Abstract

Technique of loss-of-resistance in epidural block is commonly used for epidural anesthesia in humans with approximately 90% successful rate. However, it may be one of the most difficult procedures to learn for anesthesia residents in hospital. A two-wavelength (650 nm and 532 nm) fiber-optical method has been developed according to the characteristic reflectance spectra of ex-vivo porcine tissues, which are associated with the needle insertion to localize the epidural space (ES). In an in-vivo study in piglets showed that the reflected lights from ES and its surrounding tissue ligamentum flavum (LF) are highly distinguishable. This indicates that this technique has potential to localize the ES on the spot without the help of additional guiding assistance.

© 2010 OSA

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  1. C. K. Ting, M. Y. Tsou, P. T. Chen, K. Y. Chang, M. S. Mandell, K. H. Chan, and Y. Chang, “A new technique to assist epidural needle placement: fiberoptic-guided insertion using two wavelengths,” Anesthesiology 112(5), 1128–1135 (2010).
    [CrossRef] [PubMed]
  2. P. R. Bromage, “Epidural Analgesia” (W. B. Saunders, 1978).
  3. M. J. Cousins, and B. T. Veering, “Epidural neural block,” in Neural Blockade in Clinical Anesthesia and Management of Pain, 3rd ed., M. J. Cousins, P. O. Bridenbaugh, eds. (Lippincott-Raven, 1998), pp. 243–321.
  4. J. R. Rigg, K. Jamrozik, P. S. Myles, B. S. Silbert, P. J. Peyton, R. W. Parsons, K. S. Collins, and MASTER Anaethesia Trial Study Group, “Epidural anaesthesia and analgesia and outcome of major surgery: a randomized trial,” Lancet 359(9314), 1276–1282 (2002).
    [CrossRef] [PubMed]
  5. M. Curatolo, A. Orlando, A. M. Zbinden, P. Scaramozzino, and F. S. Venuti, “A multifactorial analysis to explain inadequate surgical analgesia after extradural block,” Br. J. Anaesth. 75(3), 274–281 (1995).
    [PubMed]
  6. P. H. Pan, T. D. Bogard, and M. D. Owen, “Incidence and characteristics of failures in obstetric neuraxial analgesia and anesthesia: a retrospective analysis of 19,259 deliveries,” Int. J. Obstet. Anesth. 13(4), 227–233 (2004).
    [CrossRef] [PubMed]
  7. G. R. de Filho, H. P. Gomes, M. H. da Fonseca, J. C. Hoffman, S. G. Pederneiras, and J. H. Garcia, “Predictors of successful neuraxial block: a prospective study,” Eur. J. Anaesthesiol. 19(6), 447–451 (2002).
    [PubMed]
  8. J. Sprung, D. L. Bourke, J. Grass, J. Hammel, E. Mascha, P. Thomas, and I. Tubin, “Predicting the difficult neuraxial block: a prospective study,” Anesth. Analg. 89(2), 384–389 (1999).
    [CrossRef] [PubMed]
  9. D. D. Hood and D. M. Dewan, “Anesthetic and obstetric outcome in morbidly obese parturients,” Anesthesiology 79(6), 1210–1218 (1993).
    [CrossRef] [PubMed]
  10. C. Konrad, G. Schüpfer, M. Wietlisbach, and H. Gerber, “Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures?” Anesth. Analg. 86(3), 635–639 (1998).
    [CrossRef] [PubMed]
  11. A. M. Dogliotti, “Segmental peridural spinal anesthesia: a new method of block anesthesia,” Am. J. Surg. 20, 107–118 (1993).
    [CrossRef]
  12. T. Nagaro, T. Yorozuya, M. Kamei, N. Kii, T. Arai, and S. Abe, “Fluoroscopically guided epidural block in the thoracic and lumbar regions,” Reg. Anesth. Pain Med. 31(5), 409–416 (2006).
    [PubMed]
  13. B. C. Tsui, P. Tarkkila, S. Gupta, and R. Kearney, “Confirmation of caudal needle placement using nerve stimulation,” Anesthesiology 91(2), 374–378 (1999).
    [CrossRef] [PubMed]
  14. T. J. Lechner, M. G. van Wijk, A. J. Maas, F. R. van Dorsten, R. A. Drost, C. J. Langenberg, L. J. Teunissen, P. H. Cornelissen, and J. van Niekerk, “Clinical results with the acoustic puncture assist device, a new acoustic device to identify the epidural space,” Anesth. Analg. 96(4), 1183–1187 (2003).
    [CrossRef] [PubMed]
  15. M. P. Lewis, P. Thomas, L. F. Wilson, and R. C. Mulholland, “The ‘whoosh’ test,” Anaesthesia 47(1), 57–58 (1992).
    [CrossRef] [PubMed]
  16. B. C. Tsui, C. Guenther, D. Emery, and B. Finucane, “Determining epidural catheter location using nerve stimulation with radiological confirmation,” Reg. Anesth. Pain Med. 25(3), 306–309 (2000).
    [PubMed]
  17. M. K. Karmakar, X. Li, A. M. Ho, W. H. Kwok, and P. T. Chui, “Real-time ultrasound-guided paramedian epidural access: evaluation of a novel in-plane technique,” Br. J. Anaesth. 102(6), 845–854 (2009).
    [CrossRef] [PubMed]
  18. Ghia Jn, M. Arora Sk, Castillo, and Mukherji Sk, “Confirmation of location of epidural catheters by epidural pressure waveform and computed tomography cathetergram,” Reg. Anesth. Pain Med. 26(4), 337–341 (2001).
    [PubMed]
  19. P. H. Lennox, H. S. Umedaly, R. P. Grant, S. A. White, B. G. Fitzmaurice, and K. G. Evans, “A pulsatile pressure waveform is a sensitive marker for confirming the location of the thoracic epidural space,” J. Cardiothorac. Vasc. Anesth. 20(5), 659–663 (2006).
    [CrossRef] [PubMed]
  20. T. Grau, R. W. Leipold, R. Conradi, and E. Martin, “Ultrasound control for presumed difficult epidural puncture,” Acta Anaesthesiol. Scand. 45(6), 766–771 (2001).
    [CrossRef] [PubMed]
  21. S. F. Chen, Y. Chang, and J. C. Wu, “The spatial distribution of macular pigment in humans,” Curr. Eye Res. 23(6), 422–434 (2001).
    [CrossRef]
  22. F. P. Bolin, L. E. Preuss, R. C. Taylor, and R. J. Ference, “Refractive index of some mammalian tissues using a fiber optic cladding method,” Appl. Opt. 28(12), 2297–2303 (1989).
    [CrossRef] [PubMed]
  23. M. Sand, T. Gambichler, G. Moussa, F. G. Bechara, D. Sand, P. Altmeyer, and K. Hoffmann, “Evaluation of the epidermal refractive index measured optical coherence tomography,” Skin Res. Technol. 12(2), 114–118 (2006).
    [CrossRef] [PubMed]
  24. H. Li and S. Xie, “Measurement method of the refractive index of biotissue by total internal reflection,” Appl. Opt. 35(10), 1793–1795 (1996).
    [CrossRef] [PubMed]
  25. M. Irie, “Evaluation of porcine fat with fiber-optic spectroscopy,” J. Anim. Sci. 77(10), 2680–2684 (1999).
    [PubMed]
  26. G. A. Mook, O. W. Van Assendelft, and W. G. Zijlstra, “Wavelength dependency of the spectrophotometric determination of blood oxygen saturation,” Clin. Chim. Acta 26(1), 170–173 (1969).
    [CrossRef] [PubMed]
  27. J. Reichman, “Determination of absorption and scattering coefficients for nonhomogeneous media. 1: Theory,” Appl. Opt. 12(8), 1811–1815 (1973).
    [CrossRef] [PubMed]
  28. R. L. Longini and R. Zdrojkowski, “A note on the theory of backscattering of light by living tissue,” IEEE Trans. Biomed. Eng. BME-15(1), 4–10 (1968).
    [CrossRef]
  29. W. F. Cheong, S. A. Prahl, and A. J. Welch, “A review of the optical properties of biological tissues,” IEEE J. Quantum Electron. 26(12), 2166–2185 (1990).
    [CrossRef]
  30. L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
    [CrossRef]
  31. A. H. Hielscher, J. R. Mourant, and I. J. Bigio, “Influence of particle size and concentration on the diffuse backscattering of polarized light from tissue phantoms and biological cell suspensions,” Appl. Opt. 36(1), 125–135 (1997).
    [CrossRef] [PubMed]
  32. A. K. Popp, M. T. Valentine, P. D. Kaplan, and D. A. Weitz, “Microscopic origin of light scattering in tissue,” Appl. Opt. 42(16), 2871–2880 (2003).
    [CrossRef] [PubMed]
  33. R. D. Miller, “Miller's Anesthesia,” 7th ed., (Churchill Livingstone, 2009).
  34. H. Ellis, “The anatomy of the epidural space,” Anaesth. Intensive Care Med. 7(11), 402–404 (2006).
    [CrossRef]

