Methods and devices for preventing vaginal tears during childbirth

Abstract

Vaginal dilation devices are provided that may include a number of configurations. One feature of the vaginal dilation devices is that they are configured to dilate vaginal tissue during labor to prevent tissue damage. Another feature of the vaginal dilation devices is that they allow for both manual and automatic control of vaginal tissue dilation. In some embodiments, the vaginal dilation devices are configured to measure the force applied to the tissue by the device. Methods related to the use of the vaginal dilation devices are also provided.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 63 / 482,734, entitled "Method and Device for Preventing Vaginal Tearing During Childbirth," filed February 1, 2023, which is hereby incorporated by reference in its entirety. All publications, including patents and patent applications, mentioned in this specification are hereby incorporated by reference in their entirety to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.

[0002] Described herein generally are devices and methods for preparing tissue for childbirth, and more specifically, the devices and methods described herein are intended to prepare and dilate vaginal tissue during childbirth to prevent pelvic floor trauma and vaginal and perineal tears. [Background technology]

[0003] Approximately 134 million women give birth worldwide each year, 3 million of whom deliver vaginally in the United States. Approximately 8 in 10 women who deliver vaginally will experience some degree of vaginal tearing. Approximately 1.2 million women in the United States, or approximately 40% of women who deliver vaginally, experience spontaneous tears or episiotomies (planned surgical incisions in high-risk patients) that require surgical repair. 1.5% to 15% of tears are considered severe, requiring prolonged healing, pain management, and potentially difficult repair surgery, which can significantly reduce quality of life (QOL). Additionally, 15% to 35% of women experience pelvic floor muscle injuries, which are conditions in which the muscles are physically pulled away from the pelvis or overstretched, resulting in dysfunction. The direct cost to the health care system of treating perineal tears is estimated to exceed $650 million annually, and the costs of treating future pelvic floor disorders are even greater.

[0004] Specific risk factors for perineal tears during labor have been identified, and patient groups with these factors have been found to have a higher-than-average incidence of perineal tears. These risk factors include primipara (primigravida, first pregnancy), perineal reduction, instrumental birth (forceps, vacuum extraction), prolonged second stage of labor (>1 hour), epidural analgesia, fetal factors during labor (birth weight >4 kg, persistent occipito-posterior presentation, shoulder dystocia), episiotomy (midline or lateral midline), previous anal sphincter tears, maternal age >30 years, and maternal Asian ethnicity. In addition to the above risk factors, perineal tears are associated with an increased incidence of many pelvic floor disorders, including infection, incontinence, and prolapse. Pregnancy and childbirth are commonly associated with many pelvic floor disorders, although the exact physiological mechanisms that cause these disorders are still being investigated. Injury to the pelvic floor muscles during childbirth is thought to be one of the most important causes of pelvic floor disorders.

[0005] In vaginal birth, labor is clinically divided into three stages. The first stage begins with cervical effacement and is completed by complete cervical dilation to allow the fetus to pass through the birth canal. The second stage, which is the process of the fetus passing through the birth canal, is known as the "Cardinal Movements of Labor." It begins with complete cervical effacement and dilation and ends with the delivery of the fetus. The third stage consists of the separation and expulsion of the placenta.

[0006] During the first stage of labor, the birth canal is functionally closed and maintained in place by multiple layers of muscle and connective tissue that make up the pelvic floor. During the second stage of labor, the fetal tip (usually the head) descends into the birth canal, exerting direct pressure on the pelvic floor. As the fetus passes through the birth canal, it stretches the muscle fibers of the levator ani and the connective tissue, causing significant stretching and damage to the pelvic floor muscles and stretching the perineum to a thin membrane-like state, often resulting in perineal tears during labor.

[0007] During the second stage of labor, the tissues of the pelvic floor and perineum expand rapidly. The resting diameter of the introitus, or opening of the vagina, in an average woman is approximately 2.6 cm. During the first stage of labor, the vaginal diameter remains at this baseline while the cervix dilates, and only after the fetus passes through the cervix does the tissue expand from 2.6 cm to the average fetal (baby) head diameter of approximately 10 cm. This expansion, which increases the vagina's diameter by approximately 3.8 times and its area by approximately 15 times, occurs within a matter of seconds to minutes.

[0008] Currently, no devices or instruments have been proven to significantly reduce pelvic floor trauma during vaginal birth, no devices are able to isolate and assess factors associated with pelvic floor disorders caused by childbirth, and no effective treatments exist to help prepare vaginal and perineal tissues before or during labor.

[0009] Historically, growing gourds have been used in Africa as a means of preparing tissues for birth. Modern techniques such as perineal massage, warm compresses, and "hands-on" techniques are used in hospitals and although empirical evidence shows promise, none have proven effective in clinical trials.

[0010] One device previously introduced to pre-distend tissue to prevent tearing is called "Epi-No." Epi-No is a small balloon intended for use by pregnant women at home one to three months before their due date. To use it, the balloon is inflated to a diameter of approximately 5 cm, and the pregnant woman practices pushing the device out. However, these balloon-type dilators have problems with their shape and size changing during inflation, resulting in reduced stability within the vagina and making it difficult to accurately measure and control the degree of dilation. Summary of the Invention [Means for solving the problem]

[0011] The methods and devices described herein relate to "first in woman" (FIW) trials using dilation devices during labor, particularly the first stage of labor, and more specifically to therapeutic dilation of the lower vagina of a human patient just prior to the descent of the fetus through the birth canal. As described herein, recent studies have shown that the use of dilation devices in human patients during the first stage of labor, adjacent to the second stage, may reduce the risk of injury to the laboring patient and may also shorten the duration of labor for both the patient and the fetus.

[0012] In one embodiment, a vaginal dilation or expansion device is provided having a plurality of arms, each arm having a pad disposed thereon that is shaped and configured to conform to and contact the inner tissue walls of the lower vagina of a human patient. By moving the arms and pads radially outward from the center of the device, the vaginal dilation device can apply force to the inner wall tissue of the lower vagina to gently dilate and prepare the lower vagina of a human patient in preparation for the descent and passage of a fetus.

[0013] More specifically, disclosed herein is a method for dilating vaginal tissue of a human patient using a dilation device, particularly to prepare the human patient's birth canal for the second stage of labor, the method comprising the steps of inserting the dilation device into the human patient's vagina during the first stage of labor, dilating the diameter of the dilation device by a predetermined dilation increment to apply a force to the human patient's lower birth canal, pausing the dilation after reaching the predetermined dilation increment to dilate the human patient's vaginal tissue and reduce the force applied to the human patient's lower birth canal, then re-dilating the diameter of the dilation device by the predetermined dilation increment, and repeating the pausing and re-dilating steps until the dilation device reaches a therapeutic diameter that reduces the risk of fetal injury to the human patient's birth canal as the fetus passes through the human patient's birth canal. Optionally, the dilation device includes dilation arms arranged to move radially outward to expand the diameter of the dilation device. The method further includes monitoring the dilation state of the human patient's cervix, e.g., to monitor or measure and assess the state of dilation. The monitored dilation state can be used to determine the appropriate time to insert the dilation device, and the dilation device can be inserted before the cervix is ​​fully dilated. In one such embodiment, inserting the dilation device into the patient's vagina before the cervix is ​​fully dilated includes inserting the device when the cervix is ​​at least about 6 cm dilated.

[0014] Another optional method involves monitoring data from a force sensor, typically located on the dilation device, which physically contacts the tissue wall of the lower vagina to measure the force applied to the tissue wall. This measures the force applied to the human patient's lower birth canal and monitors data from a diameter sensor on the dilation device. Furthermore, if the measured force exceeds a predetermined force threshold, the device may be stopped from dilating and, if necessary, contracted to reduce the diameter of the device. During this process, dilation may be resumed if the measured force falls below the preset threshold.

[0015] In some embodiments, the method may include using an expansion system having or operably connected to a controller, such as a computer, microprocessor, or other suitable device, to automatically expand the diameter of the expansion device by a predetermined expansion increment. The controller may pause expansion after the predetermined expansion increment is reached and then again expand the diameter of the expansion device by the predetermined expansion increment. The controller may operate the expansion device to repeat the steps of pausing expansion and re-expanding until the diameter of the expansion device reaches a therapeutic diameter that reduces the risk of fetal injury to the human patient's birth canal as the fetus passes through the human patient's birth canal.

[0016] Optionally, the methods disclosed herein may include selecting a length of time required for the expansion device to reach a selected diameter to achieve a therapeutic effect that reduces the risk of fetus injury to the human patient's birth canal as the fetus passes through the birth canal. Such a diameter is typically about 7 cm, usually in the range of 7 cm to 10 cm. Furthermore, expansion to the selected diameter to achieve this therapeutic effect is performed during the first stage of labor. The expansion devices and expansion methods disclosed herein are used and performed during labor and are continued for a time sufficient to achieve the desired therapeutic effect. This time period is about 20 to 120 minutes, more specifically about 30 to 60 minutes, and even more specifically about 30 minutes. In some embodiments, the expansion device is expanded to about 40 mm to about 80 mm within the approximately 30-minute period.

[0017] In some embodiments, the method further includes selecting a predetermined expansion increment, optionally in the range of about 0.5 mm to 2.0 mm, or in the range of about 0.5 mm to 1.0 mm. As described herein, the method may be configured to last for a time period ranging from about 30 minutes to 60 minutes, with the predetermined expansion increments ranging from about 0.5 mm to 2.0 mm, and the expansion increments applied at generally regular intervals in time to substantially linearly expand the diameter of the expansion device to a range of about 40 mm to about 80 mm, or optionally to about 100 mm, within the 30-60 minute time period.

[0018] Typically, the method further includes monitoring and / or collecting data regarding the diameter of the expansion device and treatment time. The method may also include a step of setting the expansion frequency, i.e., selecting the interval between the time from the start of a first expansion of the expansion device to reach a predetermined diameter and the time until the start of a second, subsequent expansion. The method further includes collecting data regarding force, diameter, and treatment time at intervals of approximately 1-2 seconds, or 1-10 seconds, typically collected and stored from the time the expansion device is inserted into the human patient's vagina. The expansion device may be inserted into the human patient's vagina and expand approximately 3-4 cm, or in some cases, approximately 2-6 cm, of the lower vagina. Optionally, the method may further include administering either local or general anesthesia prior to insertion of the expansion device.

[0019] In some embodiments, each of the arms includes a scissor assembly coupled to a respective pad, and the expansion mechanism is connected to a central rod that interconnects the handles and arms, such that axial movement of the central rod changes the distance between each pad and the central rod, thereby achieving expansion.

[0020] In one embodiment, actuation of the expansion mechanism is configured to move the central rod towards the handle, i.e., towards the proximal end, which causes the arms and pads to move radially outward from the central rod.

[0021] In some embodiments, the pads are configured to maintain a substantially parallel alignment with one another as the arms and pads move radially outward.

[0022] In some embodiments, the vaginal dilation device further has a closed state in which the pads are circumferentially disposed around the central rod and an expanded state in which the pads expand in a direction away from the central rod and adjacent pads. In some embodiments, the outer diameter of the pads in the closed state is less than 4 cm. In other embodiments, the outer diameter of the pads in the expanded state is in the range of approximately 8 cm to 10 cm.

[0023] In one embodiment, the vaginal dilation device further includes a quick-release mechanism configured to rapidly reduce the outer diameter of the device. In some embodiments, the device further includes an actuation mechanism disposed on the handle, the actuation mechanism configured to couple with the quick-release mechanism. In other embodiments, the device further includes a bump-release disposed on the distal end, the bump-release configured to engage the quick-release mechanism. In some embodiments, the bump-release is configured to engage the quick-release mechanism upon entry of a fetus into the vaginal canal.

[0024] In some embodiments, when the vaginal dilation device is expanded from a closed state to an expanded state, the center of gravity of the device moves forward below the pad.

[0025] In some embodiments, the vaginal dilation device further comprises a diameter sensor configured to indicate a dilated diameter of the vagina.

[0026] In some embodiments, the vaginal dilation device further includes a controller connected to the dilation mechanism and the force sensor, the controller configured to automatically move the arms and pads radially outward based on the force measured by the force sensor. For example, in some embodiments, the force sensor can measure the force applied by the pads, and the controller can automatically expand or contract the device based on the measured force. The controller can automatically increase the force applied by the pads if the measured force is too low, or automatically decrease the force applied by the pads if the measured force is too high (e.g., above a set force threshold).

[0027] In some embodiments, the controller is configured to automatically move the arms and pad radially outward to apply a constant force to the vagina with the pad. In some embodiments, the vaginal dilation device may further include a motor connected to the central rod and a controller connected to the force sensor and the motor, the controller configured to move the central rod axially and automatically move the arms and pad radially outward based on the force measured by the force sensor. In some embodiments, the device further includes a controller connected to the dilation mechanism and the force sensor, the controller configured to automatically move the arms and pad radially outward until the force measured by the force sensor exceeds a predetermined force threshold.

[0028] In another embodiment, the controller is configured to automatically move the central rod axially to apply a constant force by the pad.

[0029] In some embodiments, the expansion mechanism is configured to automatically move the arms and pads of the device radially outward with a constant force. In some embodiments, the expansion mechanism may include a spring connected to the central rod that pushes against the central rod with a constant force, causing the arms and pads to move radially outward from the central rod. In certain embodiments, the constant force of the spring is adjustable by the user.

[0030] In some embodiments, the force that the spring exerts on the expansion device can be adjusted. In other embodiments, the spring can be an adjustable clock spring. In some embodiments, the pivot point of the spring can be adjustable.

[0031] In some embodiments, the vaginal dilation device further comprises an expandable sheath disposed on the pad. In other embodiments, the vaginal dilation device further comprises a working channel disposed on the exterior of the device or on the interior of the device.

[0032] In some embodiments, the force sensor of the vaginal dilation device comprises a plurality of force sensors disposed on the pad, in other embodiments the force sensor comprises a plurality of force sensors disposed on the underside of the pad, and in yet other embodiments the force sensor comprises a plurality of force sensors disposed on the arms.

[0033] In some embodiments, the vaginal dilation device further comprises a clutch mechanism configured to prevent over-expansion of the pad, while in other embodiments, the vaginal dilation device further comprises an automatic vibration mechanism configured to prevent pressure necrosis.

[0034] In some embodiments, the pads of the vaginal dilator device are positioned so that when they move radially outward, none of the pads contact the urethra or nerve bundles located in the anterior part of the patient's vagina, while in other embodiments, the pads are positioned so that when they move radially outward, none of the pads contact the patient's perineum.

[0035] In some embodiments, the extension mechanism is indirectly connected to the arm via a flexible assembly.

[0036] In some embodiments, the vaginal dilation device further comprises a cam connected to the dilation mechanism to linearize the force required for dilation from the closed state to the dilated state. In some embodiments, the cam is a ratchet cam. In other embodiments, the cam is a geared cam mechanism comprising multiple gears. In some embodiments, a lever mechanism or a bump mechanism can be used to linearize the force required for dilation from the closed state to the dilated state.

[0037] In some embodiments, the expansion mechanism may comprise a stent or yurt-like device, hi other embodiments, the expansion mechanism may comprise a living hinge structure.

