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Camilo GB, Carvalho ARS, Machado DC, Mogami R, Kasuki L, Gadelha MR, Melo PL, Lopes AJ. Correlations between forced oscillation technique parameters and pulmonary densitovolumetry values in patients with acromegaly. ACTA ACUST UNITED AC 2015; 48:877-85. [PMID: 26445330 PMCID: PMC4617113 DOI: 10.1590/1414-431x20154786] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 04/29/2015] [Indexed: 01/17/2023]
Abstract
The aims of this study were to evaluate the forced oscillation technique (FOT) and
pulmonary densitovolumetry in acromegalic patients and to examine the correlations
between these findings. In this cross-sectional study, 29 non-smoking acromegalic
patients and 17 paired controls were subjected to the FOT and quantification of lung
volume using multidetector computed tomography (Q-MDCT). Compared with the controls,
the acromegalic patients had a higher value for resonance frequency [15.3 (10.9-19.7)
vs 11.4 (9.05-17.6) Hz, P=0.023] and a lower value for mean
reactance [0.32 (0.21-0.64) vs 0.49 (0.34-0.96) cm
H2O/L/s2, P=0.005]. In inspiratory Q-MDCT, the acromegalic
patients had higher percentages of total lung volume (TLV) for nonaerated and poorly
aerated areas [0.42% (0.30-0.51%) vs 0.25% (0.20-0.32%), P=0.039 and
3.25% (2.48-3.46%) vs 1.70% (1.45-2.15%), P=0.001, respectively].
Furthermore, the acromegalic patients had higher values for total lung mass in both
inspiratory and expiratory Q-MDCT [821 (635-923) vs 696 (599-769) g,
P=0.021 and 844 (650-945) vs 637 (536-736) g, P=0.009,
respectively]. In inspiratory Q-MDCT, TLV showed significant correlations with all
FOT parameters. The TLV of hyperaerated areas showed significant correlations with
intercept resistance (rs=−0.602, P<0.001) and mean resistance
(rs=−0.580, P<0.001). These data showed that acromegalic patients
have increased amounts of lung tissue as well as nonaerated and poorly aerated areas.
Functionally, there was a loss of homogeneity of the respiratory system. Moreover,
there were correlations between the structural and functional findings of the
respiratory system, consistent with the pathophysiology of the disease.
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Affiliation(s)
- G B Camilo
- Programa de Pós-Graduação em Ciências Médicas, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - A R S Carvalho
- Laboratório de Fisiologia da Respiração, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - D C Machado
- Programa de Pós-Graduação em Ciências Médicas, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - R Mogami
- Programa de Pós-Graduação em Ciências Médicas, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - L Kasuki
- Instituto Estadual do Cérebro Paulo Niemeyer, Rio de Janeiro, RJ, BR
| | - M R Gadelha
- Instituto Estadual do Cérebro Paulo Niemeyer, Rio de Janeiro, RJ, BR
| | - P L Melo
- Programa de Pós-Graduação em Ciências Médicas, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - A J Lopes
- Programa de Pós-Graduação em Ciências Médicas, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, BR
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Lopes AJ, Mogami R, Camilo GB, Machado DC, Melo PL, Carvalho ARS. Relationships between the pulmonary densitometry values obtained by CT and the forced oscillation technique parameters in patients with silicosis. Br J Radiol 2015; 88:20150028. [PMID: 25747897 DOI: 10.1259/bjr.20150028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To evaluate the correlations between pulmonary densitometry values and forced oscillation technique (FOT) parameters in patients with silicosis. METHODS This cross-sectional study comprised 36 non-smoker patients with silicosis and 20 matched control subjects who were submitted to FOT and multidetector CT (MDCT). RESULTS Compared with the control subjects, the MDCT evaluation demonstrated that patients with silicosis exhibited greater total lung mass. These patients also had larger non-aerated and poorly aerated compartments, which included nodules and scarring. Compared with the control subjects, FOT evaluation demonstrated that patients with silicosis exhibited changes in both reactive and resistive properties of the respiratory system. In these patients, there was a greater heterogeneity of the respiratory system and increased work of breathing. Significant correlations between non-aerated compartment size and FOT parameters that reflect the non-homogeneity of the respiratory system were observed. The dynamic compliance of the respiratory system was negatively correlated with non-aerated compartment size, while the impedance at 4 Hz was positively correlated with non-aerated compartment size. CONCLUSION Patients with silicosis have heavier lungs. In these patients, a larger non-aerated compartment is associated with a worsening of lung function. A more significant pulmonary involvement is associated with a loss of homogeneity and increased mechanical load of the respiratory system. Advances in knowledge The findings provided by both pulmonary densitometry and FOT may add valuable information to the subjective analysis of silicosis; however, more studies are necessary to evaluate the potential use of these methods for assessing disease progression.
