Automated urine tests for ex-offenders could be rolled out islandwide from 2024
The Singapore Prison Service's automated urine testing system uses deep learning to prevent foul play.
SINGAPORE: An automated urine test system developed in Singapore could be rolled out islandwide from 2024, making drug screening tests more convenient for ex-offenders on their journey towards reintegration.
The Prison Automated Screening System (PASS), developed by the Home Team Science and Technology Agency (HTX), uses robotics, sensors and deep learning technology to automate contactless urine testing.
Four units of the PASS toilet are currently in use at Selarang Park Community Supervision Centre, with a proof-of-concept trial set to end in February 2024. If the trial is successful, the toilets could be deployed at more locations.
Ex-offenders who enter the Singapore Prison Service's (SPS) community-based programmes towards the tail-end of their sentences undergo a strict supervision regime that may include urine testing, which can help with early detection of drug abuse.
Currently, ex-offenders must report at Selarang Park Community Supervision Centre to take their tests during the supervision regime, which can typically last for months.
SPS conducts about 5,000 urine tests a month on supervisees in community-based programmes. At Selarang Park, about 200 to 300 tests are conducted each day, said Deputy Superintendent of Prisons Sameeyul Ameen Haji Sulaiman.
He said that a wider rollout of the toilet cubicles would reduce travelling time and make testing more convenient, raising the chances that supervisees will comply with the conditions of their community-based programmes and stay drug-free.
It will also help them reintegrate into society, said DSP Sameeyul. "They don't need to be disruptive to their work and (can avoid) the stigma of telling their employer, 'Hey, I have to go, I'm reporting at Selarang,'" he said.
For prison officers, PASS also addresses the "pain points" of manual urine testing, which is a labour intensive process, said DSP Sameeyul.
Prison officers must manually register supervisees, supervise the collection of the urine samples and conduct the drug tests themselves.
PASS halves the manpower required to monitor the testing, from one prison officer for every two supervisees taking a manual test, to one officer for every four supervisees taking the automated test.
It also reduces the amount of time required for a manual test, said DSP Sameeyul. A manual test typically requires a minimum of seven to eight minutes to perform and may take as long as 12 minutes, whereas PASS takes about five minutes.
The automated system also enables "consistent interpretation" of test results using the inspection technology developed by HTX, he added.
DSP Sameeyul said PASS has been "very effective" so far. Since the live trial at Selarang Park started in September, about 1,600 supervisees have used the system.
How the automated urine test works
1. Before entering the cubicle, the supervisee's identity is verified through an iris scan.
2. Inside the cubicle, he follows instructions displayed on a screen. There are no cameras for privacy, but the cubicle has a clear door to discourage foul play.
3. He deposits his urine sample inside the urinal, which has a shutter that automatically raises and drops before and after the sample is collected.
4. At the back of the system, a robotic system collects the urine and inserts a dipstick to test for drugs and adulterants. This dipstick is then raised in front of small cameras that interpret and record the result.
5. The supervisee stands waiting in the cubicle while the test is being conducted. The door automatically opens if the test is clear. If the test needs further analysis, the system alerts a prison officer.
DEEP LEARNING TO STOP FOUL PLAY
One notable feature of PASS is its use of technology to detect and prevent tampering with urine samples.
Attempts to evade detection in drug screening tests usually involve either adulteration or substitution of the urine sample, said DSP Sameeyul.
With manual dipstick tests, supervisees have been known to try various ways of fooling the system, including bringing a prepared urine sample and using a synthetic organ, he said.
HTX lead engineer of the Robotics, Automation & Unmanned Systems Centre of Expertise Tee Wen Kai said that the technological safeguards in PASS include "non-optical sensors" and deep learning to identify a genuine urine sample.
"We train our system to differentiate between real urine freshly procured from the user and one that is pre-prepared and being poured in," he said.
PASS can also ensure that there is only one person in the cubicle at a time, and alert a prison officer if this is not so.
Any concerns about cross-contamination from other supervisees using the same urinal were also allayed in tests of the flush system.
Mr Tee said that the team prepared a sample containing a concentration of drugs that was 1,000 times above the threshold of the test kit and flushed it down the urinal.
When the residual liquid was collected and tested in a forensic lab, only a negligible amount of substances was detected, he said.
The development of PASS started at the end of 2019. A contactless urinal design was chosen because of concerns about hygiene during the pandemic.
This also means PASS is currently not used for women, as the intention was to concentrate on the majority of supervisees who are male, said DSP Sameeyul.
The design considerations even extended to the entertainment options in the cubicle as supervisees stand waiting for their test results.
Initially, a corporate video from SPS was screened. After feedback, the team procured episodes of British sitcom Mr Bean for supervisees to while away the time.