[0038] A different vaginal dilation device is provided that includes a handle, a plurality of arms connected to the handle, pads disposed on each arm and designed and shaped to conform to the shape of the vagina, and a dilation mechanism connected to the arms and configured to move the arms and pads radially outward from the device with a constant force.

[0039] In some embodiments, each of the plurality of arms includes a scissor assembly coupled to a respective pad, and the extension mechanism is connected to a central rod that is connected to the handle and the arms, such that axial movement of the central rod changes the distance between the pad and the central rod.

[0040] In one embodiment, actuation of the expansion mechanism is configured to move the central rod toward the handle, i.e., toward the proximal end, causing the arms and pads to move radially outward from the central rod.

[0041] In one embodiment, the pads are arranged to maintain a substantially parallel alignment with one another as the arms and pads move radially outward.

[0042] In some embodiments, the vaginal dilation device has a closed state in which the pads are circumferentially disposed around the central rod and an expanded state in which the pads expand in a direction away from the central rod and adjacent pads. In some embodiments, the outer diameter of the pads in the closed state is less than 4 cm. In other embodiments, the outer diameter of the pads in the expanded state is in the range of approximately 8-10 cm.

[0043] In some embodiments, the vaginal dilation device further comprises a quick-release mechanism configured to rapidly reduce the outer diameter of the device. In some embodiments, the handle includes an actuation mechanism configured to couple with the quick-release mechanism. In other embodiments, the device further includes a bump release disposed at the distal end of the device and configured to engage the quick-release mechanism. In some embodiments, the bump release is configured to engage the quick-release mechanism upon entry of a fetus into the vaginal canal.

[0044] In some embodiments, when the vaginal dilation device is expanded from the closed state to the expanded state, the center of gravity of the device moves forward below the pad.

[0045] In some embodiments, the vaginal expander device further comprises a diameter sensor configured to indicate the expanded diameter of the vagina.

[0046] In some embodiments, the vaginal dilation device further includes a controller connected to the dilation mechanism and the force sensor, the controller configured to automatically move the arms and pad radially outward based on the force measured by the force sensor. For example, in some embodiments, the force sensor measures the force applied by the pad, and the controller can automatically expand or contract the device based on the measured force. The controller can automatically increase the force applied by the pad if the measured force is too small, and automatically decrease the force applied by the pad if the measured force is too large (e.g., if the force applied by the pad exceeds or falls below a desired constant force threshold).

[0047] In some embodiments, the controller is configured to automatically move the arms and pad radially outward to maintain a constant force on the vagina with the pad. In some embodiments, the vaginal dilation device further includes a motor connected to the central rod and a controller connected to the force sensor and the motor, the controller configured to automatically move the central rod axially and the arms and pad radially outward based on the force measured by the force sensor. In some embodiments, the device further includes a controller connected to the dilation mechanism and the force sensor, the controller configured to automatically move the arms and pad radially outward to maintain a constant force applied by the device. In other embodiments, the controller is configured to automatically move the central rod axially to maintain a constant force on the pad.

[0048] In some embodiments, the expansion mechanism is configured to automatically move the arms and pads of the device radially outward with a constant force. In some embodiments, the expansion mechanism includes a spring connected to a central rod, the spring pushing against the central rod with a constant force, causing the arms and pads to move radially outward from the central rod. In certain embodiments, the constant force of the spring is adjustable by the user.

[0049] In some embodiments, the vaginal dilation device further comprises an expandable sheath disposed on the pad, hi other embodiments, the vaginal dilation device further comprises a working channel disposed on the device.

[0050] In some embodiments, the force sensor of the vaginal dilation device comprises a plurality of force sensors disposed on the pad, in other embodiments, the force sensor comprises a plurality of force sensors disposed on the underside of the pad, and in yet other embodiments, the force sensor comprises a plurality of force sensors disposed on the arms.

[0051] In some embodiments, the vaginal dilation device further comprises a clutch mechanism configured to prevent over-expansion of the pad, while in other embodiments, the vaginal dilation device further comprises an automatic vibration mechanism configured to prevent pressure necrosis.

[0052] In some embodiments, the vaginal dilator devices are positioned so that none of the pads contact the urethra or nerve bundles located in the anterior portion of the patient's vagina as they move radially outward from the device, and in other embodiments, none of the pads contact the patient's perineum as they move radially outward from the device.

[0053] In some embodiments, the extension mechanism is indirectly connected to the arm via a flexible assembly.

[0054] In some embodiments, the expansion mechanism is configured to move the arms and pads radially outward from the device with a constant force for a predetermined period of time. In some embodiments, the predetermined period of time is 5-10 minutes. In other embodiments, the predetermined period of time is 5-60 minutes. In yet other embodiments, the predetermined period of time is less than 2 hours.

[0055] In another embodiment, a vaginal dilation device is provided that includes a handle, a plurality of arms connected to the handle, an expansion mechanism connected to the arms and configured to move the arms and pads radially outward from the device, and a diameter sensor on the device and configured to measure a diameter of the device, wherein each arm is provided with a pad shaped and configured to conform to a vagina.

[0056] In some embodiments, each of the plurality of arms includes a scissor assembly connected to a respective pad, and the extension mechanism is connected to a central rod connected to the handle and the arms, such that axial movement of the central rod varies the distance of the pad from the central rod.

[0057] In one embodiment, actuation of the expansion mechanism is configured to move the central rod toward the handle, i.e., toward the proximal end, causing the arms and pads to move radially outward from the central rod.

[0058] In some embodiments, when the arms and pads move radially outward, the pads are arranged in a substantially parallel configuration with respect to one another.

[0059] In some embodiments, the vaginal dilation device further includes a closed state in which the pads are circumferentially disposed around the central rod and an expanded state in which the pads extend away from the central rod and adjacent pads. In some embodiments, the outer diameter of the pads in the closed state is less than 4 cm. In other embodiments, the outer diameter of the pads in the expanded state is about 8-10 cm.

[0060] In certain embodiments, the vaginal dilation device further includes a quick-release mechanism configured to rapidly reduce the outer diameter of the device. In some embodiments, the device further includes an actuation mechanism disposed on the handle and configured to actuate the quick-release mechanism. In other embodiments, the device further includes a bump release at the distal end of the device configured to actuate the quick-release mechanism. In some embodiments, the bump release is configured to be actuated by the entry of a fetus into the vaginal canal.

[0061] In some embodiments, the vaginal expansion device is configured such that when the device is expanded from the closed state to the expanded state, the center of gravity of the device moves forward below the pad.

[0062] In some embodiments, the vaginal dilation device further includes a controller connected to the dilation mechanism and the diameter sensor, the controller configured to automatically move the arms and pads radially outward based on the diameter measured by the diameter sensor. For example, in some embodiments, the diameter sensor measures the diameter of the device, and the controller can automatically expand or contract the device based on the measured diameter. The controller can automatically increase the diameter if the measured diameter is too small, or can automatically decrease the diameter if the measured diameter is too large.

[0063] In some embodiments, the vaginal dilation device further includes a motor connected to the central rod and a controller connected to the diameter sensor and the motor, the controller configured to automatically move the central rod axially to cause the arms and pads to move radially outward at a constant rate of expansion. In some embodiments, the device further includes a controller connected to the expansion mechanism and the diameter sensor, the controller configured to automatically move the arms and pads radially outward based on the diameter measured by the diameter sensor.

[0064] In some embodiments, the vaginal dilation device further comprises an expandable sheath disposed on the pad. In other embodiments, the vaginal dilation device further comprises a working channel disposed on the exterior or interior of the device.

[0065] In some embodiments, the vaginal dilation device further comprises a clutch mechanism configured to prevent over-expansion of the pad. Other embodiments further comprise an automatic vibration mechanism configured to prevent pressure necrosis.

[0066] In some embodiments, the vaginal dilator device is positioned so that none of the pads contact the urethra or nerve bundles located in the anterior part of the patient's vagina as they move radially outward from the device, while in other embodiments, the pads are positioned so that none of the pads contact the patient's perineum as they move radially outward from the device.

[0067] In some embodiments, the extension mechanism is indirectly connected to the arm via a flexible assembly.

[0068] In some embodiments, the constant rate of expansion is adjustable by the user.

[0069] In some embodiments, the vaginal dilation device further comprises a timer configured to notify the user to enlarge the diameter of the device.

[0070] In certain embodiments, the expansion mechanism includes a trigger assembly configured to expand the device a predetermined expansion increment upon a single actuation of the trigger assembly, which in some embodiments is user adjustable.

[0071] A method of dilating the vagina during childbirth is provided, the method comprising the steps of inserting a vaginal dilation device into the vagina, measuring the force that the vaginal dilation device applies to the vagina, and dilating the vagina with the vaginal dilation device.

[0072] In some embodiments, the method further includes pausing vaginal expansion when the force applied to the vagina by the vaginal expansion device reaches a first force threshold. In certain embodiments, the method further includes resuming vaginal expansion when the force applied to the vagina by the vaginal expansion device decreases to a second force threshold. In other embodiments, resuming expansion further includes resuming vaginal expansion until the force applied to the vagina by the vaginal expansion device reaches the first force threshold. In certain embodiments, resuming expansion further includes resuming vaginal expansion until the force applied to the vagina by the vaginal expansion device reaches a third force threshold, wherein the third force threshold is configured to be greater than the first force threshold. In certain embodiments, the first force threshold is greater than the second force threshold. In other embodiments, the first force threshold is less than 8 pounds (approximately 35.6 Newtons).

[0073] In some embodiments of the method, the inserting step further comprises inserting the vaginal expansion device into the vagina during the first stage of labor. The method further comprises removing the vaginal expansion device from the vagina before the second stage of labor.

[0074] In some embodiments, measuring the force further comprises measuring the force with a vaginal dilation device.

[0075] In some embodiments, the method further comprises measuring a diameter of the vagina with a vaginal dilation device. The method further comprises dilating the vagina with the vaginal dilation device based on the measured diameter.

[0076] In some embodiments, the expanding step further comprises expanding the vagina with a constant force via a vaginal expansion device. In other embodiments, the expanding step further comprises manually expanding the vagina via a vaginal expansion device. In still other embodiments, the expanding step further comprises automatically expanding the vagina via a vaginal expansion device.

[0077] In other embodiments, the dilating step further comprises dilating the vagina with a vaginal dilation device at a location remote from the patient.

[0078] Another method of dilating the vagina during childbirth is provided. The method includes inserting a vaginal dilation device into the vagina and applying a constant force to the vagina with the vaginal dilation device to dilate the vagina. In some embodiments, the constant force is less than 8 pounds (approximately 35.6 Newtons). In other embodiments, the constant force is adjustable.

[0079] In some embodiments of the method, the inserting step includes inserting the vaginal dilation device into the vagina during the first stage of labor. In other embodiments, the method further includes removing the vaginal dilation device from the vagina prior to the second stage of labor. In still other embodiments, the method further includes removing the vaginal dilation device from the vagina when the vagina is dilated to a diameter of about 8-10 cm.

[0080] In some embodiments, the method includes measuring the diameter of the vagina with a vaginal dilation device.

[0081] In other embodiments, the step of applying a force further comprises automatically applying a constant force to the vagina with the vaginal dilation device to dilate the vagina. In some embodiments, the step of applying a force further comprises automatically applying a constant force to the vagina with a constant force spring provided in the vaginal dilation device. In other embodiments, the step of applying a force further comprises automatically applying a constant force to the vagina with an automatic controller and motor connected to the vaginal dilation device. In other embodiments, the step of applying a force further comprises applying a constant force to the vagina with the vaginal dilation device for a predetermined period of time to dilate the vagina. In some embodiments, the predetermined period of time is less than 5 minutes. In other embodiments, the predetermined period of time is between 5 and 10 minutes. In yet other embodiments, the predetermined period of time is between 5 and 60 minutes. In yet other embodiments, the predetermined period of time is less than 2 hours.

[0082] In another embodiment, the method includes measuring the force that the vaginal dilation device applies to the vagina.

[0083] A method of preventing tissue damage during childbirth is provided and includes inserting a vaginal dilation device into a human patient's vagina during the first stage of labor and dilating the patient's vagina with the vaginal dilation device.

[0084] In some embodiments, the method further comprises removing the vaginal dilation device from the human patient's vagina prior to the second stage of labor.

[0085] In another embodiment, the dilating step includes dilating the patient's vagina to about 7-10 cm with a vaginal dilation device.

[0086] A vaginal exercise device is provided that includes a handle, a plurality of arms connected to the handle, an expansion mechanism connected to the arms and configured to move the arms and pads radially outward from the device with a user-specified force, and a force sensor on the device configured to measure the force exerted by the vagina against the pads, wherein each arm is provided with a pad shaped and configured to conform to the vagina.

[0087] In some embodiments, axial movement of the expansion mechanism engages an inclined inner cam surface of the pad, causing the pad to expand radially outward, hi other embodiments, the expansion mechanism comprises a cone-shaped body.

[0088] In some embodiments, the expansion mechanism includes a plurality of living hinges.

[0089] In one embodiment, the expansion mechanism is connected to a central rod that is connected to the handle and the arm, and axial movement of the central rod changes the distance of the pad from the central rod.

[0090] In some embodiments, actuation of the expansion mechanism is configured to move the central rod toward the handle, i.e., toward the proximal end, causing the arms and pads to move radially outward from the central rod.

[0091] In some embodiments, when the arms and pads move radially outward, the pads are arranged in a substantially parallel configuration with one another.

[0092] Some embodiments further include a closed state in which the pads are circumferentially disposed around the central rod and an expanded state in which the pads extend away from the central rod and adjacent pads. In some embodiments, the outer diameter of the pads in the closed state is less than 1 cm. In other embodiments, the outer diameter of the pads in the expanded state is about 2-4 cm.

[0093] Some embodiments further comprise a diameter sensor configured to indicate a dilated diameter of the vagina.

[0094] In some embodiments, the expansion mechanism is configured to automatically move the arms and pads of the device radially outward at a user-specified force, while in other embodiments, the expansion mechanism includes a spring connected to a central rod that pushes against the central rod with a constant force, causing the arms and pads to move radially outward from the central rod.

[0095] In some embodiments, as the pads move radially outward from the device, none of the pads contact the urethra or nerve bundles located in the anterior portion of the vagina of a human patient.

[0096] In other embodiments, the pads are positioned so that none of the pads contact the patient's perineum as they move radially outward from the device.

[0097] In some embodiments, the extension mechanism is indirectly connected to the arm via a flexible assembly.

[0098] A cervical dilation device is provided, the device comprising: a handle; a plurality of arms connected to the handle; a dilation mechanism connected to the arms and configured to move the arms and pads radially outward from the device with a constant force; a force sensor on the device configured to measure the force applied to the pads; and an extension mechanism connecting the handle to the arms and dilation mechanism. Each arm is provided with a pad shaped and configured to conform to the cervix of a human patient. The extension mechanism is sized and configured to allow the arms to access the cervix while the handle remains external to the human patient.

[0099] In some embodiments, the expansion mechanism is connected to a central rod that is connected to the handle and the arm, and axial movement of the central rod changes the distance of the pad from the central rod.

[0100] In one embodiment, actuation of the expansion mechanism is configured to move the central rod toward the handle, i.e., toward the proximal end, causing the arms and pads to move radially outward from the central rod.