2010

C. K. Ting, M. Y. Tsou, P. T. Chen, K. Y. Chang, M. S. Mandell, K. H. Chan, and Y. Chang, “A new technique to assist epidural needle placement: fiberoptic-guided insertion using two wavelengths,” Anesthesiology 112(5), 1128–1135 (2010).
[CrossRef] [PubMed]

2009

M. K. Karmakar, X. Li, A. M. Ho, W. H. Kwok, and P. T. Chui, “Real-time ultrasound-guided paramedian epidural access: evaluation of a novel in-plane technique,” Br. J. Anaesth. 102(6), 845–854 (2009).
[CrossRef] [PubMed]

2006

P. H. Lennox, H. S. Umedaly, R. P. Grant, S. A. White, B. G. Fitzmaurice, and K. G. Evans, “A pulsatile pressure waveform is a sensitive marker for confirming the location of the thoracic epidural space,” J. Cardiothorac. Vasc. Anesth. 20(5), 659–663 (2006).
[CrossRef] [PubMed]

T. Nagaro, T. Yorozuya, M. Kamei, N. Kii, T. Arai, and S. Abe, “Fluoroscopically guided epidural block in the thoracic and lumbar regions,” Reg. Anesth. Pain Med. 31(5), 409–416 (2006).
[PubMed]

M. Sand, T. Gambichler, G. Moussa, F. G. Bechara, D. Sand, P. Altmeyer, and K. Hoffmann, “Evaluation of the epidermal refractive index measured optical coherence tomography,” Skin Res. Technol. 12(2), 114–118 (2006).
[CrossRef] [PubMed]

H. Ellis, “The anatomy of the epidural space,” Anaesth. Intensive Care Med. 7(11), 402–404 (2006).
[CrossRef]

2004

P. H. Pan, T. D. Bogard, and M. D. Owen, “Incidence and characteristics of failures in obstetric neuraxial analgesia and anesthesia: a retrospective analysis of 19,259 deliveries,” Int. J. Obstet. Anesth. 13(4), 227–233 (2004).
[CrossRef] [PubMed]

2003

T. J. Lechner, M. G. van Wijk, A. J. Maas, F. R. van Dorsten, R. A. Drost, C. J. Langenberg, L. J. Teunissen, P. H. Cornelissen, and J. van Niekerk, “Clinical results with the acoustic puncture assist device, a new acoustic device to identify the epidural space,” Anesth. Analg. 96(4), 1183–1187 (2003).
[CrossRef] [PubMed]

A. K. Popp, M. T. Valentine, P. D. Kaplan, and D. A. Weitz, “Microscopic origin of light scattering in tissue,” Appl. Opt. 42(16), 2871–2880 (2003).
[CrossRef] [PubMed]

2002

G. R. de Filho, H. P. Gomes, M. H. da Fonseca, J. C. Hoffman, S. G. Pederneiras, and J. H. Garcia, “Predictors of successful neuraxial block: a prospective study,” Eur. J. Anaesthesiol. 19(6), 447–451 (2002).
[PubMed]

J. R. Rigg, K. Jamrozik, P. S. Myles, B. S. Silbert, P. J. Peyton, R. W. Parsons, K. S. Collins, and MASTER Anaethesia Trial Study Group, “Epidural anaesthesia and analgesia and outcome of major surgery: a randomized trial,” Lancet 359(9314), 1276–1282 (2002).
[CrossRef] [PubMed]

2001

T. Grau, R. W. Leipold, R. Conradi, and E. Martin, “Ultrasound control for presumed difficult epidural puncture,” Acta Anaesthesiol. Scand. 45(6), 766–771 (2001).
[CrossRef] [PubMed]

S. F. Chen, Y. Chang, and J. C. Wu, “The spatial distribution of macular pigment in humans,” Curr. Eye Res. 23(6), 422–434 (2001).
[CrossRef]

Ghia Jn, M. Arora Sk, Castillo, and Mukherji Sk, “Confirmation of location of epidural catheters by epidural pressure waveform and computed tomography cathetergram,” Reg. Anesth. Pain Med. 26(4), 337–341 (2001).
[PubMed]

2000

B. C. Tsui, C. Guenther, D. Emery, and B. Finucane, “Determining epidural catheter location using nerve stimulation with radiological confirmation,” Reg. Anesth. Pain Med. 25(3), 306–309 (2000).
[PubMed]

1999

M. Irie, “Evaluation of porcine fat with fiber-optic spectroscopy,” J. Anim. Sci. 77(10), 2680–2684 (1999).
[PubMed]

B. C. Tsui, P. Tarkkila, S. Gupta, and R. Kearney, “Confirmation of caudal needle placement using nerve stimulation,” Anesthesiology 91(2), 374–378 (1999).
[CrossRef] [PubMed]

J. Sprung, D. L. Bourke, J. Grass, J. Hammel, E. Mascha, P. Thomas, and I. Tubin, “Predicting the difficult neuraxial block: a prospective study,” Anesth. Analg. 89(2), 384–389 (1999).
[CrossRef] [PubMed]

1998

C. Konrad, G. Schüpfer, M. Wietlisbach, and H. Gerber, “Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures?” Anesth. Analg. 86(3), 635–639 (1998).
[CrossRef] [PubMed]

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

1997

1996

1995

M. Curatolo, A. Orlando, A. M. Zbinden, P. Scaramozzino, and F. S. Venuti, “A multifactorial analysis to explain inadequate surgical analgesia after extradural block,” Br. J. Anaesth. 75(3), 274–281 (1995).
[PubMed]

1993

A. M. Dogliotti, “Segmental peridural spinal anesthesia: a new method of block anesthesia,” Am. J. Surg. 20, 107–118 (1993).
[CrossRef]

D. D. Hood and D. M. Dewan, “Anesthetic and obstetric outcome in morbidly obese parturients,” Anesthesiology 79(6), 1210–1218 (1993).
[CrossRef] [PubMed]

1992

M. P. Lewis, P. Thomas, L. F. Wilson, and R. C. Mulholland, “The ‘whoosh’ test,” Anaesthesia 47(1), 57–58 (1992).
[CrossRef] [PubMed]

1990

W. F. Cheong, S. A. Prahl, and A. J. Welch, “A review of the optical properties of biological tissues,” IEEE J. Quantum Electron. 26(12), 2166–2185 (1990).
[CrossRef]

1989

1973

1969

G. A. Mook, O. W. Van Assendelft, and W. G. Zijlstra, “Wavelength dependency of the spectrophotometric determination of blood oxygen saturation,” Clin. Chim. Acta 26(1), 170–173 (1969).
[CrossRef] [PubMed]

1968

R. L. Longini and R. Zdrojkowski, “A note on the theory of backscattering of light by living tissue,” IEEE Trans. Biomed. Eng. BME-15(1), 4–10 (1968).
[CrossRef]

Abe, S.

