Paediatric dual balloon catheter for oesophageal and intragastric pressure detection

Abstract

This invention discloses a pediatric double-balloon catheter for esophageal and gastric pressure monitoring, comprising an outer sheath and an inner core tube. Both ends of the outer sheath are open. The inner core tube is slidably inserted into and passes through the outer sheath. One end of the outer sheath is provided with a dynamic locking component for fixing the inner core tube, and the inner circumferential wall of the other end of the outer sheath is in a sealed sliding fit with the outer circumferential wall of the inner core tube. An esophageal pressure inflation / measurement connector is located on the exterior of the outer sheath near the dynamic locking component, and an esophageal pressure balloon is circumferentially sealed on the exterior of the outer sheath away from the dynamic locking component. This invention solves the clinical problem of traditional fixed-spacing catheters, which cannot simultaneously ensure accurate placement of the esophageal balloon in the lower esophagus and complete placement of the gastric balloon within the gastric cavity, making the same catheter applicable to a wide age range from newborns to adolescents.

Description

Technical Field

[0001] This invention relates to the field of pediatric medical devices, and more particularly to a pediatric double-balloon catheter for detecting esophageal pressure and gastric pressure. Background Technology

[0002] Accurate monitoring of esophageal and gastric pressures is of significant clinical importance for assessing respiratory mechanics, guiding mechanical ventilation parameter settings, and assisting in the diagnosis of diaphragmatic function. Transdiaphragmatic pressure (the difference between gastric and esophageal pressures) is currently a core indicator for assessing a patient's respiratory effort and diaphragmatic function, and is widely used in intensive care, respiratory medicine, and pediatrics.

[0003] In pediatric clinical practice, esophageal manometry and gastric pressure monitoring face unique technical challenges: infants and young children have small esophageal anatomical dimensions and high esophageal wall compliance, making traditional adult manometry catheters difficult to adapt to the physiological characteristics of pediatric patients. Existing double-balloon catheters mostly employ a fixed-spacing design, meaning the distance between the esophageal and gastric balloons is not adjustable. For example, the three-lumen double-balloon nutrition delivery device disclosed in CN201620879411.7 has an esophageal balloon 7 and a gastric balloon 9 with a non-adjustable spacing above one end of the same gastric tube 1 with an outlet hole 12. However, the esophageal length varies significantly among children of different ages; the esophagus of newborns is only about 8-10 cm long, while that of adolescents can reach over 20 cm. A fixed-spacing catheter cannot accurately locate both the esophagus and stomach simultaneously, often leading to the esophageal balloon mistakenly entering the stomach or approaching the cardia, resulting in erroneous pressure waveforms. Furthermore, adjusting the position of existing double-balloon catheters requires moving the entire catheter, which disrupts the ideal depth of the gastric tube tip within the stomach, creating risks associated with nasogastric feeding. Summary of the Invention

[0004] The purpose of this invention is to provide a pediatric double-balloon catheter for esophageal and gastric pressure monitoring, thereby solving the technical problems existing in the background art.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This invention discloses a pediatric double-balloon catheter for esophageal and gastric pressure monitoring, comprising an outer sheath and an inner core tube. Both ends of the outer sheath are open. The inner core tube is slidably inserted into and passes through the outer sheath. One end of the outer sheath is provided with a dynamic locking component for securing the inner core tube. The inner circumferential wall of the other end of the outer sheath is in a sealed sliding fit with the outer circumferential wall of the inner core tube. An esophageal pressure inflation / measurement connector is located on the outer side of the outer sheath near the dynamic locking component, and an esophageal pressure measurement connector is located on the outer side of the outer sheath away from the dynamic locking component. An esophageal pressure balloon is provided in a sealed manner. The outer sheath has a first micro-inflation / pressure measurement cavity inside its wall, connecting the esophageal pressure inflation / pressure measurement connector and the esophageal pressure balloon. One end of the inner core tube has an intragastric pressure inflation / pressure measurement connector on its exterior. The other end of the inner core tube is a smooth, closed, round-headed structure with multiple side nasogastric feeding holes evenly distributed circumferentially. An intragastric pressure balloon is provided in a sealed manner circumferentially near its closed end on the exterior of the inner core tube. The inner core tube has a second micro-inflation / pressure measurement cavity inside its wall, connecting the intragastric pressure inflation / pressure measurement connector and the intragastric pressure balloon.