[0101] In some embodiments, when the arms and pads move radially outward, the pads are arranged in a substantially parallel configuration to one another.

[0102] In other embodiments, the device includes a closed state in which the pads are circumferentially disposed around the central rod and an expanded state in which the pads extend away from the central rod and adjacent pads. In some embodiments, the outer diameter of the pads in the closed state is less than 1 cm. In other embodiments, the outer diameter of the pads in the expanded state is about 2-10 cm.

[0103] In some embodiments, the device further comprises a diameter sensor configured to indicate a dilated diameter of the cervix.

[0104] In some embodiments, the expansion mechanism is configured to automatically move the arms and pads of the device radially outward with a constant force.

[0105] In another embodiment, the expansion mechanism includes a spring connected to the central rod, the spring pushing against the central rod with a constant force, causing the arms and pads to move radially outward from the central rod.

[0106] In some embodiments, each of the plurality of arms includes a scissor assembly connected to a respective pad.

[0107] Some embodiments further include a quick release mechanism configured to rapidly reduce the outer diameter of the device.

[0108] In certain embodiments, the device further includes an actuation mechanism disposed on the handle and configured to couple to the quick release mechanism.

[0109] Some embodiments further include a controller connected to the extension mechanism and the force sensor, the controller configured to automatically move the arms and pads radially outward based on the force measured by the force sensor.

[0110] In one embodiment, the controller is configured to automatically move the arms and pads radially outward to apply a constant force by the pads.

[0111] Some embodiments further include a motor connected to the central rod and a controller connected to the force sensor and the motor, the controller configured to automatically move the central rod axially and move the arms and pads radially outward based on the force measured by the force sensor.

[0112] In some embodiments, the controller is configured to automatically move the central rod axially to apply a constant force by the pad.

[0113] Some embodiments further include a controller connected to the extension mechanism and the force sensor, the controller configured to automatically move the arms and pads radially outward until the force measured by the force sensor exceeds a predetermined force threshold.

[0114] A method of dilating the cervix during labor is provided, the method including the steps of inserting a cervical dilation device into the cervix, measuring a force applied by the cervical dilation device to the cervix, dilating the cervix with the cervical dilation device, and pausing cervical dilation when the force applied by the cervical dilation device to the cervix reaches a first force threshold.

[0115] In some embodiments, the method includes resuming cervical dilation when the force applied by the cervical dilation device to the cervix is ​​reduced to a second force threshold. In certain embodiments, resuming cervical dilation further includes resuming cervical dilation until the force applied by the cervical dilation device to the cervix reaches a first force threshold. In other embodiments, resuming dilation further includes resuming cervical dilation until the force applied by the cervical dilation device to the cervix reaches a third force threshold, where the third force threshold is greater than the first force threshold.

[0116] In some embodiments, the first force threshold is greater than the second force threshold, hi other embodiments, the first force threshold is less than 8 pounds (about 35.6 Newtons).

[0117] In some embodiments, the inserting step further comprises inserting a cervical dilation device into the cervix during the first stage of labor.

[0118] Some embodiments further include removing the cervical dilation device from the cervix prior to the second stage of labor.

[0119] In an embodiment, measuring the force further comprises measuring the force with a cervical dilation device.

[0120] Another embodiment of the method further comprises measuring the diameter of the cervix with a vaginal dilation device.

[0121] Another embodiment of the method further includes dilating the cervix with a cervical dilation device based on the measured diameter.

[0122] In some embodiments, the dilating step further comprises dilating the cervix with a cervical dilation device at a constant force. In additional embodiments, the dilating step further comprises manually dilating the cervix with a cervical dilation device. In other embodiments, the dilating step further comprises automatically dilating the cervix with a cervical dilation device. In other embodiments, the dilating step further comprises dilating the cervix with a cervical dilation device at a location remote from the human patient.

[0123] A method for exercising pelvic floor muscles around the vagina is provided, comprising the steps of inserting a vaginal exercise device into the vagina, applying a constant force to the vagina with the vaginal exercise device, and measuring the force that the vagina applies to the vaginal exercise device.

[0124] In some embodiments, the constant force is less than 8 pounds (about 35.6 Newtons). In other embodiments, the constant force is user adjustable.

[0125] In some embodiments, the vaginal exercise device expands outward to a diameter of 2-4 cm.

[0126] In some embodiments, the step of applying a force further comprises automatically applying a constant force to the vagina with the vaginal exercise device.

[0127] In another embodiment, the step of applying the force further comprises automatically applying a constant force to the vagina via a constant force spring provided on the vaginal exercise device.

[0128] In some embodiments, the applying step further comprises automatically applying a constant force to the vagina with an automatic controller and motor connected to the vaginal exercise device.

[0129] In some embodiments, the applying step further comprises applying a constant force to the vagina for a predetermined period of time using a vaginal exercise device to exercise the pelvic muscles surrounding the vagina.

[0130] In some embodiments, the predetermined time may be less than 5 minutes, 5 to 10 minutes, 5 to 60 minutes, or less than 2 hours. [Brief explanation of the drawings]

[0131] [Figure 1A] 1A-1D illustrate several embodiments of a vaginal dilation device. [Figure 1B] 1A-1D illustrate several embodiments of a vaginal dilation device. [Figure 1C] 1A-1D illustrate several embodiments of a vaginal dilation device. [Figure 1D] 1A-1D illustrate several embodiments of a vaginal dilation device. [Figure 2] 1A-1C illustrate a vaginal dilation device in a dilated state. [Figure 3A] FIG. 1 is a cross-sectional view of a vaginal dilation device. [Figure 3B] FIG. 1 is a cross-sectional view of a vaginal dilation device. [Figure 3C] FIG. 1 is a cross-sectional view of a vaginal dilation device. [Figure 3D] FIG. 1 is a cross-sectional view of a vaginal dilation device. [Figure 4A] FIG. 1 is a cross-sectional view of an automated vaginal dilation device. [Figure 4B] FIG. 1 is a cross-sectional view of an automated vaginal dilation device. [Figure 4C] FIG. 1 is a cross-sectional view of an automated vaginal dilation device. [Figure 4D]FIG. 1 is a cross-sectional view of an automated vaginal dilation device. [Figure 5A] 10A-10C illustrate various embodiments of pad shapes for use with vaginal dilation devices. [Figure 5B] 10A-10C illustrate various embodiments of pad shapes for use with vaginal dilation devices. [Figure 5C] 10A-10C illustrate various embodiments of pad shapes for use with vaginal dilation devices. [Figure 5D] 10A-10C illustrate various embodiments of pad shapes for use with vaginal dilation devices. [Figure 6A] 10A-10C illustrate various embodiments of force sensors positioned external to the vaginal dilation device or internal to the vaginal dilation device. [Figure 6B] 10A-10C illustrate various embodiments of force sensors positioned external to the vaginal dilation device or internal to the vaginal dilation device. [Figure 6C] 10A-10C illustrate various embodiments of force sensors positioned external to the vaginal dilation device or internal to the vaginal dilation device. [Figure 6D] 10A-10C illustrate various embodiments of force sensors positioned external to the vaginal dilation device or internal to the vaginal dilation device. [Figure 6E] 10A-10C illustrate various embodiments of force sensors positioned external to the vaginal dilation device or internal to the vaginal dilation device. [Figure 6F] 10A-10C illustrate various embodiments of force sensors positioned external to the vaginal dilation device or internal to the vaginal dilation device. [Figure 6G] 10A-10C illustrate various embodiments of force sensors positioned external to the vaginal dilation device or internal to the vaginal dilation device. [Figure 7A] 1A-1C illustrate an embodiment of a vaginal dilation device including a protective sheath. [Figure 7B] 1A-1C illustrate an embodiment of a vaginal dilation device including a protective sheath. [Figure 8A] 1A-1C illustrate various embodiments of a vaginal dilation device having a working channel or through port. [Figure 8B]1A-1C illustrate various embodiments of a vaginal dilation device having a working channel or through port. [Figure 8C] 1A-1C illustrate various embodiments of a vaginal dilation device having a working channel or through port. [Figure 8D] 1A-1C illustrate various embodiments of a vaginal dilation device having a working channel or through port. [Figure 9] 1A-1C show a vaginal dilation device including a quick release mechanism. [Figure 10A] 1A-1C illustrate a vaginal dilation device including a quick release mechanism for insertion into a female patient during labor. [Figure 10B] 1A-1C illustrate a vaginal dilation device including a quick release mechanism for insertion into a female patient during labor. [Figure 11] FIG. 1 illustrates the anatomy of the female reproductive system. [Figure 12] FIG. 1 illustrates the anatomy of the female reproductive system. [Figure 13A] 1A-1C illustrate a vaginal dilation device inserted into a female patient in both a closed and dilated state. [Figure 13B] 1A-1C illustrate a vaginal dilation device inserted into a female patient in both a closed and dilated state. [Figure 14A] 1 illustrates a vaginal dilation device inserted into a female patient during labor. [Figure 14B] 1 illustrates a vaginal dilation device inserted into a female patient during labor. [Figure 14C] 1 illustrates a vaginal dilation device inserted into a female patient during labor. [Figure 14D] 1 illustrates a vaginal dilation device inserted into a female patient during labor. [Figure 15] 1 is a diagram illustrating one method of dilating vaginal tissue during childbirth. [Figure 16] 1 is a diagram illustrating another method of expanding vaginal tissue during childbirth. [Figure 17] 1 is a diagram illustrating another method of expanding vaginal tissue during childbirth. [Figure 18] 1 is a diagram illustrating another method of expanding vaginal tissue during childbirth. [Figure 19A] 13A-13D show yet another embodiment of a vaginal dilation device. [Figure 19B] 13A-13D show yet another embodiment of a vaginal dilation device. [Figure 20A] 10A-10C show other embodiments of the vaginal dilation device. [Figure 20B] 10A-10C show other embodiments of the vaginal dilation device. [Figure 20C] 10A-10C show other embodiments of the vaginal dilation device. [Figure 20D] 10A-10C show other embodiments of the vaginal dilation device. [Figure 21A] 10A-10C show other embodiments of the vaginal dilation device. [Figure 21B] 10A-10C show other embodiments of the vaginal dilation device. [Figure 21C] 10A-10C show other embodiments of the vaginal dilation device. [Figure 22A] 10A-10C show other embodiments of the vaginal dilation device. [Figure 22B] 10A-10C show other embodiments of the vaginal dilation device. [Figure 22C] 10A-10C show other embodiments of the vaginal dilation device. [Figure 22D] 10A-10C show other embodiments of the vaginal dilation device. [Figure 22E] 10A-10C show other embodiments of the vaginal dilation device. [Figure 23A] 10A-10C show other embodiments of the vaginal dilation device. [Figure 23B] 10A-10C show other embodiments of the vaginal dilation device. [Figure 24A] 10A-10C show other embodiments of the vaginal dilation device. [Figure 24B] 10A-10C show other embodiments of the vaginal dilation device. [Figure 24C] 10A-10C show other embodiments of the vaginal dilation device. [Figure 25A]10A-10C show other embodiments of the vaginal dilation device. [Figure 25B] 10A-10C show other embodiments of the vaginal dilation device. [Figure 25C] 10A-10C show other embodiments of the vaginal dilation device. [Figure 26A] 10A-10C show other embodiments of the vaginal dilation device. [Figure 26B] 10A-10C show other embodiments of the vaginal dilation device. [Figure 26C] 10A-10C show other embodiments of the vaginal dilation device. [Figure 27] 10A-10C show other embodiments of the vaginal dilation device. [Figure 28] 1 shows another embodiment of a vaginal dilation device. [Figure 29A] 10A-10C show other embodiments of the vaginal dilation device. [Figure 29B] 10A-10C show other embodiments of the vaginal dilation device. [Figure 30] 10A-10C show other embodiments of the vaginal dilation device. [Figure 31] 10A-10C show other embodiments of the vaginal dilation device. [Figure 32] 10A-10C show other embodiments of the vaginal dilation device. [Figure 33] 10A-10C show other embodiments of the vaginal dilation or exercise device. [Figure 34A] 10A-10C show other embodiments of the vaginal dilation or exercise device. [Figure 34B] 10A-10C show other embodiments of the vaginal dilation or exercise device. [Figure 35] 10A-10C show other embodiments of the vaginal dilation or exercise device. [Figure 36] 1A-1C illustrate an embodiment of a cervical dilation device. [Figure 37] 10A-10C illustrate an embodiment of a method for expanding vaginal tissue using an expansion device. [Figure 38]10A-10C illustrate an embodiment of a dilation device including a pad placed within the vaginal canal. [Figure 39] 10A-10C illustrate another embodiment of a method for expanding vaginal tissue using an expansion device. [Figure 40] 10A-10C illustrate another embodiment of a method for expanding vaginal tissue using an expansion device. [Figure 41] 1 is a graph illustrating one embodiment of a treatment cycle. [Figure 42A] FIG. 10 illustrates data collected from a user based on an exemplary method using an augmented device. [Figure 42B] FIG. 10 illustrates data collected from a user based on an exemplary method using an augmented device. [Figure 43A] 1A-1C illustrate the anatomical structures of the pelvic floor in isolation and surrounding a dilation device placed within the vaginal canal. DETAILED DESCRIPTION OF THE INVENTION

[0132] The devices and methods described herein aim to prepare and dilate vaginal tissue during childbirth, preventing pelvic floor injury and vaginal and perineal tears. In some embodiments, the device can dilate perineal tissue until the vaginal opening reaches a target diameter of approximately 10 cm, roughly equivalent to the size of the fetal head. In one embodiment, the device is configured as a mechanical dilator that is inserted into the first 3-4 cm of the vagina, i.e., the vaginal opening, and gradually dilates the vagina from a resting diameter of 2-3 cm to a fully dilated diameter of approximately 10 cm, equivalent to the size of the fetus to be delivered. Dilation can be controlled by a manual or automated actuation system, and the device can be quickly collapsed and removed as needed.

[0133] The device described herein can be inserted during the first stage of labor and removed just before the second stage, allowing the remainder of the birth process to proceed normally. The device is intended for use before the second stage of labor and prevents the fetus from contacting the device during birth. Depending on the time it takes for the vagina to fully dilate (i.e., to dilate to approximately 10 cm), the device can be inserted early in the first stage of labor, even when only slight dilation has occurred. The target dilation diameter of 10 cm means that the device should be used in a hospital setting under the supervision of a trained obstetrician and nurse. The device can be used without anesthesia or under local anesthesia. Tissues can also be prepared after administering epidural anesthesia, completely eliminating any pain or discomfort that the device may cause. Local anesthesia can also be administered to the tissue-contacting surface of the device, thereby minimizing pain.

[0134] 1A-1C illustrate one embodiment of a vaginal dilation device 100. The vaginal dilation device 100 can include a rigid or semi-rigid pad 102, an arm 104, a handle 106, and an expansion mechanism 108. In the embodiment shown in FIGS. 1A-1C, the device 100 includes four pairs of pads 102 and arms 104. In other embodiments, any number of pads and arms can be used. For example, some embodiments may include only two or three pairs of pads and arms, while other embodiments may include five, six, seven, eight, or more pairs of pads and arms. Each pair of pads and arms can be symmetrically or asymmetrically positioned around the central axis of the device.

