Dashed black line shows the original error. The errors are computed for the best wavelength pairs with equal energy at different depths see Supplement 1 , Tables S1-S6. In addition to optical properties, variations in the region of interest or geometry can change our current results: i if a region of interest with a different size, shape or at a different location is chosen, for which our methodology will be performed and new results will be obtained; ii if a subject with a different head geometry than our head phantom is utilized.
In clinical applications, where imaging a region is important instead of imaging a structure at a specific depth, a superposed image of several wavelength pairs will be used. We plan to investigate this in detail in a future study.
Our presented concept and methodology can certainly be extended to adult human brain where we expect being able to measure the hypoxia at much less depths.
Cerebral hypoxia is a severe injury that increases the risk of development of neurological disorders in the neonatal period. With spectroscopic photoacoustic imaging, using at least two wavelengths, one can measure sO 2 and use it for the evaluation of hypoxia. Due to the spectral coloring effect, choosing the right wavelength-pair for most accurate sO 2 measurement is essential.
Using a realistic neonate head model and Monte Carlo simulations, we studied the error in sO 2 measurement due to the spectral coloring and identified optimum wavelength-pairs at different depths from the cortex down to the lateral ventricle these optimum wavelength-pairs are reported in Table 3 as well as Supplement 1 , Tables S1 to S6. We also demonstrated, for the first time, that the accuracy of sO 2 measurements can be improved by adjusting the level of light energy for each wavelength-pair, with which a greater number of wavelength-pairs become available.
Although PA spectroscopy using more wavelengths improves the accuracy of oxygenation measurement, implementation of near real-time multi-wavelength spectroscopy, using the current high energy pulsed lasers, required to study changes in hemodynamic parameters is not easily feasible. Considering the growing interest in photoacoustic brain imaging, this work could assist in a more efficient and accurate use of photoacoustic spectroscopy and help in the clinical translation of this promising imaging modality.
We would like to thank Robert J. Cooper from University College London for providing neonatal head model. Data underlying the results presented in this paper are not publicly available at this time but may be obtained from the authors upon reasonable request. See Supplement 1 for supporting content. Howlett, F. Northington, M. Gilmore, A. Tekes, T. Huisman, C. Parkinson, S. Chung, J. Jennings, J. Jamrogowicz, and A.
Bickler, J. Feiner, M. Rollins, and L. Shankaran, A. Laptook, R. Ehrenkranz, J. Tyson, S. McDonald, E. Donovan, A. Fanaroff, W. Poole, L. Wright, and R. Natarajan, A. Pappas, and S. Batista, H. Chugani, C. Behen, and S. Kratkiewicz, R. Manwar, A. Rajabi-Estarabadi, J. Fakhoury, J. Meiliute, S. Daveluy, D. Mehregan, and K.
Manwar, Y. Zhou, M. Mozaffarzadeh, and K. Express 12 2 , — Matchynski, R. Manwar, K. Madangopal, V. Lennon, K. Makki, A. Reppen, A. Woznicki, B. Hope, and S. Nasiriavanaki, J. Xia, H. Wan, A. Bauer, J. Culver, and L. Glass, K. Nash, S. Bonifacio, A. Barkovich, D. Ferriero, J. Sullivan, and M. Lingwood, K. Dunster, G. Healy, L. Ward, and P. Durduran, R. Choe, W. Baker, and A. Eggebrecht, S. Ferradal, A. Robichaux-Viehoever, M. Hassanpour, H. Dehghani, A.
Snyder, T. Hershey, and J. Photonics 8 6 , — Gibson, T. Austin, N. Everdell, M. Schweiger, S. Arridge, J. Meek, J. Wyatt, D. Delpy, and J. Kleinschmidt, H. Obrig, M. Requardt, K. Merboldt, U. Dirnagl, A. Villringer, and J. Blood Flow Metab. Cash, C. Li, J. Xia, L.
Wang, and H. Wang, Y. Wu, and J. Wang and J. Methods 13 8 , — Na and L. Express 12 7 , — Na, J. Russin, L. Lin, X. Yuan, P. Hu, K. Jann, L. Yan, K. Maslov, J. Shi, and D. Chen, J. Yang, D. Wu, D. Zeng, Y. Yi, N. Yang, and H. Express 6 9 , — Jeon, J. Kim, and C. Ning, N. Sun, R. Cao, R. Chen, K. Shung, J. Hossack, J. Lee, Q. Zhou, and S. Sivasubramanian, V. Periyasamy, and M. Biophotonics 11 1 , e Wood, K. Harutyunyan, J. De La Cerda, C. Kaffes, N.
