1
|
Qian Y, Shuai Y, Wu C, Luo W, Pan X, Zhang W. Designed Structures of Interdigital Electrodes for Thin Film SAW Devices. Micromachines (Basel) 2023; 14:1929. [PMID: 37893366 PMCID: PMC10609187 DOI: 10.3390/mi14101929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 10/07/2023] [Accepted: 10/12/2023] [Indexed: 10/29/2023]
Abstract
This paper studied the impact of the microstructure of interdigital electrodes on the performance of surface acoustic wave (SAW) resonators and proposed an innovative piston, dummy finger and tilt (PDT) structure, which was then applied to the GLONASS L3 band filters. Through the adoption of 3D finite element simulation (FEM), photolithography, and testing on an incredible high-performance surface acoustic wave (I.H.P. SAW) substrate, it is concluded that the total aperture length is 20T (T is period), resulting in a more optimal resonator performance; changing the width and length of the piston can suppress transverse modes spurious, but it does not enhance impedance ratio; to further improve the quality of the SAW resonator, the proposed PDT structure has been experimentally proven to not only effectively suppress transverse modes spurious but also possess a high impedance ratio. By utilizing a PDT structure within a "T + π" topology circuit, we successfully designed and manufactured a GLONASS L3 band filter with a bandwidth of 8 MHz and an insertion loss of 3.73 dB. The design of these resonators and filters can be applied to the construction of SAW filters in similar frequency bands such as BeiDou B2 band or GPS L2/L5 band.
Collapse
Affiliation(s)
- Yicong Qian
- Chongqing Institute of Microelectronics Industry Technology, University of Electronic Science and Technology of China, Chongqing 401332, China; (Y.Q.); (C.W.); (W.L.); (X.P.); (W.Z.)
| | - Yao Shuai
- Chongqing Institute of Microelectronics Industry Technology, University of Electronic Science and Technology of China, Chongqing 401332, China; (Y.Q.); (C.W.); (W.L.); (X.P.); (W.Z.)
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Chuangui Wu
- Chongqing Institute of Microelectronics Industry Technology, University of Electronic Science and Technology of China, Chongqing 401332, China; (Y.Q.); (C.W.); (W.L.); (X.P.); (W.Z.)
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Wenbo Luo
- Chongqing Institute of Microelectronics Industry Technology, University of Electronic Science and Technology of China, Chongqing 401332, China; (Y.Q.); (C.W.); (W.L.); (X.P.); (W.Z.)
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Xinqiang Pan
- Chongqing Institute of Microelectronics Industry Technology, University of Electronic Science and Technology of China, Chongqing 401332, China; (Y.Q.); (C.W.); (W.L.); (X.P.); (W.Z.)
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Wanli Zhang
- Chongqing Institute of Microelectronics Industry Technology, University of Electronic Science and Technology of China, Chongqing 401332, China; (Y.Q.); (C.W.); (W.L.); (X.P.); (W.Z.)
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China
| |
Collapse
|
2
|
Guiman MV, Stanciu MD, Roșca IC, Georgescu SV, Năstac SM, Câmpean M. Influence of the Grain Orientation of Wood upon Its Sound Absorption Properties. Materials (Basel) 2023; 16:5998. [PMID: 37687689 PMCID: PMC10488750 DOI: 10.3390/ma16175998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/24/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023]
Abstract
The purpose of the study was to analyze the influence of the quality class and the orthotropy of wood upon the sound absorption coefficient, the reflection and the impedance ratio of two species widely used for stringed musical instruments, namely spruce (Picea abies L. Karst) and maple (Acer pseudoplatanus L.). An impedance tube for the frequency range 100-6400 Hz was used in these experimental determinations. Knowing the influence of porosity and tortuosity on the acoustic absorption, these properties were also determined, as well as the sound reduction coefficient and the maximum values of the acoustic absorption coefficients in relation to frequency. The main results highlighted the differences between the anatomical quality class of the wood within each species, but also concerning the sound direction relative to the three main sections of wood, as an orthotropic material. The article highlights the acoustic performance parameters related to the frequency of the wooden material and its relationship to density, porosity and quality class. The results represent useful information for musical instruments manufacturers and more.
