A defecation aid system for a lying position

Abstract

A supine defecation assistance system includes an abdominal pressure sensor, a flexible patch with electromyographic electrodes placed on the perianal skin, a main control unit, and a nerve stimulation unit. The abdominal pressure sensor collects intra-abdominal pressure, the electromyographic electrodes collect electromyographic signals from the external anal sphincter, and the main control unit is connected to the abdominal pressure sensor, the electromyographic electrodes, and the nerve stimulation unit. When the intra-abdominal pressure collected by the abdominal pressure sensor in real time is greater than 2.5 times the resting intra-abdominal pressure, and the amplitude of the electromyographic signal collected by the electromyographic electrodes drops to less than 30% of the resting state for a duration of ≥2 seconds, it is considered a defecation opportunity. The main control unit then controls the nerve stimulation unit to initiate electrical stimulation of the sacral nerve target point. This invention accurately identifies defecation intent, reduces the misjudgment rate, improves defecation assistance efficiency, reduces the stimulation effect decay rate, maintains measurement accuracy in different patient positions, and enables rapid application and anti-displacement of the nursing pad.

Description

Technical Field

[0001] This invention relates to the fields of medical rehabilitation engineering and intelligent sensing and control technology, specifically to a supine defecation assistance system. Background Technology

[0002] Bowel dysfunction is a common complication among the elderly, patients with spinal cord injuries, and those bedridden after abdominal surgery. This condition not only reduces patients' quality of life, causing symptoms such as bloating, abdominal pain, and sleep disturbances, but can also lead to serious complications.

[0003] Complications of defecation function include: intestinal complications; cardiovascular burden: a sudden increase in abdominal pressure during defecation can cause blood pressure fluctuations exceeding 40 mmHg, which can induce acute myocardial infarction or stroke in elderly patients.

[0004] Traditional solutions face significant technical limitations, such as the limitations of conservative treatments. Drug interventions, such as administering bulk-forming laxatives like lactulose, are problematic because lactulose has a slow onset of action, taking approximately 48-72 hours. Stimulant laxatives, such as senna or bisacodyl, can also be used, but long-term use can lead to damage to the myenteric plexus.

[0005] Existing physical aids, such as manual defecation, require medical staff to wear finger cots, leading to poor patient compliance due to embarrassment and rectal mucosal tears. Furthermore, enema therapy can disrupt the balance of gut microbiota, resulting in a decrease in beneficial gut bacteria in long-term users, and it fails to resolve neurogenic defecation disorders.

[0006] Therefore, the existing technology has problems and needs further improvement and development. Summary of the Invention

[0007] (I) Purpose of the invention: In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a defecation assistance system for lying position.

[0008] (II) Technical Solution: In order to solve the above-mentioned technical problems, this technical solution provides a supine assisted defecation system, including an abdominal pressure sensor, a flexible patch with electromyographic electrodes placed on the perianal skin, a main control unit and a nerve electrical stimulation unit. The abdominal pressure sensor is used to collect abdominal pressure, the electromyographic electrode collects electromyographic signals of the external anal sphincter, and the main control unit is connected to the abdominal pressure sensor, the electromyographic electrode and the nerve electrical stimulation unit respectively. When the abdominal pressure collected in real time by the abdominal pressure sensor is greater than 2.5 times the resting abdominal pressure, and the amplitude of the electromyographic signal collected by the electromyographic electrode drops to less than 30% of the resting state for a duration of ≥2 seconds, it is time for defecation. The main control unit controls the nerve electrostimulation unit to start the electrical stimulation of the sacral nerve target.

[0009] The aforementioned supine defecation assistance system includes a nerve electrical stimulation unit comprising an electrode patch. The electrode patch is a butterfly-shaped flexible structure and is positioned at the sacral nerve target point, covering the S3-S4 ganglion projection area of ​​the sacrococcygeal region. A hydrogel buffer ring is provided at the edge of the electrode, and the adhesion pressure is ≤2kPa.

[0010] The supine assisted defecation system further includes a camera unit, the main control unit is connected to the camera unit, and the camera unit collects defecation information; the nerve electrical stimulation unit further includes electrode patches respectively disposed at the femoral nerve target point, the perineal nerve target point, and the tibial nerve target point; When the sphincter tone of the electromyographic signal is greater than the electromyographic amplitude at rest, the neurostimulation unit places the electrode patch on the sacral nerve target point; when the abdominal pressure and electromyographic signal meet the timing for defecation, but there is no defecation information, the neurostimulation unit activates the electrode patch on the sacral nerve target point for electrical stimulation. When the abdominal pressure exceeds 1.5 times the resting value ≥ 3 times within 30 seconds, but the electromyographic signal is not at the time of defecation, the nerve electrical stimulation unit activates the electrode patch set at the tibial nerve target point to stimulate it.

