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Abstract
Any internalized flow exhibits closely coupled interactions with its confining geometry. Efforts to gain an understanding of in vivo airway transport phenomena, therefore, dictate that careful attention to be paid to those anatomic airway features that constrain and modify regional air movement. We present a series of analyses of human small airway casts to refine and extend the current geometric description of small airway bifurcations. Airway shape factors believed to have a high propensity to alter the fluid dynamics of airflows within this region are specifically addressed. The results of these anatomic and fluidic analyses are used to develop two average symmetrical and asymmetrical bifurcation patterns. Finally, methods for the production of physical bifurcation models conforming to these requirements are presented to develop a rational representation of anatomic as well as flow similitude during airway research.
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52
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Olson DE. Case report. Class III malocclusion. JOURNAL (AMERICAN ACADEMY OF GNATHOLOGIC ORTHOPEDICS) 1991; 8:6-8. [PMID: 1938594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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53
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Olson DE. Case report. Myofacial pain. JOURNAL (AMERICAN ACADEMY OF GNATHOLOGIC ORTHOPEDICS) 1991; 8:10-2. [PMID: 1938592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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54
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Beachey WD, Olson DE. Quantifying ventilatory reserve to predict respiratory failure in exacerbations of COPD. Chest 1990; 97:1086-91. [PMID: 2331901 DOI: 10.1378/chest.97.5.1086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We developed a concept of VR in patients with acute exacerbation of advanced COPD and tested the hypothesis that it is predictable and clinically useful in the ER. Our concept of VR was based on the idea that a threshold VF and a MSV capacity are measurable; ie, VR = MSV - VF. We measured resting minute ventilation, the 15-s MVV, FEV1 and ABG values in 13 patients with exacerbation of COPD in the ER and 11 stable subjects with similar degrees of COPD. We tested if measures of VR could distinguish between ER patients progressing to respiratory failure, ER patients who avoided progression to respiratory failure and stable patients. There were significant differences in measures of the mean VR between various groups of patients. We conclude that in this COPD population, VR can be accurately predicted in the ER and that it may be a clinically valid predictor of patient outcomes.
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55
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Snyder B, Olson DE, Hammersley JR, Peterson CV, Jaeger MJ. Reversible and irreversible components of central-airway flow resistance. J Biomech Eng 1987; 109:154-9. [PMID: 3599941 DOI: 10.1115/1.3138658] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The flow energy loss (head loss) through a cast of canine central airways is found to be nearly independent of flow direction. By contrast, head loss in geometrically-simpler branching sections at comparable flow conditions is highly irreversible, with inspiratory loss being greater by nearly two units of dynamic pressure (2 X 1/2 rho V2). In these branching sections head loss appears to be independent of important geometric parameters such as the branch length/diameter ratio and the exit/inlet flow-area ratio. An analysis of these observations suggests that kinetic energy factors, not shear stresses, account for most of the energy dissipated in central airways and in simple bifurcating sections. Inspiratory loss in bifurcations is greatly increased by the onset of flow separation: irreversibility is minimal in central airways, where separation either is absent or else is much less pronounced.
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56
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De Tullio PL, Kirking DM, Arslanian C, Olson DE. Compliance measure development and assessment of theophylline therapy in ambulatory patients. J Clin Pharm Ther 1987; 12:19-26. [PMID: 3449560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The objectives of this study were: (a) to develop a drug serum level-based compliance measure which incorporated pharmacokinetic analysis of patient and drug parameters and to compare it to refill records, an indirect measure, and (b) to use that measure to determine whether pharmacist consultation increased compliance. Sixty adult, male chronic obstructive pulmonary disease out-patients who received theophylline were randomly assigned to one of two groups with counselling provided to experimental-group patients only. Compliance was measured by the ratio of actual serum theophylline level to that predicted by pharmacokinetic estimation and by the number of refills in 155 days. More experimental-group patients had actual levels within both +/- 10% and +/- 20% of predicted levels (P = 0.0006 and 0.04). They also obtained more refills than control patients (P = 0.05). The pharmacokinetically based serum level measure appeared to be the more useful measure for identifying non-compliance, which suggests that it is of greater value than existing measures. In addition, the results suggest that comprehensive consultation by a clinical pharmacists can improve compliance with theophylline therapy in the out-patient setting.