Collapse
Affiliation(s)
- Maria Violeta Guiman
- Department of Mechanical Engineering, Transilvania University of Brașov, 500036 Brașov, Romania;
| | - Mariana Domnica Stanciu
- Department of Mechanical Engineering, Transilvania University of Brașov, 500036 Brașov, Romania;
| | - Ioan Călin Roșca
- Department of Mechanical Engineering, Transilvania University of Brașov, 500036 Brașov, Romania;
| | - Sergiu Valeriu Georgescu
- Faculty of Furniture Design and Wood Engineering, Transilvania University of Brasov, 500036 Brașov, Romania; (S.V.G.); (M.C.)
| | - Silviu Marian Năstac
- Department of Mechanical Engineering, Transilvania University of Brașov, 500036 Brașov, Romania;
- Faculty of Engineering and Agronomy, Braila, “Dunarea de Jos” University of Galati, 800008 Galati, Romania
| | - Mihaela Câmpean
- Faculty of Furniture Design and Wood Engineering, Transilvania University of Brasov, 500036 Brașov, Romania; (S.V.G.); (M.C.)
| |
Collapse
|
3
|
Gómez-Martínez M, Rodríguez-García W, González-Islas D, Orea-Tejeda A, Keirns-Davis C, Salgado-Fernández F, Hernández-López S, Jiménez-Valentín A, Ríos-Pereda AV, Márquez-Cordero JC, Salvatierra-Escobar M, López-Vásquez I. Impact of Body Composition and Sarcopenia on Mortality in Chronic Obstructive Pulmonary Disease Patients. J Clin Med 2023; 12:jcm12041321. [PMID: 36835862 PMCID: PMC9967244 DOI: 10.3390/jcm12041321] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/27/2023] [Accepted: 01/29/2023] [Indexed: 02/10/2023] Open
Abstract
BACKGROUND Patients with chronic obstructive pulmonary disease (COPD) have alterations in body composition, such as low cell integrity, body cell mass, and disturbances in water distribution evidenced by higher impedance ratio (IR), low phase angle (PhA), as well as low strength, low muscle mass, and sarcopenia. Body composition alterations are associated with adverse outcomes. However, according to the European Working Group on Sarcopenia in Older People 2 (EWGSOP2), the impact of these alterations on mortality in COPD patients is not well-established. Our aims were to evaluate whether low strength, low muscle mass, and sarcopenia impacted mortality in COPD patients. METHODS A prospective cohort study performance was conducted with COPD patients. Patients with cancer, and asthma were excluded. Body composition was assessed by bioelectrical impedance analysis. Low strength and muscle mass, and sarcopenia were defined according to EWGSOP2. RESULTS 240 patients were evaluated, of whom 32% had sarcopenia. The mean age was 72.32 ± 8.24 years. The factors associated with lower risk of mortality were handgrip strength (HR:0.91, CI 95%; 0.85 to 0.96, p = 0.002), PhA (HR:0.59, CI 95%; 0.37 to 0.94, p = 0.026) and exercise tolerance (HR:0.99, CI 95%; 0.992 to 0.999, p = 0.021), while PhA below the 50th percentile (HR:3.47, CI 95%; 1.45 to 8.29, p = 0.005), low muscle strength (HR:3.49, CI 95%; 1.41 to 8.64, p = 0.007) and sarcopenia (HR:2.10, CI 95%; 1.02 to 4.33, p = 0.022) were associated with a higher risk of mortality. CONCLUSION Low PhA, low muscle strength, and sarcopenia are independently associated with poor prognosis in COPD patients.