[0135] The pads 102 are connected to arms 104, which may connect to a central rod (not shown) that extends along the longitudinal axis of the device and connects through a handle 106 to an expansion mechanism 108. The tissue-contacting pads 102 may be designed to maintain stability across all expansion diameters. In some embodiments, the pads may have a saddle-like shape that maintains a consistent waist size and pitch when expanded. These pads may be overmolded with a highly flexible, biocompatible elastomeric material to evenly distribute force against the tissue and prevent trauma. Additional pad shapes and designs are described below.

[0136] In the embodiment shown in FIGS. 1A-1C, the arms 104 include a scissor-like assembly, including shafts 110 and 112 that rotate about a pivot 114. The shafts 110 and 112 can be connected to the pads and the central rod. In FIGS. 1A-1C, the expansion mechanism 108 includes a mechanical knob configured to expand the arms of the vaginal expansion device. Manually rotating the knob moves the knob away from the handle, causing the central rod to move proximally within the handle. This causes the shafts 110 and 112 to rotate about the pivot 114, pushing the pads 102 radially outward from the central rod of the device. The scissor-like assembly of the arms 104 allows the pads 102 to remain parallel to the device and each other during expansion, thereby stabilizing the pad-to-tissue alignment during expansion. Furthermore, maintaining the pads' parallel alignment with each other helps maximize force distribution along the pads while holding the device in place within the tissue.

[0137] Rotating the knob in the opposite direction moves the central rod distally, collapsing the scissor assembly, causing the pads to move inward toward the central rod. In one embodiment, each set of arms 104 may have a different radius of curvature, allowing the arms to expand outward at different rates as desired.

[0138] While most of the embodiments described herein show the arms as a scissor-like assembly, it should be understood that other methods and devices for expanding the pad may be used, for example, the arm may be a single arm (e.g., a structure similar to a speculum) attached to the pad.

[0139] The vaginal dilator device can be sized, shaped, and configured to be inserted approximately one-third of the way into the vagina, i.e., 3-4 cm, and can be configured to gradually dilate the vaginal opening from a resting diameter of approximately 2 cm to a fully dilated diameter of approximately 10 cm. The vaginal dilator device 100 can be configured to expand from a compact, closed configuration, as shown in FIG. 1A, to an expanded configuration, as shown in FIG. 1C. When the device is in the closed state, each pad can be tightly closed with adjacent pads to form a three-dimensional shape (e.g., a circle, an oval, etc.).

[0140] In the closed state shown in FIG. 1A, adjacent pads 102 may be configured to contact each other to reduce the outer diameter of the device. In some embodiments, the diameter of the pads in the closed state may be less than 4 cm. In some embodiments, the outer diameter of the pads in the closed state is approximately 2-4 cm. In other embodiments, the pads may not contact adjacent pads in the closed state; however, this may increase the minimum outer diameter of each pad or reduce the surface area of ​​each individual pad 102, which may cause discomfort to the patient during tissue expansion.

[0141] 1B-1C, when the device expands to the expanded state, pads 102 and arms 104 move radially outward from the device, separating the pads. In one embodiment, the maximum diameter of the pads in the expanded state may be about 10 cm. In one embodiment, the maximum outer diameter of the pads in the expanded state is about 8-12 cm.

[0142] The vaginal dilation device 100 is specifically designed to promote compactness, effective dilation, and good tissue contact during dilation. As the device expands from the closed state to the expanded state, the center of gravity of the device moves below the pad, as shown by arrow 116 in FIG. 1C. This keeps the device in place without rotating or being removed from the vagina.

[0143] The vaginal dilation device 100 may further include an indicator or gauge 118. In the embodiment of FIGS. 1A-1C, the gauge 118 is located on the handle 106; however, the gauge may be located anywhere on the device or may be located remotely from the device, such as on a display monitor. In some embodiments, the gauge allows a user to determine the diameter of the pad 102. A user, such as a physician, can use the gauge to accurately gauge the amount of tissue dilation. The gauge 118 may, for example, be a simple binary readout indicating a threshold for whether dilation should continue, or may include a scale indicating the actual diameter of the device.

[0144] In other embodiments, the vaginal dilation device 100 includes a force sensor (not shown) configured to measure the force the pad exerts on or against tissue, and the gauge 118 can indicate the measured force to the user. The force sensor may be a strain gauge, a grindstone bridge, a piezoelectric crystal, a hydraulic / pneumatic load cell, an elastic device, or any other force sensor or force transducer known in the art. The gauge 118 may, for example, be a simple binary display indicating a threshold for whether dilation should continue, or it may include a scale indicating the actual force being applied to tissue. In yet other embodiments, the gauge 118 can indicate both the diameter of the pad and the force detected by the pad. Alternatively, the vaginal dilation device may include multiple gauges, including a diameter gauge and a force gauge.

[0145] The expansion device may further include a quick release mechanism configured to collapse the device from the expanded state to the closed state. The quick release mechanism may include a bump release 120 and a quick release lever 122. Additional details regarding the quick release mechanism are provided below.

[0146] FIG. 1D shows an embodiment similar to the device of FIGS. 1A-1C, except that the expansion mechanism 108 of FIG. 1D is indirectly connected to other parts of the device (e.g., the central shaft, arms, pads) via a flexible assembly or flexible tube 109. The device of FIG. 1D operates in a similar manner to the devices described in FIGS. 1A-1C, but the remote expansion mechanism allows the user to expand / dilate the device remotely from the patient. This has the advantage that, because the patient's legs are typically covered by a sheet or blanket during labor, the remote expansion mechanism allows the device to be activated without removing the cover, preserving the patient's privacy.

[0147] In other embodiments, the device may include a warning or alert mechanism, such as a visual warning (e.g., a light or a warning indicator on a display) or an audible warning (e.g., a buzzer or alarm sound) to notify the user when the device is exerting too much or too little force on the vagina. The warning mechanism may also include a timer (e.g., via an audible or visual signal) to notify the user when to expand the device.

[0148] FIG. 2 is a cross-sectional view of a vaginal dilation device 200 in an expanded state, illustrating the operation of a diameter gauge 218 in one embodiment. The vaginal dilation device 200 is a variation of the vaginal dilation device 100 described above. FIG. 2 shows the interior of the handle 206, which includes the expansion mechanism 208, diameter gauge 218, central rod 224, spring 226, and nut 228. Rotating the expansion mechanism moves the central rod 224 proximally within the handle, which in turn moves the nut 228 proximally and compresses the spring 226. Compressing the spring applies pressure to the diameter gauge 218, causing the pad 202 and arms 204 to expand radially outward, thereby moving the gauge. Because the outward movement of the scissor mechanism shown in FIG. 2 is not linear, the vaginal dilation device may further include a diameter gauge amplification mechanism 230, such as an additional spring coupled to the rotating portion of the gauge, to provide a more linear reading for the diameter gauge 218.

[0149] The tip of the gauge 218 may protrude outward through a window in the handle 206. In some embodiments, the handle may include indicator markings or diameter scales along the length of the window to allow the user to reference the diameter of the device. The markings may be colors such as green, yellow, or red to indicate the state of expansion, or may be precise diameter measurements, such as marks indicating 0-10 cm of expansion. Other markings or indicators that provide an approximate or precise reading of the diameter as the device expands may also be used.

[0150] 3A-3B show cross-sectional views of another embodiment of a vaginal dilation device 300. The vaginal dilation device shown in FIGS. 1 and 2 relates to a device that is activated by manually rotating a knob. In contrast, the vaginal dilation device 300 of FIGS. 3A-3B may include an actuation mechanism that includes a constant force device 332 and a button 336 for actuating the device's expansion. In the embodiment shown in FIGS. 3A-3B, the constant force device 332 includes a spring. Alternatively, a similar energy storage device, such as a pump, piston, elastic band, gear, or the like, may be used instead of the spring.

[0151] The vaginal dilator device of Figures 3A-3B may include an arm 304, a handle 306, a gauge 318, a central rod 324, a shuttle assembly 325, a rack assembly 334, a button 336, and a pad support 340. In the embodiment of Figures 3A and 3B, the button 336 may be connected to a pin 338. The pad support is configured to support a pad, such as pad 102 or 202 described above. It should be understood that the button 336 may be other forms of actuation device, such as a lever, a trigger, a rotary dial, or the like.

[0152] Continuing with reference to FIGS. 3A-3B, the operation of the vaginal dilation device 300 will be described. As shown, the arm 304 may include a scissor assembly. The proximal end of the scissor assembly may be connected to the handle 306 and the distal end may be connected to a shuttle assembly 325. A central rod 324 extends from the shuttle assembly 325 into the handle 306 along the longitudinal axis of the device and terminates in a rack assembly 334. A constant force device 332 (e.g., a spring) may be disposed within the handle around the central rod and compressed between the inner wall of the handle and the rack assembly. The rack assembly may include a plurality of gears or teeth that may be configured to mesh with a pin 338 on a button 336.

[0153] When button 336 is depressed, pin 338 disengages from rack assembly 334. This releases constant force device 332 (e.g., a spring) and causes it to expand, exerting a constant force on rack assembly and central rod 324 and pushing shuttle assembly 325 proximally (toward handle 306). As the distance between shuttle assembly 325 and handle 306 decreases, the scissor-like assembly expands outward, pushing the pad supports and pads (not shown) radially outward from the device. It should be understood that device 300 of FIGS. 3A and 3B may include an actuation mechanism indirectly connected to the device via flexible tubing, as shown in FIG. 1D, allowing the device to be deployed remotely from the patient.

[0154] As the constant force device 332 pushes against the rack assembly 334 and central rod 324, the gauge 318 moves proximally with the rack assembly, indicating to the user the expanded diameter of the pads of the vaginal dilation device. The device continues to expand until the next engaging tooth or gear on the rack assembly engages with the pin 338 on the button 336. The teeth on the rack assembly 334 may be spaced, for example, 1 cm apart, along the desired range of expansion, from 1 cm to 10 cm. After the rack assembly re-engages with the pin 338, the user can press the button 336 again to begin expansion to the next expansion section. In some embodiments, the button can be held in the pressed "on" position, allowing the device to continue expanding and dilating tissue with a constant force. Similarly, in other embodiments, the rack assembly may include only a single tooth or gear, allowing the device to continue expanding with a constant force after the pin 338 disengages from the single tooth.

[0155] Because the vaginal dilation device is configured to dilate with a constant force, the amount of force the device applies to tissue can be determined and controlled, maximizing the device's effectiveness while preventing tissue damage from the device itself. The constant force can be set to a level that allows for appropriate and controllable tissue dilation while reducing the risk of causing trauma. In other embodiments, the vaginal dilation device may include a clutch mechanism (e.g., another spring or torque wrench-type mechanism) to prevent excessive tissue dilation. The clutch mechanism may be configured to engage at a predetermined force threshold and prevent tissue from being subjected to forces exceeding that threshold. In other embodiments, the device may include a warning or alert mechanism, such as a visual alert (e.g., a light or warning indicator on a display) or an audible alert (e.g., a buzzer or alarm sound) to notify the user when the device is applying too much or too little force to the vagina. The alert mechanism may also include a timer (e.g., an audible or visual signal) to notify the user when the device should be dilated.

[0156] As described above, the constant force device 332 may be any device configured to apply a constant force, such as a spring, piston, pump, or the like. The constant force device may be configured to automatically apply a desired amount of constant force from the pads of the device to the tissue. In certain embodiments, the constant force device may apply a constant force of less than about 10 pounds (about 44.5 Newtons) to the tissue. In embodiments in which a spring is used as the constant force device, the coil thickness of the spring can be varied to compensate for the increase in mechanical gain as the vaginal dilation device expands, thereby maintaining a constant force applied by the device to the tissue.

[0157] 3A-3B also illustrate a mechanism that allows the pad and pad support 340 to maintain a parallel alignment with one another as the device expands. Arm 304 may include a rotating pivot point 342 configured to slide within slot 343 as the device expands. The pivot point moves along the slot, thereby maintaining the pad parallel to the central rod of the device during tissue expansion.

[0158] FIGS. 20A-20D illustrate another embodiment of a mechanism configured to maintain the pads 2002 in a parallel orientation when the device 2000 is expanded. Referring to FIGS. 20A-20C, the pads 2002 may be connected to the arms 2004 via pivots 2006. Springs 2008 may be configured to compress the pads 2002. As the device 2000 expands, the load on the pads increases, compressing the springs. The springs may be configured to generate sufficient force to overcome the initial load applied to the pads by the tissue. Thus, the springs may be selected to have a spring constant that maintains the pads in a parallel orientation during expansion of the device. FIG. 20D illustrates the device in an expanded configuration, with the springs 2008 compressing the pads 2002 to maintain the pads in a parallel orientation. The device illustrated in FIGS. 20A-20D may be configured for use as a vaginal dilation device or a vaginal exercise device.

[0159] In another embodiment, as shown in Figures 3C-3D, the vaginal dilation device includes a constant force mechanism 332, such as the spring described above, and further includes a force adjustment mechanism 344 configured to change the amount of force the constant force mechanism applies to tissue. As shown in Figures 3C-3D, the force adjustment mechanism 344 may include a wheel or knob located adjacent to the spring. When the force adjustment mechanism is adjusted from its minimum position, shown in Figure 3C, to its tensioned position, shown in Figure 3D, the force adjustment mechanism compresses the spring, increasing the force with which the spring pushes back against the rack mechanism, thereby increasing the force that the vaginal dilation device can apply to tissue.

[0160] 3A-3D may include a damper (not shown) to dampen the rapid expansion caused by the device. The damper may be, for example, a foam, spring, or piston mechanism located at the proximal end of the device.

[0161] FIGS. 21A-21C illustrate another embodiment of a vaginal dilation device 2100, including a cam 2102 configured to normalize the force curve as the arms 2104 expand. For specific configurations of vaginal dilation devices not shown in FIGS. 21A-21C, please refer to the other figures described herein, particularly FIGS. 1-3. As shown in FIG. 21A, the vaginal dilation device 2100 may include arms 2104 (e.g., a scissor-like mechanism) coupled to a central rod 2106 and a shuttle assembly 2108. The cam 2102 may be coupled to the central rod and in contact with a wheel 2110. The device may further include a constant force device (not shown in FIG. 21A) that functions and operates similarly to the constant force device 332 shown in FIGS. 3A-3D. The cam 2102 rotates along with the wheel 2110 as the constant force device pulls on the central rod 2106 and shuttle assembly 2108 in the direction of arrow 2112, thereby expanding the device 2100. Vaginal dilation devices employing a scissor-like expansion mechanism require more force during the early stages of expansion than during the later stages (e.g., expansion from 1 cm to 2 cm requires more force than expansion from 9 cm to 10 cm). This is because the scissor-like expansion mechanism gains mechanical advantage as it expands. The cam 2102 of FIGS. 21A-21C can be configured to linearize the force of the vaginal dilation device 2100 during expansion. To do so, the cam 2102 can be designed to lose its mechanical advantage at the same rate that the arms 2104 gain mechanical advantage during expansion. For example, in some embodiments, a particular angular change in the cam 2102 can cause a corresponding change in the diameter of the pads and arms 2104 of the expansion device 2100.