Millward, S. Shanmugavelandy, M. Konopleva, and R. Xu, L. Johnson, J. Hu, J. Dillman, P. Higgins, and X. Liao, M. Li, H. Lai, Y. Shih, Y. Lo, S. Tsang, P. Chao, C. Lin, F. Jaw, and Y. Petri, I. Stoffels, J. Jose, J. Leyh, A. Schulz, J. Dissemond, D. Schadendorf, and J.
Reber, M. Karlas, K. Paul-Yuan, G. Diot, D. Franz, T. Fromme, S. Ovsepian, N. Toi, Y. Asao, Y. Matsumoto, H. Sekiguchi, A.
Yoshikawa, M. Takada, M. Kataoka, T. Endo, N. Kawaguchi-Sakita, and M. Weber, P. Beard, and S. Methods 13 , Chang, 3rd W. Goodson, F. Gottrup, and T. Zaleski, and A. Hopf, T. Hunt, J. West, P. Blomquist, W. Goodson, J. Jensen, K. Jonsson, P. Paty, J. Rabkin, and R. Vikram, J. Zweier, and P. Redox Signaling 9 10 , — Yao, L. Wang, J. Yang, K. Maslov, T. Wong, L. Li, C. Huang, J. Zou, and L. Methods 12 , Hariri, J. Kim, A. Jhunjhunwala, D. Chao, and J. Mohammadi-Nejad, M.
Mahmoudzadeh, M. Hassanpour, F. Wallois, O. Muzik, C. Papadelis, A. Hansen, H. Soltanian-Zadeh, J. Gelovani, and M. Laufer, D. Delpy, C. Elwell, and P. Cox, J. Laufer, P. Maslov, H. Zhang, and L. Hochuli, L. An, P. Beard, and B. Naser, D. Sampaio, N. Wood, T. Mitcham, W. Stefan, K. Sokolov, T. Pavan, R.
Avritscher, and R. Imaging 38 2 , — Vogt, X. Zhou, R. Andriani, K. Wear, T. Pfefer, and B. Express 10 2 , — Hussain, W. Petersen, J. Staley, E. Hondebrink, and W. Kirchner, T. Adler, and L. Cai, K. Deng, C. Ma, and J. Tzoumas, A. Nunes, I. Olefir, S. Stangl, P. Symvoulidis, S. Glasl, C. Bayer, G. Multhoff, and V. Yuan and H. Sivaramakrishnan, K. Zhang, G. Stoica, and L. Xiao, Z. Yuan, J.
He, and H. X-Ray Sci. Brigadoi, P. Although myocardial ischemia occurred less frequently in the oximetry than the control group, the numbers of post-operative complications and hospital deaths were similar in the two groups [ 43 ].
In a more recent randomized study in 1, post-operative patients, Ochroch and colleagues [ 52 ] assessed the impact of pulse oximetry on the rate of transfer to the ICU from a post-surgical care floor. The percentages of patients transferred to the ICU were similar in the oximeter group and the control group 6. A lower rate of ICU transfers for pulmonary complications was noted in the oximeter group. The authors speculate that reduction in pulmonary transfers to the ICU may be due to the earlier recognition and treatment of post-operative pulmonary complications.
The lack of demonstrable benefit of pulse oximetry on outcome in clinical trials may be due to the signal-to-noise ratio [ 41 , 53 ].
Because the outcome under evaluation readmission to the ICU, myocardial infarction, or death is rare, a huge number of patients are needed to show a reduction in these events [ 41 ]. To demonstrate a reduction in complications in the study by Moller and colleagues, for example, a fold increase in enrollment would have been required [ 41 , 53 ].
The fact that randomized trials failed to demonstrate that routine monitoring with pulse oximetry improved patient outcome has not stopped anesthesiologists from using pulse oximeters [ 53 , 54 ].
They believed that maintaining oxygenation within the physiologic limits with the help of pulse oximetry might help avert irreversible injury. It is this perspective that has made pulse oximetry a crucial part of standard of care despite the absence of proven efficacy [ 41 ]. Pulse oximetry is universally used for monitoring respiratory status of patients in the ICU. Recent advances in signal analysis and reflectance technology have improved the performance of pulse oximeters under conditions of motion artifact and low perfusion.
