Diffuse optical tomography system for acute traumatic brain injury in the intensive care unit: a prospective study on healthy volunteers.

SIGNIFICANCE

Invasive neuromonitoring hinders the application of diffuse optical tomography (DOT) to critically ill adults in the intensive care unit (ICU).

AIM

We aim to develop and test a method for DOT recordings suitable for traumatic brain injury (TBI) patients in the ICU. This method is based on measurements and coregistration using a 3D optical scan and the acquisition of optical data using a custom-made helmet, which would enable a multimodal (invasive and noninvasive) neuromonitoring.

APPROACH

Coregistration accuracy between the method based on a 3D optical scan and one based on an electromagnetic digitization, the latter considered to be the gold standard, was assessed. The capacity to isolate and monitor, using functional near-infrared spectroscopy, the optical signal in the intracranial (ICT), and extracranial tissues (ECT), was tested on 23 healthy volunteers. Participants were scanned with a frequency-domain NIRS device (690 and 830 nm) during 5 Valsalva maneuvers (VM) in a simulated ICU environment.

RESULTS

The results showed an average error of coregistration of 5.5 mm and a sufficient capacity to isolate oxyhemoglobin ( ) ( ) and total hemoglobin (HbT) ( ) in the ICT from the ECT and to follow the changes of hemoglobin in the ICT during the VM ( , ; HbT, ).

CONCLUSION

The developed approach appears to be suitable for use on TBI patients in the ICU in a multimodal monitoring.