[0162] FIG. 21B illustrates a cam 2102 with a diameter gauge 2114 configured to display the diameter of the vaginal dilation device. FIG. 21C illustrates another embodiment of the cam 2102, including mechanical stops, rests, or detents to provide feedback during the dilation process. In some embodiments, as shown in FIG. 21C, stops can be positioned along the cam 2102 to correspond to predetermined device diameters. Thus, in FIG. 21C, the stops are positioned at 1 cm intervals ranging from 3 cm to 10 cm (e.g., positions corresponding to device dilation diameters of 3 cm, 4 cm, 5 cm, ... 10 cm). In some embodiments, the stops on the cam 2102 can prevent the vaginal dilation device from over-distending in the absence of user input.

[0163] 22A-22E illustrate additional embodiments for overcoming low-angle forces due to the scissors-like expansion mechanism of the vaginal expansion device 2200. For specific configurations of vaginal expansion devices not shown in FIGS. 22A-22C, please refer to the other figures described herein, particularly FIGS. 1-3. In the embodiment of FIGS. 22A-22C, a lever 2202 is pivotally coupled to a central rod 2206, and the lever 2202 is configured to engage detents or protrusions 2208 on the arms 2204. The lever 2202 is positioned at a greater angle relative to the central rod than the arms of the device, providing additional mechanical advantage to the arms 2204 as the expansion device expands and the central rod 2206 moves toward the proximal end of the device. FIG. 22B illustrates the lever 2202 fully deployed as the expansion device and arms 2204 continue to expand. 22C, the arm 2204 of the stretching device has been extended beyond the position where the lever 2202 engages the detent 2208. This allows the lever 2202 to expand autonomously without being constrained by the detent 2208. The lever will remain unconstrained until the arm retracts to a position where the lever 2202 can re-engage the detent 2208.

[0164] Figures 22D-22E illustrate a device based on a concept similar to that shown in Figures 22A-22C. For specific configurations of vaginal dilation devices not shown in Figures 22D-22E, please refer to the other vaginal dilation device figures described herein, particularly Figures 1-3. In Figures 22D-22E, the central rod 2206 may include a detent 2202 or bump 2208 instead of a lever, and the detent 2202 may be configured to engage a corresponding detent 2202 or bump 2208 on the arm 2204. The interaction of the detent 2202 and bump 2208 provides additional mechanical advantage to the arm 2204 during the initial phase of expansion. As shown in Figure 22D, once the arm is sufficiently expanded so that the detent no longer contacts the other arm, the scissor mechanism can continue expansion normally.

[0165] 23A-23B illustrate another embodiment of a vaginal dilation device 2300 with an adjustable force mechanism. For specific configurations of the vaginal dilation device not shown in FIGS. 23A-23B, please refer to the other vaginal device figures described herein, particularly FIGS. 1-3. Referring to FIG. 23A, the dilation device 2300 includes a force mechanism 2302 (e.g., a spring), arms 2304, a central rod 2306, a force adjustment mechanism 2308, a target diameter gauge 2310, and an actual diameter gauge 2312. This device may operate in a manner similar to the devices described herein, i.e., the force mechanism 2302 pulls on the central rod 2306, causing the arms 2304 to expand outward, increasing the diameter of the device. In the embodiment shown in FIG. 23A, the force adjustment mechanism 2308 can be used to vary the compression state of the force mechanism 2302. In some embodiments, the force adjustment mechanism 2308 is coupled to a target diameter gauge 2310 and may be configured to display a target diameter of expansion based on the current compression setting of the force mechanism 2302. The actual diameter gauge 2312 may be configured to display the actual expanded diameter of the device. For example, when the vaginal expansion device 2300 is inserted into a patient and is expanded to its maximum extent at a particular force setting, the force adjustment mechanism 2308 allows the user to adjust the force setting of the force mechanism 2302 to increase or decrease the diameter of the device. The desired diameter can be set according to the target diameter gauge 2310, and the actual diameter gauge 2312 allows the user to monitor the progress of the device.

[0166] FIG. 23B illustrates another embodiment of an adjustable force mechanism for use with a vaginal dilation device. For specific configurations of vaginal dilation devices not illustrated in FIG. 23B, please refer to the figures of the other vaginal dilation devices described herein, particularly FIGS. 1-3. Instead of changing the compression state of the force mechanism (e.g., a spring) as in the embodiment of FIG. 23A, in this embodiment, the force mechanism 2302 can be moved up or down along the lever 2314 by rotating the adjustment mechanism 2308. Adjusting the position of the force mechanism along the lever acts to change the position of the fulcrum of the lever, thereby adjusting the amount of force the force mechanism applies to the device. Thus, a user can monitor the actual diameter gauge (not shown) and the force gauge 2310 and adjust the position of the force mechanism depending on the desired diameter or force of the device.

[0167] 24A-24C illustrate another embodiment of a vaginal dilation device 2400 including a ratchet cam 2403. For specific vaginal dilation device configurations not shown in FIGS. 24A-24C, please refer to the other vaginal dilation device figures described herein, particularly FIGS. 1-3. Similar to the cam-based embodiments described above, the ratchet cam of this embodiment linearizes the force required to dilate the device. In this embodiment, a force mechanism 2402 pushes against a rack 2410, which engages the ratchet cam 2403. This moves the central rod 2406 proximally toward the ratchet cam, expanding the arms 2404 and thereby outwardly expanding the device. A force adjustment mechanism 2408 may be configured to vary the compression of the force mechanism 2402, as described above.

[0168] 24B and 24C illustrate additional ways to adjust the force applied by the device, similar to the embodiment shown in FIG. 23B. In FIG. 24B, the force adjustment mechanism 2408 may be configured to adjust the pivot point 2412 of the device. The pivot point of the device can then be connected to a central rod (not shown, but described above) to assist in the expansion of the device. In FIG. 24C, the pivot point 2412 is fixed, and the force adjustment mechanism 2408 is configured to adjust the position of the force mechanism 2402 relative to the pivot point (similar to the lever embodiment described with reference to FIG. 23B).

[0169] Figures 25A-25C illustrate another embodiment of a vaginal dilation device including a ratchet cam with multiple gears. For specific configurations of the vaginal dilation device not shown in Figures 25A-25C, please refer to the figures of the other vaginal devices described herein, particularly Figures 1-3. Similar to the embodiment of Figures 24A-24C, the force mechanism 2502 may be configured to apply pressure to a rack 2510 that engages the ratchet cam 2510 of the device, thereby causing the scissor-like arms (not shown) to extend outward from the central rod of the device. In this embodiment, the ratchet cam may include multiple gears, such as gears 2503a and 2503b, with different diameters. Referring to the side view of the cam 2503 and rack 2510 in Figure 25C, it can be seen that the rack 2510 has multiple levels configured to align with each gear of the ratchet cam. The use of multiple gears allows the user to vary the amount of force applied to the arms of the device. For example, small gear 2503b requires more force to extend the arm than large gear 2503a. Engagement of different gears can be accomplished in several ways. In one embodiment, the ratchet cam 2503 can be switched from small gear 2503b to large gear 2503a by pushing sideways in the direction of arrow 2512. While only two gears are shown in the embodiment of Figures 25A-25C, it should be understood that any number of gears can be used.

[0170] FIGS. 26A-26C illustrate various embodiments of constant force springs that can be used in vaginal dilation devices. For specific vaginal dilation device configurations not illustrated in FIGS. 26A-26C, please refer to the other vaginal dilation device illustrations described herein, particularly FIGS. 1-3. The constant force spring illustrated in FIGS. 26A-26C may be used, for example, as the constant force mechanism 332 illustrated in FIGS. 3C-3D. FIG. 26A illustrates rear, side, and front views, respectively, of a constant force mechanism 2632 including a cam 2603, a clock spring 2602, a target diameter gauge 2608, and a dial 2610. A ratchet mechanism (not shown) on the dial prevents the dial from reversing. The spring is configured to transmit force from the cam 2603 through a central rod (not shown, but functioning similarly to the central rod described above), which then expands the arms of the vaginal dilation device. This embodiment (FIG. 26A) may also include an actual diameter gauge (not shown) in addition to the target diameter gauge.

[0171] 26B-26C show various embodiments for adjusting the force of the clockspring 2602 shown in FIG. 26A. In FIG. 26B, a force adjustment mechanism 2612 adjusts the pivot point of a lever 2614, thereby varying the compression of the clockspring 2602. In FIG. 26C, the force adjustment mechanism 2612 directly compresses the spring, increasing or decreasing the force the spring applies to the cam.

[0172] FIG. 27 illustrates another embodiment of a constant-force vaginal dilation device 2700. In FIG. 27, the vaginal dilation device includes a series of cylinders 2702a-d slidably connected to a central rod 2706. Each cylinder 2702a-d may be separated from the others by compression springs 2704a-d. Flexible arch structures 2706a-b (e.g., leaf springs, living hinges) may span from one cylinder to the next. When the system is compressed, the arches flex, expanding the diameter of the device. A dial structure 2708 may contain hard stops 2710 corresponding to each cylinder (only one hard stop is shown in FIG. 27). Activating a hard stop on the dial locks the corresponding spring. Each time the spring is locked, the force required to compress the system increases. As shown in the front view of the dial 2708 in FIG. 27, the dial may include multiple user-actuable hard stops corresponding to different springs and corresponding forces. For example, in one embodiment, the dial includes force settings of 1 lb (approximately 453.6 grams), 2 lb (approximately 907.2 grams), 3 lb (approximately 1360.8 grams), and 4 lb (approximately 1814.4 grams) corresponding to actuation of each hard stop 2710. It should be understood that other forces and numbers of hard stops / springs may be used in other embodiments.

[0173] FIG. 28 illustrates another embodiment of a vaginal dilation device 2800 having a stent- or yurt-shaped structure. In FIG. 28, the device may include multiple scissor-like stent structures 2802 that are pre-biased to expand. When the device is inserted into tissue, such as the vagina, the stent structures can automatically expand, increasing the diameter of the device. In some embodiments, the stent structures 2802 may include a shape-memory material, such as Nitinol. The stent structures may be configured to expand with a predetermined force depending on the application and the desired maximum diameter. In some embodiments, the device may include a diameter gauge 2804 configured to display the diameter of the device. The device of FIG. 28 provides an opening within the device to allow a physician or user access to the body cavity to be dilated.

[0174] FIGS. 29A and 29B show another embodiment of a vaginal dilation device 2900 that uses a simple expansion mechanism instead of the scissor mechanism described above. In FIG. 29A, a force mechanism 2902 (e.g., a spring) can apply a force to an arm 2904, which can pivot about a central rod 2906. The arm 2904 can also be pivotally connected to a V-shaped mechanism 2908, which can also pivot relative to the central rod. When the spring expands and applies a force to the arm 2904, the arm 2904 pivots relative to the central rod, expanding the V-shaped mechanism 2908. Expansion of the arm 2904 and V-shaped mechanism can expand the vaginal dilation device, for example, by pushing the pad 2910 outward. FIG. 29B shows how adjusting the dial 2912 in either direction moves the spring in either direction along the central arm, thereby adjusting the force applied to the arm by the force mechanism.

[0175] FIG. 30 illustrates yet another embodiment of a vaginal dilation device 3000 with a simplified dilation mechanism. The embodiment of FIG. 30 includes a rotating array 3002 containing multiple spring plungers 3004. In some embodiments, each spring plunger exerts a different force against the surface 3006 of the device. For example, as shown in FIG. 30, four spring plungers 3004 may each have a different spring strength to vary the force applied to the device. The rotating array can be rotated to change which spring plunger contacts the surface of the device. As shown in FIG. 30, the thickness of the spring plunger may be varied to determine the amount of force applied by the spring. As the spring plungers exert a force against the surface 3006 of the device, the device rotates about a pivot point 3008, causing the pads 3010 to expand outward from the device, thereby dilating tissue.

[0176] 4A-4B are cross-sectional views of an automatic vaginal dilation device 400. In contrast to the manual or semi-automatic devices described above, the vaginal dilation device 400 may include a semi-automatic or fully automatic actuation mechanism 408 including a controller 448 connected to a motor 454 within the device and configured to automatically expand, deploy, and contract the pad and arms. The automatic vaginal dilation device 400 may include a pad 402, arms 404, a handle 406, a diameter sensor 418, a central rod 424, a force sensor 446, a controller 448, a receiver 450, a transmitter 452, a motor 454, and a worm gear 456. The pad 402 and arms 404 move mechanically in a manner similar to that described with reference to FIGS. 1-3.

[0177] 4A-4B, a controller 448 (e.g., a computer configured with hardware and software) can communicate with the vaginal dilation device wirelessly via a receiver 450 and a transmitter 452, or via a wired connection (not shown). The vaginal dilation device can measure the force that the pad 402 applies to tissue, or alternatively, the force applied against the pad, and transmit the measured force (e.g., wirelessly or via a wired connection) to the controller 448. The controller 448 can be configured to automatically move the arms 404 and the pad 402 radially outward based on the force measured by the force sensors.

[0178] For example, hardware and software on the controller can drive a motor 454 based on the measured force. The motor 454 can include a threaded shaft 455, which can engage a rack assembly disposed on the central rod 424. When the motor 454 is activated by the controller 448, the threaded shaft 455 controls the movement of the central rod, which can extend or retract the arms and pads of the device away from or toward the central rod. In some embodiments, the motor 454 can be replaced by, for example, a pump or a computer-operated piston.

[0179] The motor 454 may also be attached to a second threaded shaft 456 that may mesh with a gear on the diameter sensor 418. When the motor is actuated to expand or contract the vaginal dilation device, the second threaded shaft may engage and rotate the sensor 418 to indicate the diameter of the device. The measured diameter of the device may be transmitted to the controller 448 as an analog or digital signal (e.g., wireless or wired).

[0180] In other embodiments, the vaginal dilation device may include an alarm or warning mechanism, such as a visual alert (e.g., a light or a warning display) or an audible alert (e.g., a buzzer or alarm sound). The alert mechanism may be configured to notify the user when the device is exerting too much or too little force on the vagina. The alert mechanism may also include a timer configured to notify the user or a controller when to dilate the dilation device, which may be via an audible or visual signal or an input to the controller.

[0181] 4A-4B are capable of various modes of operation. For example, controller 448 can be configured to operate motor 454 to expand the device outward with a constant force (e.g., a predetermined constant force of less than about 10 pounds). In another embodiment, controller 448 can be configured to operate motor 454 to expand the device outward with a time-varying force. For example, controller 448 can be configured to operate motor 454 to expand the device until the force the device applies to tissue approaches a force threshold.

[0182] In other embodiments, a physician may initially desire to dilate the vaginal tissue with a constant first force. The constant first force may be a small force, such as less than 3 pounds (approximately 1360.8 grams). After a predetermined time has elapsed, the controller may be configured to automatically stop dilating the tissue until further instruction from the user is received, or to automatically dilate the vaginal tissue with a constant second force. The constant second force may be different from the constant first force, such as a force of approximately 3 to 5 pounds (approximately 1360.8 grams to 1814.4 grams). In this embodiment, the vaginal dilation device 400 may automatically dilate the tissue with a constant force for a predetermined time, after which the tissue dilation may be stopped or the dilation may continue with the constant second force. The controller may be configured to automatically adjust the force the device applies to the tissue (e.g., increase or decrease the constant force) until the desired amount of tissue dilation (e.g., 10 cm dilation) is achieved.

