Changi General Hospital's Dr Chionhj Chang Yin (left) and SUTD Associate Professor Foong Shaohui showing the monitoring device that is placed over a patient's bandage. ST PHOTO: GAVIN FOO

SINGAPORE - Severe post-operative 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, potential bleeding may occur before the next check.

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

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 monitoring device placed over a patient's bandage that detects real-time bleeding from wound sites following medical procedures.

BWATCH's ability to detect bleeding early will reduce the risk of a potential major episode. With greater confidence and wider use of the device, the frequency of inspections and resource requirements may be reduced with no compromise to safety.

"BWATCH offers continuous monitoring, allowing the care team to focus on other patient-centric tasks," said Associate Professor Chionh Chang Yin, chief of renal medicine and senior consultant at CGH.

Unlike other fluid-detection devices, 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 our red blood cells. Haemoglobin absorbs 525nm wavelength light. When the sensor detects the absence of 525nm wavelength light, it signals the presence of blood.

CGH and the SUTD began prototyping and conducting bench tests in 2014. BWATCH was tested in an observational clinical trial from March 1, 2019, to June 30, 2020, 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 usage in situations outside of the hospital setting, and integration into hospital systems.

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