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Öğe Doku Oksijen Saturasyonunun Ölçülmesi için Optik Bir Sistemin Geliştirilmesi ve Klinik Çalışmalarda Test Edilmesi(2020) Sircan-Kucuksayan, Aslinur; Canpolat, Murat; Özkan, Ömer; Soyuğur, Merve; Karakuzu, Fatumatuz ZehraOksijen saturasyonu metabolizmanın anahtar bileşenlerinden biridir. Doku oksijen saturasyonu (StO2) mikrodolaşıma sunulan oksijen ile doku tarafından kullanılan oksijen arasındaki dengeyi direkt olarak yansıtır. Hastaların değerlendirilmesinde hemodinamik monitörizasyon önemli rol oynamaktadır. Hemodinamik izlem kalp atım hızı, kan basıncı, kardiyak dolum basınçları, SaO2 ve SvO2 gibi parametreleri içermektedir. Ancak hemodinamik monitörizasyon ile sadece makro dolaşım değerlendirilmektedir. Hem altta yatan patofizyolojiye uygun tedavinin düzenlenmesinde hem de herhangi bir sorun ortaya çıkmadan koruyucu tedbirlerin alınabilmesi için mikro dolaşımın değerlendirilmesi gerekmektedir. StO2 mikro dolaşımın değerlendirilmesinde önemli bir parametredir. Kompleks doku kayıplarının onarımı için, vasküler desteğe sahip olan, fonksiyonel ve estetik sonuçlar veren, vücudun bir bölgesinden diğer bölgesine aktarılabilen doku parçalarına flep denir ve plastik cerrahide sıklıkla kullanılır. Flepteki mikrodolaşım bozukluğunun erken belirlenmesi flebin kurtarılmasında ön koşuldur ve flep prognozu için çok önemlidir. Bu nedenle, flepleri objektif izleme yöntemi hekimler için değerli bir araç olacaktır. Postoperatif flep takibi StO2 ölçümü ile yapılabilir. Son yıllarda birçok hastalığın tanısında optik yöntemler giderek daha fazla araştırılmaktadır. Bu araştırmalarda amaç hastalıkları minumum acı veren, girişimsel olmayan yöntemlerle ve erken aşamada teşhis etmektir. Ayrıca sonuçların değerlendirilmesinde gerçek zamanlı ve pratik çalışan sistemlerin geliştirilmesi optik yöntemlerle yapılan çalışmaların diğer hedefleridir. Bu yöntemlerde dokuya gönderilen ışık dokuyla etkileşir, geri yansıyan ışık toplanır ve analiz edilir. Kanın oksijen saturasyonunun değişimi, ışığın absorpsiyonunu da oldukça değiştirir. Dolayısıyla dokudan geri yansıyan ışık analiz edilerek doku oksijen saturasyonu belirlenebilir. Bu projenin amacı, doku oksijen saturasyonunun gerçek zamanlı ve sürekli ölçümünü sağlayan optik bir sistem geliştirmek ve plastik cerrahisinde flep yapılan hastalarda flep canlılığını belirlemede kullanımını araştırmaktır. Projemiz üç aşamadan oluşmaktadır: Birinci aşamada doku oksijen saturasyonunu ölçebileceğimiz ve hasta başı monitörü olarak klinik takip yapabileceğimiz bir cihazın ar-ge si tamamlandı ve ilk prototipi üretildi. İkinci aşama da cihaz ile hastalardan ölçümler yapılarak klinik geri bildirimlerin alındı. Cihazla alınan ölçümler sırasında yapılması gereken düzeltme ve değişiklikler belirlendi, klinik çalışmaya uygun prob tasarlandı ve kalibrasyonlar yapıldı. Üçüncü aşama ise geliştirdiğimiz cihazın Plastik, Rekonstrüktif ve Estetik Cerrahisinde flep yapılan hastalarda doku canlılığını değerlendirme ve takip etmede kullanımı araştırıldı. Yapılan klinik çalışmada 24 hastanın flebinden alınan ölçümlerde, iki hastada oksijen saturasyonunda düşme erken aşamada belirlendi. Cihazın ölçüm sonuçları ile klinik veriler karşılaştırıldığında, geliştirilen yöntemin doku oksijen saturasyonunun belirlemede %100 duyarlılık ve özgünlüğe sahip olduğu gösterildi. Sonuçlar geliştirilen optik cihazın ile in vivo StO2 değerlerinin ölçülebileceğini gösterdi. Optik cihazın flep takibinde hemen sonuç veren, sonucu kullanıcının tecrübesine bağlı olmadan objektif olarak belirleyebilen, invazif olmayan, maliyeti düşük medikal bir cihaz olarak kullanılma potansiyeli bulunmaktadır.Öğe Early detection onset of flap failure using near infrared spectroscopy(Taylor and Francis Ltd., 2022) Sircan-Küçüksayan, Aslinur; Özkan, Özlenen; Özkan, Ömer; Kucuksayan, Ertan; Ünal, Kerim; Canpolat, MuratBackground: Near-infrared spectroscopy (NIRS) is widely used to assess flap perfusions by measuring tissue oxygen saturation (StO2). However, the StO2 level for the onset of perfusion failure is still a controversial issue. Aim: This study proposes a new threshold of StO2 level for detecting the onset of perfusion failure as early as possible to increase flap salvage rates. Methods: Twenty patients undergoing flap surgery were included in this study–13 flaps were implemented to cover defects that occurred due to trauma and 7 flaps to hide imperfections that occurred after cancer treatment. Thirteen flaps were in the lower extremity, six in the mandible, and one in the breast. NIRS was used to measure StO2 in 240 flap regions of the 20 patients to determine flap viability using descriptive statistics. Results: The mean StO2 values from healthy flap and control regions were obtained as 81.6% ± 0.36 and 82% ± 0.18, respectively. The lowest StO2 value of 77.2% was defined as the onset of a vascular complication at a probability of 99.74% by subtracting three times the standard deviation from the mean StO2 of healthy flaps. Vascular complications were observed from 21 regions in the four flaps with StO2 values lower than 77.2%, but only one was lost. Conclusion: The threshold value for the onset of perfusion failure was a 5% decrease from the expected value, much lower than previously described thresholds that may facilitate the detection of perfusion failure in the early stage and increase salvage rates in flap revisions. © 2021 Acta Chirurgica Scandinavica Society.