[0011] The aforementioned supine defecation assistance system includes an abdominal pressure sensor that is a flexible array-type sensing unit, comprising three pressure sensing points distributed in an isosceles triangle, including two lumbar points and one subumbilical point, with each sensing point having a diameter of 6mm; the sensor base is made of medical-grade silicone material with a thickness of ≤0.3mm, and is adhered to the skin with low-sensitivity acrylic adhesive.

[0012] In the aforementioned supine assisted defecation system, the pressure sensing points of the abdominal pressure sensor are distributed in an isosceles triangle, and each pressure sensing point has a built-in micro gyroscope. The main control unit is connected to the micro gyroscope to monitor the spatial attitude changes of the sensing points in real time. The weight coefficients of the three pressure sensing points are dynamically allocated according to the tilt angle.

[0013] In the aforementioned supine defecation assistance system, when the tilt angle of any pressure sensing point is within the range of 15°-30°, the weighting coefficients of the three pressure sensing points are allocated as follows: The left lumbar sensor point is tilted, the weighting coefficient of the right lumbar sensor point is 0.3, and the weighting coefficient of the subumbilical sensor point is 0.2. The real-time measured abdominal pressure value = pressure value of the left lumbar sensor point × 0.5 + pressure value of the right lumbar sensor point × 0.3 + pressure value of the subumbilical sensor point × 0.2. The right lumbar sensor point is tilted, and the left lumbar sensor point is symmetrically configured with a weight coefficient of 0.3. The subumbilical sensor point has a weight coefficient of 0.2. The real-time measured abdominal pressure value = pressure value of the left lumbar sensor point × 0.3 + pressure value of the right lumbar sensor point × 0.5 + pressure value of the subumbilical sensor point × 0.2. The subumbilical sensing point is tilted, and the weight coefficients of the left and right lumbar sensing points are both 0.4. The real-time measured abdominal pressure value = pressure value of the left lumbar sensing point × 0.4 + pressure value of the right lumbar sensing point × 0.4 + pressure value of the subumbilical sensing point × 0.2.

[0014] In the aforementioned supine assisted defecation system, when the tilt angle of any pressure sensing point is >30°, the weighting coefficients of the three pressure sensing points are allocated as follows; When the left side of the waist sensor point is tilted, the corresponding weight coefficient of the right side of the waist sensor point is 0.5, and the weight coefficient of the subumbilical sensor point is 0.3. The real-time measured abdominal pressure value = pressure value of the right side of the waist sensor point × 0.5 + pressure value of the left side of the waist sensor point × 0.2 + pressure value of the subumbilical sensor point × 0.3. When the right side of the waist sensor point is tilted, the corresponding weight coefficient of the left side of the waist sensor point is 0.5, and the weight coefficient of the subumbilical sensor point is 0.3. The real-time measured abdominal pressure value = pressure value of the left side of the waist sensor point × 0.5 + pressure value of the right side of the waist sensor point × 0.2 + pressure value of the subumbilical sensor point × 0.3. The subumbilical sensing point is tilted, the weight coefficient of the left lumbar sensing point is 0.45, and the weight coefficient of the right lumbar sensing point is 0.45; the real-time measured abdominal pressure value = pressure value of the left lumbar sensing point × 0.45 + pressure value of the right lumbar sensing point × 0.45 + pressure value of the subumbilical sensing point × 0.1.

[0015] The aforementioned supine assisted defecation system includes a flexible array sensing unit that further comprises an annular elastic frame surrounding three pressure sensing points. The frame is made of silicone material, with a width of 5mm and a height of 1.2mm, and a micro suction cup is integrated on the inner side of the frame.

[0016] In the aforementioned supine defecation assistance system, the flexible patch of the abdominal pressure sensor and electromyography electrode is integrated with a disposable medical care pad using biodegradable hot melt adhesive.

[0017] The aforementioned bedridden assisted defecation system includes a nursing pad with a hollowed-out positioning area on the surface that matches the pressure sensing points of a flexible array-type sensing unit, and a diamond-shaped grid embossing in the waist and abdomen contact area.

[0018] (III) Beneficial effects: The defecation assistance system for supine position provided by the present invention can accurately identify the intention to defecate, effectively distinguish non-defecation actions such as coughing and turning over, and reduce the misjudgment rate; multi-target nerve electrical stimulation improves the efficiency of defecation assistance; reduce the stimulation effect decay rate; different weight coefficients are allocated for different tilt angles, so that the measurement accuracy is maintained when the patient changes position such as turning over and lying on his side; and the nursing pad can be quickly applied and prevented from shifting. Attached Figure Description

[0019] Figure 1This is a functional structure diagram of a supine assisted defecation system according to the present invention; Figure 2 This is a schematic diagram of the butterfly electrode patch structure of a supine auxiliary defecation system according to the present invention; Figure 3 This is a schematic diagram of the arrangement of the microchannel outlet of the butterfly electrode patch in a supine assisted defecation system according to the present invention. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to preferred embodiments. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0021] The accompanying drawings are schematic diagrams of embodiments of the present invention. It should be noted that these drawings are for illustrative purposes only and are not drawn to scale, and should not be construed as limiting the actual scope of protection of the present invention.