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57
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Olson DE, White LJ. Technology assessment--the role of the American College of Physicians. TRANSACTIONS OF THE AMERICAN CLINICAL AND CLIMATOLOGICAL ASSOCIATION 1985; 96:194-200. [PMID: 6537678 PMCID: PMC2279645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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58
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Olson DE, Parker KH, Snyder B. A pulsed wire probe for the measurement of velocity and flow direction in slowly moving air. J Biomech Eng 1984; 106:72-8. [PMID: 6727317 DOI: 10.1115/1.3138460] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
This report describes the theory and operation of a pulsed-probe anemometer designed to measure steady three-dimensional velocity fields typical of pulmonary tracheo-bronchial airflows. Local velocities are determined by measuring the transport time and orientation of a thermal pulse initiated at an upstream wire and sensed at a downstream wire. The transport time is a reproducible function of velocity and the probe wire spacing, as verified by a theoretical model of convective heat transfer. When calibrated the anemometer yields measurements of velocity accurate to +/- 5 percent and resolves flow direction to within 1 deg at airspeeds greater than or equal to 10 cm/s. Spatial resolution is +/- 0.5 mm. Measured flow patterns typical of curved circular pipes are included as examples of its application.
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59
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Stauffer JL, Olson DE, Petty TL. Complications and consequences of endotracheal intubation and tracheotomy. A prospective study of 150 critically ill adult patients. Am J Med 1981; 70:65-76. [PMID: 7457492 DOI: 10.1016/0002-9343(81)90413-7] [Citation(s) in RCA: 725] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A prospective study of the complications and consequences of translaryngeal endotracheal intubation and tracheotomy was conducted on 150 critically ill adult patients. Adverse consequences occurred in 62 percent of all endotracheal intubations and in 66 percent of all tracheotomies during placement and use of the artificial airways. The most frequent problems during endotracheal intubation were excessive cuff pressure requirements (19 percent), self-extubation (13 percent) and inability to seal the airway (11 percent). Patient discomfort and difficulty in suctioning tracheobronchial secretions were very uncommon. Problems with tracheotomy included stomal infection (36 percent), stomal hemorrhage (36 percent), excessive cuff pressure requirements (23 percent) and subcutaneous emphysema or pneumomediastinum (13 percent). Complications of tracheotomy were judged to be more severe than those of endotracheal intubation. Follow-up studies of survivors revealed a high prevalence of tracheal stenosis after tracheotomy (65 percent) and significantly less after endotracheal intubation (19 percent)(p < 0.01). Thirty-nine of 41 (95 percent) patients with endotracheal intubation and 20 of 22 (91 percent) patients with tracheotomy had laryngotracheal injury at autopsy. Ulcers on the posterior aspect of the true vocal cords were found at autopsy in 51 percent of the patients who died after endotracheal intubation. There was no significant relationship between the duration of endotracheal intubation or tracheotomy and the over-all amount of laryngotracheal injury at autopsy, although patients with prolonged endotracheal intubation followed by tracheotomy had more laryngeal injury at autopsy (P = 0.06) and more frequent tracheal stenosis (P = 0.05) than patients with short-term endotracheal intubation followed by tracheotomy. Adverse effects of both endotracheal intubation and tracheotomy are common. The value of tracheotomy when an artificial airway is required for periods as long as three weeks is not supported by data obtained in this study.
