulsion threshold, then the birth canal adaptability status during the traction period is effective passage through the birth canal.

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