[0006] Furthermore, the dynamic locking assembly includes an outer sleeve fixedly connected to the end of the outer sleeve, an inner sleeve having an internal thread on its inner peripheral wall, an inner sleeve rotatably disposed inside the outer sleeve, and an outer thread on its outer peripheral wall that matches the internal thread of the outer sleeve; one end of the inner sleeve extends to the outside of the outer sleeve and is fixedly connected to a knob, and the outer sleeve, the inner sleeve, and the knob all have through holes through which the inner core tube passes; an elastic locking ring for fixing the inner core tube is fitted between the inner end of the inner sleeve located inside the outer sleeve and the inner end face of the outer sleeve on the outside of the inner core tube.

[0007] Furthermore, the elastic locking ring has two pressure-bearing end faces and a locking end face located between the two pressure-bearing end faces in the cross-sectional direction. The two pressure-bearing end faces are in contact with the end faces of the inner sleeve and the outer sleeve, respectively, and the locking end face is in contact with the outer peripheral wall of the inner core tube.

[0008] Furthermore, both the esophageal pressure balloon and the gastric pressure balloon are made of ultra-thin-walled non-compliant polymer film material, and both the outer sheath and the inner core tube are made of medical-grade polyurethane.

[0009] Furthermore, a first scale line is provided on the outer wall of the outer sleeve, and a second scale line is provided on the outer wall of the inner core tube.

[0010] Furthermore, the outer wall of the inner core tube is coated with a medical-grade hydrophilic lubricating coating.

[0011] Furthermore, the inner peripheral wall of the other end of the outer sleeve is provided with an elastic liquid-resistant lip that is integrally formed therewith and has a sealing sliding fit with the outer peripheral wall of the inner core tube.

[0012] Furthermore, the cross-sectional width of the elastic liquid-resistant lip gradually narrows from the outside to the inside, and its inner peripheral wall is tightly fitted with the outer peripheral wall of the inner core tube.

[0013] Compared with the prior art, the beneficial technical effects of the present invention are as follows: This invention employs a sliding insertion design between an outer sheath and an inner core tube. By pushing and pulling the inner core tube, the axial distance between the esophageal and gastric balloons can be continuously adjusted. Combined with the second graduation line on the outer wall of the inner core tube, operators can make individualized and precise adjustments according to the length of the child's esophagus. This solves the clinical problem that traditional fixed-spacing catheters cannot simultaneously ensure accurate placement of the esophageal balloon in the lower esophagus and complete placement of the gastric balloon within the stomach cavity. This allows the same catheter to be used for a wide age range from newborns to adolescents, reducing the need for medical institutions to maintain a stockpile of catheters of different specifications.

[0014] This invention features a dynamic locking assembly consisting of an outer sleeve, an inner sleeve, a knob, and an elastic locking ring. After adjusting the distance between the esophageal and gastric pressure cuffs, the operator rotates the knob to screw the inner sleeve in, compressing the elastic locking ring to cause radial expansion and deformation. The locking end face tightly grips the outer wall of the inner core tube. This locking assembly effectively prevents accidental slippage of the inner core tube due to changes in the child's position, respiratory movements, or gastrointestinal peristalsis during pressure measurement, ensuring the relative position of the cuffs remains stable and thus guaranteeing the continuity and accuracy of transdiaphragmatic pressure measurement.

[0015] The outer cannula of this invention has a first micro-inflation / pressure measurement cavity (connecting the esophageal pressure inflation / pressure measurement connector and the esophageal pressure balloon) inside its wall, and a second micro-inflation / pressure measurement cavity (connecting the gastric pressure inflation / pressure measurement connector and the gastric pressure balloon) inside its wall. At the same time, the central lumen of the inner core tube remains unobstructed and can be used for nasogastric feeding or gastrointestinal decompression. The three functional cavities are independent of each other, and no airway entanglement or blockage will occur during the spacing adjustment process. This enables the simultaneous performance of pressure measurement and feeding / decompression operations, avoiding the trauma and infection risks caused to the child by repeated tube insertion.

[0016] The inner wall of the inner end of the outer sheath of the present invention is provided with an integrally formed elastic liquid-blocking lip. The cross-section of the lip is a tapered or semi-circular structure with a thick base and a sharp end. Under elastic tension, it always tightly wraps the outer wall of the inner core tube 360°. This design not only ensures the smoothness of the inner core tube during sliding adjustment, but also effectively prevents the leakage of body fluids such as digestive tract mucus and gastric contents into the body through the gap between the inner and outer tubes under static and dynamic conditions, reducing the risk of cross-infection and ensuring the cleanliness and safety of the operating environment. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings.