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Affiliation(s)
- A J Lopes
- 1 Postgraduate Programme in Medical Sciences, State University of Rio de Janeiro, Rio de Janeiro, Brazil
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Melo PL, Silva MT, Martins JM, Newman DJ. Technical developments of functional electrical stimulation to correct drop foot: sensing, actuation and control strategies. Clin Biomech (Bristol, Avon) 2015; 30:101-13. [PMID: 25592486 DOI: 10.1016/j.clinbiomech.2014.11.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 11/13/2014] [Accepted: 11/13/2014] [Indexed: 02/07/2023]
Abstract
This work presents a review on the technological advancements over the last decades of functional electrical stimulation based neuroprostheses to correct drop foot. Functional electrical stimulation is a technique that has been put into practice for several years now, and has been shown to functionally restore and rehabilitate individuals with movement disorders, such as stroke, multiple sclerosis and traumatic brain injury, among others. The purpose of this technical review is to bring together information from a variety of sources and shed light on the field's most important challenges, to help in identifying new research directions. The review covers the main causes of drop foot and its associated gait implications, along with several functional electrical stimulation-based neuroprostheses used to correct it, developed within academia and currently available in the market. These systems are thoroughly analyzed and discussed with particular emphasis on actuation, sensing and control of open- and closed-loop architectures. In the last part of this work, recommendations on future research directions are suggested.
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Affiliation(s)
- P L Melo
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, Sala 1.02, 1049-001 Lisboa, Portugal; Man-Vehicle Lab, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
| | - M T Silva
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, Sala 1.02, 1049-001 Lisboa, Portugal
| | - J M Martins
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, Sala 1.02, 1049-001 Lisboa, Portugal
| | - D J Newman
- Man-Vehicle Lab, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
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Veiga J, Lopes AJ, Jansen JM, Melo PL. Fluctuation analysis of respiratory impedance waveform in asthmatic patients: effect of airway obstruction. Med Biol Eng Comput 2012; 50:1249-59. [PMID: 23011080 DOI: 10.1007/s11517-012-0957-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 09/18/2012] [Indexed: 12/21/2022]
Abstract
Fluctuation analysis has great potential to contribute to pulmonary clinical science and practice. We evaluated the relationship between asthma and the respiratory impedance recurrence period density entropy (RPDEnZrs) and the variability (SDZrs). A non-invasive and simple protocol for assessing respiratory mechanics during spontaneous breathing was used in a group of 74 subjects with various levels of airway obstruction. Airway obstruction resulted in a reduction in the RPDEnZrs that was significantly correlated with both spirometric indices of airway obstruction (R = 0.48, p < 0.0001) and mean respiratory impedance (R = -0.83, p < 0.0001). These results suggest that the impedance pattern becomes less complex in asthmatic patients, which may explain the reduction in respiratory systems' adaptability to daily life activities. Preliminary evaluations indicate that RPDEnZrs may contribute to the asthma diagnosis, presenting accuracies of 82 and 87 % in patients with moderate and severe airway obstruction, respectively. On the other hand, SDZrs increased with obstruction (p < 0.0001) and was inversely correlated with spirometric indices of obstruction (R = -0.42, p = 0.0003) and directly associated with mean impedance (R = 0.88, p < 0.0001). This analysis contributes to elucidate previous studies and identified respiratory changes in patients with moderate and severe obstruction with an adequate accuracy (85 and 87 %, respectively).
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Affiliation(s)
- J Veiga
- Biomedical Instrumentation Laboratory, Institute of Biology and Faculty of Engineering, State University of Rio de Janeiro, Rio de Janeiro, Brazil
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Alves CE, Nunes LQ, Melo PL. Mechanical analysis of an oscillatory positive expiratory pressure device used in respiratory rehabilitation. Annu Int Conf IEEE Eng Med Biol Soc 2011; 2010:2477-80. [PMID: 21096164 DOI: 10.1109/iembs.2010.5626560] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This article aims to characterize the mechanical behavior of the Acapella Blue, a respiratory rehabilitation device designed to aid sputum clearance. In this scope, the present study initially describes in detail the peak-to-peak oscillation amplitude (App) and peak frequency (fp) behavior, as well as positive pressure level (Ppl), in the flow range more comonly found in practice. The parameters were evaluated in all 5 adjustment levels of the equipment in intervals of 50 mL/s. The device characterization has shown fp up to 23 Hz, App from 0.2 to 2.8 cmH(2)O and Ppl ranging from 1.2 to 13.5 cmH(2)O. The studied device may produce oscillation in the ranges of ciliary movements and respiratory system resonance frequency of patients with respiratory diseases. Data obtained in this work may help to optimize the use of the Acapella Blue device in respiratory rehabilitation. Suggestions for the practical use of the device are also presented.