[0183] In other embodiments, rather than automatically expanding over a predetermined period of time, the vaginal dilator device is configured to automatically expand and dilate the tissue until a threshold force (measured by sensor 446) is reached. For example, a physician or controller can set the threshold force to approximately 3 pounds (1360.8 grams). The vaginal dilator device can then be configured to automatically dilate the vaginal tissue until sensor 446 measures a force equal to or greater than the force threshold of 3 pounds (1360.8 grams), at which point the device automatically stops dilating the tissue. It should be understood that in other embodiments, the threshold force can be any force and is not limited to 3 pounds (1360.8 grams).

[0184] In yet other embodiments, the controller may be configured to activate the vaginal dilation device to expand until a predetermined threshold force is measured, at which point the controller may be configured to automatically activate the device to slightly contract to allow the vaginal tissue to relax, thereby reducing the force it exerts on the tissue.

[0185] In yet other embodiments, the controller may be configured to actuate the vaginal dilation device based on the sensed diameter of the device or based on the sensed force and the device diameter. The diameter may be measured or sensed by the diameter sensor 418. In some embodiments, the controller may be configured to dilate the device until a predetermined diameter is reached. In other embodiments, the controller may be configured to actuate the device with a first force until a first diameter is reached, and then actuate the device with a second force until a second diameter is reached. For example, the controller may actuate the device with a force of 3 pounds (approximately 1360.8 grams) until the device diameter reaches 3 cm, and then automatically actuate the device with a force of 4 pounds (approximately 1814.4 grams) until the device diameter reaches 4 cm. In this manner, the process of varying the applied force until the device reaches a predetermined diameter can continue until the target dilation diameter is achieved.

[0186] FIG. 31 illustrates another embodiment of a vaginal dilation device 3100 with a cam and motor, configured to automatically vibrate the device. For specific vaginal dilation device configurations not shown in FIG. 31 , please refer to other figures described herein, particularly FIGS. 1-3. This device functions similarly to the cam-equipped vaginal dilation device shown in FIGS. 21A-21C. In operation, a motor 3102 may include an offset wheel that rotates relative to a cam 3104, thereby vibrating the arms (not shown) and pads (not shown) of the vaginal dilation device. The arms and pads, as well as the entire device, can vibrate radially inward and outward, as described in other embodiments, to promote tissue relaxation and dilation and prevent pain.

[0187] FIG. 32 illustrates another embodiment of a vaginal dilation device 3200 that uses a motor 3202 and barrel cam 3204 to normalize the force curve during device expansion. For specific vaginal dilation device configurations not shown in FIG. 32, please refer to the other figures described herein, particularly FIGS. 1-4. The barrel cam with variable pitch grooves can compensate for the varying force curves seen in devices with scissor-like expansion mechanisms 3203. The pitch of the cam grooves is large at the beginning of device expansion and decreases as expansion progresses toward the end stage. This means that the mechanical advantage of the scissor mechanism increases at the same rate as the mechanical advantage of the barrel cam is lost.

[0188] The motor that drives the barrel cam is under a constant load. The addition of a clutch 3206 with an adjustable preload 3208 between the motor and barrel cam allows the user to control the amount of force transmitted to the scissor mechanism. The clutch acts as a fail-safe, preventing the device from "runaway" and opening out of control. In some embodiments, the cam groove may have irregularities or "bumps" that cause the scissor mechanism to oscillate during expansion.

[0189] Figures 5A-5D illustrate various embodiments of pad shapes for use with vaginal dilation devices. The pads described herein may be covered with foam, silicone, or other soft, rubbery, or gel-like materials that are atraumatic to vaginal tissue. Pad 502 typically has a "saddle" shape, with raised features at both the distal and proximal ends of the pad to cradle and conform to the vaginal tissue. The distal or anterior curve better conforms to the natural shape of the anatomy, providing better force distribution and stability. The proximal or posterior curve resembles a "heel" shape, preventing the device from slipping off the patient. As the vaginal dilation device expands and contacts the tissue, the tissue may slide slightly over the pad, but the contact surface at the vaginal opening remains in the "valley" of the pad. In the embodiment shown in Figures 5B-5C, the pad may have a notch or ridge in the middle region to further conform or engage the anatomy. In other embodiments, the pad may be slit to avoid putting pressure on the anterior or posterior anatomy.

[0190] In other embodiments, springs can be incorporated within or beneath the pad. These springs maintain the force of the pad on the tissue within a specific range and prevent the user from overextending the device. For example, a spring incorporated within or beneath the pad can apply a constant force to the pad, similar to the constant force device described in FIG. 3. In other embodiments, the device or pad can further include an automatic vibration mechanism configured to prevent pressure necrosis. For example, a spring or other similar device located above or below the pad can be configured to automatically vibrate, reducing pressure on the tissue. Additionally, the pad can include a heating or vibration element to promote tissue relaxation.

[0191] FIGS. 6A-6G show various embodiments of force sensors located on the exterior or interior of the vaginal dilation device. In FIG. 6A, the force sensor 646 is located on the epidermis of the pad 602. In FIG. 6B, the force sensor 646 is located beneath the epidermis of the pad 602. In FIG. 6C, the force sensor 646 is located on the surface of the pad support 640 below the pad 602. In FIG. 6D, multiple force sensors 646 are located beneath the epidermis of the pad 602. In FIG. 6E, multiple force sensors 646 are located on the surface of the pad support 640 below the pad 602. FIG. 6F shows an embodiment of the vaginal dilation device 600 including a force sensor 646 located on the pad 602 and both a diameter gauge 618a and a force gauge 618b. In FIG. 6G, the force sensor 646 is located proximal to the arm 604. As the arm 604 and pad 602 expand to dilate tissue, the arm exerts pressure on the force sensor 646, and the applied force can be measured.

[0192] 7A and 7B illustrate an embodiment of a vaginal dilation device 700 covered with a protective sheath 758 that forms an expandable sterile barrier to prevent pre- and post-partum infection. The protective sheath may be made of an elastic material such as latex, silicone, etc. In some embodiments, the sheath may be constructed of a non-elastic material that folds inside and around the device and expands as the device is dilated.

[0193] FIGS. 8A-8D illustrate various embodiments of a vaginal dilation device 800 with a working channel or through-port. In FIG. 8A, the device 800 includes a through-port 860 through which a user can insert other devices, such as a cervical monitoring device, a scope, a fetal monitoring device, or a cervical dilation device. Additionally, other common tools, such as air, water, suction, a surgical cutting device, an ultrasound, or other imaging devices, can be inserted into the through-port. In FIGS. 8B-8C, the vaginal dilation device 800 can include a flexible working channel 862. The working channel is constructed from a flexible, bendable material and can accommodate any of the above devices. In FIG. 8B, the working channel extends through the handle of the vaginal dilation device and through the central axis of the pad 802. In FIG. 8C, the working channel is positioned along the side of the handle of the device, passing through the spaces between the pads when they are expanded. In Figure 8D, a working channel is shown positioned along the side of the handle, passing through the spaces between pads 802 and out through a protective sheath 858. The working channel and through ports shown in Figures 8A-8D may be surrounded by a seal to maintain sterility of the anatomy. The working channel or through port may include a one-way valve to prevent bacteria and other particles from entering the patient's body while allowing fluids and tissue to be removed.

[0194] Figure 9 illustrates a vaginal dilation device 100 with a quick release mechanism. The quick release mechanism can include a bump release 120, a quick release lever 122, and a quick release pin 164. The device shown in Figure 9 is a simplified version of the device 100 described above, and includes a central rod 124 and a shuttle assembly 125. The discussion regarding the quick release mechanism can be applied to any of the vaginal dilation devices described herein.

[0195] In situations where the vaginal dilation device 100 needs to be quickly removed from the patient, the quick-release lever 122 can be pulled or flipped to retract the device to a nearly closed position. This feature allows the user to quickly stop applying force to the tissue, preventing pinching during rapid retraction. When the quick-release lever 122 is actuated, it releases the spacer, thereby allowing the central rod 124 to move distally from the handle 106 of the device. This moves the shuttle assembly 125 away from the handle, changing the angle of the arms and moving the pad (not shown) toward the central rod of the device.

[0196] 10A-10B illustrate the use of a vaginal dilation device 100 with a quick-release mechanism. In FIG. 10A, the fetus is nearing delivery and the device 100 is inserted into the patient's vagina. Ideally, the device should be removed before the fetus passes through the cervix, and the user can remove the device by actuating the quick-release lever 122 to retract the device to a closed configuration. However, in some cases, the fetus may advance into the vaginal canal while the device 100 is still in the vagina. In such a situation, as shown in FIG. 10B, the fetus contacts the bump release 120, automatically retracting the device to a closed configuration and allowing for easy removal. In some embodiments, actuation of the bump release may activate an alarm or visual and audio signals to alert the physician that the fetus has contacted the device.

[0197] Figures 11-12 illustrate the anatomy of the female reproductive system and surrounding tissues. The pelvic floor is defined by the pubococcygeus-puborectalis complex (PC), which extends anteriorly from both pelvic sidewalls and posteriorly forms a V-shaped sling around the anorectal junction. The levator hiatus refers to the V-shaped space between the walls of these muscles. Within this V are the urethra (U) anteriorly, the vaginal canal (VC) in the middle, and the anus (A) posteriorly. In young women who have not given birth (nulliparous women), the area of ​​the levator hiatus varies from 6 to 36 cm during the Valsalva maneuver. 2 The bony structures surrounding the pelvic region, such as the pubic symphysis, pubic crest, and ischium, are also shown in Figures 11 and 12.

[0198] Figures 43A and 43B also illustrate the anatomy of the pelvic floor. Figure 43A is an axial cross-sectional view showing the anatomy of the pelvic floor of a healthy, non-pregnant subject (e.g., a nulliparous woman). The illustrated anatomy includes the pubis 4302, urethra 4304, levator ani muscle 4306, perineal body 4308, rectum 4310, sacrum 4312, obturator internus muscle 4314, ischial spine 4316, gluteus maximus muscle 4318, vagina 4322, and ischiorectal fossa adipose tissue 4320.

[0199] 43B shows an axial cross-sectional view of a pregnant woman (e.g., a primipara) with a vaginal dilation device 4330 inserted and dilated (e.g., to about 70 mm), illustrating at least some of the anatomical structures that interact with or are displaced by the dilation device.

[0200] At the plane of the smallest diameter of the fetal head, the average fetal head area is 70-100cm 2(corresponding to a head circumference of 300-350 mm), which requires significant stretching and deformation of the levator ani complex. MRI-based computer modeling has shown that the most inferior and medial portion of the levator ani complex must stretch 3.26 times its length during birth. Given such rapid stretching, it is remarkable that severe muscle damage does not occur more frequently, since such stretching is generally thought to far exceed the elastic limit of tissue, which is approximately 150%.

[0201] FIGS. 13A and 13B show a vaginal dilation device 100 inserted into a female patient in a closed and expanded state, respectively. The vaginal dilation device shown in FIGS. 13A and 13B can be any of the vaginal dilation devices described herein. FIG. 13A shows the device 100 inserted into the vagina in a closed state. To enhance patient comfort, the outer diameter of the device in the closed state can be less than 4 cm. FIG. 13B shows the device 100 inserted into the vagina in an expanded state. The outer diameter of the device in the expanded state reaches a maximum of approximately 10 cm. FIG. 13B also shows the orientation of the pads 102 relative to the anatomical structures. The vaginal dilation device 100 includes four pads 102, which are positioned to avoid pressure on critical anatomical areas, such as the urethra U, perineum, and anus A, during expansion. In other embodiments, the device may include four or more pads but does not include pads that expand directly upward to avoid pressure on the urethra or pads that expand directly downward to avoid pressure on the perineum and anus.

[0202] Methods of using a vaginal dilation device are described below. Figures 14A-14D show a vaginal dilation device inserted into a female patient in labor. The vaginal dilation device used in these methods of use may be any of the vaginal dilation devices described herein, including the fully manual vaginal dilation device shown in Figures 1-2, the semi-automatic vaginal dilation device shown in Figure 3, or the semi-automatic or fully automatic vaginal dilation device shown in Figure 4. Additionally, the vaginal dilation device shown in Figures 14A-14D may include other additional features described herein, such as a force sensor, a diameter gauge / sensor, a working channel, a protective sheath, etc.

[0203] FIG. 14A illustrates a vaginal dilation device 1400 inserted into a patient's vagina, which may include a pad 1402, an actuation mechanism 1408, a diameter gauge 1418a, and a force gauge 1418b. The device may also include sensors (not shown) for measuring force and / or diameter, as described above. In the embodiment of FIG. 14A, the device has an actuation mechanism including a mechanical knob; however, in other embodiments, the actuation mechanism may include a constant-force device such as a spring or a fully automated system consisting of a controller and motor. The device 1400 in FIG. 14A is shown in a closed, or compact, configuration. The device may be inserted at any point during the first stage of labor, typically upon the patient's arrival at the hospital before delivery. On average, women spend 14 hours in the hospital before the second stage of labor begins. The diameter gauge 1418a indicates the outer diameter of the device's pad and can indicate how much the vaginal tissue has dilated. The force gauge 1418b can indicate the amount of force the pad exerts on or against the tissue.

[0204] FIG. 14B shows the vaginal dilation device 1400 after it has been partially dilated. The diameter gauge 1418a indicates the dilated diameter of the device to the user. The force gauge 1418b is monitored by the user or a controller (not shown) to ensure proper and safe use of the device and to prevent tissue damage. FIG. 14C shows the vaginal dilation device in a fully dilated configuration, effectively dilating the vaginal tissue to a desired diameter (e.g., 10 cm). The diameter gauge 1418a indicates to the user that the device's diameter has reached the target value. The force gauge 1418b is also monitored by the user or a controller to ensure safety and prevent tissue trauma. FIG. 14D shows another view of the vaginal dilation device in its dilated state. In this device, the diameter gauge 1418a and force gauge 1418b are located on top of the device for easy user reading. The pad 1402 is positioned to apply pressure to the vaginal tissue but not to apply pressure to sensitive tissue areas such as the urethra, perineum, or anus.

[0205] Figure 15 is a graph illustrating two vaginal tissue dilation methods used in a case study. As shown in the graph, the vaginal tissue diameter increased from 1.1 cm to 7 cm over a 1 hour and 15 minute period. To avoid tissue damage, the force applied to the tissue was increased in stages. For example, initially, approximately 2.5 pounds of force was applied by the device to the tissue, and after approximately 500 seconds, the tissue was dilated to 4 cm. The tissue then relaxed, and after approximately 1000 seconds, the force applied by the device to the tissue decreased to approximately 1 pound. Next, approximately 3 pounds of force was applied by the device to the tissue, and the tissue was dilated to 4.5 cm. A period of no further dilation was then performed, during which the force applied was reduced to less than 2 pounds. This process was performed in stages. For example, approximately 4.5 pounds of force was applied to the tissue to dilate to 5 cm. Approximately 5.5 pounds of force was used to dilate to 5.5 cm. Approximately 4 pounds of force was used to dilate to 6 cm. Approximately 6 pounds of force was used to dilate to 6.5 cm. Approximately 7 pounds of force was used to dilate to 7 cm. This method allowed for safe and effective dilation of vaginal tissue while minimizing tissue damage.

