Infotech Oulu Annual Report 2012 - Biomedical Engineering Research Group (BME)

Professor Tapio Seppänen, Department of Computer Science and Engineering, Faculty of Technology, and Professor Timo Jämsä, Department of Medical Technology, Faculty of Medicine, University of Oulu

tapio.seppanen(at)ee.oulu.fi, timo.jamsa(at)oulu.fi
http://www.cse.oulu.fi/bme


 

The mission is to carry out basic, applied and translational research in biomedical engineering. We focus on the cardiovascular system, the respiration system, the central nervous system and the musculoskeletal system.


 

Scientific Progress

Cardiovascular and respiratory system research

We developed a new, fast, and real-time applicable method to estimate respiration from single channel electrocardiograms. This approach allows for transparent respiration monitoring during mundane activities, which may increase the user acceptance and utilization rates of such systems leading to better treatment of conditions such as cardiac disorders, sleep apnea, asthma, and chronic obstructive pulmonary disease. Based on a statistical shape theory, the method is robust and shows consistent performance in varying body positions and respiratory frequencies. We invented a method to coalesce the information in multichannel ECG into a new single channel signal describing the total electrical activity of the heart in order to reduce extra-cardiac effects and to make beat delineation more accurate and resilient. The effects of EMG noise, respiration, and body position changes can be greatly reduced using optimized quadratic functionals. Lately, multimodal approaches for automatic emotion recognition have gained significant scientific interest. We proposed a novel method for automatic emotion recognition by combining physiological signals and facial expressions. In this approach, heart rate variability parameters, respiration frequency, and facial expressions were used to classify a person’s emotions while watching pictures with emotional content.

Central nervous system research

Animal studies often require reliable measures for anaesthetic drug effects. Lately, electroencephalogram (EEG) based depth of anaesthesia estimation has been widely applied to rat models. We investigated the reliability of different EEG spectral properties in revealing awakening from isoflurane anaesthesia in rats. The results showed that the increase in frontal relative gamma activity, especially in the 50-150 Hz frequency band, seems to be the most reliable EEG indicator for the awakening of a rat from isoflurane anaesthesia. We also designed an algorithm based on Bayesian Information Criterion for the assessment of the switch-like change in the signal characteristics occurring just before the awakening of a rat. The algorithm was shown to be able to detect the sudden change in the EEG related to the moment of awakening, with a precision comparable to careful visual inspection. In addition, we performed the first comparison of a set of conventional and directed functional connectivity measures with eight-node simulation data, based on a real resting closed eye EEG source signal. Parametric modelling-based measures (directed transfer function, partial-directed coherence) were shown to have the highest sensitivity of connections and tolerance to SNR in simulations based on resting closed eye EEG.

Musculoskeletal system research

Current clinical diagnostic tools have only limited ability to assess fracture risk or early osteoarthritis at an individual level. Using a biomechanical approach and advanced image analysis, we showed that structural parameters can discriminate femoral neck fractures from controls, even within subjects with similar bone density (BMD). The method provides additional information beyond standard clinical BMD. We developed computational finite element (FE) models and showed that FE analysis can yield reasonable accuracy in the assessment of experimental failure load. We also showed that dual-energy digital radiography can be applied for bone assessment, and it correlates well with the mechanical properties of bone. We demonstrated that the novel axial transmission ultrasound technique can discriminate fracture subjects from controls with a similar accuracy to that of DXA.

In collaboration with University of Eastern Finland and Mikkeli Hospital, we developed multimodal technology for the detection of early degenerative changes of articular cartilage. We demonstrated quantitative magnetic resonance imaging (MRI), ultrasound, and spectral infrared spectroscopy as potential tools for improved clinical diagnostics. Novel quantitative MRI techniques were developed and proved to be more sensitive to osteochondral degeneration compared to the established techniques.

It is not only bone density or structure that defines who will encounter a fracture. We have performed studies on the extraskeletal risk factors as well, showing that reduced physical performance is a significant determinant of a fracture. We have studied algorithms for fall detection. In our field test, where our algorithms were implemented into an accelerometer-based fall detector, we recorded totally 18 real-life falls. We were the first to collect acceleration data during a fall that resulted in a hip fracture. The data gave valuable information on fall mechanics and tools for improved fall detection sensitivity and specificity.


 

Personnel

professors, doctors

13

doctoral students

16

others

2

total

31

person years

18


 

External Funding

Source

EUR

Academy of Finland

86 000

Ministry of Education and Culture

79 000

Tekes

309 000

other domestic public

130 000

domestic private

31 000

total

635 000


 

Doctoral Theses

Karjalainen T (2012) Nitinol shape memory alloy in flexor tendon repair. Acta Univ Oul. Medica D 1181.