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Affiliation(s)
- C E Alves
- Biomedical Instrumentation Laboratory, State University of Rio de Janeiro, Brazil.
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Sa PM, Faria AD, Ferreira AS, Lopes AJ, Jansen JM, Melo PL. Validation of the Forced Oscillation Technique in the diagnostic of respiratory changes in patients with silicosis. Annu Int Conf IEEE Eng Med Biol Soc 2011; 2010:398-401. [PMID: 21096531 DOI: 10.1109/iembs.2010.5627284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Silicosis is a typical occupational respiratory disease characterized by irreversible alterations throughout the alveolar and interstitial structure. The objectives of this study were (1) investigate the potential of the Forced Oscillation Technique (FOT) in the analysis of the patients with silicosis, and (2) evaluate the ability of FOT to identify early alterations in the respiratory mechanics of these patients. Sixty-one volunteers were analyzed: 20 healthy subjects and 41 with silicosis; these, were divided into 4 groups according to spirometric results: normal spirometric exam (n = 11); mild obstruction (n = 20); moderate and severe obstruction (n = 10.). A significant (p〈0.0001) increase in total resistance (R0) and mean resistance (Rm) were observed, as well as a decrease in the dynamic compliance (p〈0.0003) and mean reactance (p〈0.000004). R0 and Rm obtained adequate accuracy for clinical use (>80%). FOT parameters adequately described the pathophysiological changes associated with silicosis and presented adequate accuracy for clinical use, indicating that this technique can be helpful in the evaluation respiratory mechanics in this disease.
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Affiliation(s)
- P M Sa
- Biomedical Instrumentation Laboratory, Institute of Biology, Faculty of Engineering, State University of Rio de Janeiro, Brazil.
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Faria AD, Lopes AJ, Jansen JM, Pinheiro GC, Melo PL. Diagnostic performance of the Forced Oscillation Technique in the detection of early respiratory changes in rheumatoid arthritis. Annu Int Conf IEEE Eng Med Biol Soc 2010; 2010:6034-6037. [PMID: 21097117 DOI: 10.1109/iembs.2010.5627605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The objective of this study was to evaluate the clinical potential of the Forced Oscillation Technique (FOT) in the detection of the early alterations in respiratory mechanics of Rheumatoid Arthritis (RA) patients. A total of 36 individuals were analyzed, 18 healthy and 18 with RA. The clinical usefulness of the parameters was evaluated investigating sensibility (Se), specificity (Sp) and the area under the receiver operating characteristic curve (AUC). In the RA group, all the 3 studied parameters obtained high accuracy for clinical use (AUC>0.9), while in spirometric parameters, no parameter obtained appropriate accuracy for clinical use (AUC < 0.7). In conclusion, the parameters obtained by FOT presented adequate Se and Sp, indicating that this technique can be helpful in the evaluation of the early respiratory mechanical alterations in patients with RA.
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Affiliation(s)
- A D Faria
- Biomedical Instrumentation Laboratory, Institute of Biology Roberto Alcantara Gomes and Electrical Engineering Faculty, State University of Rio de Janeiro, Brazil.
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Lemes LNA, Melo PL. Simplified oscillation method for assessing nasal obstruction non-invasively and under spontaneous ventilation: a pilot study. Med Biol Eng Comput 2003; 41:439-44. [PMID: 12892367 DOI: 10.1007/bf02348087] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The clinical application of the current methods of measuring nasal obstruction has been limited by complicated, invasive and stressful procedures that require the full co-operation of the patient. A pilot study is described where a simple way of evaluating nasal obstruction, based on oscillation methods, was investigated. The technique did not disturb spontaneous breathing and required little co-operation and comprehension. Significant differences were obtained when clinically classified normal (5.2 +/- 1.8 cmH2O l(-1) s) and patient (10.6 +/- 5.9 cmH2O l(-1) s) groups were evaluated (p<0.01). A significant reduction (p<0.02) was also observed in impedance results before (8.5 +/- 1.1 cmH2O l(-1) s) and after (5.2 +/- 1.7 cmH2O l(-1) s) clinically successful nasal surgery, closely reflecting the clinical conditions of the subjects. This simple forced oscillation technique showed good potential for future clinical applications in the pre-screening of nasal patients and the evaluation of therapeutic surgery.
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Affiliation(s)
- L N A Lemes
- Biomedical Instrumentation Laboratory, Institute of Biology, Faculty of Engineering, State University of Rio de Janeiro, Brazil
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