T. Nagaro, T. Yorozuya, M. Kamei, N. Kii, T. Arai, and S. Abe, “Fluoroscopically guided epidural block in the thoracic and lumbar regions,” Reg. Anesth. Pain Med. 31(5), 409–416 (2006).
[PubMed]

Altmeyer, P.

M. Sand, T. Gambichler, G. Moussa, F. G. Bechara, D. Sand, P. Altmeyer, and K. Hoffmann, “Evaluation of the epidermal refractive index measured optical coherence tomography,” Skin Res. Technol. 12(2), 114–118 (2006).
[CrossRef] [PubMed]

Arai, T.

T. Nagaro, T. Yorozuya, M. Kamei, N. Kii, T. Arai, and S. Abe, “Fluoroscopically guided epidural block in the thoracic and lumbar regions,” Reg. Anesth. Pain Med. 31(5), 409–416 (2006).
[PubMed]

Arora Sk, M.

Ghia Jn, M. Arora Sk, Castillo, and Mukherji Sk, “Confirmation of location of epidural catheters by epidural pressure waveform and computed tomography cathetergram,” Reg. Anesth. Pain Med. 26(4), 337–341 (2001).
[PubMed]

Backman, V.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

Bechara, F. G.

M. Sand, T. Gambichler, G. Moussa, F. G. Bechara, D. Sand, P. Altmeyer, and K. Hoffmann, “Evaluation of the epidermal refractive index measured optical coherence tomography,” Skin Res. Technol. 12(2), 114–118 (2006).
[CrossRef] [PubMed]

Bigio, I. J.

Bogard, T. D.

P. H. Pan, T. D. Bogard, and M. D. Owen, “Incidence and characteristics of failures in obstetric neuraxial analgesia and anesthesia: a retrospective analysis of 19,259 deliveries,” Int. J. Obstet. Anesth. 13(4), 227–233 (2004).
[CrossRef] [PubMed]

Bolin, F. P.

Bourke, D. L.

J. Sprung, D. L. Bourke, J. Grass, J. Hammel, E. Mascha, P. Thomas, and I. Tubin, “Predicting the difficult neuraxial block: a prospective study,” Anesth. Analg. 89(2), 384–389 (1999).
[CrossRef] [PubMed]

Castillo,

Ghia Jn, M. Arora Sk, Castillo, and Mukherji Sk, “Confirmation of location of epidural catheters by epidural pressure waveform and computed tomography cathetergram,” Reg. Anesth. Pain Med. 26(4), 337–341 (2001).
[PubMed]

Chan, K. H.

C. K. Ting, M. Y. Tsou, P. T. Chen, K. Y. Chang, M. S. Mandell, K. H. Chan, and Y. Chang, “A new technique to assist epidural needle placement: fiberoptic-guided insertion using two wavelengths,” Anesthesiology 112(5), 1128–1135 (2010).
[CrossRef] [PubMed]

Chang, K. Y.

C. K. Ting, M. Y. Tsou, P. T. Chen, K. Y. Chang, M. S. Mandell, K. H. Chan, and Y. Chang, “A new technique to assist epidural needle placement: fiberoptic-guided insertion using two wavelengths,” Anesthesiology 112(5), 1128–1135 (2010).
[CrossRef] [PubMed]

Chang, Y.

C. K. Ting, M. Y. Tsou, P. T. Chen, K. Y. Chang, M. S. Mandell, K. H. Chan, and Y. Chang, “A new technique to assist epidural needle placement: fiberoptic-guided insertion using two wavelengths,” Anesthesiology 112(5), 1128–1135 (2010).
[CrossRef] [PubMed]

S. F. Chen, Y. Chang, and J. C. Wu, “The spatial distribution of macular pigment in humans,” Curr. Eye Res. 23(6), 422–434 (2001).
[CrossRef]

Chen, P. T.

C. K. Ting, M. Y. Tsou, P. T. Chen, K. Y. Chang, M. S. Mandell, K. H. Chan, and Y. Chang, “A new technique to assist epidural needle placement: fiberoptic-guided insertion using two wavelengths,” Anesthesiology 112(5), 1128–1135 (2010).
[CrossRef] [PubMed]

Chen, S. F.

S. F. Chen, Y. Chang, and J. C. Wu, “The spatial distribution of macular pigment in humans,” Curr. Eye Res. 23(6), 422–434 (2001).
[CrossRef]

Cheong, W. F.

W. F. Cheong, S. A. Prahl, and A. J. Welch, “A review of the optical properties of biological tissues,” IEEE J. Quantum Electron. 26(12), 2166–2185 (1990).
[CrossRef]

Chui, P. T.

M. K. Karmakar, X. Li, A. M. Ho, W. H. Kwok, and P. T. Chui, “Real-time ultrasound-guided paramedian epidural access: evaluation of a novel in-plane technique,” Br. J. Anaesth. 102(6), 845–854 (2009).
[CrossRef] [PubMed]

Collins, K. S.

J. R. Rigg, K. Jamrozik, P. S. Myles, B. S. Silbert, P. J. Peyton, R. W. Parsons, K. S. Collins, and MASTER Anaethesia Trial Study Group, “Epidural anaesthesia and analgesia and outcome of major surgery: a randomized trial,” Lancet 359(9314), 1276–1282 (2002).
[CrossRef] [PubMed]

Conradi, R.

T. Grau, R. W. Leipold, R. Conradi, and E. Martin, “Ultrasound control for presumed difficult epidural puncture,” Acta Anaesthesiol. Scand. 45(6), 766–771 (2001).
[CrossRef] [PubMed]

Cornelissen, P. H.

T. J. Lechner, M. G. van Wijk, A. J. Maas, F. R. van Dorsten, R. A. Drost, C. J. Langenberg, L. J. Teunissen, P. H. Cornelissen, and J. van Niekerk, “Clinical results with the acoustic puncture assist device, a new acoustic device to identify the epidural space,” Anesth. Analg. 96(4), 1183–1187 (2003).
[CrossRef] [PubMed]

Crawford, J.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

Curatolo, M.

M. Curatolo, A. Orlando, A. M. Zbinden, P. Scaramozzino, and F. S. Venuti, “A multifactorial analysis to explain inadequate surgical analgesia after extradural block,” Br. J. Anaesth. 75(3), 274–281 (1995).
[PubMed]

da Fonseca, M. H.

G. R. de Filho, H. P. Gomes, M. H. da Fonseca, J. C. Hoffman, S. G. Pederneiras, and J. H. Garcia, “Predictors of successful neuraxial block: a prospective study,” Eur. J. Anaesthesiol. 19(6), 447–451 (2002).
[PubMed]

de Filho, G. R.

