scholarly journals MAS: Standalone Microwave Resonator to Assess Muscle Quality

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5485
Author(s):  
Viktor Mattsson ◽  
Leanne L. G. C. Ackermans ◽  
Bappaditya Mandal ◽  
Mauricio D. Perez ◽  
Maud A. M. Vesseur ◽  
...  

Microwave-based sensing for tissue analysis is recently gaining interest due to advantages such as non-ionizing radiation and non-invasiveness. We have developed a set of transmission sensors for microwave-based real-time sensing to quantify muscle mass and quality. In connection, we verified the sensors by 3D simulations, tested them in a laboratory on a homogeneous three-layer tissue model, and collected pilot clinical data in 20 patients and 25 healthy volunteers. This report focuses on initial sensor designs for the Muscle Analyzer System (MAS), their simulation, laboratory trials and clinical trials followed by developing three new sensors and their performance comparison. In the clinical studies, correlation studies were done to compare MAS performance with other clinical standards, specifically the skeletal muscle index, for muscle mass quantification. The results showed limited signal penetration depth for the Split Ring Resonator (SRR) sensor. New sensors were designed incorporating Substrate Integrated Waveguides (SIW) and a bandstop filter to overcome this problem. The sensors were validated through 3D simulations in which they showed increased penetration depth through tissue when compared to the SRR. The second-generation sensors offer higher penetration depth which will improve clinical data collection and validation. The bandstop filter is fabricated and studied in a group of volunteers, showing more reliable data that warrants further continuation of this development.

2021 ◽  
Vol 8 ◽  
Author(s):  
Xiaofan Jing ◽  
Lingling Tan ◽  
Hongbo Fu ◽  
Ling Yang ◽  
Ming Yang

Objectives: Sarcopenia is an important predictor of dependence in activities of daily living (ADL disability); however, the association between muscle quality and ADL disability has not been established. We aimed (1) to assess the feasibility of measuring trunk muscle mass and muscle quality by chest CT images; and (2) to explore the possible associations of ADL disability with these muscle mass and muscle quality indicators among older inpatients.Methods: We included older patients in an acute care ward. ADL disability was defined as the Barthel Index (BI) score ≤ 60 points. Unenhanced chest CT images at the 12th thorax (T12) vertebral level were used to segment skeletal muscle area (SMA) and intermuscular adipose tissue (IMAT) and to measure the mean skeletal muscle radiodensity (SMD). Skeletal muscle index (SMI), the muscle mass indicator, was calculated by SMA (cm2)/body height squared (m2). The percentage of IMAT (IMAT%) was calculated using the equation: IMAT% = IMAT/(SMA+ IMAT) ×100%. Skeletal muscle radiodensity, IMAT, and IMAT% were the muscle quality indicators. Kendall's tau rank correlation coefficients (τ) were calculated to explore the correlations. Univariate and multivariate logistic regression models were performed to calculate odds ratios (OR) and 95% confidence interval (CI).Results: We included 212 participants. Skeletal muscle index and SMD were positively and significantly associated with the BI score (τ = 0.14 and 0.31, respectively, both P < 0.001); whereas IMAT and IMAT% were negatively and significantly associated with the BI score (τ = −0.21, P < 0.001; τ = −0.21, P < 0.012). After adjusting for confounders, SMI (adjusted OR 1.03, 95% CI 0.97–1.09) was not independently associated with ADL disability; however, SMD (adjusted OR 0.94, 95% CI 0.88–0.99), IMAT (adjusted OR 1.11, 95% CI 1.03–1.20), and IMAT% (adjusted OR 1.09, 95% CI 1.02–1.16) were independently associated with ADL disability. Subgroup analysis found similar results in men; however, none of these indicators were independently associated with ADL disability in women.Conclusion: Trunk muscle quality indicators (SMD, IMAT, and IMAT%) measured by chest CT images, but not SMI, are independently associated with ADL disability in a single-center study population of older inpatients, especially in men. Further research is necessary to validate our findings.


2020 ◽  
Vol 3 ◽  
Author(s):  
Shannon Zhou ◽  
Libbie Silverman ◽  
Andrew Young ◽  
David Roodman ◽  
Attaya Suvannasankha ◽  
...  

