Ana Baños

University of Zurich, Zürich, Zurich, Switzerland

Are you Ana Baños?

Claim your profile

Publications (4)9.66 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripening to predict preterm labor is very inaccurate. We used frequency-domain near-infrared spectroscopy (FD-NIRS) to non-invasively investigate the changes of the optical properties (i.e., absorption and scattering of light) in the uterine cervix during regular pregnancies. Optical properties of uterine cervices were measured in 13 patients at various time points of regular pregnancies. For each gestational trimester, mean values with 95% confidence intervals were calculated for oxy-, deoxy-, and total hemoglobin concentration (O(2)Hb, HHb, tHb), tissue oxygen saturation and water content and statistically significant differences between the trimesters were determined. The wavelength-dependent scattering (scatter power) was calculated by an exponential fit. O(2)Hb, and tHb and the scatter power showed an increase as a function of the gestational age. Differences between the second and the third trimester were statistically significant. HHb and the water content showed no significant change over time. Our results show that FD-NIRS is a promising diagnostic tool for providing information about cervical content of hemoglobin, water, and extracellular matrix proteins. We propose this technology to assess the cervical ripening and eventually to predict preterm labor.
    Lasers in Medical Science 03/2011; 26(2):205-12. · 2.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Mastodynia is correlated with the menstrual cycle. Using frequency-domain near-infrared spectroscopy (FD-NIRS), we investigated changes in breast perfusion in women who were or were not using hormonal contraception. Healthy volunteers, on or not on hormonal contraception, were examined. Optical properties were measured in all quadrants of both breasts, and physiological parameters were calculated. Measurements were repeated every other day during one complete menstrual cycle. Measurements were comparable in all quadrants. Data remained unchanged during the entire cycle in patients using hormonal contraception. However, a biphasic variation of deoxyhemoglobin, oxyhemoglobin, total hemoglobin (tHb), and water content (H(2)O) was observed in women not using contraception. tHb and H(2)O distinctly increased during the ovulation period and remained elevated throughout the luteal phase. It was concluded that FD-NIRS allows accurate measurement of optical properties of human breasts. As opposed to the menstrual cycles of persons using oral contraception, spontaneous menstrual cycles exhibit biphasic variations of tissue perfusion parameters. These findings are important for the investigation of mastodynia.
    Lasers in Medical Science 04/2009; 24(6):901-7. · 2.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The influence of sex hormones on the human uterine cervix is likely to be important in the process of cervical ripening. Frequency domain near-infrared spectroscopy (FD-NIRS) was used to investigate non-invasively the changes in the optical properties that reflect physiologic parameters and tissue composition of the uterine cervix in the different phases of the menstrual cycle. Twenty premenopausal and nine postmenopausal women were examined. Optical properties of the uterine cervix were measured, and physiological parameters [concentration of water, oxyhemoglobin (O(2)Hb) and deoxyhemoglobin (HHb), total hemoglobin (tHb), oxygen saturation (StO(2)), water, and scattering power] were calculated. Analysis of variance (ANOVA) was used to test for statistical significance. The optical properties of the anterior cervical lip did not differ from those of the posterior lip. HHb was significantly lower in cervices during menstrual bleeding than during the follicular, luteal, or postmenopausal phases. The ratio of O(2)Hb to HHb was highly significantly increased by a factor of 2 when cervices during the menstrual bleeding were compared with those during the follicular, luteal, or postmenopausal phases. The scattering power was significantly lower during menstrual bleeding than during the follicular or postmenopausal phases. We demonstrated that withdrawal of sex hormones during menstrual bleeding is associated with a significant decrease in HHb and scattering power, with stable values of O(2)Hb, tHb, StO(2), and H(2)O compared with the values during the follicular, luteal or postmenopausal phases of the menstrual cycle. Cervical softening during menstrual bleeding seems to be different from cervical softening for labor.
    Lasers in Medical Science 12/2008; 24(4):561-6. · 2.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripening to predict preterm labor has a substantial inter- and intraobserver variability. We used frequency domain near-infrared spectroscopy (FD-NIRS) to non-invasively investigate the changes of the optical properties (i.e., absorption and scattering of light) in the uterine cervix during drug-induced cervical ripening. Ten volunteers scheduled for abortion were examined. Optical properties of the uterine cervix were measured and physiological parameters were calculated prior to and after induction of cervical ripening using topical misoprostol. Mean relative changes, +/-standard error of the mean as well as statistical significance using the t-test were calculated for oxy- and deoxyhemoglobin, total hemoglobin, oxygen-saturation, and water. The wavelength-dependent decrease of scattering (scatter power) was calculated by an exponential fit and tested with the Wilcoxon test. Misoprostol induced a decrease in total hemoglobin of 21 +/- 6% (P < 0.05), a decrease in oxyhemoglobin of 22 +/- 6% (P < 0.05), a decrease in deoxyhemoglobin of 16 +/- 11% and an increase of 36 +/- 8% (P < 0.005) in water content. The scatter power was significantly lower (P < 0.05) after cervical ripening. Our results show that FD-NIRS is a promising diagnostic tool to detect changes in cervical concentrations of hemoglobin and water. A severe tissue edema, probably due to a hormone-induced inflammatory process, seems to be important for cervical ripening. The reduction in total hemoglobin is likely to be a consequence of the increased water content of the tissue resulting in a dramatic increase of the distance between vessels. We propose this technology to assess the cervical ripening and eventually to predict preterm labor.
    Lasers in Surgery and Medicine 10/2007; 39(8):641-6. · 2.46 Impact Factor

Publication Stats

15 Citations
9.66 Total Impact Points

Institutions

  • 2007–2011
    • University of Zurich
      Zürich, Zurich, Switzerland