G. R. de Filho, H. P. Gomes, M. H. da Fonseca, J. C. Hoffman, S. G. Pederneiras, and J. H. Garcia, “Predictors of successful neuraxial block: a prospective study,” Eur. J. Anaesthesiol. 19(6), 447–451 (2002).
[PubMed]

Dewan, D. M.

D. D. Hood and D. M. Dewan, “Anesthetic and obstetric outcome in morbidly obese parturients,” Anesthesiology 79(6), 1210–1218 (1993).
[CrossRef] [PubMed]

Dogliotti, A. M.

A. M. Dogliotti, “Segmental peridural spinal anesthesia: a new method of block anesthesia,” Am. J. Surg. 20, 107–118 (1993).
[CrossRef]

Drost, R. A.

T. J. Lechner, M. G. van Wijk, A. J. Maas, F. R. van Dorsten, R. A. Drost, C. J. Langenberg, L. J. Teunissen, P. H. Cornelissen, and J. van Niekerk, “Clinical results with the acoustic puncture assist device, a new acoustic device to identify the epidural space,” Anesth. Analg. 96(4), 1183–1187 (2003).
[CrossRef] [PubMed]

Ellis, H.

H. Ellis, “The anatomy of the epidural space,” Anaesth. Intensive Care Med. 7(11), 402–404 (2006).
[CrossRef]

Emery, D.

B. C. Tsui, C. Guenther, D. Emery, and B. Finucane, “Determining epidural catheter location using nerve stimulation with radiological confirmation,” Reg. Anesth. Pain Med. 25(3), 306–309 (2000).
[PubMed]

Evans, K. G.

P. H. Lennox, H. S. Umedaly, R. P. Grant, S. A. White, B. G. Fitzmaurice, and K. G. Evans, “A pulsatile pressure waveform is a sensitive marker for confirming the location of the thoracic epidural space,” J. Cardiothorac. Vasc. Anesth. 20(5), 659–663 (2006).
[CrossRef] [PubMed]

Feld, M.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

Ference, R. J.

Finucane, B.

B. C. Tsui, C. Guenther, D. Emery, and B. Finucane, “Determining epidural catheter location using nerve stimulation with radiological confirmation,” Reg. Anesth. Pain Med. 25(3), 306–309 (2000).
[PubMed]

Fitzmaurice, B. G.

P. H. Lennox, H. S. Umedaly, R. P. Grant, S. A. White, B. G. Fitzmaurice, and K. G. Evans, “A pulsatile pressure waveform is a sensitive marker for confirming the location of the thoracic epidural space,” J. Cardiothorac. Vasc. Anesth. 20(5), 659–663 (2006).
[CrossRef] [PubMed]

Gambichler, T.

M. Sand, T. Gambichler, G. Moussa, F. G. Bechara, D. Sand, P. Altmeyer, and K. Hoffmann, “Evaluation of the epidermal refractive index measured optical coherence tomography,” Skin Res. Technol. 12(2), 114–118 (2006).
[CrossRef] [PubMed]

Garcia, J. H.

G. R. de Filho, H. P. Gomes, M. H. da Fonseca, J. C. Hoffman, S. G. Pederneiras, and J. H. Garcia, “Predictors of successful neuraxial block: a prospective study,” Eur. J. Anaesthesiol. 19(6), 447–451 (2002).
[PubMed]

Gerber, H.

C. Konrad, G. Schüpfer, M. Wietlisbach, and H. Gerber, “Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures?” Anesth. Analg. 86(3), 635–639 (1998).
[CrossRef] [PubMed]

Ghia Jn,

Ghia Jn, M. Arora Sk, Castillo, and Mukherji Sk, “Confirmation of location of epidural catheters by epidural pressure waveform and computed tomography cathetergram,” Reg. Anesth. Pain Med. 26(4), 337–341 (2001).
[PubMed]

Gomes, H. P.

G. R. de Filho, H. P. Gomes, M. H. da Fonseca, J. C. Hoffman, S. G. Pederneiras, and J. H. Garcia, “Predictors of successful neuraxial block: a prospective study,” Eur. J. Anaesthesiol. 19(6), 447–451 (2002).
[PubMed]

Grant, R. P.

P. H. Lennox, H. S. Umedaly, R. P. Grant, S. A. White, B. G. Fitzmaurice, and K. G. Evans, “A pulsatile pressure waveform is a sensitive marker for confirming the location of the thoracic epidural space,” J. Cardiothorac. Vasc. Anesth. 20(5), 659–663 (2006).
[CrossRef] [PubMed]

Grass, J.

J. Sprung, D. L. Bourke, J. Grass, J. Hammel, E. Mascha, P. Thomas, and I. Tubin, “Predicting the difficult neuraxial block: a prospective study,” Anesth. Analg. 89(2), 384–389 (1999).
[CrossRef] [PubMed]

Grau, T.

T. Grau, R. W. Leipold, R. Conradi, and E. Martin, “Ultrasound control for presumed difficult epidural puncture,” Acta Anaesthesiol. Scand. 45(6), 766–771 (2001).
[CrossRef] [PubMed]

Guenther, C.

B. C. Tsui, C. Guenther, D. Emery, and B. Finucane, “Determining epidural catheter location using nerve stimulation with radiological confirmation,” Reg. Anesth. Pain Med. 25(3), 306–309 (2000).
[PubMed]

Gupta, S.

B. C. Tsui, P. Tarkkila, S. Gupta, and R. Kearney, “Confirmation of caudal needle placement using nerve stimulation,” Anesthesiology 91(2), 374–378 (1999).
[CrossRef] [PubMed]

Hamano, T.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

Hammel, J.

J. Sprung, D. L. Bourke, J. Grass, J. Hammel, E. Mascha, P. Thomas, and I. Tubin, “Predicting the difficult neuraxial block: a prospective study,” Anesth. Analg. 89(2), 384–389 (1999).
[CrossRef] [PubMed]

Hielscher, A. H.

Ho, A. M.

M. K. Karmakar, X. Li, A. M. Ho, W. H. Kwok, and P. T. Chui, “Real-time ultrasound-guided paramedian epidural access: evaluation of a novel in-plane technique,” Br. J. Anaesth. 102(6), 845–854 (2009).
[CrossRef] [PubMed]

Hoffman, J. C.

G. R. de Filho, H. P. Gomes, M. H. da Fonseca, J. C. Hoffman, S. G. Pederneiras, and J. H. Garcia, “Predictors of successful neuraxial block: a prospective study,” Eur. J. Anaesthesiol. 19(6), 447–451 (2002).
[PubMed]

Hoffmann, K.

M. Sand, T. Gambichler, G. Moussa, F. G. Bechara, D. Sand, P. Altmeyer, and K. Hoffmann, “Evaluation of the epidermal refractive index measured optical coherence tomography,” Skin Res. Technol. 12(2), 114–118 (2006).
[CrossRef] [PubMed]

Hood, D. D.

D. D. Hood and D. M. Dewan, “Anesthetic and obstetric outcome in morbidly obese parturients,” Anesthesiology 79(6), 1210–1218 (1993).
[CrossRef] [PubMed]

Irie, M.

M. Irie, “Evaluation of porcine fat with fiber-optic spectroscopy,” J. Anim. Sci. 77(10), 2680–2684 (1999).
[PubMed]

Itzkan, I.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

Jamrozik, K.

