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- Albinsson, John, et al.
(författare)
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Combined use of Iteration, Quadratic Interpolation and an Extra Kernel for high-resolution 2D particle tracking : a first evaluation
- 2010
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Ingår i: 2010 ieee international ultrasonics symposium. - New York : IEEE Press. - 9781457703829 ; , s. 2000-2003
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Konferensbidrag (refereegranskat)abstract
- A novel 2D particle tracking method, that uses 1) iteration, 2) fast quadratic sub-pixel estimation (with only 28 multiplications per movement), and 3) a previous kernel, has been evaluated and compared with a full-search block-matching method. The comparison with high-frequency ultrasound data (40 MHz) was conducted in silico and on phantoms, which comprised lateral, diagonal, and ellipsoidal movement patterns with speeds of 0–15 mm/s. The mean tracking error was reduced by 68% in silico and 71% for the phantom measurements. When only sub-pixel estimation was used, the decrease in the tracking error was 61% in silico and 57% for the phantom measurements. As well as decreasing the tracking error, the new method only used 70% of the computational time needed by the full-search block-matching method. With a fast method having good tracking ability for high-frequency ultrasound data, we now have a tool to better investigate tissue movements and its dynamic functionality.
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| 2. |
- Albinsson, John, et al.
(författare)
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Improved tracking performance of lagrangian block-matching methodologies using block expansion in the time domain : In silico, phantom and invivo evaluations
- 2014
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Ingår i: Ultrasound in Medicine and Biology. - : Elsevier. - 0301-5629 .- 1879-291X. ; 40:10, s. 2508-2520
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate tracking performance when an extra reference block is added to a basic block-matching method, where the two reference blocks originate from two consecutive ultrasound frames. The use of an extra reference block was evaluated for two putative benefits: (i) an increase in tracking performance while maintaining the size of the reference blocks, evaluated using in silico and phantom cine loops; (ii) a reduction in the size of the reference blocks while maintaining the tracking performance, evaluated using in vivo cine loops of the common carotid artery where the longitudinal movement of the wall was estimated. The results indicated that tracking accuracy improved (mean - 48%, p<0.005 [in silico]; mean - 43%, p<0.01 [phantom]), and there was a reduction in size of the reference blocks while maintaining tracking performance (mean - 19%, p<0.01 [in vivo]). This novel method will facilitate further exploration of the longitudinal movement of the arterial wall. (C) 2014 World Federation for Ultrasound in Medicine & Biology.
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| 4. |
- Bergman, Stefan, 1959-, et al.
(författare)
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Chronic Widespread Pain in Adolescents Is Highly Associated to Stress and Anxiety
- 2015
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Ingår i: Arthritis & Rheumatology. - Hoboken, NJ : John Wiley & Sons. - 2326-5191 .- 2326-5205. ; 67:Suppl. S10
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Tidskriftsartikel (refereegranskat)abstract
- Background/Purpose: Chronic widespread pain (CWP), one of the hallmarks of fibromyalgia, is not uncommon in adolescents and it has previously been shown that adolescents with pain often become young adults with pain. CWP often co-varies with anxiety, depression, and stress symptoms in adults, but the knowledge regarding this is small in youth and young adults.The aim was to study the associations between CWP, anxiety, depression and stress in adolescents attending first year of high school.Methods: A computerized questionnaire to 296 adolescents attending Swedish high school, with validated questions regarding presence and distribution of pain (Epipain mannequin), stress symptoms (ELO question), anxiety and depression (Hospital Anxiety and Depression Scale – HADS), and health related quality of life (HRQL as measured by EQ5D). Pain was considered chronic when persistent for more than three months, and the subgroup CWP was defined according to the 1990 ACR criteria for fibromyalgia. Statistical analyses in SPSS v21 with comparison of means by Student’s t-test and proportions by chi2-test or Fischer’s exact test.Results: 257 (87%) out of 296 eligible students, mean (SD) age 16.1 (0.7) and 65.8% girls, responded to the questionnaire. Prevalence of chronic pain was 20.8% and that of the subgroup CWP was 4.7%, without any gender differences (boys 18.2% vs girls 22.2%; p=0.224, and 3.4% vs 5.4%; p=0.692). High level (4 or 5 on a 5 point scale) of stress symptoms were less common in boys (16.0% vs 28.2%; p=0.015), as was possible or probable anxiety (17.1% vs 44.4%; p<0.001), but not depression (10.3% vs 12.5%; p=0.764). Students with high level of stress reported CWP five times more often than those with less stress (30.4% vs 5.8%; p=0.001). Students with probable anxiety reported CWP ten times more often than students with no anxiety (17.6% vs 1.8%; p=0.001), and CWP was also more common, but not statistically significant, in students with probable depression (20.0% vs 3.1%; p=0.163). Those reporting CWP had significantly lower HRQL (0.58 vs 0.87; p=0.038) than students with no chronic pain.Conclusion: The high prevalence of chronic pain and the strong associations between CWP and reports of stress and anxiety in adolescents highlights that a multifactorial background to chronic pain must be considered early in life. An apparent lower score in EQ5D also indicates that the presence of CWP has an marked impact on HRQL also in adolescents.
