A smart tablet controls not only itself, but also the patient

The newly created company Proteus Biomedical, part of the Silicon Valley structure, is developing a system for monitoring the intake of medicines and their effects. The proposed system, called the "Raisin system" (raisin – highlight), consists of a tablet that reports with an electrical signal that it has been swallowed, and a sensor that monitors the reactions developing in the body.

According to one of the founders of the company, former emergency physician George Savage, the motivation for the creation of this system was the fact that many medical problems are based on difficulties with the selection of drugs. Thus, about 40% of repeated calls to medical institutions for heart attacks occur due to incorrect intake of medications by patients.

Even if the patient follows the doctor's instructions, the treatment protocol may be suboptimal. The doses of drugs are selected based on the results of large-scale clinical trials, so they may not meet the needs of specific patients.

Each Raisin system tablet contains an indigestible sensor, which is a microchip the size of a grain of sand and a thin-film battery that activates upon contact with an aqueous medium after ingestion. The battery is non-toxic, because materials similar to those used in the production of multivitamin tablets are used for its manufacture. After ingestion, the sensor emits modulated high-frequency electromagnetic waves that propagate through the tissues of the body. Unlike the method of radio frequency identification, the signal does not go beyond the body, because its propagation is limited by the electrical conductivity of tissues.

The electric current is registered by a receiver, which is pasted in the form of a patch on the skin of the chest or abdomen or injected subcutaneously. The receiver not only registers signals from a sensor swallowed with a tablet, but also contains a sensor that provides monitoring of physiological parameters such as heart rate, breathing and body movements. The heart rate is recorded by evaluating the electrical activity of the heart, breathing is recorded by evaluating changes in the resistance of the electrodes during the expansion and contraction of the chest, motor activity is evaluated using a miniature vibration sensor. Complex processing of the results makes it possible to identify behavioral indicators, such as the nature of sleep.

Theoretically, subcutaneous chips can be used to simultaneously monitor biochemical parameters, such as blood glucose levels. However, at the present stage, the company pays attention to biophysical parameters that can be evaluated on the surface of the skin.

With the help of a cell phone or computer, the collected data is uploaded to the server, after which, based on their processing, the attending physician adjusts the dosage or changes the medications taken.

Other companies are developing similar technologies. For example, specialists from the Georgia Institute of Technology have developed a MagneTrace system designed to record the movement of magnetized tablets through the patient's digestive tract and send it to a computer. But the possibilities of the Raisin system are immeasurably greater: it allows for round-the-clock monitoring to compare the intake of drugs with the physiological reactions of the body.

In connection with the use of such technologies, the question of confidentiality of information inevitably arises. According to Savage, the electrical signal emitted by the tablet spreads exclusively through the tissues and cannot be registered remotely, for example, by employers who want to know what drugs employees are taking. Moreover, Proteus states that the necessary data protection measures will be provided during the production of the system.

An important point is also that the signal limited by the skin will not overlap with the signals from the pills taken by the housemates or hospital ward. Even when entering into direct physical contact, the transmission of an electrical signal from the skin of one person to the skin of another is so insignificant that it will not lead to an unintentional exchange of information.

Savage claims that the Raisin system can be especially useful for patients with mental illnesses who, despite their desire, are sometimes unable to adhere to the treatment regimen due to the nature of the disease. In this case, the system can be used to notify relatives or staff about the missed dose by the patient.

The figure shows an example for just such a case: the display shows an assessment of the patient's health status and the degree of compliance with the prescribed regimen of taking risperidone, an antipsychotic drug used to treat schizophrenia, psychotic states with delirium and other mental illnesses.

The system will also eliminate the need for frequent examination of patients with dangerous infectious diseases, such as tuberculosis.

The developers claim that if the results of clinical trials launched earlier this year demonstrate the safety and effectiveness of this complex technology, the first representatives of the Raisin system will appear on the market in 2011.

Evgeniya Ryabtseva
Portal "Eternal youth" www.vechnayamolodost.ru based on the materials of TechnologyReview 

28.03.2008