Collapse
Affiliation(s)
- Manuel Gómez-Martínez
- Heart Failure and Respiratory Distress Clinic, Instituto Nacional de Enfermedades Respiratorias “Ismael Cosío Villegas”, Mexico City C.P. 14080, Mexico
| | - Wendy Rodríguez-García
- Licenciatura en Nutriología, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, Mexico City C.P. 09230, Mexico
| | - Dulce González-Islas
- Heart Failure and Respiratory Distress Clinic, Instituto Nacional de Enfermedades Respiratorias “Ismael Cosío Villegas”, Mexico City C.P. 14080, Mexico
- Correspondence: (D.G.-I.); (A.O.-T.); Tel.: +52-5554871700 (D.G.-I. & A.O.-T.)
| | - Arturo Orea-Tejeda
- Heart Failure and Respiratory Distress Clinic, Instituto Nacional de Enfermedades Respiratorias “Ismael Cosío Villegas”, Mexico City C.P. 14080, Mexico
- Correspondence: (D.G.-I.); (A.O.-T.); Tel.: +52-5554871700 (D.G.-I. & A.O.-T.)
| | - Candace Keirns-Davis
- Heart Failure and Respiratory Distress Clinic, Instituto Nacional de Enfermedades Respiratorias “Ismael Cosío Villegas”, Mexico City C.P. 14080, Mexico
| | - Fernanda Salgado-Fernández
- Heart Failure and Respiratory Distress Clinic, Instituto Nacional de Enfermedades Respiratorias “Ismael Cosío Villegas”, Mexico City C.P. 14080, Mexico
| | - Samantha Hernández-López
- Heart Failure and Respiratory Distress Clinic, Instituto Nacional de Enfermedades Respiratorias “Ismael Cosío Villegas”, Mexico City C.P. 14080, Mexico
| | - Angelia Jiménez-Valentín
- Heart Failure and Respiratory Distress Clinic, Instituto Nacional de Enfermedades Respiratorias “Ismael Cosío Villegas”, Mexico City C.P. 14080, Mexico
| | - Alejandra Vanessa Ríos-Pereda
- Heart Failure and Respiratory Distress Clinic, Instituto Nacional de Enfermedades Respiratorias “Ismael Cosío Villegas”, Mexico City C.P. 14080, Mexico
| | - Juan Carlos Márquez-Cordero
- Heart Failure and Respiratory Distress Clinic, Instituto Nacional de Enfermedades Respiratorias “Ismael Cosío Villegas”, Mexico City C.P. 14080, Mexico
| | - Mariana Salvatierra-Escobar
- Heart Failure and Respiratory Distress Clinic, Instituto Nacional de Enfermedades Respiratorias “Ismael Cosío Villegas”, Mexico City C.P. 14080, Mexico
| | - Iris López-Vásquez
- Heart Failure and Respiratory Distress Clinic, Instituto Nacional de Enfermedades Respiratorias “Ismael Cosío Villegas”, Mexico City C.P. 14080, Mexico
| |
Collapse
|
4
|
Ballarin G, Scalfi L, Monfrecola F, Alicante P, Bianco A, Marra M, Sacco AM. Body Composition and Bioelectrical-Impedance-Analysis-Derived Raw Variables in Pole Dancers. Int J Environ Res Public Health 2021; 18:ijerph182312638. [PMID: 34886363 PMCID: PMC8656643 DOI: 10.3390/ijerph182312638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/24/2021] [Accepted: 11/25/2021] [Indexed: 11/20/2022]
Abstract
Few data are available on the body composition of pole dancers. Bioelectrical impedance analysis (BIA) is a method that is used to estimate fat-free mass (FFM) and fat mass (FM), while raw BIA variables, such as the impedance ratio (IR) and phase angle (PhA), are markers of body cell mass and the ratio between extracellular and total body water. The aim of this study was to evaluate the body composition of pole dancers compared to controls, in particular, those raw BIA variables that are considered as markers of muscle composition. Forty female pole dancers and 59 controls participated in the study. BIA was performed on the whole body and upper and lower limbs, separately, at 5, 50, 100 and 250 kHz. The FFM, FFM index, FM and body fat percentage (BF%) were predicted. The bioelectrical impedance indexes IR and PhA were also considered. Pole dancers exhibited higher FFMI and BI indexes and lower BF%. PhA was greater and IRs were smaller in pole dancers than in controls for the whole body and upper limbs. Considering the training level, FFM, whole-body IR and PhA were higher in the professionals than non-professionals. Raw BIA variables significantly differed between the pole dancers and controls, suggesting a higher BCM; furthermore, practicing pole dancing was associated with a greater FFM and lower FM.