Öğe Estimating joint cartilage thickness on an animal model ex vivo using diffuse reflectance spectroscopy(Springer, 2019) Sırcan Küçüksayan, Aslınur; Canpolat, MuratA diffuse reflectance visible light spectroscopy method has been developed to estimate bovine cartilage thickness in real time. The system consists of a miniature UV-VIS spectrometer, a halogen tungsten light source, and an optical fiber probe including two 400-mu m diameter fibers with a center-to-center separation of 1.2 mm used to acquire the spectra. A total of four patellae were obtained from bovine just after sacrifice. In the study, ten cattle patella cartilage samples were prepared in a cylindrical shape and thinned by a 200-mu m step. Spectra were acquired from the 123 cartilage samples. Cartilage samples were divided into training and validation groups. A correlation between the thickness of the cartilage samples and the absorption spectra was obtained using the data of the training group. The relative thickness of the cartilage was estimated with an average error of 15% in the validation group using the correlation. Diffuse reflectance spectroscopy has the potential to estimate the thickness of cartilage lesions during arthroscopic evaluation of knee cartilages.Öğe Evaluation of scrotal pigmentation in infants with spectroscopic method and its correlation with 17-hydroxyprogesterone blood levels(Alanya Alaaddin Keykubat Üniversitesi, 2020) Başaran, Abdurrahman; Küçüksayan, Aslınur Sırcan; Canpolat, Murat; Güney, Sevtap VelipaşaoğluAim: To evaluate the scrotal melanin density in infants using spectrometry and to determine the correlation between spectrometric evaluations, physical examinations and blood 17-hydroxyprogesterone levels. Material and methods: A total of 40 infants were enrolled to the study, 22 of whom were diagnosed by a physician as having scrotal hyperpigmentation and 18 with normal scrotal pigmentation, who were admitted for the evaluation of prolonged jaundice. Age, gestational week, birth weight and scrotal pigmentation noted by the physician were recorded. Spectral data were acquired from scrotum and thigh. A correlation between the spectral measurements and the blood 17-hydroxyprogesterone level was determined by comparing spectral value in the wavelength range of 620-800 nm and 17-hydroxyprogesterone levels. Results: No statistically significant difference was observed between the groups who were categorized by the physician as having “hyperpigmented” or “normal” scrotal color in terms of the infant’s age, gestational week, birth weight, 17-hydroxyprogesterone level or spectrometric values. We observed a strong correlation between 17-hydroxyprogesterone levels and spectrometric values in all groups. Conclusion: This preliminary study is the first one in the literature which evaluates scrotal pigmentation with an objective spectrometric method and determines its relationship with 17-hydroxyprogesterone levels. Further studies are needed to employ this method as a non-invasive, indirect screening test for the screening of congenital adrenal hyperplasia in male infants.Öğe Histopathological and biochemical assessment of a novel diagnostic method for ovarian torsion(Taylor & Francis Ltd, 2020) Özekinci, Murat; Küçüksayan, Ertan; Erdoğan, Gülgün; Aslan, Mutay; Peştereli, Elif; Canpolat, Murat; Sırcan Küçüksayan, AslınurOvarian torsion is agynecologic emergency that affects females of all ages. Early diagnosis is important to preserve ovarian function. The false positive rate for sonographic diagnosis of ovarian torsion is 50%; therefore, a new real-time approach is required to improve diagnostic accuracy. We investigated diffuse reflectance spectroscopy for diagnosing ovarian torsion. Spectroscopic measurements were performed in vivo prior to, during and after detorsion. After bilateral oophorectomy, hemoxygenase and myeloperoxidase enzyme activity in ovarian tissue was evaluated and the tissues were examined for pathology. Spectroscopic data were compared to histopathological and biochemical data to assess the diagnostic value of the spectroscopic method for differentiating healthy and damaged ovarian tissue. We found a good correlation between spectroscopy and histopathology. We also found a correlation between the spectroscopic data and heme oxygenase enzyme activity. We found no correlation between the histopathological tissue damage score and myeloperoxidase enzyme activity. Diffuse reflectance spectroscopy may be of prognostic and diagnostic value for ovarian torsion in vivo.