Microfluidic Rheotaxis Evaluation for Sperm Fertility Assessment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sperm evaluation methods, such as CASA, fail to account for rheotaxis, a crucial aspect of sperm quality that influences fertilization capacity, and lack the ability to predict in vivo fertility accurately.
Innovation Solution
A microfluidic system with probes that mimic the female reproductive tract's dimensions and hydrodynamic features, allowing for the quantification of sperm rheotaxis through image processing to determine a rheotaxis quality index (RHEOLEX), which can be used as a biomarker for male fertility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional CASA methods are used for sperm evaluation, then motility and concentration can be measured, but rheotaxis quality cannot be assessed
Solution Approach 1:
A microfluidic device serves as an intermediary between the sperm sample and the evaluation system. The device incorporates probes with confinement regions that passiveaally separate and concentrate rheotactic sperm based on their swimming behavior in fluid flow, enabling rheotaxis quality assessment without requiring complex active manipulation or sophisticated imaging systems.
Solution Approach 2:
The microfluidic device creates a simplified physical model of the female reproductive tract environment within the lab setting. By replicating the hydrodynamic conditions and geometric constraints of the natural environment, the device allows sperm to exhibit their natural rheotactic behavior, which can then be observed and measured using standard microscopy equipment.
2Reliability
If sperm evaluation focuses only on motility and concentration, then assessment is simple, but in vivo fertility prediction accuracy deteriorates
Solution Approach 1:
The microfluidic device performs preliminary separation and concentration of rheotactic sperm before the actual measurement process. By pre-concentrating the target sperm population in the confinement regions during the sample loading process, the system eliminates the need for time-consuming active sorting or complex image analysis, enabling rapid fertility assessment within minutes.
Solution Approach 2:
The system leverages the inherent rheotactic behavior of sperm as the separation mechanism. Sperm naturally respond to the fluid flow and geometric constraints in the microfluidic device, automatically concentrating in the confinement regions based on their swimming capabilities. This self-organizing behavior eliminates the need for external actuation, complex control systems, or energy-intensive sorting processes.
3Quantity of substance
If microfluidic probes with confinement regions are used, then rheotactic sperm can be concentrated, but device structure becomes more complex
Solution Approach 1:
The microfluidic device is divided into multiple independent probes, each containing a confinement region. This segmentation allows the system to process and concentrate sperm from different regions of the sample simultaneously, increasing the overall concentration efficiency while maintaining a relatively simple structure in each individual probe that can be manufactured using standard microfabrication techniques.
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 system provides a rapid, point-of-care method to assess sperm fertility by measuring rheotaxis, correlating with low DNA fragmentation and improving the prediction of in vivo fertility.
Implementation Method 1
oviductal secretions after coitus, generate a fluid flow from oviduct to uterus which has been proposed to guide motile sperm to fertilization site by positive rheotaxis
Data Source
AI summary
The present technology relates to a systems for quantifying rheotaxis in a sperm-containing sample. The system includes a microfluidic system having an inlet for charging fluids into a passage. One or more probes defining a confinement region suitable for retaining motile sperm are within the passage. The system further comprises an image processing computing device for obtaining a sequence of images of the confinement region of at least one of the one or more probes having motile sperm retained therein. The sequence of images of the confinement region is processed to determine a signal intensity value for said sequence of images, wherein said signal intensity value is based on a concentration of the motile sperm located in the confinement region at the flow rate. A rheotaxis quality value is determined for said sperm-containing sample based on the signal intensity value. Methods for quantifying rheotaxis in a sperm-containing sample are also disclosed.