[0022] This invention provides a defecation assistance system for a supine position, such as... Figure 1 As shown, the device includes an abdominal pressure sensor, a flexible patch with electromyographic electrodes placed on the perianal skin, a main control unit, and a nerve stimulation unit. The abdominal pressure sensor is used to collect intra-abdominal pressure, and the electromyographic electrodes collect electromyographic signals from the external anal sphincter. The main control unit is connected to the abdominal pressure sensor, the electromyographic electrodes, and the nerve stimulation unit. When the intra-abdominal pressure collected by the abdominal pressure sensor in real time is greater than 2.5 times the resting abdominal pressure, and the amplitude of the electromyographic signal collected by the electromyographic electrodes drops to less than 30% of the resting state for a duration of ≥2 seconds, this is considered a time for defecation. At this time, the main control unit controls the nerve stimulation unit to activate the electrode patch placed on the sacral nerve target point, thus initiating electrical stimulation of the sacral nerve target point.

[0023] The supine defecation assistance system uses a dual-threshold determination strategy based on intra-abdominal pressure and electromyographic signals of the external anal sphincter to determine whether there is an intention to defecate. Once the intention to defecate is determined, percutaneous nerve electrical stimulation is used to defecate, avoiding invasive procedures. It is suitable for long-term bedridden patients, such as those with spinal cord injury or postoperative LARS (low anterior rectal resection syndrome).

[0024] The abdominal pressure sensor is a miniature barometric pressure sensor with an accuracy of ±0.5 mmHg, implanted in the lumbar and abdominal restraint belt to monitor changes in intra-abdominal pressure in real time. The baseline resting abdominal pressure is 10-15 mmHg. When the intra-abdominal pressure exceeds 2.5 times the resting abdominal pressure, i.e., 25-37.5 mmHg, it is the defecation abdominal pressure threshold, avoiding misjudgments based on non-defecation actions such as coughing or turning over.

[0025] In the supine defecation assistance system, a flexible patch with electromyographic electrodes is placed on the perianal skin. This patch can be attached to the surface projection area of ​​the external anal sphincter, typically a 2-3 cm circumferential area centered on the anus and extending along the line connecting the coccyx to the perineum, to ensure effective stimulation or monitoring. The electromyographic electrodes are used to collect the electromyographic activity (EMG) signal of the external anal sphincter. When the amplitude of the collected EMG signal drops to less than 30% of the resting state, indicating sphincter relaxation, and the duration is ≥2 seconds, it is considered a pre-defecation sign.

[0026] When the intra-abdominal pressure is greater than 2.5 times the resting intra-abdominal pressure, and the amplitude of the electromyographic signal drops to less than 30% of the resting state, and the duration is ≥2 seconds, the system determines that it is an intention to defecate, and starts electrical stimulation to assist defecation, turning passive waiting for defecation into active triggering assistance.

[0027] In a preferred embodiment of the supine assisted defecation system of the present invention, the nerve electrical stimulation unit includes an electrode patch, which is a butterfly-shaped flexible structure. The electrode patch is disposed on the sacral nerve target point, covering the S3-S4 ganglion projection area of ​​the sacrococcygeal region, and a hydrogel buffer ring is provided at the edge of the electrode. The adhesion pressure is ≤2kPa. A preferred embodiment is as follows: The electrode patch of this invention adopts a biomimetic butterfly-shaped symmetrical structure, such as... Figure 2 As shown, the overall dimensions are 60mm × 45mm, consisting of a central stimulation area and bilateral wings. The central stimulation area is circular with a diameter of 15mm, corresponding to the core target point of the S3-S4 ganglion projection area in the sacrococcygeal region. It contains four gold-plated electrode contacts with a diameter of 3mm, spaced 5mm apart, arranged in a square or circular pattern for precise release of electrical stimulation signals. The bilateral wings are symmetrical arc-shaped wing structures, with a wingspan of 25mm and a thickness of 0.3mm on each side. They are made of shape memory polyimide substrate and integrally formed using 4D printing technology. They can adaptively bend according to the physiological curvature of the sacrococcygeal region, with a deformation angle of ±30°, ensuring a contact area with the skin surface of ≥90%. The edges of the electrode patches are rounded with a radius of 0.5mm to avoid skin pressure. Two 5mm diameter fixing holes are provided at the ends of the wings for use with medical tape to assist in fixation and prevent displacement.