J. R. Rigg, K. Jamrozik, P. S. Myles, B. S. Silbert, P. J. Peyton, R. W. Parsons, K. S. Collins, and MASTER Anaethesia Trial Study Group, “Epidural anaesthesia and analgesia and outcome of major surgery: a randomized trial,” Lancet 359(9314), 1276–1282 (2002).
[CrossRef] [PubMed]

Kamei, M.

T. Nagaro, T. Yorozuya, M. Kamei, N. Kii, T. Arai, and S. Abe, “Fluoroscopically guided epidural block in the thoracic and lumbar regions,” Reg. Anesth. Pain Med. 31(5), 409–416 (2006).
[PubMed]

Kaplan, P. D.

Karmakar, M. K.

M. K. Karmakar, X. Li, A. M. Ho, W. H. Kwok, and P. T. Chui, “Real-time ultrasound-guided paramedian epidural access: evaluation of a novel in-plane technique,” Br. J. Anaesth. 102(6), 845–854 (2009).
[CrossRef] [PubMed]

Kearney, R.

B. C. Tsui, P. Tarkkila, S. Gupta, and R. Kearney, “Confirmation of caudal needle placement using nerve stimulation,” Anesthesiology 91(2), 374–378 (1999).
[CrossRef] [PubMed]

Kii, N.

T. Nagaro, T. Yorozuya, M. Kamei, N. Kii, T. Arai, and S. Abe, “Fluoroscopically guided epidural block in the thoracic and lumbar regions,” Reg. Anesth. Pain Med. 31(5), 409–416 (2006).
[PubMed]

Konrad, C.

C. Konrad, G. Schüpfer, M. Wietlisbach, and H. Gerber, “Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures?” Anesth. Analg. 86(3), 635–639 (1998).
[CrossRef] [PubMed]

Kwok, W. H.

M. K. Karmakar, X. Li, A. M. Ho, W. H. Kwok, and P. T. Chui, “Real-time ultrasound-guided paramedian epidural access: evaluation of a novel in-plane technique,” Br. J. Anaesth. 102(6), 845–854 (2009).
[CrossRef] [PubMed]

Langenberg, C. J.

T. J. Lechner, M. G. van Wijk, A. J. Maas, F. R. van Dorsten, R. A. Drost, C. J. Langenberg, L. J. Teunissen, P. H. Cornelissen, and J. van Niekerk, “Clinical results with the acoustic puncture assist device, a new acoustic device to identify the epidural space,” Anesth. Analg. 96(4), 1183–1187 (2003).
[CrossRef] [PubMed]

Lechner, T. J.

T. J. Lechner, M. G. van Wijk, A. J. Maas, F. R. van Dorsten, R. A. Drost, C. J. Langenberg, L. J. Teunissen, P. H. Cornelissen, and J. van Niekerk, “Clinical results with the acoustic puncture assist device, a new acoustic device to identify the epidural space,” Anesth. Analg. 96(4), 1183–1187 (2003).
[CrossRef] [PubMed]

Leipold, R. W.

T. Grau, R. W. Leipold, R. Conradi, and E. Martin, “Ultrasound control for presumed difficult epidural puncture,” Acta Anaesthesiol. Scand. 45(6), 766–771 (2001).
[CrossRef] [PubMed]

Lennox, P. H.

P. H. Lennox, H. S. Umedaly, R. P. Grant, S. A. White, B. G. Fitzmaurice, and K. G. Evans, “A pulsatile pressure waveform is a sensitive marker for confirming the location of the thoracic epidural space,” J. Cardiothorac. Vasc. Anesth. 20(5), 659–663 (2006).
[CrossRef] [PubMed]

Lewis, M. P.

M. P. Lewis, P. Thomas, L. F. Wilson, and R. C. Mulholland, “The ‘whoosh’ test,” Anaesthesia 47(1), 57–58 (1992).
[CrossRef] [PubMed]

Li, H.

Li, X.

M. K. Karmakar, X. Li, A. M. Ho, W. H. Kwok, and P. T. Chui, “Real-time ultrasound-guided paramedian epidural access: evaluation of a novel in-plane technique,” Br. J. Anaesth. 102(6), 845–854 (2009).
[CrossRef] [PubMed]

Lima, C.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

Longini, R. L.

R. L. Longini and R. Zdrojkowski, “A note on the theory of backscattering of light by living tissue,” IEEE Trans. Biomed. Eng. BME-15(1), 4–10 (1968).
[CrossRef]

Maas, A. J.

T. J. Lechner, M. G. van Wijk, A. J. Maas, F. R. van Dorsten, R. A. Drost, C. J. Langenberg, L. J. Teunissen, P. H. Cornelissen, and J. van Niekerk, “Clinical results with the acoustic puncture assist device, a new acoustic device to identify the epidural space,” Anesth. Analg. 96(4), 1183–1187 (2003).
[CrossRef] [PubMed]

Mandell, M. S.

C. K. Ting, M. Y. Tsou, P. T. Chen, K. Y. Chang, M. S. Mandell, K. H. Chan, and Y. Chang, “A new technique to assist epidural needle placement: fiberoptic-guided insertion using two wavelengths,” Anesthesiology 112(5), 1128–1135 (2010).
[CrossRef] [PubMed]

Manoharan, R.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

Martin, E.

T. Grau, R. W. Leipold, R. Conradi, and E. Martin, “Ultrasound control for presumed difficult epidural puncture,” Acta Anaesthesiol. Scand. 45(6), 766–771 (2001).
[CrossRef] [PubMed]

Mascha, E.

J. Sprung, D. L. Bourke, J. Grass, J. Hammel, E. Mascha, P. Thomas, and I. Tubin, “Predicting the difficult neuraxial block: a prospective study,” Anesth. Analg. 89(2), 384–389 (1999).
[CrossRef] [PubMed]

Mook, G. A.

G. A. Mook, O. W. Van Assendelft, and W. G. Zijlstra, “Wavelength dependency of the spectrophotometric determination of blood oxygen saturation,” Clin. Chim. Acta 26(1), 170–173 (1969).
[CrossRef] [PubMed]

Mourant, J. R.

Moussa, G.

M. Sand, T. Gambichler, G. Moussa, F. G. Bechara, D. Sand, P. Altmeyer, and K. Hoffmann, “Evaluation of the epidermal refractive index measured optical coherence tomography,” Skin Res. Technol. 12(2), 114–118 (2006).
[CrossRef] [PubMed]

Mukherji Sk,

Ghia Jn, M. Arora Sk, Castillo, and Mukherji Sk, “Confirmation of location of epidural catheters by epidural pressure waveform and computed tomography cathetergram,” Reg. Anesth. Pain Med. 26(4), 337–341 (2001).
[PubMed]

Mulholland, R. C.

M. P. Lewis, P. Thomas, L. F. Wilson, and R. C. Mulholland, “The ‘whoosh’ test,” Anaesthesia 47(1), 57–58 (1992).
[CrossRef] [PubMed]

Myles, P. S.

J. R. Rigg, K. Jamrozik, P. S. Myles, B. S. Silbert, P. J. Peyton, R. W. Parsons, K. S. Collins, and MASTER Anaethesia Trial Study Group, “Epidural anaesthesia and analgesia and outcome of major surgery: a randomized trial,” Lancet 359(9314), 1276–1282 (2002).
[CrossRef] [PubMed]

Nagaro, T.

T. Nagaro, T. Yorozuya, M. Kamei, N. Kii, T. Arai, and S. Abe, “Fluoroscopically guided epidural block in the thoracic and lumbar regions,” Reg. Anesth. Pain Med. 31(5), 409–416 (2006).
[PubMed]

Nusrat, A.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

Orlando, A.