[0018] Figure 1 This is a schematic diagram of the overall external structure of the present invention; Figure 2 This is a schematic cross-sectional view of the overall structure of the present invention; Figure 3 for Figure 2 Enlarged structural diagram at point A; Figure 4 This is a cross-sectional view of the outer sleeve of the present invention; Figure 5 This is a cross-sectional view of the inner core tube structure of the present invention; Figure 6 This is a schematic diagram of the dynamic locking component structure of the present invention; Explanation of reference numerals in the attached diagram: 1. Outer sleeve; 2. Inner core tube; 3. Esophageal pressure inflation / pressure measurement connector; 4. Esophageal pressure cuff; 5. First miniature inflation / pressure measurement channel; 6. Intragastric pressure inflation / pressure measurement connector; 7. Side nasogastric feeding port; 8. Intragastric pressure cuff; 9. Second miniature inflation / pressure measurement channel; 10. Outer sleeve; 11. Inner sleeve; 12. Knob; 13. Elastic locking ring; 13-1. Pressure-bearing end face; 13-2. Locking end face; 14. First graduation line; 15. Second graduation line; 16. Elastic liquid-resistant lip. Detailed Implementation

[0019] like Figures 1-6 As shown, a pediatric double-balloon catheter for esophageal and gastric pressure monitoring includes an outer sheath 1 and an inner core tube 2, both of which are made of medical-grade polyurethane (PU).

[0020] Both ends of the outer sheath 1 are open. The inner core tube 2 is slidably inserted into and passes through the outer sheath 1. One end of the outer sheath 1 is provided with a dynamic locking component for fixing the inner core tube 2. The inner peripheral wall of the other end of the outer sheath 1 is in a sealed sliding fit with the outer peripheral wall of the inner core tube 2. The end of the outer sheath 1 with the dynamic locking component is located outside the patient's body, and the other end extends into the patient's body.

[0021] An esophageal pressure inflation / pressure measurement connector 3 is provided on the outside of the outer sheath 1 near the dynamic locking component. An esophageal pressure balloon 4 is provided circumferentially and sealed on the outside of the outer sheath 1 away from the dynamic locking component. That is, the esophageal pressure balloon 4 is located on the outer wall of the end of the outer sheath 1 located inside the patient's body. A first micro inflation / pressure measurement cavity 5 is provided inside the tube wall of the outer sheath 1, connecting the esophageal pressure inflation / pressure measurement connector 3 and the esophageal pressure balloon 4.

[0022] The main lumen of the inner tube 2 is used for nasogastric feeding or decompression operations. One end of the inner tube 2 (the end located outside the body) is provided with an intragastric pressure inflation / measurement connector 6. The other end of the inner tube 2 is a smooth, closed, round-headed structure with multiple side feeding holes 7 evenly distributed circumferentially. An intragastric pressure balloon 8 is circumferentially sealed near its closed end on the outside of the inner tube 2. The round-headed closed end of the inner tube 1 can effectively protect the digestive tract mucosa during cannulation. The multiple side feeding holes 7 arranged in a circumferential array can effectively avoid the risk of blockage by the gastric fundus mucosa of traditional end-hole structures. Furthermore, the circumferential array arrangement of the side feeding holes 7 ensures that the nutrient solution flows out from below the balloon and directly into the gastric fundus or pylorus, avoiding interference from fluid flushing on the intragastric pressure balloon measurement waveform. In addition, the outer wall of the inner core tube 2 is coated with a medical-grade hydrophilic lubricating coating. This coating causes a sharp drop in the coefficient of friction upon contact with digestive fluids, ensuring smooth sliding. The inner core tube 2 also has a second micro-inflation / pressure measurement cavity 9 within its wall, connecting the gastric pressure inflation / pressure measurement connector 6 and the gastric pressure balloon 8.

[0023] In this embodiment, the maximum working expansion volume of the esophageal pressure balloon 4 and the gastric pressure balloon 8 is strictly limited to a micro-volume range of 0.2 to 0.6 mL to match the esophageal anatomical compliance of infants and adolescents, and to prevent over-inflation from causing baseline drift in transdiaphragmatic pressure measurement. The first micro-inflation / pressure measurement channel 5 in the outer sheath 1 and the second micro-inflation / pressure measurement channel 9 in the inner core tube 2 are both rigid conductive channels to prevent attenuation and phase delay of respiratory pressure signals caused by changes in airway volume compliance.