[0028] The electrode patch of this invention has a four-layer composite structure, from top to bottom as follows: The first layer, the protective layer, is a 10μm thick polyethylene terephthalate (PET) film covered with release paper, which is peeled off before use.

[0029] The second layer, the conductive layer, uses nano-Ag paste to print circuits with a line width of 0.2mm and an impedance of ≤50Ω. The serpentine trace design ensures stable conductivity during stretching, with a maximum stretching rate of 20%.

[0030] The third layer is a flexible substrate: 50μm thick shape memory polyimide (SMPI), with a Tg temperature of 180℃ and an elongation at break of 300%, ensuring no risk of cracking during body surface activities.

[0031] The fourth layer is a hydrogel layer: the central stimulation area is covered with a 200μm thick conductive hydrogel with a conductivity ≥1S / cm and a pH value of 6.5-7.5.

[0032] The electrode patch of the present invention can preferably also have a buffer ring set at the edge of the electrode. The buffer ring is set at 1mm from the outer edge of the patch. The buffer ring is an annular hydrogel buffer ring with a semi-circular cross-section. The semi-circle is 3mm wide and 1.5mm high. It uses highly elastic transparent hydrogel and achieves dynamic adjustment of bonding pressure through a biomimetic microarray structure to ensure that the average bonding pressure is ≤2kPa.

[0033] In a preferred embodiment of the supine defecation-assisted system of the present invention, the nerve electrical stimulation unit includes electrode patches for three sets of core stimulation targets set at the sacral nerve target, the femoral nerve target, and the perineal nerve target, covering the defecation-related neural pathways, and also includes electrode patches for one set of auxiliary adjustment stimulation targets set at the tibial nerve target. The sacral nerve target point is the S3-S4 nerve root. When the electrode patch is placed on the sacral nerve target point, the central stimulation area of ​​the electrode patch corresponds to the S3-S4 nerve root. The sacral nerve target point directly activates the defecation reflex arc, promoting rectal peristalsis and relaxation of the external anal sphincter. The femoral nerve target point is the femoral nerve course area. Stimulation of this target point can regulate the coordinated contraction of the lower limb muscle groups, indirectly increasing abdominal pressure to assist defecation. The perineal nerve target point is a superficial nerve in the perineum. Stimulation of this target point can enhance the coordination of the anal sphincter and pelvic floor muscles, avoiding excessive muscle tension or relaxation during defecation, and assisting in enhancing sphincter coordination function. The tibial nerve target point is located above the medial malleolus. Stimulation of this target point can inhibit abnormal bladder-rectal reflexes and reduce frequent fluctuations in abdominal pressure.

[0034] The supine assisted defecation system also includes a camera unit. The main control unit is connected to the camera unit, which collects defecation information, which is either a defecation image or a signal indicating whether defecation has occurred, input through an input unit. Specifically, the camera unit can be a webcam.

[0035] When the electromyographic signal of the external anal sphincter indicates that the sphincter tone is greater than the amplitude of the electromyographic signal at rest, the neurostimulation unit places the electrode patch on the sacral nerve target point. When the abdominal pressure and electromyographic signal meet the criteria for defecation, but there is no defecation signal, the neurostimulation unit activates the electrode patch on the sacral nerve target point for electrical stimulation. Specifically, when the defecation criteria are met, the electrode patch on the sacral nerve target point is activated first for stimulation, and simultaneously, based on the sphincter tone status fed back by the electromyographic signal, the electrode patch on the perineal nerve target point is activated in conjunction for electrical stimulation to enhance sphincter coordination. If the increase in abdominal pressure is insufficient, the electrode patch on the femoral nerve target point can be activated in addition for electrical stimulation to indirectly increase intra-abdominal pressure through lower limb muscle contraction.

[0036] When abdominal pressure exceeds 1.5 times the resting value ≥ 3 times within 30 seconds, but the electromyographic signal is not at the time of defecation, the nerve electrical stimulation unit activates the electrode patch set at the tibial nerve target point to stimulate, inhibit abnormal reflexes, and avoid interference of ineffective electrical stimulation with intestinal function.

[0037] The supine assisted defecation system of the present invention includes an abdominal pressure sensor that is a flexible array-type sensing unit comprising three pressure sensing points arranged in an isosceles triangle: two lateral points and one subumbilical point. Each sensing point has a diameter of 6 mm. The sensor substrate is made of medical-grade silicone material with a thickness of ≤0.3 mm and is adhered to the skin using low-sensitivity acrylic adhesive. Each pressure sensing point in the isosceles triangle arrangement incorporates a miniature gyroscope. The main control unit is connected to the miniature gyroscope for real-time monitoring of the spatial attitude changes of the sensing points. The weighting coefficients of the three pressure sensing points are dynamically allocated according to the tilt angle.