Multiwavelength oximeters may prove to be useful in detecting dyshemoglobinemia. Monitoring with pulse oximetry continues to be a critical component of standard of care of critically ill patients despite the paucity of data that such devices improve outcome.
Jubran A. Pulse oximetry. Crit Care. Pulse oximetry: analysis of theory, technology, and practice. J Clin Monit. Accuracy of pulse oximeters: the European multi-center trial. Anesth Analg. PubMed Google Scholar. Potential errors in pulse oximetry, II. Effects of changes in saturation and signal quality. Accuracy of pulse oximetry in the intensive care unit. Intensive Care Med. Jubran A, Tobin MJ. Reliability of pulse oximetry in titrating supplemental oxygen therapy in ventilator-dependent patients.
Pulse oximeters. Health Devices. Do changes in pulse oximeter oxygen saturation predict equivalent changes in arterial oxygen saturation? Pulse oximeter probes. A comparison between finger, nose, ear and forehead probes under conditions of poor perfusion. Forehead oximetry in critically ill patients: the case for a new monitoring site. Respir Care Clin N Am. Evaluation of a new pulse oximeter sensor. Am J Crit Care. Heart Lung. Comparison of forehead Max-Fast pulse oximetry sensor with finger sensor at high positive end-expiratory pressure in adult patients with acute respiratory distress syndrome.
Anaesth Intensive Care. Response time of pulse oximeters assessed using acute decompression. In: Tobin MJ, editor. Principles and Practice of Intensive Care Monitoring. Google Scholar. Comparison of desaturation and resaturation response times between transmission and reflectance pulse oximeters.
Acta Anaesthesiol Scand. The desaturation response time of finger pulse oximeters during mild hypothermia. Potential errors in pulse oximetry, I. Pulse oximeter evaluation. The pulse oximetry gap in carbon monoxide intoxication. Ann Emerg Med. Measurement of carboxyhemoglobin and methemoglobin by pulse oximetry: a human volunteer study. Accuracy of carboxyhemoglobin detection by pulse CO-oximetry during hypoxemia.
Emergency department management of suspected carbon monoxide poisoning: role of pulse CO-oximetry. Respir Care. Performance of the RAD pulse CO-oximeter compared with standard laboratory carboxyhemoglobin measurement. Noninvasive measurement of carboxyhemoglobin: how accurate is accurate enough? Evaluation of pulse oximetry in sickle cell anemia patients presenting to the emergency department in acute vasoocclusive crisis. Am J Emerg Med. Does ambient light affect the accuracy of pulse oximetry?
The effect of nail polish on pulse oximetry. Effect of nail polish on oxygen saturation determined by pulse oximetry in critically ill patients. Predictors of pulse oximetry data failure. Randomized evaluation of pulse oximetry in 20, patients: I. Design, demography, pulse oximetry failure rate, and overall complication rate. The Australian Incident Monitoring Study. The pulse oximeter: applications and limitations - an analysis of incident reports.
Influence of pulse oximeter lower alarm limit on the incidence of hypoxaemia in the recovery room. Br J Anaesth. Barker SJ. The effect of motion on pulse oximetry and its clinical significance. Next-generation pulse oximetry. The effects of motion on the performance of pulse oximeters in volunteers revised publication. Clinical evaluation of a prototype motion artifact resistant pulse oximeter in the recovery room. Pollard V, Prough DS.
Signal extraction technology: a better mousetrap? Knowledge of pulse oximetry among critical care nurses. Dimens Crit Care Nurs. Monitoring during mechanical ventilation. Principles and Practice of Mechanical Ventilation. Clinical use of pulse oximetry: official guidelines from the Thoracic Society of Australia and New Zealand.
Randomized evaluation of pulse oximetry in 20, patients: II. Perioperative events and postoperative complications. The incidence of hypoxemia during surgery: evidence from two institutions. Can J Anaesth. Hypoxemia during surgery: learning from history, science, and current practice. Postoperative hypoxemia: common, undetected, and unsuspected after bariatric surgery. J Surg Res. Pulse oximetry saturation to fraction inspired oxygen ratio as a measure of hypoxia under general anesthesia and the influence of positive end-expiratory pressure.
J Crit Care. Crit Care Med. Use of a pulse oximeter in an adult emergency department: impact on the number of arterial blood gas analyses ordered. Effect of pulse oximetry on clinical practice in the intensive care unit. The impact of continuous pulse oximetry monitoring on intensive care unit admissions from a postsurgical care floor. Shah A, Shelley KH.
Is pulse oximetry an essential tool or just another distraction?
0コメント