As originally asked by Sean Hillman.

Sean Hillman
Business Manager, Colour Standards Laboratory at Lucideon Limited
Dear Patricia,

Thank you for your comment.

Yes, we can develop bespoke ceramic colours based on L*a*b* values. It will help the process if you have physical samples to send us or reflectance curves.

Please contact me at: [email protected]

so we can discuss this in greater depth and I can show you the colours that we already have available.

Best regards

Sean

Patricia Le Coupanec
Experienced Optical Systems Engineer
Hello Sean,
I may be interested in your color standards format for a project we have for medical imaging where we will need to develop a specific set of color swatches for our calibration process. Can you generate an accurate colored ceramic swatch based on color coordinates we give you in the chromatic Lab space?
Best regards,
Patricia

Gregory K. E. Hall
Contract Biomedical Systems Safety Engineer at Medtronic CRHF at Populus
I don’t have a great answer for this, but… There are other properties of light. Changes in polarization? Others?

Sean Hillman
Business Manager, Colour Standards Laboratory at Lucideon Limited
Hi Dr Morris,

Yes, I would like to discuss how ceramic strips could be used the devices you mention.

If you E-mail me your ‘phone number I will call you at some convenient time.

My E-mail is [email protected]

Best regards

Sean

Sean Hillman
Business Manager, Colour Standards Laboratory at Lucideon Limited
Hi Oleg,

Thank you for that information, it is very interesting.

Do you know what the colour standards are? What shape/size are the racks?

I wonder if any of our existing colours could be used, or if we would just have to develop some new colours?

Regards

Sean

Oleg Rechkin
Clinical Education Specialist, MI at GE Healthcare
Sean,

colour standards are used for calbrating BacT/ALERT bacteriology analyzers by bioMerieux.
These analyzers are based on colorimetric method patented by Organon Teknika (was acquired by bioMerieux in early 2000s). Microorganisms which are present at a nutrient medium produce CO2 as the result of metabolism. CO2 production causes change of sensor colour. Measuring reflected light, the BacT/ALERT monitors and detects color changes in the sensor. Different algorithms analyze the growth curves to determine positive samples.

Four racks with different reflectance standards are used for getting readings of measurement cells during calibration and creation of calibration curve.

David (Dan) Morris
Professor, Chemistry and Mathematics
No one has mentioned the large number of reflectance meters that are used to measure the color of urinalysis test strips. These instruments are found in just about every medical clinic, doctor’s office, and large laboratories that do urine analysis. A starting place to find out about them online is to google the CLINITEK family of meters from Siemens, and the Chemstrip Test Strip Analyzers from Roche. Overseas companies, including 77 Elektronika in Hungary and Macherey Nagel in Germany also market reflectance (color measuring) instruments for urinalysis. The instruments are pre-calibrated at the factory. They are classified as medical devices in the US. Let me know if you want to discuss how the ceramic strips might be used with these devices.

Sean Hillman
Business Manager, Colour Standards Laboratory at Lucideon Limited
Dear Shabbir,

I would be very interested to learn more about the Colour Standards that you use to calibrate the spectrophotometric devices.

Best regards

Sean

Shabbir Bambot
Co-founder and CEO
We use color standards to calibrate spectrophotometric devices. These applications are different from the common glucometer example. One product we developed is currently sold by Philips and is called the Bilicheck device for detecting jaundice in newborns. We also use similar standards to calibrate devices for diagnosis/triage of cancer.

Sean Hillman
Business Manager, Colour Standards Laboratory at Lucideon Limited
OK, Thanks Glenn.

Regards

Sean

Glenn Neuman
Director of Scientific Affairs at New World Regulatory Solutions, Inc.
Modern glucometers tend to use electrical signal rather than color. Urine analysis pads are color based. Iris, Analyticon, Roche and Siemens all sell instruments that measure color change.

