Vein Pattern Locating Technology for Cannulation: A Review of the Low-Cost Vein Finder Prototypes Utilizing near Infrared (NIR) Light to Improve Peripheral Subcutaneous Vein Selection for Phlebotomy <s> Wavelength <s> Multispectral imaging has shown promise in subcutaneous vein detection and localization in human subjects. While many limitations of single-wavelength methods are addressed in multispectral vein detection methods, their performance is still limited by artifacts arising from background skin reflectance and optimality of postprocessing algorithms. We propose a background removal technique that enhances the contrast and performance of multispectral vein detection. We use images acquired at visible wavelengths as reference for removing skin reflectance background from subcutaneous structures in near-infrared images. Results are validated by experiments on human subjects. <s> BIB001 </s> Vein Pattern Locating Technology for Cannulation: A Review of the Low-Cost Vein Finder Prototypes Utilizing near Infrared (NIR) Light to Improve Peripheral Subcutaneous Vein Selection for Phlebotomy <s> Wavelength <s> BackgroundSubcutaneous veins localization is usually performed manually by medical staff to find suitable vein to insert catheter for medication delivery or blood sample function. The rule of thumb is to find large and straight enough vein for the medication to flow inside of the selected blood vessel without any obstruction. The problem of peripheral difficult venous access arises when patient’s veins are not visible due to any reason like dark skin tone, presence of hair, high body fat or dehydrated condition, etc.MethodsTo enhance the visibility of veins, near infrared imaging systems is used to assist medical staff in veins localization process. Optimum illumination is crucial to obtain a better image contrast and quality, taking into consideration the limited power and space on portable imaging systems. In this work a hyperspectral image quality assessment is done to get the optimum range of illumination for venous imaging system. A database of hyperspectral images from 80 subjects has been created and subjects were divided in to four different classes on the basis of their skin tone. In this paper the results of hyper spectral image analyses are presented in function of the skin tone of patients. For each patient, four mean images were constructed by taking mean with a spectral span of 50 nm within near infrared range, i.e. 750–950 nm. Statistical quality measures were used to analyse these images.ConclusionIt is concluded that the wavelength range of 800 to 850 nm serve as the optimum illumination range to get best near infrared venous image quality for each type of skin tone. <s> BIB002 </s> Vein Pattern Locating Technology for Cannulation: A Review of the Low-Cost Vein Finder Prototypes Utilizing near Infrared (NIR) Light to Improve Peripheral Subcutaneous Vein Selection for Phlebotomy <s> Wavelength <s> Advance biomedical engineering technologies are continuously changing the medical practices to improve medical care of patients nowadays. In this paper, we describe the concept used to prototype a device for needle insertion navigation during intravenous catheterization process via Near Infrared (NIR) imaging technique. A vein locator prototype using the NIR imaging technique and augmented reality (AR) technology have been developed in this work which is meant to be used in the process of intravenous catheterization. The challenges faced during the development of this prototype included the calibration of composite images in the see-through display. In this prototype, the Vuzix STAR 1200XL eyewear system has been used as the head mounted display and the imaging video is input by IR CCD camera. Additional, We select the optimum illumination by using NIR LED with wavelength of 830nm and 850nm in prototying to obtain the best contrast NIR venous image for different types of skin tone. <s> BIB003 </s> Vein Pattern Locating Technology for Cannulation: A Review of the Low-Cost Vein Finder Prototypes Utilizing near Infrared (NIR) Light to Improve Peripheral Subcutaneous Vein Selection for Phlebotomy <s> Wavelength <s> This work presents a portable, affordable and reliable vein locating device to overcome the complications in vein localization irrespective of age and tissue thickness during medical procedures like Phlebotomy and intravenous infusion. A prototype has been developed using infrared (IR) detector and multispectral near infrared (NIR) (740,765,770,780 nm) source. The differential absorption of the NIR by veins due to the presence of deoxyhemoglobin, helps in enhancing the localization of the vein. The detector is integrated with the single board computer (SBC) and connected with LCD through serial programming interface (SPI) for real time display of veins. The initial observations have found to be successful. It is expected that this affordable device will help in reducing time and improving accessibility to locate antecubital and cephalic vein without multiple incision and minimal pain. <s> BIB004
