Tuesday, March 10, 2009


Bio-sensors are increasingly being considered as monitors for vital health parameters. Latest to arrive on the scene is an intelligent pill that sends digital signals to an external receiver after being swallowed. Developed by a US company the pill, when swallowed, can send digital signals to an external receiver for recording vital parameters in side the body. The pill consists of a food based sensor that is digestible in the body and activation is achieved through exposure to the stomach fluids. The existing invasive system calls for introducing retrievable sensors, monitors or cameras into the body through oral or anus route and the computerized system receives digital signals via the cable which are monitored live or recorded for diagnostic purpose. The familiar angiogram uses the venous route to assess the health of the heart and its arteries before deciding on relevant treatment or otherwise.
The sensor containing pill after reacting with the stomach fluids sends detectable signals to a receiver which can record the data with date and time stamps. It further decodes information about the medicines used, heart rate, activity and respiratory rate. The receiver is designed as a small bandage type skin patches which can be connected to 3G phone networks for easy access from any where in the world. Patients, recuperating at homes and old age sick persons can use this system so that hospitals located in far away places can monitor the health condition for prompt and effective intervention as and when required. Though the system is in final stages of development, the industry expects its availability during the year 2011-2012.
Bio-active silk films made by boiling silk cocoons and preparing purified silk solution are cast into lenses, microlens arrays and holograms to make edible optical sensors which can be used in food packs to detect infection by organisms like E.coli. Polymers like silk proteins used as edible sensors are strong, flexible, benign and biodegradable. The idea is to include such optical edible sensors in bags of fresh produce like spinach which will provide the consumers with a read out of whether the product is contaminated before consumption.
Luminescent sensors are still in the conceptual stage and probably they may yet provide the industry with a relatively low cost tool for monitoring microbial quality of food. These probes, 20-200 nm in particle size are made incorporating edible dyes like erythrosine or naturally occurring phytochemicals like quinones or flavonols and provide high signals due to more than 10000 particles present. They are easily dispersible without the risk of sedimentation,  versatile and selective in their properties. The signals generated can be easily and precisely detected with inexpensive, portable and reliable instruments.
With the threat of pathogenic microorganisms posing serious health challenges, both industry and the safety monitoring agencies are worried about the future of the food processing sector, especially those handling fresh produce for cold consumption without heat processing. Quick and reliable detection systems like the ones mentioned above can only restore the rapidly declining consumer confidence on products marketed by the organized food industry and the efficiency of the enforcement agencies in protecting consumer health.   

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