M. Curatolo, A. Orlando, A. M. Zbinden, P. Scaramozzino, and F. S. Venuti, “A multifactorial analysis to explain inadequate surgical analgesia after extradural block,” Br. J. Anaesth. 75(3), 274–281 (1995).
[PubMed]

Owen, M. D.

P. H. Pan, T. D. Bogard, and M. D. Owen, “Incidence and characteristics of failures in obstetric neuraxial analgesia and anesthesia: a retrospective analysis of 19,259 deliveries,” Int. J. Obstet. Anesth. 13(4), 227–233 (2004).
[CrossRef] [PubMed]

Pan, P. H.

P. H. Pan, T. D. Bogard, and M. D. Owen, “Incidence and characteristics of failures in obstetric neuraxial analgesia and anesthesia: a retrospective analysis of 19,259 deliveries,” Int. J. Obstet. Anesth. 13(4), 227–233 (2004).
[CrossRef] [PubMed]

Parsons, R. W.

J. R. Rigg, K. Jamrozik, P. S. Myles, B. S. Silbert, P. J. Peyton, R. W. Parsons, K. S. Collins, and MASTER Anaethesia Trial Study Group, “Epidural anaesthesia and analgesia and outcome of major surgery: a randomized trial,” Lancet 359(9314), 1276–1282 (2002).
[CrossRef] [PubMed]

Pederneiras, S. G.

G. R. de Filho, H. P. Gomes, M. H. da Fonseca, J. C. Hoffman, S. G. Pederneiras, and J. H. Garcia, “Predictors of successful neuraxial block: a prospective study,” Eur. J. Anaesthesiol. 19(6), 447–451 (2002).
[PubMed]

Perelman, L. T.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

Peyton, P. J.

J. R. Rigg, K. Jamrozik, P. S. Myles, B. S. Silbert, P. J. Peyton, R. W. Parsons, K. S. Collins, and MASTER Anaethesia Trial Study Group, “Epidural anaesthesia and analgesia and outcome of major surgery: a randomized trial,” Lancet 359(9314), 1276–1282 (2002).
[CrossRef] [PubMed]

Popp, A. K.

Prahl, S. A.

W. F. Cheong, S. A. Prahl, and A. J. Welch, “A review of the optical properties of biological tissues,” IEEE J. Quantum Electron. 26(12), 2166–2185 (1990).
[CrossRef]

Preuss, L. E.

Reichman, J.

Rigg, J. R.

J. R. Rigg, K. Jamrozik, P. S. Myles, B. S. Silbert, P. J. Peyton, R. W. Parsons, K. S. Collins, and MASTER Anaethesia Trial Study Group, “Epidural anaesthesia and analgesia and outcome of major surgery: a randomized trial,” Lancet 359(9314), 1276–1282 (2002).
[CrossRef] [PubMed]

Sand, D.

M. Sand, T. Gambichler, G. Moussa, F. G. Bechara, D. Sand, P. Altmeyer, and K. Hoffmann, “Evaluation of the epidermal refractive index measured optical coherence tomography,” Skin Res. Technol. 12(2), 114–118 (2006).
[CrossRef] [PubMed]

Sand, M.

M. Sand, T. Gambichler, G. Moussa, F. G. Bechara, D. Sand, P. Altmeyer, and K. Hoffmann, “Evaluation of the epidermal refractive index measured optical coherence tomography,” Skin Res. Technol. 12(2), 114–118 (2006).
[CrossRef] [PubMed]

Scaramozzino, P.

M. Curatolo, A. Orlando, A. M. Zbinden, P. Scaramozzino, and F. S. Venuti, “A multifactorial analysis to explain inadequate surgical analgesia after extradural block,” Br. J. Anaesth. 75(3), 274–281 (1995).
[PubMed]

Schüpfer, G.

C. Konrad, G. Schüpfer, M. Wietlisbach, and H. Gerber, “Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures?” Anesth. Analg. 86(3), 635–639 (1998).
[CrossRef] [PubMed]

Seiler, M.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

Shields, S.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

Silbert, B. S.

J. R. Rigg, K. Jamrozik, P. S. Myles, B. S. Silbert, P. J. Peyton, R. W. Parsons, K. S. Collins, and MASTER Anaethesia Trial Study Group, “Epidural anaesthesia and analgesia and outcome of major surgery: a randomized trial,” Lancet 359(9314), 1276–1282 (2002).
[CrossRef] [PubMed]

Sprung, J.

J. Sprung, D. L. Bourke, J. Grass, J. Hammel, E. Mascha, P. Thomas, and I. Tubin, “Predicting the difficult neuraxial block: a prospective study,” Anesth. Analg. 89(2), 384–389 (1999).
[CrossRef] [PubMed]

Tarkkila, P.

B. C. Tsui, P. Tarkkila, S. Gupta, and R. Kearney, “Confirmation of caudal needle placement using nerve stimulation,” Anesthesiology 91(2), 374–378 (1999).
[CrossRef] [PubMed]

Taylor, R. C.

Teunissen, L. J.

T. J. Lechner, M. G. van Wijk, A. J. Maas, F. R. van Dorsten, R. A. Drost, C. J. Langenberg, L. J. Teunissen, P. H. Cornelissen, and J. van Niekerk, “Clinical results with the acoustic puncture assist device, a new acoustic device to identify the epidural space,” Anesth. Analg. 96(4), 1183–1187 (2003).
[CrossRef] [PubMed]

Thomas, P.

J. Sprung, D. L. Bourke, J. Grass, J. Hammel, E. Mascha, P. Thomas, and I. Tubin, “Predicting the difficult neuraxial block: a prospective study,” Anesth. Analg. 89(2), 384–389 (1999).
[CrossRef] [PubMed]

M. P. Lewis, P. Thomas, L. F. Wilson, and R. C. Mulholland, “The ‘whoosh’ test,” Anaesthesia 47(1), 57–58 (1992).
[CrossRef] [PubMed]

Ting, C. K.

C. K. Ting, M. Y. Tsou, P. T. Chen, K. Y. Chang, M. S. Mandell, K. H. Chan, and Y. Chang, “A new technique to assist epidural needle placement: fiberoptic-guided insertion using two wavelengths,” Anesthesiology 112(5), 1128–1135 (2010).
[CrossRef] [PubMed]

Tsou, M. Y.

C. K. Ting, M. Y. Tsou, P. T. Chen, K. Y. Chang, M. S. Mandell, K. H. Chan, and Y. Chang, “A new technique to assist epidural needle placement: fiberoptic-guided insertion using two wavelengths,” Anesthesiology 112(5), 1128–1135 (2010).
[CrossRef] [PubMed]

Tsui, B. C.

B. C. Tsui, C. Guenther, D. Emery, and B. Finucane, “Determining epidural catheter location using nerve stimulation with radiological confirmation,” Reg. Anesth. Pain Med. 25(3), 306–309 (2000).
[PubMed]

B. C. Tsui, P. Tarkkila, S. Gupta, and R. Kearney, “Confirmation of caudal needle placement using nerve stimulation,” Anesthesiology 91(2), 374–378 (1999).
[CrossRef] [PubMed]

Tubin, I.

J. Sprung, D. L. Bourke, J. Grass, J. Hammel, E. Mascha, P. Thomas, and I. Tubin, “Predicting the difficult neuraxial block: a prospective study,” Anesth. Analg. 89(2), 384–389 (1999).
[CrossRef] [PubMed]

Umedaly, H. S.