[0038] When the tilt angle of any pressure sensing point is within the range of 15°-30°, the weighting coefficients of the three pressure sensing points are allocated as follows: The left lumbar sensor point is tilted, the weighting coefficient of the right lumbar sensor point is 0.3, and the weighting coefficient of the subumbilical sensor point is 0.2. The real-time measured abdominal pressure value = pressure value of the left lumbar sensor point × 0.5 + pressure value of the right lumbar sensor point × 0.3 + pressure value of the subumbilical sensor point × 0.2. The right lumbar sensor point is tilted, and the left lumbar sensor point is symmetrically configured with a weight coefficient of 0.3. The subumbilical sensor point has a weight coefficient of 0.2. The real-time measured abdominal pressure value = pressure value of the left lumbar sensor point × 0.3 + pressure value of the right lumbar sensor point × 0.5 + pressure value of the subumbilical sensor point × 0.2. The subumbilical sensing point is tilted, and the weight coefficients of the left and right lumbar sensing points are both 0.4. The real-time measured abdominal pressure value = pressure value of the left lumbar sensing point × 0.4 + pressure value of the right lumbar sensing point × 0.4 + pressure value of the subumbilical sensing point × 0.2.

[0039] When the tilt angle of any pressure sensing point is greater than 30°, the weighting coefficients of the three pressure sensing points are allocated as follows; When the left side of the waist sensor point is tilted, the corresponding weight coefficient of the right side of the waist sensor point is 0.5, and the weight coefficient of the subumbilical sensor point is 0.3. The real-time measured abdominal pressure value = pressure value of the right side of the waist sensor point × 0.5 + pressure value of the left side of the waist sensor point × 0.2 + pressure value of the subumbilical sensor point × 0.3. When the right side of the waist sensor point is tilted, the corresponding weight coefficient of the left side of the waist sensor point is 0.5, and the weight coefficient of the subumbilical sensor point is 0.3. The real-time measured abdominal pressure value = pressure value of the left side of the waist sensor point × 0.5 + pressure value of the right side of the waist sensor point × 0.2 + pressure value of the subumbilical sensor point × 0.3. The subumbilical sensing point is tilted, the weight coefficient of the left lumbar sensing point is 0.45, and the weight coefficient of the right lumbar sensing point is 0.45; the real-time measured abdominal pressure value = pressure value of the left lumbar sensing point × 0.45 + pressure value of the right lumbar sensing point × 0.45 + pressure value of the subumbilical sensing point × 0.1.

[0040] The flexible array sensing unit of the present invention also includes an annular elastic frame surrounding three pressure sensing points. The frame is made of silicone material, with a width of 5mm and a height of 1.2mm, and a micro suction cup is integrated on the inner side of the frame.

[0041] The abdominal pressure sensor and the flexible patch of the electromyography electrode are integrated with a disposable medical pad using biodegradable hot melt adhesive. The surface of the pad has a hollowed-out positioning area that matches the pressure sensing points of the flexible array sensing unit, and a diamond-shaped grid embossing is provided in the waist and abdomen contact area.

[0042] The present invention provides a supine defecation assistance system, preferably in which the flexible circuit layer of the electrode patch of the electrostimulation unit integrates a micro-flow valve and a saline microchannel, with the microchannel outlet located inside the hydrogel layer of the electrode patch. When the electromyographic signal shows a decrease in stimulation effect, such as an increase in electromyographic amplitude of <10% after three consecutive stimulations, the electrostimulation unit controls the flow valve to release 0.1-0.3 ml of saline, which permeates through the hydrogel layer to the skin surface, reducing electrode-skin impedance and maintaining moisture.

[0043] A preferred embodiment of the microchannel outlet array arrangement of the saline microchannel of the present invention is as follows: the saline microchannels are distributed in an equilateral triangular grid array inside the hydrogel layer. Each microchannel outlet is a circular opening with a diameter of 0.5 mm and a depth of 0.3 mm, matching the thickness of the hydrogel layer. The edges of the microchannel outlets are rounded with a 0.1 mm radius to avoid stress concentration that could cause the hydrogel to crack.

[0044] The microchannel outlet array has an adjacent outlet center spacing of 3mm, and is distributed in three concentric circles along the outer periphery of the central stimulation area of ​​the electrode patch. Figure 3 As shown, the first ring is located in the inner ring: surrounding the four electrode contacts, six outlets are set to form an inner ring with a diameter of 10 mm; the second ring is located in the middle ring: located at the edge of the central stimulation area, twelve outlets are set to form a middle ring with a diameter of 15 mm; the third ring is located in the outer ring: distributed on the inner side of both wings, with eight outlets on each wing arranged in an arc, covering the edge area of ​​the S3-S4 ganglion projection area. The total number of outlets in the microchannel outlet array is 6 + 12 + 16 = 34, ensuring that the saline solution covers more than 90% of the area in contact with the skin of the electrode patch.

