Rapid analysis of kidney stones

October 1, 2015, Fraunhofer-Gesellschaft

Kidney stones rank among the most common illnesses. Their recurrence might be prevented with the right postoperative care. However, for this to be effective, composition of the stones should be known. Fraunhofer researchers are developing a system for rapid analysis of urinary stones immediately after the surgical procedure.

An increasing number of citizens in western European countries are affected by kidney stone disease. The number of new cases has tripled in the last 10 years. Kidney stones are often no larger than a grain of rice, yet some can grow to a diameter of several centimeters. Sometimes a urinary stone might block the ureter, causing colick pain in the flank. If it cannot be dissolved, the kidney stone is treated using extracorporeal shock-wave therapy or applying minimally invasive endoscopic modalities.

Many patients suffer from and need retreatments. Scientific studies have shown that new stone formation might be reduced by 50 percent if individualized follow-up care and proper metaphylaxis measures are offered to the patient. The recommendations regarding dietary habits or the use of particular medication strategies are based on the knowledge of the stone composition. In collaboration with an industrial partner and the Division of Urotechnology, University Medical Center Freiburg, researchers at the Fraunhofer Institute for Physical Measurement Techniques IPM are developing a novel Raman spectroscopy based diagnostic system for rapid and automated analysis of , thus significantly improving patient follow-up care after stone treatment. Fraunhofer researchers in this project are working hand in hand with urologists specialized in modern methods of treating urinary stone disease.

"Only a small number of kidney stone patients receive a comprehensive consultation and follow-up after they have been treated," says physician and researcher Dr. Arkadiusz Miernik at Fraunhofer IPM. This may be because conventional stone analysis technologies such as infrared spectroscopy are costly and time-consuming, including preperation of stone samples. Analysis can also only be performed in a dedicated laboratory facility. Since only a few centers offer this type of analysis, it can take up to three weeks to receive results. "The patient in most cases has already been discharged and will not be seeing the doctor again. We advise stone patients to drink plenty of fluids, increase physical activities and lose weight if necessary. Unfortunately this is only a general recommendation. From the clinical point of view we need individualized approaches and these must include results of a compositional analysis of the stone. This allows us to evaluate the individual risk of disease recurrence and detect potential metabolic abnormalities," says Miernik.

Preparation of stone samples no longer necessary

Miernik and his team use a technique known as Raman spectroscopy, which allows them to rapidly characterize and conclusively identify specific stone types. This method utilizes a characteristic spectrum in the visible wavelength range of the examined sample called a "chemical fingerprint". "These samples are illuminated using laser light. About 1 percent of the photons are reflected back in a different wave spectrum highly specific to the sample. We record these signals in a database," explains Miernik. Researchers use computer software to filter out the fluorescent background occuring during Raman spectroscopy using computer software.

This method employs relatively inexpensive optical components, and it also works on wet, unprepared samples. The time taken to prepare specimens is substantially reduced. "The stones previously had to be dried and pulverized prior to analysis. Our system makes this unnecessary. Stone fragments collected during the surgical procedure do not need to be further processed. They can in principle be put directly into the Raman spectrometer for analysis," explains Miernik. Currently there are a few specialized laboratories that can carry out this procedure using large-scale analytical equipment. A compact device suitable for use in a clinical setting and allowing immediate, post interventional automated analysis is not yet available.

A demonstration system, including the hardware and software required for stone analysis developed by the Fraunhofer IPM researchers, already exists as a prototype. This prototype must first be made more compact before it is ready for the market. A unique feature of the system is its spectral database. An information index has been built up of data on the nine pure substances making up 99 percent of urinary stones. The researchers examined nearly 160 kidney stone samples in setting up the software during the first validation phase. Moreover, the results were confirmed after a conventional infrared based analysis in a reference laboratory. "Once the complete system is ready for clinical use, the physician (urologist) will be able to examine stone samples directly after surgical intervention on his own, thus increasing the quality of patients' care substantially." says Miernik.

Explore further: Greater risk for kidney stones in summer

Related Stories

Greater risk for kidney stones in summer

August 7, 2015

Kidney stones affect approximately 3.8 million people in the U.S. each year and they are especially more common in the summer. The stones are described as small, hard deposits of mineral and acid salts that form when urine ...

Stone removal helps half of patients with recurrent UTI

September 26, 2015

(HealthDay)—Half of patients with recurrent urinary tract infections and asymptomatic renal calculi can be rendered infection-free with stone extraction, according to a study published in the October issue of The Journal ...

Zinc in the body may contribute to kidney stones

June 1, 2015

New research on kidney stone formation reveals that zinc levels may contribute to kidney stone formation, a common urinary condition that can cause excruciating pain. The research found that zinc may be the core by which ...

New test predicts individual's risk of a second kidney stone

August 7, 2014

A new tool that takes multiple factors into account can accurately predict how likely a patient who experienced a painful kidney stone will develop another one in the future. The tool, which is described in an upcoming issue ...

Recommended for you

Using machine learning to design peptides

December 10, 2018

Scientists and engineers have long been interested in synthesizing peptides—chains of amino acids responsible for conducting many functions within cells—to both mimic nature and to perform new activities. A designed peptide, ...

Biomimetic strategy leads to strong, recyclable rubber

December 10, 2018

Inspired by nature, Chinese scientists have produced a synthetic analogue to vulcanized natural rubber. Their material is just as tough and durable as the original. In the journal Angewandte Chemie, they reveal the secret ...

Custom-made artificial mother-of-pearl

December 10, 2018

Natural mother-of-pearl, such as mussels, is one of the hardest, most stable and stiff natural materials. Researchers have always been fascinated by it. The structure of mother-of-pearl is exquisite under the electron microscope; ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.