Collapse
Affiliation(s)
- Giada Ballarin
- Department of Movement Sciences and Wellbeing, University of Naples “Parthenope”, 80133 Naples, Italy;
- Department of Public Health, School of Medicine, Federico II University, 80131 Naples, Italy; (L.S.); (F.M.); (P.A.); (A.B.)
| | - Luca Scalfi
- Department of Public Health, School of Medicine, Federico II University, 80131 Naples, Italy; (L.S.); (F.M.); (P.A.); (A.B.)
| | - Fabiana Monfrecola
- Department of Public Health, School of Medicine, Federico II University, 80131 Naples, Italy; (L.S.); (F.M.); (P.A.); (A.B.)
| | - Paola Alicante
- Department of Public Health, School of Medicine, Federico II University, 80131 Naples, Italy; (L.S.); (F.M.); (P.A.); (A.B.)
| | - Alessandro Bianco
- Department of Public Health, School of Medicine, Federico II University, 80131 Naples, Italy; (L.S.); (F.M.); (P.A.); (A.B.)
| | - Maurizio Marra
- Department of Clinical Medicine and Surgery, School of Medicine, Federico II University, 80131 Naples, Italy;
| | - Anna Maria Sacco
- Department of Public Health, School of Medicine, Federico II University, 80131 Naples, Italy; (L.S.); (F.M.); (P.A.); (A.B.)
- Correspondence:
| |
Collapse
|
5
|
de Blasio F, de Blasio F, Miracco Berlingieri G, Bianco A, La Greca M, Franssen FME, Scalfi L. Evaluation of body composition in COPD patients using multifrequency bioelectrical impedance analysis. Int J Chron Obstruct Pulmon Dis 2016; 11:2419-2426. [PMID: 27757027 PMCID: PMC5053371 DOI: 10.2147/copd.s110364] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Background Multifrequency bioelectrical impedance analysis (MF-BIA) is a technique that measures body impedance (Z) at different frequencies (5, 10, 50, 100, and 250 kHz). Body composition may be estimated using empirical equations, which include BIA variables or, alternatively, raw BIA data may provide direct information on water distribution and muscle quality. Objectives To compare raw MF-BIA data between COPD patients and controls and to study their relationship with respiratory and functional parameters in COPD patients. Methods MF-BIA was performed (Human Im-Touch analyzer) in 212 COPD patients and 115 age- and BMI-matched controls. Fat-free mass (FFM) and fat mass were estimated from BIA data, and low- to high-frequency (5 kHz/250 kHz) impedance ratio was calculated. Physical fitness, lung function and respiratory muscle strength were also assessed in COPD patients. Results After adjusting for age, weight, and body mass index, FFM and the 5/250 impedance ratio were lower in COPD patients (P<0.001) and were negatively affected by disease severity. In both male and female patients, the 5/250 impedance ratio was significantly correlated mainly with age (r=−0.316 and r=−0.346, respectively). Patients with a 5/250 impedance ratio below median value had lower handgrip strength (P<0.001), 6-minute walk distance (P<0.005), respiratory muscle strength (P<0.005), forced expiratory volume in 1 second (P<0.05) and vital capacity (P<0.005). Finally, the 5/250 impedance ratio was reduced (P<0.05) in patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) III and IV (compared to those with GOLD I and II) or a BODE index between 6 and 10 points (compared to those with BODE index between 1 and 5 points). Conclusion MF-BIA may be a useful tool for assessing body composition and nutritional status in COPD patients. In particular, the impedance ratio could give valuable information on cellular integrity and muscle quality.
