Blood coagulation is a complex, dynamic physiological process by which clots are formed to end bleeding at an injured site. During heart-bypass surgery, blood is diverted out of the body to a heart-lung machine, which maintains heart- and lung functions. The machine is operated by a perfusionist, whose role includes monitoring appropriate parameters to ensure that the patient is effectively treated with an anticoagulant to avoid blood clots. For this purpose, heparin, an anticoagulant drug, is administered during surgery—followed by a rapid reversal afterwards to prevent excessive bleeding.¹ To maintain the delicate balance between clotting and bleeding, the clotting time of the patient is monitored every 30 to 60 minutes during surgery and several times after surgery, until a normal clotting time is restored.² Currently, blood samples taken from a patient’s intravenous line are tested at bedside, with measured clotting-time values used to adjust the anticoagulation therapy.

Analog Devices is a partner in the Biomedical Diagnostics Institute (BDI),³ a Centre for Science, Engineering, and Technology, funded by Science Foundation Ireland.⁴ BDI is a multidisciplinary research institute focused on the development of next-generation biomedical diagnostic devices. Under one of the BDI Integration Programs, Analog Devices is working with Dublin City University⁵ and a global specialty pharmaceutical and medication delivery company to develop a coagulation-monitoring device for patients undergoing treatment in the critical-care environment. This system will provide rapid, automated information on patient clotting status—improving patient safety, workflow, and decision support—leading to improvements in patient outcomes.