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60
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Jackson AC, Olson DE. Comparison of direct and acoustical area measurements in physical models of human central airways. JOURNAL OF APPLIED PHYSIOLOGY: RESPIRATORY, ENVIRONMENTAL AND EXERCISE PHYSIOLOGY 1980; 48:896-902. [PMID: 7451301 DOI: 10.1152/jappl.1980.48.5.896] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Total cross-sectional areas were computed from direct measurements made on two human central airway casts. Acoustic pulse-response measurements were obtained on rigid-walled positive replicas of these casts. From the acoustic response data of each cast, we computed the area-distance function of the acoustically equivalent structure (i.e., the structure with regular branching and negligible viscous losses, but with similar acoustic properties). The acoustic data predicted equivalent areas that compared favorably to the total cross-sectional areas in the casts at all points from the beginning of the trachea to distances about 6 cm beyond the carina corresponding to airways of the third, fourth, or fifth generation. These results indicate that, at least in the central airways, branching asymmetry and internal energy losses introduced negligible errors in estimates of cross-sectional areas derived from acoustic pulse-response measurements. This rapid noninvasive technique thus shows promise as a method of detecting upper and central airway obstruction.
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61
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Pardee NE, Winterbauer RH, Morgan EH, Allen JD, Olson DE. Combinations of four physical signs as indicators of ventilatory abnormality in obstructive pulmonary syndromes. Chest 1980; 77:354-8. [PMID: 7357938 DOI: 10.1378/chest.77.3.354] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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62
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63
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Olson DE, Sudlow MF, Horsfield K, Filley GF. Convective patterns of flow during inspiration. ARCHIVES OF INTERNAL MEDICINE 1973; 131:51-7. [PMID: 4682063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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64
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Iliff LD, Olson DE, Sudlow MF. The organization of air flow in a cast replica of the human central airways. J Physiol 1972; 223:17P-18P. [PMID: 5046144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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65
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Olson DE, Iliff LD, Sudlow MF. [Some aspects of the physics of flow in the central airways]. BULLETIN DE PHYSIO-PATHOLOGIE RESPIRATOIRE 1972; 8:391-408. [PMID: 4638840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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66
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Horsfield K, Dart G, Olson DE, Filley GF, Cumming G. Models of the human bronchial tree. J Appl Physiol (1985) 1971; 31:207-17. [PMID: 5558242 DOI: 10.1152/jappl.1971.31.2.207] [Citation(s) in RCA: 336] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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67
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68
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Olson DE, Dart GA, Filley GF. Pressure drop and fluid flow regime of air inspired into the human lung. J Appl Physiol (1985) 1970; 28:482-94. [PMID: 5437439 DOI: 10.1152/jappl.1970.28.4.482] [Citation(s) in RCA: 81] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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69
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Keenan TW, Morré DJ, Olson DE, Yunghans WN, Patton S. Biochemical and morphological comparison of plasma membrane and milk fat globule membrane from bovine mammary gland. J Biophys Biochem Cytol 1970; 44:80-93. [PMID: 5409465 PMCID: PMC2107778 DOI: 10.1083/jcb.44.1.80] [Citation(s) in RCA: 183] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Purified plasma membrane fractions from lactating bovine mammary glands and membranes of milk fat globules from the same source were similar in distribution and fatty acid composition of phospholipids. The sphingomyelin content of the phospholipid fraction of both membranes was higher than in these fractions from other cell components, beta-carotene, a constituent characteristic of milk fat, was present in the lipid fraction of the plasma membrane. Cholesterol esters of plasma membrane were similar in fatty acid composition to those of milk fat globule membranes. Disc electrophoresis of either membrane preparation on polyacrylamide gels revealed a single major protein component characteristic of plasma membrane from other sources. Distinct morphological differences between plasma membrane and milk fat globule membranes were observed in both thin sections and in negatively stained material. Plasma membrane was vesicular in appearance while milk fat globule membranes had a platelike aspect. These observations are consistent with derivation of fat globule membrane from plasma membrane accompanied by structural rearrangement of membrane constituents.
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70
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Shair FH, Wagner WW, Olson DE. Pulmonary gas transplant time. Science 1969; 165:823-4. [PMID: 5796561 DOI: 10.1126/science.165.3895.823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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71
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Filley GF, Bigelow DB, Olson DE, Lacquet LM. Pulmonary gas transport. A mathematical model of the lung. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1968; 98:480-489. [PMID: 5673101 DOI: 10.1164/arrd.1968.98.3.480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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