[0045] The microchannel outlet of this invention adopts an inverted funnel-shaped embedded structure. The top of the outlet is in contact with the hydrogel side, the microchannel outlet diameter is 0.5mm, and the bottom of the microchannel outlet is connected to the microchannel side with a diameter of 0.3mm. It is formed on the polyimide substrate of the flexible circuit layer by laser etching process, and the inner wall of the outlet is coated with a 50nm thick titanium coating.

[0046] The microchannel array of this invention adopts a main channel and branch channels. The flexible circuit layer has built-in Y-type polyimide microchannels. The main channel extends from the liquid reservoir interface at the tail of the patch to the central stimulation area, and then branches into 34 microchannels, each 5-15mm long, which are connected to the microchannel outlets respectively.

[0047] This invention incorporates a miniature one-way valve at the microchannel outlet to prevent saline reflux or hydrogel reverse osmosis. A saline release triggering and impedance feedback mechanism is also included.

[0048] The electrode patch of this invention uses four central contacts to collect electromyographic signals from the sacrococcygeal region in real time. The sampling frequency is 1 kHz, and the amplitude increase of electromyographic vibration is measured within three consecutive stimulation cycles. The stimulation parameters are: frequency 50 Hz, pulse width 200 μs, and intensity 20-50 mA. When the increase is <10%, it is determined that the stimulation effect has decayed, and the physiological saline is released immediately by the micro one-way valve.

[0049] The controller of the miniature one-way valve can measure the skin-electrode impedance through the electrode contacts before release. If the initial impedance is >5000Ω, 0.3ml of physiological saline is released directly. When the increase is 8%-10%, release 0.1ml, retest the impedance after 30 seconds, and if it is still >3000Ω, release an additional 0.1ml; when the increase is 5%-8%, release 0.2ml; when the increase is <5%, release 0.3ml.

[0050] After the controller of the miniature one-way valve releases the saline solution, it continuously monitors the impedance and samples it every 5 minutes. When the impedance rises back to above 4000Ω, it automatically triggers the next 0.1ml supplementary release.

[0051] The flexible circuit layer of this invention integrates a micro-flow valve and a saline microchannel. Through the arrayed layout of the microchannel outlet, precise flow control, and impedance closed-loop feedback, it realizes the on-demand release of saline, ensures that the electrode-skin interface impedance is stable at <3000Ω, and improves the long-term effectiveness of nerve electrical stimulation.

[0052] The supine defecation assistance system provided by this invention uses an abdominal pressure sensor and a dual-parameter judgment strategy based on a resting abdominal pressure of 2.5 times the threshold and an electromyographic signal amplitude dropping to below 30% of the resting state for ≥2 seconds. This accurately identifies the intention to defecate, effectively distinguishing non-defecation actions such as coughing and turning over, reducing the misjudgment rate to below 5%, and overcoming the technical bottleneck of passive waiting or blind stimulation in traditional physical assistance methods. Secondly, this invention integrates three core target points: the sacral nerve (S3-S4), tibial nerve, and perineal nerve. It dynamically switches stimulation modes according to different types of defecation disorders: for example, sacral nerve stimulation is prioritized when sphincter tone is abnormal; tibial nerve regulation is activated when abdominal pressure fluctuates frequently but the sphincter does not relax. This increases the defecation success rate by 40% compared to single-target stimulation, making it particularly suitable for patients with neurogenic defecation disorders such as spinal cord injury and postoperative LARS. Multi-target nerve electrical stimulation improves the efficiency of defecation assistance. Third, the butterfly-shaped electrode patch of this invention uses a shape-memory polyimide substrate with a deformation angle of ±30°, and a hydrogel buffer ring to ensure an adhesion pressure of ≤2kPa. Combined with an equilateral triangular array of 34 saline microchannel outlets, it ensures a stable electrode-skin interface impedance of <3000Ω, reduces the stimulation effect attenuation rate by 60%, and eliminates the risk of pressure ulcers with long-term wear. Fourth, this invention employs a flexible array-type abdominal pressure sensor. Through isosceles triangularly distributed pressure sensing points and a micro-gyroscope, a dynamic weighting coefficient algorithm is used to allocate different weighting coefficients for different tilt angles, maintaining measurement accuracy even when the patient changes position, such as turning over or lying on their side. This is an adaptive abdominal pressure monitoring technology. Finally, the sensor and disposable nursing pad are integrated with biodegradable hot melt adhesive. The nursing pad's surface features a hollowed-out positioning area and a diamond-shaped grid embossed design for rapid application and anti-displacement. The saline solution is released on demand via a micro-flow valve, avoiding the risk of cross-infection.

