Team:BIT/Hardware

Hardware
To integrate the early screening operation method of colorectal cancer constructed by our project, we built a novice-friendly In Vitro Diagnostic (IVD) Device.
As a sample-to-answer(STA) platform, it is able to surmount the complexity of the process of using traditional detection equipment, which is bulky and inconvenient to carry. And it also can achieve rapid detection of CRC-associated miRNA biomarkers in less than 1 hour with a result at fM sensitivity.
Based on the interactive interface in the smart mobile phones, it is prettily adaptive to the end user experience.

Device sampling process

Device modeling diagram

Device internal structure

Design framework
The hardware module in the design mainly includes five modules: SlipChip(Click), Temperature control(Click), Fluorescence detection(Click), Support structure(Click) and Software (Click). You can click the text to view the detailed design.
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Main technical principles
• Integrate the biological detection process through the SlipChip, and pre-embed the lyophilized bead reagent in the SlipChip to reduce the complicated sampling process and reduce the possibility of false positives and false negatives due to non-standard experimental operations.
• The machine-driven SlipChip is used to prevent the uncertainty caused by manual operation from being reduced, and it is convenient to use.
• By constructing supporting instruments to achieve a high degree of integration of the detection process, it avoids the trouble caused by the use of large-scale experimental device such as microplate readers and PCR machines, which is conducive to the use of large-scale early screening.
• Realizing the visualization of results and Bluetooth interactive control by building a software system based on WeChat applets is conducive to the realization of intelligent human-computer interaction process and is suitable for terminal user experience.
Innovation
The hardware module integrates the CRC detection method constructed by the biological module into the SlipChip, and the construction of the instrument meets the biological reaction conditions and realizes the detection of the reaction results. At the same time, the device uses Bluetooth communication to upload the CRC detection process and results to the smartphone, providing examples for the popularization of colorectal cancer early screening detection, and providing a new strategy for the construction of a standardized cancer detection platform.
SlipChip(Click to view more designs)
The biological module has constructed a detection method for colorectal cancer-related miRNAs. In order to integrate the above-mentioned biological reaction process, save the trouble caused by multiple steps in the detection process, and achieve the ultimate goal of point-of-care testing, we A portable SlipChip with simple operation and multi-channel detection is designed.
We make the reaction-related reagents into freeze-dried beads and pre-embed them in the SlipChip, and use an electric push rod to push the SlipChip, which can greatly reduce the detection process. After testing, the steps of each stage of the biological module can be implemented on the SlipChip.

SlipChip schematic diagram

SlipChip physical diagram

Temperature Control(Click to view more designs)
In order to avoid using a heavy PCR instrument for nucleic acid amplification, we have developed a temperature control module to provide a suitable temperature for the reaction, and are committed to achieving the goals of instrument miniaturization, low power consumption, and high control accuracy.
The temperature control module built by us has a heating rate of up to 2.26℃/s, good uniform temperature performance, high control accuracy, and small steady-state error. It can achieve accurate temperature control and help achieve high specificity and high sensitivity nucleic acid Amplification and CRISPR/Cas12 reaction detection.

Temperature control system diagram

Temperature control system construction circuit board

Temperature control curve

LAMP amplification result on the SlipChip

Fluorescence Detection(Click to view more designs)
The biological module constructs a fluorescence detection method based on the Crispr/Cas12 detection system, which couples the amount of miRNA in the human body with the intensity of the fluorescence signal. Traditional fluorescence detection relies on large-scale experimental device such as a microplate reader. For this reason, we have developed a miniaturized and compact fluorescence detection module that is adapted to detect the intensity of the fluorescence signal in the SlipChip.
We have constructed a multi-channel, high detection accuracy, high repeatability and high linearity fluorescence detection module for the SlipChip, which has good repeatability for the detection of fluorescent dyes, high detection precision and low fluorescence interference between different channels At the same time, it has good linearity to fluorescent dyes.

Confocal optical path design

Fluorescence detection effect diagram

Scanning fluorescence intensity results

Fluorescence standard curve

Software(Click to view more designs)
Due to the need for miniaturization of the instrument, we abandoned the development of the interactive panel in the traditional instrument, and instead looked for a human-computer interaction method that is more suitable for the end user experience. Smart phones are popular all over the world and mobile phones have rich and diverse data communication methods that can realize Bluetooth interaction. We use the small program development function that comes with Wechat, a commonly used communication app in mainland China, to develop human-computer interaction interfaces. It mainly realizes functions such as Bluetooth control and visualization of results.




Support Structure(Click to view more designs)
We design the corresponding support structure to integrate the various functional modules constructed by the hardware module. Assemble each module of the instrument, and after testing, the detection process of biological module construction can be realized. The detection device we built provides a new strategy for the construction of a standardized cancer detection platform.

3D model design drawing

main component design drawing

3D modeling diagram

3D printing device physical diagram