Optimization of Surgical Illuminant Spectra for Organ Microstructure Visualization

Abstract

In a delicate operation, the appearance of organs and tissues is an essential factor for surgeons to figure out the hemodynamic state of the tissue or identify vascular regions. In open surgery, surgeons have a direct view of the surgical area with the naked eye or through a microscope. Under these circumstances, the spectral characteristics of a surgical illuminant are the most effective factor to ensure successful operations. In this study, we designed an optimal surgical illuminant to enhance microvascular structures. Two factors were used in the design: illuminant whiteness and the contrast between tissues and blood vessels. We subsequently prototyped a tunable light source using 14 types of light-emitting diodes (LEDs) with different spectral radiances to reproduce the illuminant spectra of the designed and conventional surgical illuminant. Using this light source, we conducted subjective evaluation experiments with three rat ceca whose detected vessel regions were measured with a conventional and optimal illuminant. We confirmed that the optimal illuminant was significantly superior to the conventional illuminant to view fine vascular structures. INDEX TERMS Light emitting diodes, lighting, surgical instruments, microstructure, color appearance.

The Influence of Illumination Color on the Subjective Visual Recognition of Biological Specimens

“…On the other hand, when blood vessels are exposed, blue illumination can effectively differentiate blood vessels and the surrounding tissues because the difference of light absorption between blood vessels and the surrounding tissues is larger with short wavelength rather than long wavelength. 5 Although a particular test color yielded better visual recognition compared to white in six out of the seven biological specimens, tissue discrimination in the abdominal cavity was more evident under white illumination compared to every test color. This might reflect the difference of visual information used in each recognition task.…”

“…However, only a limited number of subjective experiments have been previously reported. 4,5 Although Argyraki et al 4 reported that white illumination is more suitable in the recognition of the human vein beneath the skin compared to the illumination in which the red component has been suppressed, Kurabuchi et al 5 demonstrated that the recognition of blood vessels on the rat cecum was improved by an illumination containing less red component compared to white illumination. Because these studies claim the superiority of distinct illuminating colors using different tissues, it is still unknown whether each tissue has a specific color that can enhance its visual recognition or whether one color can improve the recognition of every tissue component.…”

“…Therefore, we carried out visual recognition experiments to observe the subjective preference for the illumination color based on questionnaires using several rat tissues under the illumination of multiple colors. Because the previous subjective studies reported the effect of bluish illumination containing less red component, 4,5 we focused on the effect of illumination colors along red-blue axis in this study for comparison.…”

A methodological validation of psychophysical approaches for quantifying the color discrimination capability of white light sources

“… Note : A 29 typical color quality metrics were computed, including the CIE Color Rendering Index (CRI), 1 Gamut Area Index(GAI), 2 Full Spectrum Color Index (FSCI), 3 Color Quality Scale (CQS: Qa, Qf, Qp, Qg), 4 Feeling of Contrast Index (FCI), 5 Color Discrimination Index (CDI), 6 Cone Surface Area (CSA), 7 Color Preference Index (CPI), 8 Cone Sensitivity Difference (CSD), 9 CRI‐CAM02UCS, 10 CRI2012, 11 Memory Color Rendering Index (MCRI), 12 IES TM‐30 (Rf and Rg), 13 CIE‐Rf, 14 Mean Chroma Shift of CQS (ΔC*), 14,15 two combined metrics named Color Quality Index (respectively denoted as CQI1 and CQI2), 15,16 the arithmetic mean value of GAI and CRI, 17 Gamut Volume Index (GVI), 18 Daylight Spectrum Index (DSI), 19 Degree of neutrality (Sneutral), 20 White Sensation (WS), 21 Percent tint, 21 Rd, 22 CDM 23 …”

“…In the field of lighting research and applications, several visual attributes are considered when assessing the color quality of white light sources, such as color fidelity, 1,2 color preference, 3 white sensation of lighting, 4 color vividness 5,6 and color discrimination. [7][8][9] Among these visual dimensions, the color discrimination of lighting is defined as the capability of light sources that "allows the observer to discriminate amongst a large variety of object colors simultaneously viewed" 8 and it is highly valued in many applications like medical inspection, 10 museum exhibition 11 and clothing presentation. 12,13 The color discrimination capability of white light sources is most usually quantified by the Farnsworth-Munsell 100 (FM-100) Hue Test.…”