P. H. Lennox, H. S. Umedaly, R. P. Grant, S. A. White, B. G. Fitzmaurice, and K. G. Evans, “A pulsatile pressure waveform is a sensitive marker for confirming the location of the thoracic epidural space,” J. Cardiothorac. Vasc. Anesth. 20(5), 659–663 (2006).
[CrossRef] [PubMed]

Valentine, M. T.

Van Assendelft, O. W.

G. A. Mook, O. W. Van Assendelft, and W. G. Zijlstra, “Wavelength dependency of the spectrophotometric determination of blood oxygen saturation,” Clin. Chim. Acta 26(1), 170–173 (1969).
[CrossRef] [PubMed]

Van Dam, J.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

van Dorsten, F. R.

T. J. Lechner, M. G. van Wijk, A. J. Maas, F. R. van Dorsten, R. A. Drost, C. J. Langenberg, L. J. Teunissen, P. H. Cornelissen, and J. van Niekerk, “Clinical results with the acoustic puncture assist device, a new acoustic device to identify the epidural space,” Anesth. Analg. 96(4), 1183–1187 (2003).
[CrossRef] [PubMed]

van Niekerk, J.

T. J. Lechner, M. G. van Wijk, A. J. Maas, F. R. van Dorsten, R. A. Drost, C. J. Langenberg, L. J. Teunissen, P. H. Cornelissen, and J. van Niekerk, “Clinical results with the acoustic puncture assist device, a new acoustic device to identify the epidural space,” Anesth. Analg. 96(4), 1183–1187 (2003).
[CrossRef] [PubMed]

van Wijk, M. G.

T. J. Lechner, M. G. van Wijk, A. J. Maas, F. R. van Dorsten, R. A. Drost, C. J. Langenberg, L. J. Teunissen, P. H. Cornelissen, and J. van Niekerk, “Clinical results with the acoustic puncture assist device, a new acoustic device to identify the epidural space,” Anesth. Analg. 96(4), 1183–1187 (2003).
[CrossRef] [PubMed]

Venuti, F. S.

M. Curatolo, A. Orlando, A. M. Zbinden, P. Scaramozzino, and F. S. Venuti, “A multifactorial analysis to explain inadequate surgical analgesia after extradural block,” Br. J. Anaesth. 75(3), 274–281 (1995).
[PubMed]

Wallace, M.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

Weitz, D. A.

Welch, A. J.

W. F. Cheong, S. A. Prahl, and A. J. Welch, “A review of the optical properties of biological tissues,” IEEE J. Quantum Electron. 26(12), 2166–2185 (1990).
[CrossRef]

White, S. A.

P. H. Lennox, H. S. Umedaly, R. P. Grant, S. A. White, B. G. Fitzmaurice, and K. G. Evans, “A pulsatile pressure waveform is a sensitive marker for confirming the location of the thoracic epidural space,” J. Cardiothorac. Vasc. Anesth. 20(5), 659–663 (2006).
[CrossRef] [PubMed]

Wietlisbach, M.

C. Konrad, G. Schüpfer, M. Wietlisbach, and H. Gerber, “Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures?” Anesth. Analg. 86(3), 635–639 (1998).
[CrossRef] [PubMed]

Wilson, L. F.

M. P. Lewis, P. Thomas, L. F. Wilson, and R. C. Mulholland, “The ‘whoosh’ test,” Anaesthesia 47(1), 57–58 (1992).
[CrossRef] [PubMed]

Wu, J. C.

S. F. Chen, Y. Chang, and J. C. Wu, “The spatial distribution of macular pigment in humans,” Curr. Eye Res. 23(6), 422–434 (2001).
[CrossRef]

Xie, S.

Yorozuya, T.

T. Nagaro, T. Yorozuya, M. Kamei, N. Kii, T. Arai, and S. Abe, “Fluoroscopically guided epidural block in the thoracic and lumbar regions,” Reg. Anesth. Pain Med. 31(5), 409–416 (2006).
[PubMed]

Zbinden, A. M.

M. Curatolo, A. Orlando, A. M. Zbinden, P. Scaramozzino, and F. S. Venuti, “A multifactorial analysis to explain inadequate surgical analgesia after extradural block,” Br. J. Anaesth. 75(3), 274–281 (1995).
[PubMed]

Zdrojkowski, R.

R. L. Longini and R. Zdrojkowski, “A note on the theory of backscattering of light by living tissue,” IEEE Trans. Biomed. Eng. BME-15(1), 4–10 (1968).
[CrossRef]

Zijlstra, W. G.

G. A. Mook, O. W. Van Assendelft, and W. G. Zijlstra, “Wavelength dependency of the spectrophotometric determination of blood oxygen saturation,” Clin. Chim. Acta 26(1), 170–173 (1969).
[CrossRef] [PubMed]

Zonios, G.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

Acta Anaesthesiol. Scand.

T. Grau, R. W. Leipold, R. Conradi, and E. Martin, “Ultrasound control for presumed difficult epidural puncture,” Acta Anaesthesiol. Scand. 45(6), 766–771 (2001).
[CrossRef] [PubMed]

Am. J. Surg.

A. M. Dogliotti, “Segmental peridural spinal anesthesia: a new method of block anesthesia,” Am. J. Surg. 20, 107–118 (1993).
[CrossRef]

Anaesth. Intensive Care Med.

H. Ellis, “The anatomy of the epidural space,” Anaesth. Intensive Care Med. 7(11), 402–404 (2006).
[CrossRef]

Anaesthesia

M. P. Lewis, P. Thomas, L. F. Wilson, and R. C. Mulholland, “The ‘whoosh’ test,” Anaesthesia 47(1), 57–58 (1992).
[CrossRef] [PubMed]

Anesth. Analg.

C. Konrad, G. Schüpfer, M. Wietlisbach, and H. Gerber, “Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures?” Anesth. Analg. 86(3), 635–639 (1998).
[CrossRef] [PubMed]

J. Sprung, D. L. Bourke, J. Grass, J. Hammel, E. Mascha, P. Thomas, and I. Tubin, “Predicting the difficult neuraxial block: a prospective study,” Anesth. Analg. 89(2), 384–389 (1999).
[CrossRef] [PubMed]

T. J. Lechner, M. G. van Wijk, A. J. Maas, F. R. van Dorsten, R. A. Drost, C. J. Langenberg, L. J. Teunissen, P. H. Cornelissen, and J. van Niekerk, “Clinical results with the acoustic puncture assist device, a new acoustic device to identify the epidural space,” Anesth. Analg. 96(4), 1183–1187 (2003).
[CrossRef] [PubMed]

Anesthesiology

D. D. Hood and D. M. Dewan, “Anesthetic and obstetric outcome in morbidly obese parturients,” Anesthesiology 79(6), 1210–1218 (1993).
[CrossRef] [PubMed]

C. K. Ting, M. Y. Tsou, P. T. Chen, K. Y. Chang, M. S. Mandell, K. H. Chan, and Y. Chang, “A new technique to assist epidural needle placement: fiberoptic-guided insertion using two wavelengths,” Anesthesiology 112(5), 1128–1135 (2010).
[CrossRef] [PubMed]

B. C. Tsui, P. Tarkkila, S. Gupta, and R. Kearney, “Confirmation of caudal needle placement using nerve stimulation,” Anesthesiology 91(2), 374–378 (1999).
[CrossRef] [PubMed]

Appl. Opt.

Br. J. Anaesth.