[0053] The above description illustrates preferred embodiments of the present invention and helps those skilled in the art to more fully understand the technical solution of the present invention. However, these embodiments are merely illustrative and should not be construed as limiting the specific implementation of the present invention to these embodiments. For those skilled in the art, several simple deductions and modifications can be made without departing from the inventive concept, and all such modifications should be considered within the protection scope of the present invention.

Claims

1. A system for assisting defecation in a lying position, characterized in that It includes an abdominal pressure sensor, a flexible patch with electromyographic electrodes placed on the perianal skin, a camera unit, a main control unit, and a nerve electrical stimulation unit; The abdominal pressure sensor is used to collect abdominal pressure, the electromyographic electrode collects electromyographic signals of the external anal sphincter, the camera unit collects defecation information, and the main control unit is connected to the abdominal pressure sensor, the electromyographic electrode, the camera unit and the nerve electrical stimulation unit respectively; the nerve electrical stimulation unit includes electrode patches respectively set at the femoral nerve target point, the perineal nerve target point and the tibial nerve target point; When the abdominal pressure collected in real time by the abdominal pressure sensor is greater than 2.5 times the resting abdominal pressure, and the amplitude of the electromyographic signal collected by the electromyographic electrode drops to less than 30% of the resting state for a duration of ≥2 seconds, it is time for defecation. The main control unit controls the nerve electrostimulation unit to start the electrical stimulation of the sacral nerve target. When the sphincter tone of the electromyographic signal is greater than the electromyographic amplitude at rest, the neurostimulation unit places the electrode patch on the sacral nerve target point; when the abdominal pressure and electromyographic signal meet the timing for defecation, but there is no defecation information, the neurostimulation unit activates the electrode patch on the sacral nerve target point for electrical stimulation. When the abdominal pressure exceeds 1.5 times the resting value ≥ 3 times within 30 seconds, but the electromyographic signal is not at the time of defecation, the nerve electrical stimulation unit activates the electrode patch set at the tibial nerve target point to stimulate it. The neuro-electro-stimulation unit includes an electrode patch. The flexible circuit layer of the electrode patch integrates a micro-flow valve and a saline microchannel. The microchannel outlet of the saline microchannel is located inside the hydrogel layer of the electrode patch. When the electromyographic signal shows a decrease in stimulation effect, the electro-stimulation unit controls the flow valve to release 0.1-0.3 ml of saline. When the increase in electromyographic amplitude is <10% within three consecutive stimulation cycles, it is determined that the stimulation effect has decreased. The skin-electrode impedance is measured through the electrode contact. If the initial impedance is >5000Ω, 0.3 ml of saline is released directly. When the increase is 8%-10%, 0.1 ml is released. The impedance is remeasured after 30 seconds. If it is still >3000Ω, an additional 0.1 ml is released. The saline penetrates through the hydrogel layer to the skin surface, reducing the electrode-skin impedance and maintaining moisture.

2. The supine assisted defecation system according to claim 1, characterized in that, The electrode patch has a butterfly-shaped flexible structure and is placed at the sacral nerve target point, covering the S3-S4 ganglion projection area of ​​the sacrococcygeal region. A hydrogel buffer ring is provided at the edge of the electrode, and the adhesion pressure is ≤2kPa.

3. The supine defecation assistance system according to claim 1, characterized in that, The abdominal pressure sensor is a flexible array-type sensing unit, including three pressure sensing points distributed in an isosceles triangle, including two lumbar points and one subumbilical point, with each pressure sensing point having a diameter of 6mm; the sensor substrate is made of medical-grade silicone material with a thickness of ≤0.3mm, and is attached to the skin with low-sensitivity acrylic adhesive.

4. The supine assisted defecation system according to claim 3, characterized in that, In the isosceles triangle distribution of pressure sensing points of the abdominal pressure sensor, each pressure sensing point has a built-in micro gyroscope. The main control unit is connected to the micro gyroscope to monitor the spatial attitude changes of the sensing points in real time. The weight coefficients of the three pressure sensing points are dynamically allocated according to the tilt angle.

5. The supine defecation assistance system according to claim 4, characterized in that, When the tilt angle of any pressure sensing point is within the range of 15°-30°, the weighting coefficients of the three pressure sensing points are allocated as follows: The left lumbar sensor point is tilted, the weighting coefficient of the right lumbar sensor point is 0.3, and the weighting coefficient of the subumbilical sensor point is 0.

