Bluetooth CCD Systems
 
Development of A Microfluidics-based Flow Instrument
2011

Aims
droppedImage


1) Development of a microfluidics instrument capable of monitoring in real-time a fluorescence emission (eg. Flow cytometry, immunoassay, enzyme assay).

2) The system was also required to record data for post-event analysis, facilitate windowing of the data to provide region-of-interest analysis and also relay real-time data to a tablet PC via Bluetooth.

A simple schematic is shown below of the concept using an LED light bar and a line-scan CCD camera.
Figure 1: Schematic of the Illumination System


A labVIEW application has been developed to relay data from the PC running the CCD camera to a tablet PC running windows 7 via a bluetooth connection.
A simple Bluetooth server application was combined with modified LV code form the camera manufacturer and paired via Bluetooth with a simple Bluetooth client application running on a Windows 7 tablet.

droppedImage_1


Figure 2: Illustration of Data Relay Concept
    

USB2.0 3648-Pixel 16-bit CCD Line Camera with External Trigger, Board-Level
TCN-1304-U
droppedImage_2


http://www.mightexsystems.com/family_info.php?cPath=5_48&categories_id=48

Figure 3: Mightex Line Scan CCD Camera

Mightex’s TCN-1304-U line camera is a cost-effective high-performance B/W board-level line camera, based on a single-line, 3648-pixel CCD chip with USB2.0 (480 Mb/s) interface. CCD line cameras have several advantages over their area-array counterparts, including high optical linear resolution that allows systems developers to use the cameras to capture two-dimensional (2-D) images by moving the object or the CCD perpendicularly to the scan line. The TCN-1304-U is a compact, board-level line-scan camera ideal for a variety of OEM applications in industry process control, optical spectroscopy and bio-medical imaging etc.. Setting up the TCN-1304-U line camera is very easy, the user simply installs the latest version of the operating software onto any desktop or notebook PC and then connects the USB cable from the line camera to the PC. There is no need to install a DAC card, or use an external power supply. A full-featured SDK and a Linux driver are also available.

droppedImage_3




Illumination source

Basing the initial work on a blue light source (wavelength of around 480nm) and a green fluorescence output (wavelength of around 530nm), the following LED light bar was obtained for use with the system. A simple orange Perspex filter will be used as a Bandpass system to remove the blue excitation light and permit transmission of the resultant green fluorescence light.

Whilst standard fluorescence systems operate using a right-angle based system – to remove the need for a filter, it is hoped that the intensity of the LED bar and the attenuation of this radiation by the simple filter will be sufficient to remove the background excitation radiation.

droppedImage_4


Figure 4: KingBright 12 LED Kightbar
Blue 12-seg LED lightbar, DD-12PBWB
RS Stock No. 616-4807
Manufacturers Part No. DD-12PBWB
Catalogue page 2 – 2972



Microfluidic Channel System

The initial channel system will be formed using a cut sheet of translucent polymer, which can be sourced from Polymax Ltd. This will be cut using the Craft Robocutter and sandwiched between two microscope slides.

The magnetic bonding frame containing 12 neyodynium disc magnets previously designed will be used to secure the structure.
droppedImage_5


Figure 5: 3D Design Schematic for Magnetic Bonding Device

Software Development

droppedImage_6


Figure 6: Schematic of LabVIEW Code Generation

Simple Bluetooth Server – LabVIEW Example Code

droppedImage_7



Figure 7: Front Panel for Simple Bluetooth Server VI


droppedImage_8


droppedImage_9


Figure 8: Block Diagram for Simple Bluetooth Server VI

Simple Bluetooth Client – LabVIEW Example Code
droppedImage_10



Figure 9: Front Panel for Simple Bluetooth Client VI

droppedImage_11


Figure 10: Block Diagram for Simple Bluetooth Client VI.


Mightex CCD Example Code
droppedImage_12


Figure 11: Front Panel for Mightex CCD Code VI

droppedImage_13



Figure 12: Block Diagram for Mightex CCD Code VI


droppedImage_14


Figure 13: Front Panel for Combined CCD/Bluetooth Server VI


droppedImage_15


Figure 14: Block Diagram for Combined CCD / Bluetooth Server VI – Part 1

droppedImage_16

Figure 15: Block Diagram for Combined CCD / Bluetooth Server VI – Part 2


droppedImage_17



Figure 16: Front Panel of Modified Bluetooth Client VI


droppedImage_18

Figure 17: Block Diagram of Modified Bluetooth Client VI

Conclusions

Modifications have been made to the LabVIEW code to facilitate the integration of the CCD code with the Simple Bluetooth Server, and additionally modifications have been made to the Bluetooth client application.

The CCD application is currently unreliable, as the sub-routines calling the DLL files required for the camera often result in a crash.  Reduction of the error checking routine to minimal improves system stability, however system crashes occasionally occur.
droppedImage_19


The removal of excessive and extraneous code components from both the applications and the inclusion of a timing loop have improved stability.

Further work is required to finalise the programme, simplifying the programme structure and including additional loops to activate and de-activate the Bluetooth server.

Currently, the connection routine is difficult to establish due to timing elements, and often a de-bugging method using “Highlight Execution” and “run continuously” is required to slow the connection and facilitate repeated attempts.

As such there is a requirement for a connection sub-routine as a separate element in the overall structure.

However, the system has successfully demonstrated the integration of the CCD line camera, and a LabVIEW application to both log pixel data and relay data in real-time to a tablet PC running Windows7.