M. K. Karmakar, X. Li, A. M. Ho, W. H. Kwok, and P. T. Chui, “Real-time ultrasound-guided paramedian epidural access: evaluation of a novel in-plane technique,” Br. J. Anaesth. 102(6), 845–854 (2009).
[CrossRef] [PubMed]

M. Curatolo, A. Orlando, A. M. Zbinden, P. Scaramozzino, and F. S. Venuti, “A multifactorial analysis to explain inadequate surgical analgesia after extradural block,” Br. J. Anaesth. 75(3), 274–281 (1995).
[PubMed]

Clin. Chim. Acta

G. A. Mook, O. W. Van Assendelft, and W. G. Zijlstra, “Wavelength dependency of the spectrophotometric determination of blood oxygen saturation,” Clin. Chim. Acta 26(1), 170–173 (1969).
[CrossRef] [PubMed]

Curr. Eye Res.

S. F. Chen, Y. Chang, and J. C. Wu, “The spatial distribution of macular pigment in humans,” Curr. Eye Res. 23(6), 422–434 (2001).
[CrossRef]

Eur. J. Anaesthesiol.

G. R. de Filho, H. P. Gomes, M. H. da Fonseca, J. C. Hoffman, S. G. Pederneiras, and J. H. Garcia, “Predictors of successful neuraxial block: a prospective study,” Eur. J. Anaesthesiol. 19(6), 447–451 (2002).
[PubMed]

IEEE J. Quantum Electron.

W. F. Cheong, S. A. Prahl, and A. J. Welch, “A review of the optical properties of biological tissues,” IEEE J. Quantum Electron. 26(12), 2166–2185 (1990).
[CrossRef]

IEEE Trans. Biomed. Eng.

R. L. Longini and R. Zdrojkowski, “A note on the theory of backscattering of light by living tissue,” IEEE Trans. Biomed. Eng. BME-15(1), 4–10 (1968).
[CrossRef]

Int. J. Obstet. Anesth.

P. H. Pan, T. D. Bogard, and M. D. Owen, “Incidence and characteristics of failures in obstetric neuraxial analgesia and anesthesia: a retrospective analysis of 19,259 deliveries,” Int. J. Obstet. Anesth. 13(4), 227–233 (2004).
[CrossRef] [PubMed]

J. Anim. Sci.

M. Irie, “Evaluation of porcine fat with fiber-optic spectroscopy,” J. Anim. Sci. 77(10), 2680–2684 (1999).
[PubMed]

J. Cardiothorac. Vasc. Anesth.

P. H. Lennox, H. S. Umedaly, R. P. Grant, S. A. White, B. G. Fitzmaurice, and K. G. Evans, “A pulsatile pressure waveform is a sensitive marker for confirming the location of the thoracic epidural space,” J. Cardiothorac. Vasc. Anesth. 20(5), 659–663 (2006).
[CrossRef] [PubMed]

Lancet

J. R. Rigg, K. Jamrozik, P. S. Myles, B. S. Silbert, P. J. Peyton, R. W. Parsons, K. S. Collins, and MASTER Anaethesia Trial Study Group, “Epidural anaesthesia and analgesia and outcome of major surgery: a randomized trial,” Lancet 359(9314), 1276–1282 (2002).
[CrossRef] [PubMed]

Phys. Rev. Lett.

L. T. Perelman, V. Backman, M. Wallace, G. Zonios, R. Manoharan, A. Nusrat, S. Shields, M. Seiler, C. Lima, T. Hamano, I. Itzkan, J. Van Dam, J. Crawford, and M. Feld, “Observation of periodic fine structure in reflectance from biological tissue: a new technique for measuring nuclear size distribution,” Phys. Rev. Lett. 80(3), 627–630 (1998).
[CrossRef]

Reg. Anesth. Pain Med.

Ghia Jn, M. Arora Sk, Castillo, and Mukherji Sk, “Confirmation of location of epidural catheters by epidural pressure waveform and computed tomography cathetergram,” Reg. Anesth. Pain Med. 26(4), 337–341 (2001).
[PubMed]

B. C. Tsui, C. Guenther, D. Emery, and B. Finucane, “Determining epidural catheter location using nerve stimulation with radiological confirmation,” Reg. Anesth. Pain Med. 25(3), 306–309 (2000).
[PubMed]

T. Nagaro, T. Yorozuya, M. Kamei, N. Kii, T. Arai, and S. Abe, “Fluoroscopically guided epidural block in the thoracic and lumbar regions,” Reg. Anesth. Pain Med. 31(5), 409–416 (2006).
[PubMed]

Skin Res. Technol.

M. Sand, T. Gambichler, G. Moussa, F. G. Bechara, D. Sand, P. Altmeyer, and K. Hoffmann, “Evaluation of the epidermal refractive index measured optical coherence tomography,” Skin Res. Technol. 12(2), 114–118 (2006).
[CrossRef] [PubMed]

Other

R. D. Miller, “Miller's Anesthesia,” 7th ed., (Churchill Livingstone, 2009).

P. R. Bromage, “Epidural Analgesia” (W. B. Saunders, 1978).

M. J. Cousins, and B. T. Veering, “Epidural neural block,” in Neural Blockade in Clinical Anesthesia and Management of Pain, 3rd ed., M. J. Cousins, P. O. Bridenbaugh, eds. (Lippincott-Raven, 1998), pp. 243–321.

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Figures (7)

Fig. 1
Fig. 1

Schematic diagram of the set up is shown for measuring the reflectance spectrum of an ex vivo tissue. Details are described in the text.

Fig. 2
Fig. 2

Reflectance spectra (500-700 nm) of in-vitro porcine tissues at back spine are displayed. They are corrected with the spectrum of the xenon lamp.

Fig. 3
Fig. 3

Schematic diagram of the system is used to locate ES in piglet in vivo.

Fig. 4
Fig. 4

(a) Incident lights from the upper (red) and lower (green) portions of the acceptance angle of the cone form traveling tracks in the fiber core. The exit directions of these lights at the bevel surface of the fiber are shown. (b) A magnified diagram of the dashed box in (a) is shown. See details in the text.

Fig. 5
Fig. 5

Responses obtained from periosteum, muscle, LF and ES. High amplitudes in each plot are responses from 650 nm and the lows are from 532 nm.

Fig. 6
Fig. 6

(a) Relative absorption spectra of HbO2 and Hb between 400 nm to 700 nm are shown. (b) Wavelengths between 500 nm to 700 nm are displayed for revealing the absorptions at 532 nm and 650 nm for HbO2 and Hb.

Fig. 7
Fig. 7

Simulations for refractive angle γ [at point B in Fig. 3(a)] with respect to the various bevel angles at the output end of an optic fiber while the tissue is under the condition of given refractive index. (a) Incident light is at the border of the acceptance angle of 16.2°, of which the refractive light travels along the red track shown in Fig. 3(a). (b) Incident light is at the center of the acceptance angle, 0.0°. (c) Incident light is at the border of the acceptance angle of 16.2°, of which the refractive light travels along the red track shown in Fig. 3(a). (d) A magnification of combined plot for the bevel angle is between 75.0° and 90.0° in plots (a), (b), and (c), which are represented by A, B, and C respectively. From which one can see different behaviors of the lights travel within the red and green tracks, or the upper and the lower portions of the incident light cone that separated by the fiber axis.

Equations (2)

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N A 0.279 = n a i r sin θ a = ( n 1 2 n 2 2 ) .
θ c = sin 1 ( n 2 n 1 ) .

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