Hydrogel Cervical Dilator With Osmotic Swelling Rate Control
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Solution Overview
Problem
Existing cervical dilators face challenges in controlling the rate of tissue expansion, leading to potential tissue damage and scarring due to mechanical dehydration, and they lack effective osmotic control and design features to prevent infection and ensure safe, controlled dilation.
Innovation Solution
A cervical dilator is developed with a dehydrated hydrogel stem containing an osmotically active compound, such as a polyelectrolyte or low-molecular weight salt, which expands radially upon hydration, combining osmotic and mechanical expansion for controlled tissue dilation, and is manufactured by axial stretching and drying to achieve anisotropic swelling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If mechanical dilators are used to force tissue expansion, then the dilation speed is improved, but tissue damage and scarring occur due to exceeding the dehydration rate
Solution Approach 1:
The patent replaces purely mechanical dilation systems with a hybrid system that combines osmotic action (chemical/physical gradient) and mechanical expansion. The hydrogel dilator uses osmotic pressure to draw water from tissue, causing controlled dehydration and softening, then expands mechanically to provide controlled dilation at a safe rate that matches tissue dehydration capacity, preventing cell membrane rupture and scarring.
Solution Approach 2:
The patent changes the physical state parameters of the dilator material by using a hydrogel that transitions from a dehydrated state (for insertion) to a hydrated state (for expansion). This phase change allows the device to control the dilation rate by regulating water absorption from tissue, thereby matching the tissue's dehydration rate and avoiding harmful rapid expansion.
2Object-affected harmful factors
If osmotic dilators are used for tissue softening, then tissue damage is reduced, but the dilation rate is difficult to control and may exceed safe limits
Solution Approach 1:
The patent merges two previously separate mechanisms into a single integrated device: osmotic dehydration (using hydrogel's water-absorbing property) and mechanical expansion (using the hydrogel's swelling capability). This combination allows the dilator to first soften tissue through controlled osmotic water withdrawal, then expand mechanically at a rate controlled by the hydrogel's hydration kinetics, providing both safety and controllability.
Solution Approach 2:
The hydrogel dilator is self-regulating in its dilation rate. As it absorbs water from the surrounding tissue, the osmotic gradient automatically decreases, slowing down the water absorption rate. This self-limiting mechanism prevents excessive dilation speed without requiring external control systems, making the device both safe and easy to operate.
3Adaptability or versatility
If natural laminaria stems are used for cervical expansion, then osmotic and mechanical expansion are achieved, but hydration is slow and irregular with low mechanical strength
Solution Approach 1:
The patent changes the material composition from natural laminaria polysaccharide hydrogel to a synthetic hydrogel system. This synthetic hydrogel has modified physical and chemical parameters including faster water absorption kinetics, more regular hydration pattern, and enhanced mechanical strength. The synthetic polymer structure allows for controlled pore size and hydrophilicity, optimizing both hydration speed and structural integrity during expansion.
Solution Approach 2:
The patent employs composite material design by combining synthetic hydrogel polymer matrix with appropriate crosslinking agents and potential reinforcement structures. This composite approach maintains the beneficial osmotic and mechanical expansion properties of natural laminaria while overcoming its limitations of slow hydration and low mechanical strength, achieving both versatility and performance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The dilator provides controlled, safe, and efficient cervical tissue expansion with reduced risk of damage, faster ripening, and improved mechanical strength, while minimizing the risk of infection through a designed structure.
Implementation Method 1
The xerogel is hypertonic with respect to the contacting tissue and thus draws water from the tissue. The osmotic gradient gradually decreases as the osmolarity increases in the tissue and decreases in the hydrogel stem
Implementation Method 2
The stem expands in its volume as the xerogel hydrates to become the hydrogel. This expansion generates a controlled mechanical pressure against the cervical tissue assisting in its dehydration
Implementation Method 3
axial stretching and drying to achieve anisotropic swelling
Data Source
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AI summary
A cervical dilator including a stem comprising a partly or fully dehydrated hydrogel comprising a water-insoluble synthetic hydrophilic polymer capable of radial expansion due to absorption of water from a bodily fluid. The cervical dilator softens and ripens the cervical tissue and expands the cervical canal by a combined action of radial hydrogel stem expansion and osmotic withdrawal of water from the tissue. The osmotic withdrawal is caused by at least one osmotically active compound, such as a water-soluble salt, a polyelectrolyte, or a mixture thereof, wherein the at least one osmotically active compound is dispersed in the hydrogel. The cervical dilator may also include a non-toxic plasticizer of the hydrogel, such as water.