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| 6. |
- Brorsson, Sofia, et al.
(författare)
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12-weeks of hand exercise provides better hand function, muscle balance and muscle strength in the rheumatoid arthritis hand
- 2010
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Ingår i: Abstract Archive Sessions Index 2010. - : EULAR.
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Konferensbidrag (refereegranskat)abstract
- Background:Impaired grip ability in RA is due to reduced strength in the flexor muscles as well as by dysfunctional extensor muscles leading to inability to open the hand. Furthermore the extensor muscles are important for stabilization during flexion force production and active for developing a controlled grip force. There is today scientific evidence showing that various forms of hand exercise are beneficial for improving hand function and strength in RA patients (Ronningen and Kjeken 2008; Brorsson, Hilliges et al. 2009). However, comparatively little research has evaluated and specific designed hand exercise program for the extensor muscles controlling the hand and fingers (Weiss, Moore et al. 2004; O'Brien, Jones et al. 2006).Objectives:The objectives for this study were to evaluate the effect of an exercise program on hand strength, hand function and perceived function of daily life activities among RA patients and to explore the possibility to improve the balance between the extensor and flexor muscle forces in the hand.Methods:The study group comprised of 20 patients with RA (median disease duration 20 years) that performed a hand exercise program for twelve weeks. The finger extension force was measured with a newly developed device (EX-it), finger flexion force was measured with the Grippit. Hand function was evaluated with the Grip Ability Test (GAT) and self reported questionnaire Disability Arm Shoulder and Hand (DASH).Results:Hand strength (both extension and flexion force) and hand function improved significantly after twelve weeks. The RA group showed improvement in the results of the DASH questionnaire (p < 0.05), but on individual level, the result was partly significant. The relation between extension and flexion force in the hand was not correlated, however, after the exercise there was a strong association between flexion and extension force (p < 0.001). The result on individual level is related to age and duration time.Conclusion:Twelve weeks of hand exercise significantly improved hand strength, hand function and perceived function for RA patients. Furthermore, exercise improved the relation between the finger extension and flexion force. Hand exercise is thus an effective intervention for RA patients, providing better strength and function.References:Brorsson, S., M. Hilliges, et al. (2009). A six-week hand exercise programme improves strength and hand function in patients with rheumatoid arthritis. J Rehabil Med 41(5): 338-42.O'Brien, A.V., P. Jones, et al. (2006). Conservative hand therapy treatments in rheumatoid arthritis–a randomized controlled trial. Rheumatology (Oxford) 45(5): 577-83.Ronningen, A. and I. Kjeken (2008). ffect of an intensive hand exercise programme in patients with rheumatoid arthritis. Scand J Occup Ther: 1-11.Weiss, A. P., D. C. Moore, et al. (2004). Metacarpophalangeal joint mechanics after 3 different silicone arthroplasties. J Hand Surg [Am] 29(5): 796-803.
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| 9. |
- Brorsson, Sofia, et al.
(författare)
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A new electronic grip force measurement device for hand evaluation
- 2013
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Ingår i: Abstracts of the Annual European Congress of Rheumatology EULAR. June 12-15, 2013. Madrid, Spain.
