New sensor can detect bleeding after invasive procedures

Developed by CGH, SUTD, it allows constant monitoring of patients, early sounding of alert

Changi General Hospital's Associate Professor Chionh Chang Yin (far left) and Singapore University of Technology and Design's Associate Professor Foong Shaohui with the BWATCH sensor. The wireless, lightweight device is placed over a patient's bandag
Changi General Hospital's Associate Professor Chionh Chang Yin (left) and Singapore University of Technology and Design's Associate Professor Foong Shaohui with the BWATCH sensor. The wireless, lightweight device is placed over a patient's bandage to detect bleeding in real time.ST PHOTO: GAVIN FOO

Severe post-procedure bleeding is a rare but potentially life-threatening complication. Patients may be incapacitated and unable to call for assistance.

Even with intensive checks by nurses, the problem may occur before the next inspection.

To continuously monitor patients for bleeding following any invasive procedure, as well as to reduce the high demand for nursing manpower, a technological solution is thus required.

Changi General Hospital (CGH) and the Singapore University of Technology and Design (SUTD) have developed the Blood Warning Technology with Continuous Haemoglobin (BWATCH) sensor - a wireless, lightweight device that is placed over a patient's bandage to detect bleeding in real time.

Its ability to sound the alert early will lower the risk of a potential major complication, said Associate Professor Chionh Chang Yin, chief of renal medicine and senior consultant at CGH.

He added that with wide use of the sensor, the frequency of inspections and resource requirements may be cut with no compromise on safety. "BWATCH offers continuous monitoring, allowing the care team to focus on other patient-centric tasks," he said.

Unlike other fluid-detection tools, BWATCH is unique as it does not require direct contact with the wound, and specifically detects blood.

The device works by utilising the light absorption properties of haemoglobin, a protein in people's red blood cells.

Haemoglobin absorbs light at the 525 nanometre wavelength.

When the sensor detects the absence of light at that wavelength, it signals the presence of blood.

CGH and SUTD began prototyping the device and conducting tests in 2014.

BWATCH was assessed in an observational clinical trial from March 1, 2019, to June 30 last year, with all instances of early bleeding detected.

While the focus of the device has been on patients with kidney failure who undergo haemodialysis treatment, BWATCH has the potential to be applied for any wound types or locations that are prone to external bleeding.

Potential applications include situations outside the hospital setting, and integration into hospital systems.

This is the first instance of a joint patent between CGH and SUTD, and BWATCH has been patented in Singapore and the United States.

A version of this article appeared in the print edition of The Straits Times on May 01, 2021, with the headline 'New sensor can detect bleeding after invasive procedures'. Subscribe