[0024] In addition, the esophageal pressure balloon 4 and the gastric pressure balloon 8 are both made of extremely thin-walled, non-compliant polymer thin-walled materials (such as directional drawstring polyurethane film or PET film with a specific micron-level thickness). The above material characteristics can ensure that they can fully expand and adhere to the esophageal and gastric mucosal walls under extremely low (0.2-1.0 mL) micro-inflation conditions, while the balloon material itself does not produce elastic stress resistance that significantly interferes with the measurement.

[0025] The dynamic locking assembly includes an outer sleeve 10 fixedly connected to one end of the outer sleeve 1 located outside the body. The inner peripheral wall of the outer sleeve 10 has an internal thread. An inner sleeve 11 is rotatably mounted inside the outer sleeve 10. The outer peripheral wall of the inner sleeve 11 has an external thread that matches the internal thread of the outer sleeve 10, meaning the inner sleeve 11 is threadedly connected to the outer sleeve 10. One end of the inner sleeve 11 extends to the outside of the outer sleeve 10 and is fixedly connected to a knob 12. The outer sleeve 10, the inner sleeve 11, and the knob 12 all have through holes through which the inner core tube 2 passes. An elastic locking ring 13 for fixing the inner core tube 2 is fitted between the inner end of the inner sleeve 11 located inside the outer sleeve 10 and the inner end face of the outer sleeve 10, outside the inner core tube 2. Specifically: the elastic locking ring 13 has two pressure-bearing end faces 13-1 and a locking end face 13-2 located between the two pressure-bearing end faces 13-1 in the cross-sectional direction. The two pressure-bearing end faces 13-1 are in contact with the end faces of the inner sleeve 11 and the outer sleeve 10, respectively, and the locking end face 13-2 is in contact with the outer peripheral wall of the inner core tube 2.

[0026] In practical applications, the operator can hold the esophageal pressure inflation / pressure measurement connector 3 on the outer sheath 1 with one hand and the gastric pressure inflation / pressure measurement connector 6 on the inner core tube 2 with the other hand, and perform a "syringe-like" linear sliding push-pull action to adjust the distance between the esophageal pressure balloon 4 and the gastric pressure balloon 8. During the adjustment process, the two air paths (the first micro inflation / pressure measurement cavity in the outer sheath wall and the second micro inflation / pressure measurement cavity in the inner core tube wall) and the one liquid path (the central lumen of the inner core tube) will not interfere or become entangled, ensuring the convenience and stability of the adjustment. After the inner core tube 2 and the outer sleeve 1 are slidably adjusted, the operator can rotate the knob 12 to make the inner sleeve 11 rotate into the inner sleeve 10. During the rotation, the inner sleeve 11 will vertically squeeze the elastic locking ring 13, causing the elastic locking ring 13 to undergo violent radial expansion deformation. Its locking end face 13-2 tightly hugs the outer peripheral wall of the inner core tube 2, thereby achieving effective locking and fixing of the adjusted inner core tube 2.

[0027] To prevent the elastic locking ring 13 from excessively compressing the inner core tube 2 after the inner sleeve 11 is over-tightened, causing the tube wall of the inner core tube 2 to bend and collapse inward, thus affecting the normal nasal feeding fluid transmission and pressure monitoring functions of the catheter, a metal skeleton can be added to the tube wall of the inner core tube 2 to improve its structural strength. For example, a tungsten wire spiral spring or a metal wire braided mesh can be embedded in the tube wall of the inner core tube 2. Under the premise of ensuring that the inner core tube 2 is effectively clamped, it has sufficient pressure resistance to prevent tube collapse and thus keep the tube open.

[0028] The outer wall of the outer sheath 1 is provided with a first scale line 14, and the outer wall of the inner core tube 2 is provided with a second scale line 15. The first scale line 14 allows the operator to visually observe the absolute insertion depth of the outer sheath 1 and the esophageal pressure balloon 4 relative to the patient's nostrils or incisors. The second scale line 15 allows the operator to visually read and calculate the relative distance between the esophageal pressure balloon 4 and the gastric pressure balloon 8 during the adjustment process.