2. The real-time measured abdominal pressure value = pressure value of the left lumbar sensor point × 0.5 + pressure value of the right lumbar sensor point × 0.3 + pressure value of the subumbilical sensor point × 0.

2. The right lumbar sensor point is tilted, and the left lumbar sensor point is symmetrically configured with a weight coefficient of 0.

3. The subumbilical sensor point has a weight coefficient of 0.

2. The real-time measured abdominal pressure value = pressure value of the left lumbar sensor point × 0.3 + pressure value of the right lumbar sensor point × 0.5 + pressure value of the subumbilical sensor point × 0.

2. The subumbilical sensing point is tilted, and the weight coefficients of the left and right lumbar sensing points are both 0.

4. The real-time measured abdominal pressure value = pressure value of the left lumbar sensing point × 0.4 + pressure value of the right lumbar sensing point × 0.4 + pressure value of the subumbilical sensing point × 0.

2.

6. The supine defecation assistance system according to claim 4, characterized in that, When the tilt angle of any pressure sensing point is greater than 30°, the weighting coefficients of the three pressure sensing points are allocated as follows; When the left side of the waist sensor point is tilted, the corresponding weight coefficient of the right side of the waist sensor point is 0.5, and the weight coefficient of the subumbilical sensor point is 0.

3. The real-time measured abdominal pressure value = pressure value of the right side of the waist sensor point × 0.5 + pressure value of the left side of the waist sensor point × 0.2 + pressure value of the subumbilical sensor point × 0.

3. When the right side of the waist sensor point is tilted, the corresponding weight coefficient of the left side of the waist sensor point is 0.5, and the weight coefficient of the subumbilical sensor point is 0.

3. The real-time measured abdominal pressure value = pressure value of the left side of the waist sensor point × 0.5 + pressure value of the right side of the waist sensor point × 0.2 + pressure value of the subumbilical sensor point × 0.

3. The subumbilical sensing point is tilted, the weight coefficient of the left lumbar sensing point is 0.45, and the weight coefficient of the right lumbar sensing point is 0.45; the real-time measured abdominal pressure value = pressure value of the left lumbar sensing point × 0.45 + pressure value of the right lumbar sensing point × 0.45 + pressure value of the subumbilical sensing point × 0.

1.

7. The supine defecation assistance system according to claim 3, characterized in that, The flexible array sensing unit also includes an annular elastic frame surrounding three pressure sensing points. The frame is made of silicone, with a width of 5mm and a height of 1.2mm, and a micro suction cup is integrated on the inner side of the frame.

8. The supine defecation assistance system according to claim 1, characterized in that, The abdominal pressure sensor and the flexible patch of electromyography electrodes are integrated with a disposable medical care pad using biodegradable hot melt adhesive.

9. The supine defecation assistance system according to claim 8, characterized in that, The surface of the nursing pad is provided with a hollowed-out positioning area that matches the pressure sensing points of the flexible array-type sensing unit, and a diamond-shaped grid embossing is provided in the waist and abdomen contact area.

10. The supine defecation assistance system according to claim 1, characterized in that, The saline microchannels are distributed in an equilateral triangular grid array inside the hydrogel layer. Each microchannel outlet is a circular opening with a diameter of 0.5 mm and a depth of 0.3 mm, matching the thickness of the hydrogel layer. The edges of the microchannel outlets are rounded with a 0.1 mm radius to avoid stress concentration that could cause the hydrogel to crack.

11. The supine defecation assistance system according to claim 10, characterized in that, Microchannel outlet array: The center-to-center spacing between adjacent outlets is 3mm. They are distributed in three concentric circles around the outer periphery of the central stimulation area of ​​the electrode patch. The first circle is located in the inner circle: 6 outlets are set around the outside of the 4 electrode contacts, forming an inner ring with a diameter of 10mm. The second circle is located in the middle circle: 12 outlets are set at the edge of the central stimulation area, forming a middle ring with a diameter of 15mm. The third circle is located in the outer circle: distributed on the inner side of the bilateral wings, with 8 outlets on each wing arranged in an arc shape, covering the edge area of ​​the S3-S4 ganglion projection area. The total number of outlets in the microchannel outlet array is 6+12+16=34, ensuring that the physiological saline is released to cover more than 90% of the area of ​​the electrode patch in contact with the skin.

12. The supine assisted defecation system according to claim 10, characterized in that, The microchannel outlet adopts an inverted funnel-shaped embedded structure. The top of the outlet is in contact with the hydrogel side, the microchannel outlet diameter is 0.5mm, and the bottom of the microchannel outlet is connected to the microchannel side with a diameter of 0.3mm. It is formed on the polyimide substrate of the flexible circuit layer by laser etching process, and the inner wall of the outlet is coated with a 50nm thick titanium coating.

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