[0206] It should be understood that these values ​​are illustrative only, and that individual women's bodies and tissues may respond differently to treatment. Generally, however, a method for expanding vaginal tissue may include inserting a vaginal expansion device into the vagina, measuring the force applied to the vagina by the vaginal expansion device, expanding the vagina with the vaginal expansion device, and pausing or stopping the expansion of the vagina when the force applied to the vagina by the vaginal expansion device increases to a first force threshold. In some embodiments, the method may further include measuring the diameter of the vagina with the vaginal expansion device. The method may then include resuming the expansion of the vagina when the force applied to the vagina by the vaginal expansion device decreases to a second force threshold. This may occur, for example, when a user or controller determines that the tissue has sufficiently relaxed and it is time to expand the vaginal tissue to a larger diameter. In some embodiments, expansion continues until the force applied by the vaginal expansion device increases again to the first force threshold, or alternatively, until the force applied by the vaginal expansion device increases to a third force threshold greater than the first force threshold. In some embodiments, the first, second, and third force thresholds are in a range of less than approximately 8 pounds of force.

[0207] In the embodiment shown in Figure 15, the viscoelastic properties of the patient's muscle and connective tissue can be utilized to achieve maximum expansion. The tissue is stretched by the device to a preset maximum stress or force, then the tissue is allowed to relax to relieve stress, and the diameter of the device can then be increased again to the maximum stress value. This cycle of stressing the tissue, releasing the stress, and re-stressing with an increased diameter can be repeated until a full tissue preparation diameter of approximately 10 cm is achieved.

[0208] FIG. 16 is a graph illustrating another method for dilating vaginal tissue with a constant force during labor. FIG. 16 shows the results of constant force dilation in a case study. Vaginal tissue can be dilated with a constant force using any of the vaginal dilation devices described herein, particularly those described with reference to FIGS. 3 and 4. Referring to the constant force dilation chart in FIG. 16, the vaginal diameter increased from a baseline diameter of 1.0 cm to 5.5 cm over approximately one hour. Force was maintained low by increasing the diameter stepwise and frequently. Similar to the stepwise dilation test described with reference to FIG. 15, the force decreased rapidly during the initial dilation to the new diameter, allowing for more frequent diameter increases to provide sustained relief of stress on the tissue.

[0209] FIG. 17 is a graph showing the stages of labor and the relative dilation diameter of a patient's cervix and vagina. During the latent or first stage of labor, the cervix dilates to approximately 3-4 cm over approximately 8 hours. Approximately during the final 6 hours of labor, the cervix dilates to approximately 10 cm. FIG. 17 also illustrates the natural stretching of perineal tissue. As a natural tissue response, perineal tissue typically remains at approximately 2 cm of dilation until the final stages of labor, then rapidly stretches to 10 cm just prior to labor, which can result in tearing and tissue damage. In some embodiments, perineal tissue can be gradually dilated using a vaginal dilation device. For example, during the first stage of labor, the perineal tissue can be dilated to approximately 7-10 cm using the vaginal dilation device. During the second stage of labor, the vaginal dilation device can be removed from the patient, and birth can proceed with the perineal tissue stretched and relaxed.

[0210] The vaginal dilation devices described herein can be used in a hospital setting under the supervision of trained obstetricians and nurses during the first stage of labor. The devices can be designed as single-use dilators configured to be inserted into the anterior third of the vagina and configured to incrementally dilate vaginal and perineal tissues from a resting diameter of 2-3 cm to a fully dilated diameter of approximately 10 cm in preparation for fetal delivery. Dilation can be controlled manually or by an automated actuation system, allowing for rapid device removal if necessary.

[0211] The device can be inserted at any time during the first stage of labor and configured to dilate in 5- to 15-minute increments. Between dilations, the patient can remove the device and ambulate if desired. Progression of cervical dilation can be used as an indicator of labor progress. To reduce or eliminate discomfort, the device can be used under epidural or local vaginal anesthesia. In some embodiments, the device can dilate tissue for approximately 1-3 hours to effectively relieve internal tissue stress and prepare the tissue for the second stage of labor. The device can then be removed before the onset of the second stage of labor, allowing labor to occur unimpeded.

[0212] FIG. 18 is a graph illustrating another method for dilating vaginal tissue during labor. FIG. 18 illustrates another embodiment for dilating vaginal tissue. In this embodiment, a vaginal dilation device is configured to dilate tissue at a constant rate. As the device dilates the tissue, the force it applies to the tissue increases. This method can be used in situations where rapid tissue dilation is required. A typical woman's vagina has a resting diameter of approximately 2-3 cm. In one embodiment, it is desirable to dilate the vagina to approximately 9-10 cm in approximately 2 hours, which corresponds to approximately 3.5 cm / hour. Therefore, the constant rate dilation method in this embodiment can include dilating the device at a constant rate to achieve approximately 3-3.5 cm of dilation per hour. This can be achieved in various ways, such as approximately 0.5 cm of dilation every 10 minutes, 1 cm of dilation every 20 minutes, etc. Any of the devices described herein can be used for constant rate dilation. For example, in the devices of FIGS. 1-2, constant rate dilation can be achieved by rotating the dilation mechanism or knob at a set interval or at a constant rate. By monitoring the diameter gauge in combination with rotation of the expansion mechanism, consistent expansion can be achieved. Similarly, the automated system in Figure 4 can be programmed to expand the device at any rate for any length of time.

[0213] 19A-19B illustrate another embodiment of a vaginal dilation device 1900. The device may include a pad 1902, a handle 1906, an arm (not shown), an expansion mechanism 1908, a central rod 1924, and a diameter gauge 1918, as well as any of the configurations described with reference to the figures herein. In the embodiment of FIGS. 19A-19B, the expansion mechanism 1908 includes a trigger assembly configured to expand the device in predetermined expansion increments.

[0214] FIG. 19B shows a cross-sectional view of device 1900. In FIG. 19B, central rod 1924 can have a hexagonal or non-circular shape, and plate 1966 can be configured to engage the central rod and prevent axial movement of the rod. When the trigger assembly is actuated, plate 1966 moves parallel, allowing axial movement of the central rod. When the trigger assembly is actuated, the central rod moves proximally, causing arms (not shown) and pads (not shown) to extend outward from the device, as described in other vaginal dilation device embodiments above.

[0215] In some embodiments, a single "click" or actuation of the trigger assembly may be configured to expand the device a preset amount of expansion. For example, the device may be configured to expand a precise amount with each actuation of the trigger assembly. This design makes device 1900 particularly suited for constant rate expansion. In one embodiment, the device may be configured to expand a predetermined amount of expansion (e.g., approximately 0.5 cm) with each actuation of the trigger assembly. A user may expand the device at a constant rate by actuating the trigger assembly at preset time intervals (e.g., every 10 minutes). In other embodiments, device 1900 may include a force sensor as described above, and the user may expand the device based on the force sensed by the device. It should be understood that in other embodiments, the preset amount of expansion may be any amount (e.g., 0-1 cm, 0-2 cm, 0-3 cm, or 0-4 cm per actuation), and the preset time interval may be any length of time (e.g., 0-2 hours or more).

[0216] All embodiments of the vaginal dilation device described herein can be used for applications other than dilating vaginal tissue for childbirth. For example, in some embodiments, the vaginal dilation device described herein can be used to treat vaginismus. When using a vaginal dilation device in a woman to prepare for childbirth, the target tissue diameter is generally in the range of 8 to 10 cm, whereas when using a vaginal dilation device to treat vaginismus, it may be desirable to dilate the vaginal muscles in the range of 1 to 4 cm. Therefore, many of the features that enable the vaginal dilation device described herein to dilate beyond 10 cm are unnecessary for vaginismus treatment. For example, instead of dilating from a base diameter of 1 cm to 10 cm or more, a dilation device for treating vaginismus according to some embodiments may be configured to dilate from 1 cm to 4 cm. A method for treating vaginismus may include, for example, dilating a vaginal dilation device described herein within a patient's vagina and dilating the vaginal dilation device to 4 cm. In treating vaginismus, the vaginal dilation device may be dilated within the vagina at a constant rate or with a constant force. The user of the device can monitor the force the device is applying to the vagina and the diameter of the device within the tissue. Additionally, any of the devices described herein may be used as vaginal exercise devices or as cervical dilation devices.

[0217] FIG. 33 illustrates one embodiment of a vaginal dilation device 3300 optimized for the treatment of vaginismus. Because the device only needs to dilate to approximately 4 cm, the previously described scissor-like dilation mechanism can be replaced with a simple conical structure 3302. The conical structure is coupled to a central rod 3304. Manual rotation of a knob 3306 pulls the central rod and conical structure proximally. A pad 3308 includes an internal camming surface 3310 configured to engage the conical structure. As the conical structure moves proximally, the internal camming surface 3310 of the pad 3308 pushes the pad outward, dilating the tissue. It should be understood that the previously described constant force devices (e.g., springs) or automatic devices (e.g., motors) can be applied to the device of FIG. 33 in place of the manual knob.

[0218] Figure 34 illustrates another embodiment of an expandable vaginal dilation device. This embodiment uses a living hinge structure 3402 configured to expand in diameter when compressed axially. Axial compression of the device may be similar to any of the previous embodiments in which the central rod moves proximally within the device. Beneficially, a smaller hinge, as shown in Figure 34, increases the initial hinge angle, reducing the initial force required to open and expand the device.

[0219] 37-39 illustrate additional optional embodiment methods for using an expandable vaginal dilation device. These optional methods can be used to promote vaginal tissue dilation during labor. In some aspects, the methods are performed during the first stage of labor, and the dilation device is removed prior to the second stage.

[0220] In some embodiments, the method is performed during the active phase of labor. The active phase of labor is understood to be the phase that includes the time when the mother experiences accelerated cervical dilation. In some embodiments, accelerated cervical dilation typically begins when the cervical dilation reaches 6 cm.

[0221] Additionally or alternatively, it should be understood that these methods may be practiced by users who are not in labor, for example, these methods may be used by pregnant users to prepare for labor.

[0222] 37 illustrates an additional method 3700 for using a vaginal dilation device. The additional method 3700 can be performed with any of the expandable vaginal dilation devices described herein. The method 3700 can be performed as an additional step before the desired incremental dilation treatment method begins, as shown in FIG. 41. The optional method 3700 begins with inserting the device into the user's vagina at 3702.

[0223] The additional method may further include initially expanding the device (e.g., an expansion arm of the device) to a predetermined diameter in step 3704. Expanding the device to the predetermined diameter may result in fixation of the device. In some embodiments involving automated or semi-automated devices, a controller in communication with the expansion mechanism of the device may be used to automatically perform the initial expansion operation (e.g., expansion to fixate the device).

[0224] The initial rapid expansion may, for example, include a larger expansion change than subsequent expansion increments. In some embodiments, the rapid expansion includes expanding the device to a diameter of about 4-7 cm (or about 5-6 cm, about 5.5 cm, etc.).

[0225] The rapid expansion can be performed at a constant rate or at a variable rate. In some embodiments, including a constant rate, the expansion rate is about 0.5-0.9 mm / sec (or about 0.6-0.8 mm / sec, or about 0.7 mm / sec).

[0226] In some embodiments, the inflation rate can be manually controlled, and in some embodiments, the device includes a controller configured to automatically implement a user-selected inflation rate, as described herein.

[0227] The device includes a diameter sensor, embodiments of which are described above (e.g., diameter sensor 418).

[0228] The device also includes one or more force sensors, embodiments of which are described above (e.g., force sensors 446, 646).

[0229] In some embodiments, the rapid expansion is performed manually. In some embodiments, the rapid expansion is performed by actuation of a controller connected to or associated with the device (e.g., the expansion mechanism of the device). For example, a user initiates the rapid expansion, and the controller automatically expands the device to the desired amount of expansion. The controller may be connected to or in communication with a force sensor and / or a diameter sensor.

[0230] The method shown in FIG. 37 also includes the additional step 3706 of holding the expansion, i.e., the diameter of the device, while the device (e.g., the expansion arms of the device) collects data from the user. The device may pause expansion after a rapid expansion to collect force data from the vaginal canal tissue. The collected force data provides data indicative of strain on the tissue and can provide information regarding the safety of the user. The collected force data also provides information regarding the stress response of individual tissues to the rapid expansion.

[0231] Figures 38(A)-38(C) show an embodiment of a vaginal dilation device 3800 comprising four pads. The device comprises two anterior pads 3810 and two posterior pads 3812. Figure 38(A) shows the vaginal dilation device 3800 positioned within the vaginal canal. The vaginal walls are not shown. The vaginal canal is surrounded by the pubic bone 3802, levator ani muscle loop 3804, and perineal body 3806. The dashed line 3804 indicates the line of action of the levator ani muscle fibers.

[0232] 38(B) and 38(C) illustrate the force 3814 exerted by the pads 3810 and 3812 and the reaction forces from the anatomical structures within the vaginal canal surrounding the device. Also shown is a reaction force 3816 from the pubic bone. The force 3814 exerted by the pads and the reaction force 3816 of the pubic bone contribute to a distension tension 3818 in the tissues within the vaginal canal (e.g., the levator ani, perineal body, other connective tissue, and fat).

[0233] In some embodiments of devices including pads and a scissor-like expansion mechanism, the radial reaction force exerted on each pad by the tissues composing the lower birth canal may be transmitted through the scissor-like mechanism to an axial force transducer attached to one end of a lead screw. The nonlinear relationship between the circumferential tension of the lower birth canal, the force exerted by the pad, and the force recorded by the load cell may be pre-calibrated for a predetermined expansion range (e.g., 40-85 mm). It should be understood that in some embodiments, the pad itself includes a force sensor.

[0234] In some embodiments, the device collecting data from the user may be configured to synchronously collect force, diameter, and / or treatment time data at a predetermined frequency. In some embodiments, the device may be configured to record force, diameter, and treatment time data every 1 second (or every 0.5-2 seconds, or every 0.5 seconds, 1.5 seconds, 2 seconds, etc.). An example of this data collection is shown in Figures 42A and 42B.

[0235] In some embodiments, force, diameter, and treatment time data collected from the user is used to predict the user's response to vaginal dilation. Data from the sensors in the dilation device can be analyzed to predict the response of the patient's vaginal canal tissues during labor. This data can be used to adjust the dilation process (e.g., the duration for which dilation occurs, the dilation increment, etc.). This data can also be used to predict the risk of injury to the user's pelvic floor tissues (e.g., levator ani, etc.). In some embodiments, this data can be used in a predictive tool to provide the user with a predicted progression of labor. The user's data can also be used to predict the likelihood that the user will require potential intervention during labor.

[0236] In some embodiments, data collected from multiple users can be stored in an aggregated database. This aggregated data can be used to develop algorithms and implement machine learning to predict an individual user's tissue response to dilation, suggest dilation techniques, and provide predictive risk assessments. For example, the aggregated data can be used to provide improved tools for predicting injury risk, predicting labor progress, and predicting the need for potential intervention during labor.