Sean Hillman
Business Manager, Colour Standards Laboratory at Lucideon Limited
Hi Gary,

Yes, the big advantage that our Colour Standards have over plastic or printed ones is that they don’t change colour over time as they are ceramic. This means that we still have Colour Standards in service that were made in 1983 when we first started making them. Mind you, it also means that we don’t get much replacement business unless people damage or lose them. Even if they are soiled they can still be cleaned thanks to their durable surface!

Thanks

Sean

Gary Neel
GM at Omni Biomedical
Due to the high volume of standards required in glucose meter low cost stabilized plastic from the old GE plastics group was used. These days there is still a need but it is much less due to the shift to electrochemical assay technology.

Sean Hillman
Business Manager, Colour Standards Laboratory at Lucideon Limited
Gentlemen,

Thank you for your comments, this is very interesting stuff.

We make permanent ceramic Colour Standards which are usually used to check the performance of spectrophotometers, but I think that it would be fairly straightforward to make small (5 x 5 x1mm) pieces that could fit on test strips and be used to check/calibrate optical sensors like you are describing. It might be easier than using glucose test solutions, although these also test the strips as well as the instruments, mind you, it must be difficult to decide if the solution, test strip or instrument are at fault if the reading is wrong.

I guess that now I need to speak to the manufacturers of these devices and the names you have mentioned will be a good starting place.

Again, many thanks for all your help.

If I can reciprocate in any way, please let me know.

Best wishes

Sean

Gary Neel
GM at Omni Biomedical
There is a long history of reflect-acne based diagnostic products…..most patents have expired now. Roche makes the Compaq that contains 17 strips in a drum shaped cartridge. Reflowtron used three LEDs and an integrating sphere with reference photodiode for several diagnostics test. Digital pregnancy test use reflectance to read the color development.

David J. Benefiel, MD
Biomedical Engineering
In the hospital operating room environment, calibration is required in order to use these consumer devices in the operating room. Then the reading can be entered in the chart and become part of the medical record. There are hospital laboratory requirements for periodic calibration. The device can be programmed to require calibration in order to continue to test. Each lot of strips has a unique number. If a new lot is introduced to the machine, calibration is required with a test solution to validate that the new lot is within required tolerances. The advantage of using these devices in the OR is that the staff does not have to send a sample to the lab and wait for the result. The disadvantage is that the calibration and entering the patient identifier into the machine takes time away from patient care. On balance, it is better to get fast turnaround for tight glucose management.

Gary Neel
GM at Omni Biomedical
In the mid 1980s the color back-up feature was must have feature. In the 1990- present almost all companies moved to electrochemical based glucose meters to get better performance and lower blood volume. Manufactures now recommend use of control solution to check if something is wrong with the test strips. The meters have an internal reference that checks the electronics.

David Kopa
Customer Operations Planning Manager at Autonomic Technologies, Inc.
Hi Sean,
There are many blood glucose meters on the market, and the manufacturers must provide control solutions in order to validate that the devices are working properly. Although all use some type of glucose enzyme to catalyze the reaction with sugar, only a few still use the “photometric” technology that you reference above–i.e., an enzyme in the test strip reacts with glucose, producing a product which in turn reacts with a colored dye, the reflectance of which is proportional to the sugar concentration in the sample. Today, most meters on the market use “electrochemical” technology, wherein the glucose molecules react with a glucose enzyme (e.g., glucose oxidase), releasing electrons, and generating a current that is measured by the meter. The strength of the current is proportional to the concentration of glucose in the original sample, and the meter calculates a blood glucose concentration accordingly.

Neven Karlovac
CEO at Cellmic LLC
Another category is readers for lateral flow immunoassay strips, also known as rapid diagnostic tests or RDT. One example is HRDT-1 reader you can find on www.holomic.com. Most readers are designed to measure luminance of a single color (the pink of colloidal gold) but they could be adapted for multicolor measurements.

Bruce Flora
Product Engineer
Glucose meters have two calibration modes. An internal mode to be sure the electronics are working properly. The other is normal control solution. The solution is spike glucose and additives to simulate blood samples. There are multiple concentrations. Results should be within 20% of actual values.