Öğe Investigating spectroscopic measurement of sublingual veins and tissue to estimate central venous oxygen saturation(2022) Sırcan Küçüksayan, Aslınur; Eray, Oktay; Büyükaksu, Murat; Gümüş, Birce; Dursun, Oğuz; Canpolat, MuratAbstract: BACKGROUND: Venous oxygen saturation reflects venous oxygenation status and can be used to assess treatment and prognosis in critically ill patients. A novel method that can measure central venous oxygen saturation (ScvO2) non-invasively may be beneficial and has the potential to change the management routine of critically ill patients. OBJECTIVE: The study aims to evaluate the potential of sublingual venous oxygen saturation (SsvO2) to be used in the estimation of ScvO2. METHODS: We have developed two different approaches to calculate SsvO2. In the first one, near-infrared spectroscopy (NIRS) measurements were performed directly on the sublingual veins. In the second approach, NIRS spectra were acquired from the sublingual tissue apart from the sublingual veins, and arterial oxygen saturation was measured using a pulse oximeter on the fingertip. RESULTS: Twenty-six healthy subjects were included in the study. In the first and second approaches, average SsvO2 values were 75.0% ± 1.8 and 75.8% ± 2.1, respectively. The results of the two different approaches were close to each other and similar to ScvO2 of healthy persons (> 70%). CONCLUSION: Oxygen saturation of sublingual veins has the potential to be used in intensive care units, non-invasively and in real-time, to estimate ScvO2.Öğe Noninvasive assessment of oral lesions using elastic light single-scattering spectroscopy: a pilot study(Springer, 2020) Sırcan Küçüksayan, Aslınur; Yaprak, Neslihan; Derin, Alper Tunga; Özbudak, İrem Hicran; Turhan, Murat; Canpolat, MuratPurpose: In the present study, we investigated the potential application of elastic light single-scattering spectroscopy (ELSSS) as a noninvasive, adjunctive tool to differentiate between malignant and benign oral lesions in vivo. Methods: ELSSS spectra were acquired from 52 oral lesions of 47 patients prior to surgicalbiopsy using a single optical fiber probe. The sign of the spectral slope was used as a diagnostic parameter and was compared to the histopathology findings to obtain sensitivity and specificity of the ELSSS system in differentiating between benign and malignant tissues. Results: The sign of the spectral slope was positive for the benign tissues and negative for the malignant tissues. Nine malignant lesions and one high-grade dysplasia were correctly classified as cancerous. Six out of the ten low-grade dysplasia were correctly classified as cancerous, and four of them were misclassified as benign. Thirty benign lesions were correctly classified as benign, and two were misclassified as malignant. Our results indicate that the sign of the spectral slope enables the differentiation between malignant and benign oral lesions with a sensitivity of 80% and specificity of 94%. Conclusions: ELSSS has the potential to be developed as an adjunctive screening tool in the noninvasive evaluation of oral lesions in vivo. This new diagnostic system may reduce the number of unnecessary biopsies. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.Öğe Prediction of the extent of germ cell loss utilising a noninvasive spectroscopy method in rat testicular damage model(Wiley, 2021) Celik-Ozenci, Ciler; Sircan-Kucuksayan, Aslinur; Sahin, Pinar; Gungor-Ordueri, Nazli Ece; Canpolat, MuratThe aim of this study is to investigate the efficiency of elastic light single-scattering spectroscopy system, a noninvasive method, to acquire spectra during testicular biopsy from normal and damaged seminiferous tubules with various degrees of germ cell loss. Adult control rats and doxorubicin-injected rats to achieve seminiferous germ cell loss (for 10 days [10D], 20 days [D20], 30 days [D30], 40 days [D40], and 50 days [D50]) were used. Spectroscopic measurements were acquired utilising a single-fibre optical probe, and histopathology of the biopsied testicular tissue samples were compared. Time-dependent testicular damage comprising various degrees of seminiferous tubule degeneration after doxorubicin-administration was observed. In D30, D40 and D50 groups, where significant germ cell loss was identified, elastic light single-scattering spectroscopy system signals were well correlated with disturbed spermatogenesis where significant differences in spectral signals were obtained. Our findings indicate that the elastic light single-scattering spectroscopy system has the potential to enable instant imaging of spermatogenesis in rats and could also be useful in humans for clinical applications, such as to increase sperm recovery success during micro-TESE for men with nonobstructive azoospermia.