Collapse
Affiliation(s)
- Francesca de Blasio
- Department of Public Health, Medical School, "Federico II" University of Naples
| | - Francesco de Blasio
- Respiratory Medicine and Pulmonary Rehabilitation Section, Clinic Center, Private Hospital, Naples; Department of Medicine and Health Sciences "V Tiberio", University of Molise, Campobasso
| | | | - Andrea Bianco
- Department of Medicine and Health Sciences "V Tiberio", University of Molise, Campobasso; Department of Cardio-Thoracic and Respiratory Sciences, Second University of Naples, Naples, Italy
| | - Marta La Greca
- Department of Public Health, Medical School, "Federico II" University of Naples
| | | | - Luca Scalfi
- Department of Public Health, Medical School, "Federico II" University of Naples
| |
Collapse
|
6
|
Kuchnia AJ, Teigen LM, Cole AJ, Mulasi U, Gonzalez MC, Heymsfield SB, Vock DM, Earthman CP. Phase Angle and Impedance Ratio: Reference Cut-Points From the United States National Health and Nutrition Examination Survey 1999-2004 From Bioimpedance Spectroscopy Data. JPEN J Parenter Enteral Nutr 2016; 41:1310-1315. [PMID: 27670250 DOI: 10.1177/0148607116670378] [Citation(s) in RCA: 37] [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] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND Raw bioimpedance parameters (eg, 50-kHz phase angle [PA] and 200-kHz/5-kHz impedance ratio [IR]) have been investigated as predictors of nutrition status and/or clinical outcomes. However, their validity as prognostic measures depends on the availability of appropriate reference data. Using a large and ethnically diverse data set, we aimed to determine if ethnicity influences these measures and provide expanded bioimpedance reference data for the U.S. POPULATION METHODS The National Health and Nutrition Examination Survey (NHANES) is an ongoing compilation of studies conducted by the U.S. Centers for Disease Control and Prevention designed to monitor nutrition status of the U.S. POPULATION The NHANES data sets analyzed were from the years 1999-2000, 2001-2002, and 2003-2004. RESULTS Multivariate analysis showed that PA and IR differed by body mass index (BMI), age, sex, and ethnicity (n = 6237; R2 = 41.2%, P < .0001). Suggested reference cut-points for PA stratified by age decade, ethnicity, and sex are provided. CONCLUSION Ethnicity is an important variable that should be accounted for when determining population reference values for PA and IR. We have provided sex-, ethnicity-, and age decade-specific reference values from PA for use by future studies in U.S. POPULATIONS Interdevice differences are likely to be important contributors to variability across published population-specific reference data and, where possible, should be evaluated in future research. Ultimately, further validation with physiologically relevant reference measures (eg, dual-energy x-ray absorptiometry) is necessary to determine if PA/IR are appropriate bedside tools for the assessment of nutrition status in a clinical population.
Collapse
Affiliation(s)
- Adam J Kuchnia
- 1 Department of Food Science and Nutrition, University of Minnesota-Twin Cities, Saint Paul, Minnesota, USA
| | - Levi M Teigen
- 1 Department of Food Science and Nutrition, University of Minnesota-Twin Cities, Saint Paul, Minnesota, USA
| | - Abigail J Cole
- 1 Department of Food Science and Nutrition, University of Minnesota-Twin Cities, Saint Paul, Minnesota, USA
| | - Urvashi Mulasi
- 1 Department of Food Science and Nutrition, University of Minnesota-Twin Cities, Saint Paul, Minnesota, USA
| | - M Cristina Gonzalez
- 2 Post-graduate Program on Health and Behavior, Catholic University of Pelotas, Pelotas, RS, Brazil
| | - Steven B Heymsfield
- 3 Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA
| | - David M Vock
- 4 School of Public Health, University of Minnesota-Twin Cities, Minneapolis, Minnesota, USA
| | - Carrie P Earthman
- 1 Department of Food Science and Nutrition, University of Minnesota-Twin Cities, Saint Paul, Minnesota, USA
| |
Collapse
|
7
|
Earthman CP. Body Composition Tools for Assessment of Adult Malnutrition at the Bedside: A Tutorial on Research Considerations and Clinical Applications. JPEN J Parenter Enteral Nutr 2016; 39:787-822. [PMID: 26287016 DOI: 10.1177/0148607115595227] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Because of the key role played by the body's lean tissue reserves (of which skeletal muscle is a major component) in the response to injury and illness, its maintenance is of central importance to nutrition status. With the recent development of the Academy of Nutrition and Dietetics/American Society for Parenteral and Enteral Nutrition diagnostic framework for malnutrition, the loss of muscle mass has been recognized as one of the defining criteria. Objective methods to evaluate muscle loss in individuals with acute and chronic illness are needed. Bioimpedance and ultrasound techniques are currently the best options for the clinical setting; however, additional research is needed to investigate how best to optimize measurements and minimize error and to establish if these techniques (and which specific approaches) can uniquely contribute to the assessment of malnutrition, beyond more subjective evaluation methods. In this tutorial, key concepts and statistical methods used in the validation of bedside methods to assess lean tissue compartments are discussed. Body composition assessment methods that are most widely available for practice and research in the clinical setting are presented, and clinical cases are used to illustrate how the clinician might use bioimpedance and/or ultrasound as a tool to assess nutrition status at the bedside. Future research needs regarding malnutrition assessment are identified.