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Konferensbidrag (refereegranskat)abstract
- Background: Hand grip force is a good indicator of general muscle strength and can also be used to predict multiple outcomes such as changes in activities of daily living (ADL), disability, mortality and general upper extremity strength. Hand grip force is often measured as the amount of static grip force a subject can produce when measured with a hydraulic dynamometer such as the Jamar or with an electronic device such as the Grippit. The Grippit device measures an average grip force, a peak grip force and force over a set time period. Grippit has shown good reliability for healthy subjects. Grippit, which was developed over 20 years ago in Gothenburg, Sweden is no longer manufactured. Therefore, the need for anewly developed and modernized measurement instrument for use in evaluating hand rehabilitation has arisen. Objectives: The aim of this study was to evaluate the test-retest reliability of the newly developed instrument GRIP-it and to describe and validate the relationship between grip force measurements from GRIP-it and the original Grippit device. Methods: Healthy controls (n=43) were included in the study. Two devices were used to evaluate grip force (Newton, N), (i) GRIP-it a newly developed device and (ii) Grippit. Both instruments were used to measure mean and maximal force over 10 seconds. Results: GRIP-it displayed a mean measurement error of -1.7 ± 0.5% and the corresponding error for Grippit was -1.6 ± 1.9%. All subjects completed the grip force tests and the results for three attempts for each hand. The test-retest reliability was excellent for both pieces of equipment, with ICCs ranging from 0.963 to 0.947 (CI 95% between 0.103 and 0.041) for GRIP-it and from 0.979 to 0.968 (CI 95% between 0.087 and 0.042) for Grippit. Relationships between Grippit and GRIP-itThere was a significant difference between the measured values derived from Grippit and GRIP-it for both the dominant hand (P < 0.001) and the non-dominant hand (P < 0.01). Grippit gives in general a higher grip force measurement than GRIP-it which is also indicated by the slope (β1) of the regression lines that deviates from 1. However, there were no substantial differences in the grip force when comparing the measurements for the dominant hand with the non-dominant hand for either Grippit (P = 0.071) or GRIP-it (P = 0.404). Based on these non-significant differences between hands and the fact that the model estimates for the intercept (β0) and the slope (β1) are contained within the confidence intervals of the model estimates for the opposite hand, a combined model was derived. The linear regression analysis, with grip force measurements for both hands included, gives: GRIP-it = 49.0 + 0.779 · Grippit. This explains 89.6% of the variance in grip force analyzed by GRIP-it (P < 0.001) see Figure 2. To enable an estimation of grip force measured by Grippit based on GRIP-it values a regression analysis with Grippit as dependent variable gives: Grippit = -18.1 + 1.15 · GRIP-it, which explains 89.6% of the variance in grip force analyzed by Grippit (P < 0.001).Conclusions: This study showed that GRIP-it has excellent test-retest reliability. Measurements of grip force with GRIP-it are strongly related to those from the original Grippit. The newly developed GRIP-it shows great potential for use in the assessment of hand function and the evaluation of hand rehabilitation.
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| 10. |
- Brorsson, Sofia, 1973-, et al.
(författare)
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A new force measurement device for evaluating finger extension function in the healthy and rheumatoid arthritis hand
- 2008
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Ingår i: Technology and Health Care. - Amsterdam : IOS Press. - 0928-7329 .- 1878-7401. ; 16:4, s. 283-292
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Tidskriftsartikel (refereegranskat)abstract
- Although often neglected, finger extension force is of great importance for developing grip strength. This paper describes the design and evaluation of a new finger extension force measurement device (EX-it) based on the biomechanics of the hand. Measurement accuracy and test-retest reliability were analysed. The device allows measurements on single fingers as well as all the fingers (excluding the thumb) of both healthy and deformed hands. The coefficient of variation in the device was 1.8% of the applied load, and the test-retest reliability showed a coefficient of variation no more than 7.1% for healthy subjects. This study also provides reference values for finger extension force in healthy subjects and patients with rheumatoid arthritis (RA). Significant differences were found in extension strength between healthy subject and RA patients (men, p < 0.05 and women, p < 0.001). EX-it provides objective and reliable data on the extension force capacity of normal and dysfunctional hands and can be used to evaluate the outcome of therapeutic interventions after hand trauma or disease
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