[0029] In this embodiment, the inner peripheral wall of the other end of the outer sleeve 1 (the end located inside the body) is provided with an elastic liquid-resistant lip 16 integrally formed with it and sealingly sliding with the outer peripheral wall of the inner core tube 2. The cross-sectional width of the elastic liquid-resistant lip 16 gradually narrows from the outside to the inside. Specifically, the cross-section of the elastic liquid-resistant lip 16 is a tapered or semi-circular structure with a thick base and a sharp end, which has extremely strong anti-outward rigidity. Furthermore, its inner peripheral wall is tightly fitted with the outer peripheral wall of the inner core tube, and its elastic deformation performance can ensure the effective sliding of the inner core tube 2 when subjected to force. Moreover, the elastic liquid-resistant lip 16 always tightly wraps the inner core tube 360 ​​degrees under elastic tension, realizing an effective seal between the inner core tube 2 and the outer sleeve 1 located inside the body.

[0030] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A pediatric double-balloon catheter for esophageal and gastric pressure monitoring, characterized in that: The device includes an outer sheath and an inner core tube. Both ends of the outer sheath are open. The inner core tube is slidably inserted into and passes through the outer sheath. One end of the outer sheath is equipped with a dynamic locking component for fixing the inner core tube. The inner circumferential wall of the other end of the outer sheath is in a sealed sliding fit with the outer circumferential wall of the inner core tube. An esophageal pressure inflation / testing connector is located on the outside of the outer sheath near the dynamic locking component. An esophageal pressure balloon is circumferentially sealed on the outside of the outer sheath away from the dynamic locking component. The outer sheath has a first micro-inflation / pressure measurement cavity inside its wall, connecting the esophageal pressure inflation / pressure measurement connector and the esophageal pressure balloon; one end of the inner core tube has an intragastric pressure inflation / pressure measurement connector outside, and the other end of the inner core tube has a smooth, closed, rounded head structure with multiple side nasogastric feeding holes evenly distributed circumferentially; an intragastric pressure balloon is circumferentially sealed near its closed end on the outside of the inner core tube; and the inner core tube has a second micro-inflation / pressure measurement cavity inside its wall, connecting the intragastric pressure inflation / pressure measurement connector and the intragastric pressure balloon.

2. The pediatric double-balloon catheter for esophageal and gastric pressure monitoring according to claim 1, characterized in that: The dynamic locking assembly includes an outer sleeve fixedly connected to the end of the outer sleeve. The inner peripheral wall of the outer sleeve has an internal thread. An inner sleeve is rotatably disposed inside the outer sleeve. The outer peripheral wall of the inner sleeve has an external thread adapted to the internal thread of the outer sleeve. One end of the inner sleeve extends to the outside of the outer sleeve and is fixedly connected to a knob. The outer sleeve, the inner sleeve, and the knob all have through holes through which the inner core tube passes. An elastic locking ring for fixing the inner core tube is fitted between the inner end of the inner sleeve located inside the outer sleeve and the inner end face of the outer sleeve on the outside of the inner core tube.

3. The pediatric double-balloon catheter for esophageal and gastric pressure monitoring according to claim 2, characterized in that: The elastic locking ring has two pressure-bearing end faces and a locking end face located between the two pressure-bearing end faces in the cross-sectional direction. The two pressure-bearing end faces are in contact with the end faces of the inner sleeve and the outer sleeve, respectively, and the locking end face is in contact with the outer peripheral wall of the inner core tube.

4. The pediatric double-balloon catheter for esophageal and gastric pressure monitoring according to claim 1, characterized in that: Both the esophageal and gastric air-pressure cuffs are made of ultra-thin-walled non-compliant polymer film material, and both the outer sheath and the inner core tube are made of medical-grade polyurethane.

5. The pediatric double-balloon catheter for esophageal and gastric pressure monitoring according to claim 1, characterized in that: The outer sleeve has a first scale line on its outer wall, and the inner core tube has a second scale line on its outer wall.

6. The pediatric double-balloon catheter for esophageal and gastric pressure monitoring according to claim 1, characterized in that: The outer wall of the inner core tube is coated with a medical-grade hydrophilic lubricating coating.

7. The pediatric double-balloon catheter for esophageal and gastric pressure monitoring according to claim 1, characterized in that: The outer sleeve has an elastic liquid-resistant lip integrally formed therewith and which slides in a sealing fit with the outer peripheral wall of the inner core tube.

8. The pediatric double-balloon catheter for esophageal and gastric pressure monitoring according to claim 7, characterized in that: The cross-sectional width of the elastic liquid-resistant lip gradually narrows from the outside to the inside, and its inner peripheral wall is tightly fitted with the outer peripheral wall of the inner core tube.

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