Collapse
Affiliation(s)
- Carrie P Earthman
- Department of Food Science and Nutrition, University of Minnesota-Twin Cities, St Paul, Minnesota
| |
Collapse
|
8
|
Kuchnia A, Earthman C, Teigen L, Cole A, Mourtzakis M, Paris M, Looijaard W, Weijs P, Oudemans-van Straaten H, Beilman G, Day A, Leung R, Compher C, Dhaliwal R, Peterson S, Roosevelt H, Heyland DK. Evaluation of Bioelectrical Impedance Analysis in Critically Ill Patients: Results of a Multicenter Prospective Study. JPEN J Parenter Enteral Nutr 2016; 41:1131-1138. [PMID: 27221673 DOI: 10.1177/0148607116651063] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND In critically ill patients, muscle loss is associated with adverse outcomes. Raw bioelectrical impedance analysis (BIA) parameters (eg, phase angle [PA] and impedance ratio [IR]) have received attention as potential markers of muscularity, nutrition status, and clinical outcomes. Our objective was to test whether PA and IR could be used to assess low muscularity and predict clinical outcomes. METHODS Patients (≥18 years) having an abdominal computed tomography (CT) scan and admitted to intensive care underwent multifrequency BIA within 72 hours of scan. CT scans were landmarked at the third lumbar vertebra and analyzed for skeletal muscle cross-sectional area (CSA). CSA ≤170 cm2 for males and ≤110 cm2 for females defined low muscularity. The relationship between PA (and IR) and CT muscle CSA was evaluated using multivariate regression and included adjustments for age, sex, body mass index, Charlson Comorbidity Index, and admission type. PA and IR were also evaluated for predicting discharge status using dual-energy x-ray absorptiometry-derived cut-points for low fat-free mass index. RESULTS Of 171 potentially eligible patients, 71 had BIA and CT scans within 72 hours. Area under the receiver operating characteristic (c-index) curve to predict CT-defined low muscularity was 0.67 ( P ≤ .05) for both PA and IR. With covariates added to logistic regression models, PA and IR c-indexes were 0.78 and 0.76 ( P < .05), respectively. Low PA and high IR predicted time to live ICU discharge. CONCLUSION Our study highlights the potential utility of PA and IR as markers to identify patients with low muscularity who may benefit from early and rigorous intervention.
