Researchers at the University of Tehran Devise New Sputum Test for COVID-19

This electrochemical diagnostic tool uses carbon nanotubes to diagnose an upper respiratory infection in 30 seconds

By The Institute’s Editorial Staff

Mohammad Abdolahad, an associate professor of electrical engineering at the University of Tehran, holding the ROS Detector in Sputum Sample.

THE INSTITUTE Nasopharyngeal swabs are the most common way to collect a sample from a person in order to test her for COVID-19. Retrieving the specimen requires a medical professional to insert a long shaft into a person’s nasal cavity. The procedure is often uncomfortable for people and requires medical professionals to break social distancing parameters.

IEEE Member Mohammad Abdolahad led a team of undergraduate students and post-doctoral candidates at the University of Tehran that developed a non-invasive, electrochemical diagnostic system. Called the ROS [reactive oxygen species] Detector in Sputum Sample (RDSS), the test screens for respiratory inflammation in real-time and doesn’t require a medical professional to swab for the specimen. ROS are reactive chemical species that contain oxygen and can severely damage DNA, RNA, and proteins. This tool can determine the presence of ROS produced by respiratory inflammation.

Abdolahad is an associate professor of electrical engineering at the University of Tehran’s School of Electrical and Computer Engineering as well as an adjunct professor at the university’s School of Medical Sciences.

The Institute asked him about how RDSS works.

This interview has been edited and condensed for clarity.

What problem are you trying to solve?

Since controlling the spread of the virus [largely] depends on screening suspected cases, it is important to have widely available, reliable, and fast [testing] methods. Unfortunately, the current screening methods, such as Polymerase chain reaction, do not satisfy these requirements. [PCR checks for the presence of the SARS-CoV-2 virus, which causes COVID-19]

Consequently, we have developed a fast method to screen for respiratory inflammation [in] real-time. The test can also help inform doctors if the patient has an increased chance of contracting COVID-19. Respiratory diseases can make a patient immunoresistant and by being diagnosed, the patient now knows that she needs to take additional steps in order to protect herself against coronavirus.

Explain how the system works.

The ROS test is done by taking a sample of the patient’s sputum. [The patient takes a deep breath and holds it in for five seconds. She then slowly breathes out and repeats these steps until she coughs up sputum.] The patient then spits the sputum into a falcon tube [a plastic cup].

Each individual sample is tested using the RDSS probe. The doctor [puts] the probe into the sample and the results are [displayed] on the monitor after 30 seconds.

What technologies are you using?

The system consists of an integrated monitor that connects to a probe, which has a disposable sensor located on top of it. The probe is used to test the [sputum] samples and the monitor displays the results to the medical professional conducting the test.

The sensor on top of the probe is fabricated using multi-wall carbon nanotubes, which sit on the tip of several steel needles. The needles are arranged in three electrodes—working, counter, and reference—with a triangular distance of 3 millimeters from each other. [Reference electrodes measure the potential of the working electrode without passing current through it while counter electrodes pass current.]

The tool [is portable], which allows the device to be utilized freely by phlebotomists and physicians in laboratories or clinics.

The software [programmed in the device] was designed based on experimental calibration [in order to] analyze the data and provide a diagnosis in under 30 seconds.

What challenges have you faced, and how did you overcome them?

The first challenge was calibrating the sensor in correlation with the presence and severity of COVID-19 in the [patients].

We conducted a study and tested more than 100 people to better understand the differences between COVID-19 and [other types of] respiratory diseases. We found that in some respiratory illnesses, such as asthma and acute pneumonia, there is an increase in ROS. Seasonal influenza on the other hand induces a reduction in ROS levels [in the] immune system and suppresses certain bacterial clearance [the effect a drug has on bacteria].

The other challenge that we faced was collecting enough data to calibrate the sensor. It was a challenge to find participants for the study due to quarantine restrictions and the danger of working closely with infected cases. [In the end we were able to] test the sensor on more than 300 participants—both confirmed COVID-19 cases and negative cases.

What is the potential impact of the technology?

A real-time ROS-based respiratory inflammation warning system during the pandemic could help control the spread of the virus. It can [also] be used as a support system to help determine the severity of respiratory inflammatory diseases based on ROS levels in the patient’s sputum culture.

How close are you to the final product?

We [completed developing the system] and received a temporary certificate from the Iranian Food and Drug Administration that allows us to sell the system to medical centers. Our U.S. patent was also received its Notice of the Office communication on four main claims and passed the examiner queries. Hence it will be granted soon. 

The sensor has been deployed in four hospitals, as a non-invasive real-time complementary system, for further observational clinical trials.

How can other IEEE members get involved?

We have only tested [the system] on [patients] in Iran [and] the system can be improved by [testing samples in other countries]. Researchers can also try to find alternative, [inexpensive] materials [to use] as sensing agents for the ROS detection system.

IEEE members who work in similar areas can help test ROS levels in the sputum culture of COVID-19 patients who were treated. This would help us find a suitable drug dose to treat the patients [with] and [better understand how] to monitor the severity of the patients’ symptoms.

Courtesy of IEE SPECTRUM

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