Background/Objective:  Low muscle mass (myopenia), poor muscle quality, myosteatosis, and muscle loss are associated with mortality in solid tumors. However, their impact in hematological malignancies remains unclear. We sought to determine how muscle phenotype relates to survival in patients with multiple myeloma.  Methods:  We performed a retrospective review of patients with multiple myeloma treated at Indiana University Hospital from 2012-2016. Total skeletal muscle area (SMA) (cm2) and radiodensity were measured on baseline (closest to diagnosis) and last CT scans at the third lumbar vertebrae area. SMA was normalized to height (SMA cm2/m2) to define skeletal muscle index (SKMI). Myopenia was defined as (SKMI) <52.4 cm2/m2 (men) and <38.5 cm2/m2 (women). Myosteatosis and obesity were defined per published BMI-specific cutoffs. Difference in survival between groups was estimated using log rank test.   Results:  Of 455 patients with multiple myeloma, 137 had more than one CT scan; 42 of these have been assessed to date. Half (21/42) were myopenic. Myopenia was equally prevalent across BMI categories and showed no association with survival. More than half of patients displayed myostetatosis; however, this was not associated with survival.  Obesity and myopenic obesity were likewise not correlated with survival. Below-median baseline SKMI correlated with mortality, HR 2.721 (95% CI, 1.160-5.564: P=0.0129). As well, below-median final SMA correlated with mortality, HR 2.381 (95% CI, 1.094-5.181, P=0.0213). On average patients lost .7129% of SMA (95% CI; -6.072%-4.646%). Females had higher mortality, HR 2.355 (95% CI 0.9895-5.604, P=0.0215).   Conclusion and Potential Impact:  Although this study represents a fraction of treated patients to date, myopenia was prevalent among patients at diagnosis of multiple myeloma. Low muscle mass and sex appear to be important prognostic factors for survival. Additional measurements as well as univariate and multivariate analyses are necessary to verify these findings and identify additional factors that contribute to survival in multiple myeloma. 


2015 ◽  
Vol 65 ◽  
pp. 34-43 ◽  
Author(s):  
Damien Zufferey ◽  
Thomas Hofer ◽  
Jean Hennebert ◽  
Michael Schumacher ◽  
Rolf Ingold ◽  
...  

2021 ◽  
Vol 39 (3_suppl) ◽  
pp. 56-56
Author(s):  
Hiroaki Nozawa ◽  
Shigenobu Emoto ◽  
Koji Murono ◽  
Yasutaka Shuno ◽  
Soichiro Ishihara

56 Background: Systemic chemotherapy can cause loss of skeletal muscle mass in colorectal cancer (CRC) patients in the neoadjuvant and palliative settings. However, it is largely unknown how the body composition is changed by chemotherapy rendering unresectable CRC to resectable disease or how it affects the prognosis. This study aimed at elucidating the effects of systemic chemotherapy on skeletal muscles and survival in stage IV CRC patients who underwent conversion therapy. Methods: We reviewed 98 stage IV CRC patients who received systemic chemotherapy in our hospital. According to the treatment setting, patients were divided into the ‘Conversion’, ‘Neoadjuvant chemotherapy (NAC)’, and ‘Palliation’ groups. The cross-sectional area of skeletal muscles at the third lumbar level and changes in the skeletal muscle index (SMI), defined as the area divided by height squared, during chemotherapy were compared among patient groups. The effects of these parameters on prognosis were analyzed in the Conversion group. Results: The mean SMI increased by 8.0% during chemotherapy in the Conversion group (n = 38), whereas it decreased by 6.2% in the NAC group (n = 18) and 3.7% in the Palliation group (n = 42, p < 0.0001). Moreover, patients with increased SMI during chemotherapy had a better overall survival (OS) than those whose SMI decreased in the Conversion group (p = 0.021). The increase in SMI was an independent predictor of favorable OS on multivariate analysis (hazard ratio: 0.26). Conclusions: Stage IV CRC patients who underwent conversion to resection often had an increased SMI. As such an increase in SMI further conveys a survival benefit in conversion therapy, it may be important to make efforts to preserve muscle mass by meticulous approaches, such as nutritional support, muscle exercise programs, and pharmacological intervention even during chemotherapy in patients with metastatic CRC.


2001 ◽  
Vol 90 (4) ◽  
pp. 1205-1210 ◽  
Author(s):  
Stephen M. Roth ◽  
Matthew A. Schrager ◽  
Robert E. Ferrell ◽  
Steven E. Riechman ◽  
E. Jeffrey Metter ◽  
...  

The relationship between ciliary neurotrophic factor (CNTF) genotype and muscle strength was examined in 494 healthy men and women across the entire adult age span (20–90 yr). Concentric (Con) and eccentric (Ecc) peak torque were assessed using a Kin-Com isokinetic dynamometer for the knee extensors (KE) and knee flexors (KF) at slow (0.52 rad/s) and faster (3.14 rad/s) velocities. The results were covaried for age, gender, and body mass or fat-free mass (FFM). Individuals heterozygous for the CNTF null (A allele) mutation (G/A) exhibited significantly higher Con peak torque of the KE and KF at 3.14 rad/s than G/G homozygotes when age, gender, and body mass were covaried ( P < 0.05). When the dominant leg FFM (estimated muscle mass) was used in place of body mass as a covariate, Con peak torque of the KE at 3.14 rad/s was also significantly greater in the G/A individuals ( P < 0.05). In addition, muscle quality of the KE (peak torque at 3.14 rad · s−1 · leg muscle mass−1) was significantly greater in the G/A heterozygotes ( P < 0.05). Similar results were seen in a subanalysis of subjects 60 yr and older, as well as in Caucasian subjects. In contrast, A/A homozygotes demonstrated significantly lower Ecc peak torque at 0.52 rad/s for both KE and KF compared with G/G and G/A groups ( P < 0.05). No significant relationships were observed at 0.52 rad/s between genotype and Con peak torque. These data indicate that individuals exhibiting the G/A genotype possess significantly greater muscular strength and muscle quality at relatively fast contraction speeds than do G/G individuals. Because of high positive correlations between fast-velocity peak torque and muscular power, these findings suggest that further investigations should address the relationship between CNTF genotype and muscular power.