[0237] Figure 39 illustrates another embodiment of a method 3900 of using a stretching device. The method can include step 3902 of inserting the device into a user's vagina, step 3904 of activating the device to perform an initial rapid stretch to anchor it within the vagina, and the additional step 3906 of maintaining the stretch while the device collects data from the user. Unless otherwise stated, these steps can be similar to or performed according to those described in connection with Figure 37.

[0238] The method 3900 further includes resuming expansion of the device 3908. Expansion of the device may be performed according to any expansion / expansion method described herein.

[0239] Figure 40 illustrates another method 4000 of using an expansion device. Method 4000 can include step 4002 of inserting the device into a user's vagina, as described above with reference to Figures 37 and 39, and the additional step 4004 of activating the device to perform an initial rapid expansion to secure the device, and the additional step 4006 of maintaining the expansion while the device collects data from the user. Unless otherwise noted, the steps of method 4000 are similar to those described above with reference to Figures 37 and 39.

[0240] The method 4000 may further include expanding the device by a desired expansion increment, which may be between about 0.5 mm and 2 mm.

[0241] The method includes monitoring the force during expansion. If the force exceeds a predetermined threshold during expansion, as shown in decision process 4010, expansion is paused until the force falls below the predetermined threshold. After the force falls below the threshold, expansion is resumed.

[0242] The method includes a step 4012 of continuing to expand the device by the desired expansion increment.

[0243] Once the device has expanded by the desired expansion increment, expansion is paused, as shown in step 4014. This pause may last for about 10 seconds to 3 minutes (or about 1 minute, 2 minutes, 90 seconds, etc.).

[0244] If the desired duration or diameter has not been reached, as indicated by decision process 4016, the process returns to step 4008 and the expansion and pause cycle is performed again.

[0245] In some embodiments, the expansion rate may be constant, while in other embodiments, the expansion rate may vary.

[0246] The desired expansion increment may be the same over multiple cycles, or in some embodiments, the desired expansion increment may change from cycle to cycle.

[0247] In some additional embodiments, the device is expanded by the desired expansion increment after a predetermined time has elapsed since the previous expansion. In any such embodiment, after the desired expansion increment is reached, expansion is paused until the next expansion time. In some embodiments, expansion occurs every 90 seconds (or 1 minute, 2 minutes, 180 seconds, etc.).

[0248] Once the desired diameter or desired time is reached, the expansion is stopped, as shown in step 4018.

[0249] In some embodiments, the treatment time can be user-adjustable. The treatment time may be, for example, 30 to 90 minutes (or 30 to 60 minutes, 20 to 120 minutes, etc.). For example, a user may select a 60-minute treatment time. In this case, the device may be configured to expand by approximately 1 mm approximately every 2 minutes after contacting the patient's tissue and completing the initial expansion. FIG. 41 illustrates this treatment cycle. As shown in FIG. 41, the device undergoes initial expansion until it reaches a diameter of 55 mm (and in some embodiments, remains there), then begins the treatment method described herein, expanding by 1 mm every 2 minutes for the entire treatment time of approximately 1 hour (e.g., 55 to 65 minutes, 60 to 65 minutes, etc.). As another example, a user may select a 30-minute treatment time. In this case, the device may be configured to expand by 1 mm approximately every 1 minute during the treatment method.

[0250] In some embodiments, the device is configured to automatically determine the expansion rate based on the selected treatment time.

[0251] In some embodiments, method 4000 can be performed by a controller connected to or in communication with the force sensor, diameter sensor, and expansion mechanism. Unless otherwise noted, the controller and devices can be similar to those described herein (e.g., with respect to FIGS. 4A-4B).

[0252] In some embodiments, the method 4000 can be performed manually.

[0253] In some embodiments, the method includes collecting force, diameter, and treatment duration data synchronously throughout the treatment period.

[0254] 42A and 42B show data from the first study of women using a dilation device to reduce the risk of patient injury during labor. Figures 42A and 42B show the results of a treatment using a dilation device to dilate a patient's vaginal tissue over approximately one hour. The treatment prepares the patient's birth canal for the second stage of labor to reduce the likelihood of injury during that stage. These methods involve inserting a dilation device into the patient's vagina during the first stage of labor and expanding the diameter of the device by a predetermined dilation increment in this example. This expansion applies force to the patient's lower birth canal. After the predetermined dilation increment is reached, the method pauses the expansion to allow the patient's vaginal tissue to open, thereby applying less force to the human patient's lower birth canal than previously applied. After the predetermined time has elapsed, the method again expands the diameter of the device by the predetermined dilation increment. This incremental expansion process is repeated, as can be seen from the characteristic graph of the device's diameter increasing gradually and at a nearly constant rate (linear) over time. This cyclic dilation is performed until the diameter of the dilation device reaches a diameter selected to achieve the desired therapeutic effect, such as reducing the possibility of injury to the patient as the fetus passes through the birth canal. In this study, the dilation method typically begins after a monitoring step in which the patient's cervical dilation status, i.e., the clinician's assessment of the degree of cervical dilation, is monitored or measured. This monitored dilation status is used to determine when to insert the dilation device before complete cervical dilation. Typically, the clinician waited until the cervical dilation reached approximately 6 cm.

[0255] FIGS. 42A and 42B show example user force, diameter, and treatment time data. In some embodiments, the device is configured to record force, diameter, and treatment time data once per second (or every 0.5-2 seconds, or 0.5 seconds, 1.5 seconds, 2 seconds, etc.). The patients shown in FIGS. 42A and 42B are primiparas in the first stage of labor. These patients were treated using the Materna Prep device, developed by the assignee herein. In this study, the device was a disposable, semi-automatic dilator used during the first stage of labor to prepare the vaginal canal for vaginal birth. The device gently pre-stretches the vagina and surrounding pelvic tissues during labor, thereby substantially controlling the tissue strain rate during labor. For more information, see "EASE: The Materna Prep Pivotal Study" (Mayo Clinic clinical trial website). The device is typically introduced into the lower part of the patient's vagina, often within the first 4 cm of the vaginal canal, and usually within the first 3-6 cm. The subjects were primiparas or women whose pregnancies had ended within 24 weeks of pregnancy, and the device was introduced during the first stage of labor. For example, the device was introduced when the cervical dilation was 5-7 cm or less (based on routine clinical measurement or estimation), but it may also be introduced at any time before complete effacement.

[0256] Example 1

[0257] A user may use a vaginal dilation device as described herein. The device may be placed within the user's vaginal canal. The device is configured to collect force, diameter, and treatment time data every second. The collected data is shown in FIG. 42A. FIG. 42A shows a graph with the diameter of the device on the left Y-axis, the force the device applies to the vaginal canal on the right Y-axis, and time on the X-axis. Diameter data 4202 is represented by the top trendline. Force data 4204 is represented by the bottom trendline. The device performs an initial rapid expansion, expanding the device (e.g., the padding of the device) to a diameter of 55 mm. This 55 mm diameter is held for four minutes. During this hold period, the device continues to collect force, diameter, and treatment time data. The device then continues to expand. The device is set, either by default or by the user, for a 60-minute treatment time. The device expands by 1 mm every two minutes. After approximately 60 minutes of treatment, the device reaches a diameter of 80 mm. In some embodiments, after the device reaches its final diameter, it holds that diameter for a period of time to collect force, diameter, and treatment time data, as shown in Figure 42A. After the expansion protocol is complete, the device can be retracted and removed.

[0258] The data shown in FIG. 42A shows that during increased dilation, the measured force initially spikes, then gradually decreases before the next diameter increase. This force decay is best seen in portion 4206 of the force trend line after the initial rapid dilation. Similar force decays are seen with each diameter increase. These force decays demonstrate how the described dilation method takes advantage of the viscoelastic properties of the tissue surrounding the vaginal canal. The force decays represent the tissue's ability to stretch in response to the increased force applied by the diameter increase. After the tissue stretches in response to the increased force, as shown by the decrease in measured force, the tissue can prepare for the next diameter increase.

[0259] Example 2

[0260] A user uses a vaginal dilation device described herein. The device can be placed within the user's vaginal canal. The device is configured to collect force, diameter, and treatment time data every second. The collected data is shown in FIG. 42B. FIG. 42B shows a graph of data with diameter values ​​on the left Y-axis, measured force on the right Y-axis, and time on the X-axis. In this example, the patient received approximately 60 minutes of treatment, and the device, placed within the lower vaginal canal, reached approximately 80 mm of dilation before preparing for birth. The time shown on the X-axis indicates that the diameter of the vaginal dilation device increased seven times over a period of approximately 10 minutes, representing approximately one dilation every 100 seconds. Diameter data 4212 is shown by the upper trendline. The upper trendline indicates that for this patient, the device gradually expanded in approximately equal increments until the diameter of the lower vaginal canal increased by approximately 5 mm, i.e., approximately 0.7 mm of incremental dilation. Force data 4214 is shown by the lower trendline. The device performs an initial rapid expansion, expanding the device (e.g., the pads of the device) to a diameter of 55 mm. The 55 mm diameter is held for 5 minutes. During this hold period, the device continues to collect force and diameter data. After the hold, the device continues expansion. For this user, the measured force exceeds a pre-set force threshold or force limit 4216. Once the force limit is reached, the device pauses or stops expansion, as shown at points 4218, 4220, and 4222. The device then resumes treatment when the measured force falls below the force limit.

[0261] Once the muscle relaxes and the force decreases, the device resumes treatment. In some embodiments, this means that the diameter hold time measurement does not begin until the measured force reaches a predetermined value below the predetermined force limit. In some embodiments, the device is configured to wait a predetermined time after falling below the predetermined force limit.

[0262] It should be appreciated that in some embodiments, the device may miss one or more force and / or diameter recordings, as shown at 4224, which may result in irregularities in the trend lines.

[0263] In other embodiments, rather than for preparing for childbirth or treating vaginismus, the vaginal dilation device may be used as a home training device similar to "Kegel exercises." In such embodiments, a user may contract their vaginal muscles against any of the vaginal dilation devices described herein to build muscle strength to treat pelvic floor disorders. In such embodiments, a device that provides adjustable force or that displays the force or diameter of the device is preferred.

[0264] 35, a vaginal exercise device 3500 includes a simple expansion mechanism including a pair of arms 3502 that are pivotable about a central rod 3504. A spring or other constant force mechanism 3506 can apply a preload to the arms, which causes the pads 3508 to expand outward due to the preload. A force dial 3510 provides feedback to the user of the actual force they are applying to the device. The device features a knob 3512 that not only allows the user to adjust the amount of force the device applies to the tissue, but also allows the user to see the amount of resistance they are applying to the device.

[0265] FIG. 36 illustrates various embodiments of a cervical dilation device 3600. The cervical dilation device can incorporate any of the configurations of the vaginal dilation devices described above. Additionally, the pads and extension device 3602 of the device can be configured to provide access to the cervical anatomy. The cervical dilation device can be used to accurately measure the diameter of the cervical os during labor and / or to assist in the cervical dilation process. Any of the methods described above related to vaginal dilation can be used to dilate a patient's cervix. In some embodiments, the cervical dilation device is configured to dilate the cervical os from approximately 1 cm to 10 cm.

[0266] The scope of the present invention is not to be limited by the subject specification, but only by the plain meaning of the terms used in the claims.

Claims

1. 1. A method of dilating vaginal tissue of a human patient with a dilation device to prepare the patient's birth canal for a second stage of labor, comprising: inserting the expansion device into the human patient's vagina during a first stage of labor; expanding the diameter of the expansion device by a predetermined expansion increment to apply a force to the lower birth canal of the human patient; pausing dilation after reaching the predetermined dilation increment to dilate the vaginal tissue of the human patient and reduce the force applied to the lower birth canal of the human patient; re-expanding the diameter of the expansion device by the predetermined expansion increment; and pausing the dilation until the diameter of the dilation device reaches a diameter that provides a therapeutic effect that reduces the risk of injury to the fetus as it passes through the birth canal of the human patient, and repeating the re-dilation step.

2. The method of claim 1 , wherein the expansion device includes expansion arms arranged to move radially outward to expand the diameter of the expansion device.

3. 10. The method of claim 1, further comprising the step of monitoring the dilation status of the human patient's cervix and inserting the dilation device into the human patient's vagina before full cervical dilation is achieved.

4. 4. The method of claim 3, wherein the step of inserting the dilation device into the vagina of the human patient before full dilation of the cervix is ​​achieved is performed when the cervix is ​​dilated to about 6 cm or more.

5. 10. The method of claim 1, further comprising monitoring data from a force sensor measuring the force applied to the lower birth canal of the human patient and data from a diameter sensor provided on the expansion device.

6. monitoring data from a force sensor measuring a force applied to the lower birth canal of the human patient; and ceasing expansion if the measured force exceeds a preset force threshold.

7. The method of claim 6 , further comprising the step of resuming expansion if the measured force falls below the set force threshold.

8. providing a controller on the stretching device to automatically expand the diameter of the stretching device by the predetermined expansion increment; pausing expansion after the predetermined expansion increment is reached; re-expanding the diameter of the expansion device to the predetermined expansion increment; 2. The method of claim 1, comprising: pausing the expansion to expand the expansion device until a predetermined diameter is reached and repeating the re-expansion steps to achieve a therapeutic effect that reduces the risk of the fetus damaging the birth canal of the human patient as the fetus passes through the birth canal of the human patient.

9. 10. The method of claim 1, comprising selecting the length of time required to dilate to a predetermined diameter to achieve a therapeutic effect that reduces the risk of the fetus damaging the birth canal of the human patient as the fetus passes through the birth canal of the human patient.

10. 10. The method of claim 9, wherein the length of time is configured to range from about 20 minutes to 120 minutes.

11. 10. The method of claim 9, wherein the length of time is configured to range from about 30 minutes to 60 minutes.

12. 10. The method of claim 9, wherein the length of time is about 30 minutes and the expansion device is expanded in a range of about 40 mm to about 80 mm in 30 minutes.

13. The method of claim 1 , further comprising the step of selecting the predetermined expansion increment before inserting the expansion device into the human patient.

14. The method of claim 13, wherein the predetermined expansion increment is configured to be in the range of approximately 0.5 mm to 2.0 mm.

15. 10. The method of claim 9, wherein the length of time is about 30 to 60 minutes, the predetermined expansion increments are in the range of 0.5 to 2.0 mm, and the predetermined expansion increments are applied at regular time intervals to cause the expansion device to expand in a generally linear manner in the range of about 40 mm to about 80 mm over the 30 to 60 minute period.

16. The method of claim 1 further comprising collecting diameter and treatment time data.

17. 10. The method of claim 1, further comprising the step of selecting a predetermined time interval from the start of a first expansion of the expansion device to a predetermined diameter to the start of a second, subsequent expansion.

18. 10. The method of claim 1, further comprising collecting data regarding applied force, diameter of the expansion device, and treatment time approximately every 1-2 seconds after the expansion device is inserted into the human patient's vagina.

19. 10. The method of claim 1, wherein inserting the stretching device into the vagina of the human patient comprises inserting the stretching device into the vagina of the human patient so that it stretches over the lower 3-4 cm of the vagina.

20. The method of claim 1 , further comprising administering local anesthesia prior to insertion of the stretching device.

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