Collapse
Affiliation(s)
- Adam Kuchnia
- 1 Food Science and Nutrition, University of Minnesota-Twin Cities, Minnesota, USA
| | - Carrie Earthman
- 1 Food Science and Nutrition, University of Minnesota-Twin Cities, Minnesota, USA
| | - Levi Teigen
- 1 Food Science and Nutrition, University of Minnesota-Twin Cities, Minnesota, USA
| | - Abigail Cole
- 1 Food Science and Nutrition, University of Minnesota-Twin Cities, Minnesota, USA
| | | | - Michael Paris
- 2 Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Willem Looijaard
- 3 Department of Intensive Care Medicine, VU University Medical Center Amsterdam, Amsterdam, the Netherlands
| | - Peter Weijs
- 3 Department of Intensive Care Medicine, VU University Medical Center Amsterdam, Amsterdam, the Netherlands
| | | | - Gregory Beilman
- 4 Division of Critical Care/Acute Care Surgery, University of Minnesota Medical Center, Minneapolis, Minnesota, USA
| | - Andrew Day
- 5 Clinical Evaluation Research Unit, Kingston General Hospital and Department of Critical Care Medicine, Queen's University, Kingston, Ontario, Canada
| | - Roger Leung
- 5 Clinical Evaluation Research Unit, Kingston General Hospital and Department of Critical Care Medicine, Queen's University, Kingston, Ontario, Canada
| | - Charlene Compher
- 6 School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Rupinder Dhaliwal
- 5 Clinical Evaluation Research Unit, Kingston General Hospital and Department of Critical Care Medicine, Queen's University, Kingston, Ontario, Canada
| | - Sarah Peterson
- 7 Food and Nutrition, Rush University Medical Center, Chicago, Illinois, USA
| | - Hannah Roosevelt
- 7 Food and Nutrition, Rush University Medical Center, Chicago, Illinois, USA
| | - Daren K Heyland
- 5 Clinical Evaluation Research Unit, Kingston General Hospital and Department of Critical Care Medicine, Queen's University, Kingston, Ontario, Canada
| |
Collapse
|
9
|
Fu MR, Cleland CM, Guth AA, Kayal M, Haber J, Cartwright F, Kleinman R, Kang Y, Scagliola J, Axelrod D. L-dex ratio in detecting breast cancer-related lymphedema: reliability, sensitivity, and specificity. Lymphology 2013; 46:85-96. [PMID: 24354107 PMCID: PMC4040962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Advances in bioelectrical impedance analysis (BIA) permit the assessment of lymphedema by directly measuring lymph fluid changes. The objective of the study was to examine the reliability, sensitivity, and specificity of cross-sectional assessment of BIA in detecting lymphedema in a large metropolitan clinical setting. BIA was used to measure lymph fluid changes. Limb volume by sequential circumferential tape measurement was used to validate the presence of lymphedema. Data were collected from 250 women, including healthy female adults, breast cancer survivors with lymphedema, and those at risk for lymphedema. Reliability, sensitivity, specificity and area under the ROC curve were estimated. BIA ratio, as indicated by L-Dex ratio, was highly reliable among healthy women (ICC=0.99; 95% CI = 0.99 - 0.99), survivors at-risk for lymphedema (ICC=0.99; 95% CI = 0.99 - 0.99), and all women (ICC=0.85; 95% CI = 0.81 - 0.87); reliability was acceptable for survivors with lymphedema (ICC=0.69; 95% CI = 0.54 to 0.80). The L-Dex ratio with a diagnostic cutoff of >+7.1 discriminated between at-risk breast cancer survivors and those with lymphedema with 80% sensitivity and 90% specificity (AUC=0.86). BIA ratio was significantly correlated with limb volume by sequential circumferential tape measurement. Cross-sectional assessment of BIA may have a role in clinical practice by adding confidence in detecting lymphedema. It is important to note that using a cutoff of L-Dex ratio >+7.1 still misses 20% of true lymphedema cases, it is important for clinicians to integrate other assessment methods (such as self-report, clinical observation, or perometry) to ensure the accurate detection of lymphedema.
Collapse
Affiliation(s)
- M R Fu
- College of Nursing, New York University, New York, USA.
| | - C M Cleland
- College of Nursing, New York University, New York, USA
| | - A A Guth
- Department of Surgery, New York University School of Medicine, New York, USA
| | - M Kayal
- Department of Medicine, Columbia University, New York, NY, USA
| | - J Haber
- College of Nursing, New York University, New York, USA
| | - F Cartwright
- Department of Nursing and Oncology Services, NYU Langone Medical Center, New York, USA
| | - R Kleinman
- NYU Clinical Cancer Center, NYU Langone Medical Center, New York, USA
| | - Y Kang
- Department of Statistics, Columbia University, New York, NY, USA
| | - J Scagliola
- NYU Clinical Cancer Center, NYU Langone Medical Center, New York, USA
| | - D Axelrod
- Department of Surgery, New York University School of Medicine, New York, USA
| |
Collapse
|