2021 ◽  
Vol 13 (1) ◽  
pp. 37-44
Author(s):  
ZBIGNIEW M. OSSOWSKI

Background: The loss of muscle function and reduced mobility levels are the main reasons for the limitations of independence and disability in older people. The main aim of this study was to determine the relationship between the skeletal muscle index and mobility in older women. Material and methods: ‪The study involved 166 older women. Skeletal muscle mass and other body components were determined by bioimpedance using an InBody 720 device. Functional mobility was evaluated with the timed up-and-go test. 30-second chair stand was also used to measure the level of functional strength in lower extremities. Results: ‪The skeletal muscle index was positively correlated with functional mobility (r=-0.22; p=0.00) and 30-second chair stand (r=-0.47; p=0.00). However, the strength of lower extremities was a significantly better parameter in predicting mobility in older women than the skeletal muscle index and skeletal muscle mass. Conclusions: The functional strength of lower extremity muscles and the skeletal muscle index can have a positive effect on functional mobility in older people. The results may be helpful in clinical practice when diagnosing mobility limitations and in the process of programming physical activity of older women aimed at the prevention of sarcopenia.


Diabetes Care ◽  
2012 ◽  
Vol 35 (8) ◽  
pp. 1672-1679 ◽  
Author(s):  
S. Volpato ◽  
L. Bianchi ◽  
F. Lauretani ◽  
F. Lauretani ◽  
S. Bandinelli ◽  
...  

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 755 ◽  
Author(s):  
Carina O. Walowski ◽  
Wiebke Braun ◽  
Michael J. Maisch ◽  
Björn Jensen ◽  
Sven Peine ◽  
...  

Assessment of a low skeletal muscle mass (SM) is important for diagnosis of ageing and disease-associated sarcopenia and is hindered by heterogeneous methods and terminologies that lead to differences in diagnostic criteria among studies and even among consensus definitions. The aim of this review was to analyze and summarize previously published cut-offs for SM applied in clinical and research settings and to facilitate comparison of results between studies. Multiple published reference values for discrepant parameters of SM were identified from 64 studies and the underlying methodological assumptions and limitations are compared including different concepts for normalization of SM for body size and fat mass (FM). Single computed tomography or magnetic resonance imaging images and appendicular lean soft tissue by dual X-ray absorptiometry (DXA) or bioelectrical impedance analysis (BIA) are taken as a valid substitute of total SM because they show a high correlation with results from whole body imaging in cross-sectional and longitudinal analyses. However, the random error of these methods limits the applicability of these substitutes in the assessment of individual cases and together with the systematic error limits the accurate detection of changes in SM. Adverse effects of obesity on muscle quality and function may lead to an underestimation of sarcopenia in obesity and may justify normalization of SM for FM. In conclusion, results for SM can only be compared with reference values using the same method, BIA- or DXA-device and an appropriate reference population. Limitations of proxies for total SM as well as normalization of SM for FM are important content-related issues that need to be considered in longitudinal studies, populations with obesity or older subjects.


2020 ◽  
Vol 16 ◽  
pp. 174550652096200
Author(s):  
Tomohiro Yasuda

Objectives: The purpose of this study was to examine the prediction of skeletal muscle mass and maximum muscle strength using simplified morphology evaluation in young Japanese women from the thigh and calf perspective. Methods: A total of 249 Japanese young women (aged 18–25 years) were used for data analyses in this study. Thigh and calf girths were measured using a tape measure at 50% of thigh length and at 30% proximal of calf length, respectively. Muscle thickness was measured using B-mode ultrasound at the anterior and posterior thigh (at 50% of thigh length) and at the posterior lower leg (at 30% proximal of calf length), respectively. The measurements were carried out on the right side of the body while the participants stood with their elbows extended and relaxed. A stepwise multiple regression analysis (method of increasing and decreasing the variables; criterion set at p < 0.05) was performed for skeletal muscle index (defined by appendicular skeletal muscle mass/height2), handgrip strength, or sit-to-stand test and five variable factors (girth (thigh and calf) and muscle thickness (anterior and posterior thigh and posterior calf)). Results: Unlike the sit-to-stand test, skeletal muscle index or handgrip strength was correlated ( p < 0.001) with the girth or muscle thickness for both thigh and calf. Unlike the sit-to-stand test, the prediction equations for skeletal muscle index and handgrip strength estimation showed significant correlations with multiple regression analysis of data obtained from the calf girth and muscle thickness. In both skeletal muscle index and handgrip strength, calf girth was adopted as a Step 1, respectively. Conclusion: Our results indicated that skeletal muscle index and handgrip strength could be evaluated by the simplified morphology methods, especially that for the calf girth measurement, which may be a good indicator of screening/preventing for sarcopenia in healthy Japanese young women.


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