In the electromagnetic spectrum's range of 740 nm to 940 nm, the light can penetrate to about 5 mm deep of the skin tissue reaching the deoxygenated hemoglobin. The vein with the deoxygenated hemoglobin forms a dark contrast to the skin tissue due to the higher light absorption coefficient and lower backscatter light coefficient BIB003 . Based on the studies presented, there were variations in wavelength set by different researchers, 9 out of 21 (42.85%) used 850 nm, followed by 4 out of 21 (19.04%) for both 940 nm and 740 nm, and the remaining 19.07% are the studies with varying wavelength. From Table 2 , Dhakshayani, M. et al., 2015 BIB004 showed that optimizing the wavelength by utilizing a multispectral IR source, can achieve good visibility of veins considering the types of patients based on color, age and tissue thickness, also the near infrared rays of shorter wavelengths 740, 765 nm exhibits high absorption of light by deoxygenated hemoglobin, with deep penetration at a longer wavelength of 770 and 780 nm. A similar study by Wang F et al., 2013 BIB001 stated that using multispectral imaging IR with a significant finding that a hairy forearm affects the image of the vein by the formation of a strong reflectance glare while, Kimori et al., 2015 [46] used 850 nm transmitted through the subcutaneous tissue and being compared as deeper than the light source of a commercial vein finder. Another study showed variation in the selected wavelength based on skin color. For fair skin, the image quality was reported to be slightly better in the range of 750 to 800 nm as compared to darker skin having the overall range considered suitable is 800 to 850 nm BIB002 . Among the studies, Anupongongarch et al., 2015  used the light source with the highest wavelength up to 1000 nm. This variation indicates that the standardization for the optimum wavelength for the purpose of vein viewing is not been set to date yet. See Figure 4 , sample vein images at a given commonly used wavelength of 850 nm and with a lower wavelength of 696 nm. In the electromagnetic spectrum's range of 740 nm to 940 nm, the light can penetrate to about 5 mm deep of the skin tissue reaching the deoxygenated hemoglobin. The vein with the deoxygenated hemoglobin forms a dark contrast to the skin tissue due to the higher light absorption coefficient and lower backscatter light coefficient BIB003 . Based on the studies presented, there were variations in wavelength set by different researchers, 9 out of 21 (42.85%) used 850 nm, followed by 4 out of 21 (19.04%) for both 940 nm and 740 nm, and the remaining 19.07% are the studies with varying wavelength. From Table 2 , Dhakshayani, M. et al., 2015 BIB004 showed that optimizing the wavelength by utilizing a multispectral IR source, can achieve good visibility of veins considering the types of patients based on color, age and tissue thickness, also the near infrared rays of shorter wavelengths 740, 765 nm exhibits high absorption of light by deoxygenated hemoglobin, with deep penetration at a longer wavelength of 770 and 780 nm. A similar study by Wang F et al., 2013 BIB001 stated that using multispectral imaging IR with a significant finding that a hairy forearm affects the image of the vein by the formation of a strong reflectance glare while, Kimori et al., 2015 [46] used 850 nm transmitted through the subcutaneous tissue and being compared as deeper than the light source of a commercial vein finder. Another study showed variation in the selected wavelength based on skin color. For fair skin, the image quality was reported to be slightly better in the range of 750 to 800 nm as compared to darker skin having the overall range considered suitable is 800 to 850 nm BIB002 . Among the studies, Anupongongarch et al., 2015  used the light source with the highest wavelength up to 1000 nm. This variation indicates that the standardization for the optimum wavelength for the purpose of vein viewing is not been set to date yet. See Figure 4 , sample vein images at a given commonly used wavelength of 850 nm and with a lower wavelength of 696 nm. 