Imaging the seizure during surgery with a hyperspectral camera.

An epilepsy patient with recurring sensorimotor seizures involving the left hand every 10 min, was imaged with a hyperspectral camera during surgery. By calculating the changes in oxygenated, deoxygenated blood, and total blood volume in the cortex, a focal increase in oxygenated and total blood volume could be observed in the sensory cortex, corresponding to the seizure-onset zone defined by intracranial electroencephalography (EEG) findings. This probably reflects very local seizure activity. After multiple subpial transections in this motor area, clinical seizures abated.

The use of near-infrared light for safe and effective visualization of subsurface blood vessels to facilitate blood withdrawal in children.

Obtaining access to blood vessels can be difficult, especially in children. Visualization of subsurface blood vessels might be a solution. Ultrasound and visible light have been used to this purpose, but have some drawbacks. Near-infrared light might be a better option since subsurface blood vessels can be visualized in high contrast due to less absorption and scattering in tissue as compared to visible light. Our findings with a multispectral imaging system support this theory. A device, the VascuLuminator, was developed, based on transillumination of the puncture site with near-infrared light. The VascuLuminator was designed to meet the requirements of compact and safe use. A phantom study showed that the maximum depth of visibility (5.5mm for a 3.6mm blood vessel) is sufficient to visualize blood vessels in typical locations for peripheral venous and arterial access. A quantitative comparison of the VascuLuminator and to two other vessel imaging devices, using reflection of near-infrared light instead of transillumination, was conducted. The VascuLuminator is able to decrease failure at first attempt in blood withdrawal in pediatric patients from 10/80 (13%) to 1/45 (2%; P=.05).

Visualizing veins with near-infrared light to facilitate blood withdrawal in children.

INTRODUCTION: This study aims to evaluate for the first time the value of visualizing veins by a prototype of a near-infrared (NIR) vascular imaging system for venipuncture in children. METHODS: An observational feasibility study of venipunctures in children (0-6 years) attending the clinical laboratory of a pediatric university hospital during a period of 2 months without (n = 80) and subsequently during a period of 1 month with a prototype of an NIR vascular imaging system (n = 45) was conducted. Failure rate (ie, more than 1 puncture) and time of needle manipulation were determined. RESULTS: With the NIR vascular imaging system, failure rate decreased from 10/80 to 1/45 (P = .05) and time decreased from 2 seconds (1-10) to 1 second (1-4, P = .07). CONCLUSION: This study showed promising results on the value of an NIR vascular imaging system in facilitating venipunctures.

The effect of zirconia and titanium implant abutments on light reflection of the supporting soft tissues.

OBJECTIVES: To determine the difference in light reflection of oral mucosa covering titanium (Ti) or zirconia (ZrO(2)) abutments as it relates to the thickness of the covering mucosa. MATERIAL AND METHODS: Fifteen anterior implants (Astra Osseo speed(®)) in 11 patients were fitted with a Ti or a ZrO(2) abutment (cross-over, within-subject comparison). Hyper-spectral images were taken with a camera fitted on a surgical microscope. High-resolution images with 70 nm interval between 440 and 720 nm were obtained within 30 s (1392 × 1024 pixels). Black- and white-point reference was used for spatial and spectral normalization as well as correction for motion during exposure. Reflection spectra were extracted from the image on a line mid-buccal of the implant, starting 1 mm above the soft tissue continuing up to 3 mm apically. RESULTS: Median soft tissue height is 2.3 mm (min: 1.2 mm and max: 3.1 mm). The buccal mucosa rapidly increases in the thickness, when moving apically. At 2.2 mm, thickness is 3 mm. No perceivable difference between the Ti and ZrO(2) abutment can be observed when the thickness of the mucosa is 2±0.1 mm (95% confidence interval) or more. CONCLUSION: It is expected that the difference in light reflection of soft tissue covering Ti or ZrO(2) abutments is no longer noticeable for the human eye when the mucosa thickness exceeds 2 mm. Haemoglobin peaks in the reflection spectrum can be observed and make hyper-spectral imaging a practical and useful tool for measuring soft tissue health.