'Lit-control' device where the pH sensor has been implemented.Urinary pH is a good indicator to predict the risk of stone-formation in the kidney (renal lithiasis). The usual control of the pH in the urine allows taking clinical measures, either pharmacological or dietetic, in order to prevent stone-formation. Nevertheless, the standard way to measure the urinary pH requires taking a sample and sending it to the lab. There are also reactive stripe kits, which would make easier the control of urinary pH, but they are not precise enough.
At the Instituto de Microelectrónica de Barcelona (IMB-CNM) of the CSIC, the scientists of the Chemical Transducters group have developed and patented a new ISFET/REFET sensor to measure the urinary pH. It is based on the same technology used for most electronic components, which enables its production at a very low cost.
The Spanish company Devicare, which has signed a license for the exclusive use of this sensor in health applications, is leading the development of a device for the self-control of renal lithiasis, where the ISFET/REFET sensor will be implemented. The device, in turn, is based on a patent of the Renal Lithiasis Laboratory at the Universitat de les Illes Balears.
Robust, precise and cost-effective
ISFET are chips with chemical sensors integrated. In this case, the device has two ISFET sensors: one of them measures the pH and the other has a microfluidic structure that works as a reference. Actually, ISFET/REFET is the acronym of “Ion-Sensitive field-effect transistor - Reference Field effect Transistor”.
The sensor created by the scientists at IMB-CNM is robust and accurate. It has a lifetime of several months and an affordable cost, which makes possible its use in a self-diagnostic device. Another advantage is that the sensor performs an automatic calibration when the system is turned on, which simplifies a lot its use.
The sensor has been validated in an essay involving 30 patients, by doctors and scientists at the University of the Illes Balears (UIB), at the IMB-CNM and the company Devicare. The results of the essay will be published in the World Journal of Urology magazine.
Device for self-diagnostics
The sensor has been implemented within the first easy to use device for measuring urinary pH, suitable for use by lithiasic patients at home. The device, which has been called “Lit-control”, is nowadays being validated and tested by urologists. In its development have been also involved the Centre de Desenvolupament de Sensors, Instruments i Sistemes (CD6) at the Universitat Politecnica de Catalunya (UPC) and the technological centre ASCAMM. The founder of Devicare, Rosendo Garganta, says that Lit-control could be on the market a the end of 2014.
According to some studies, the prevalence of kidney stones in economically developed countries could range from 4% to 20%. In Spain, there are annually between 300,000 and 400,000 new cases (nephritic syndrome). Prevalence in Spain is 5%, with more than 2 million people affected. Recurrence is also high: up to 60% of the affected people will have new kidney-stones formation episodes during the five years after the first crisis, and up to 80% of the patients during the 10 years after the crisis. It is estimated that worldwide there are 700 millions of people affected.
Contact:
Ferran Vera
Grupo de Transductors Químics
Institut de Microelectrònica de Barcelona - CNM (CSIC)
Tel.: 935 947 700