Kenttä T (2012) Dynamics of cardiac repolarization during exercise – rate-dependence and prognostic significance. Acta Univ Oul. Medica D 1177.

Rieppo L (2012) Infrared spectroscopic characterization of articular cartilage. Diss Forestry Nat Sci 90, Univ Eastern Finland.


 

Selected Publications

Enwald HPK, Niemelä RM, Keinänen-Kiukaanniemi S, Leppäluoto J, Jämsä T, Herzig KH, Oinas-Kukkonen H & Huotari MLA (2012) Human information behaviour and physiological measurements as a basis to tailor health information. An explorative study in a physical activity intervention among prediabetic individuals in Northern Finland. Health Inf Libr J 29: 131-140.

Hägglund H, Uusitalo A, Peltonen J, Koponen A, Aho J, Tiinanen S, Seppänen T, Tulppo M & Tikkanen H (2012) Cardiovascular autonomic nervous system function and aerobic capacity in type 1 diabetes. Front Physio3:356. doi: 10.3389/fphys.2012.00356.

Kangas M, Vikman I, Nyberg L, Korpelainen R, Lindblom J & Jämsä T (2012) Comparison of real-life accidental falls in older people with experimental falls in middle-aged test subjects. Gait Posture 35 (3): 500-505.

Kenttä T, Viik J, Karsikas M, Seppänen T, Nieminen T, Lehtimäki T, Nikus K, Lehtinen R, Kähönen M & Huikuri HV (2012) Postexercise recovery of the spatial QRS/T angle as a predictor of sudden cardiac death. Heart Rhythm 9: 1083-1089.

Kiviniemi A, Breskovic T, Uglesic L, Kuch B, Maslov P, Sieber A, Seppänen T, Tulppo M & Dujic Z (2012) Heart rate variability during static and dynamic breath-hold dives in elite diver. Autonomic Neuroscience 169: 95-101.

Kobrina Y, Rieppo L, Saarakkala S, Jurvelin JS & Isaksson H (2012) Clustering of infrared spectra reveals histological zones in intact articular cartilage. Osteoarthr Cart 20(5): 460-468.

Koivumäki JEM, Thevenot J, Pulkkinen P, Kuhn V, Link TM, Eckstein F & Jämsä T (2012) Cortical bone finite element models in the estimation of experimentally measured failure loads in the proximal femur. Bone 51: 737-740.

Koivumäki JEM, Thevenot J, Pulkkinen P, Kuhn V, Link TM, Eckstein F & Jämsä T (2012) CT-based finite element models can be used to estimate experimentally measured failure loads in the proximal femur. Bone 50: 824-829.

Kortelainen J, Jia X, Seppänen T & Thakor N (2012) Increased electroencephalographic gamma activity reveals awakening from isoflurane anaesthesia in rats. Br J Anesthesia 109: 782-789.

Kortelainen J, Tiinanen S, Huang X, Li X, Laukka S, Pietikäinen M & Seppänen T (2012) Multimodal emotion recognition by combining physiological signals and facial expressions: a preliminary study. EMBC 2012, Aug 28-Sep 1, San Diego, USA, 5238-5241.

Mononen ME, Mikkola MT, Julkunen P, Ojala R, Nieminen MT, Jurvelin JS & Korhonen RK (2012) Effect of superficial collagen patterns and fibrillation of femoral articular cartilage on knee joint mechanics-a 3D finite element analysis. J Biomech 45(3): 579-587.

Määttä M, Terho E, Jokinen H, Pulkkinen P, Korpelainen J, Heikkinen J, Keinänen-Kiukaanniemi S, Jämsä T & Korpelainen R (2012) Lifestyle factors and sitespecific risk of hip fracture in community dwelling older women - a 13-year prospective population-basedcohort study. BMC Muscul Disorders 13: 173.

Nieminen MT, Nissi MJ, Mattila L & Kiviranta I (2012) Evaluation of chondral repair using quantitative MRI. J Magnetic Res Imag 36(6): 1287-1299.

Noponen K & Seppänen T (2012) Optimal anisotropic lead scaling of multichannel ECG to reduce magnitude signal variability. BIBE 2012, Nov 11-13, Larnaca, Cyprus, 197-201.

Noponen K, Tiinanen S & Seppänen T (2012) Deriving respiration from electrocardiogram by serial comparison with statistical mean shape. CinC 2012, Sep 9-12, Krakow, Poland, 809-812.

Rieppo L, Rieppo J, Jurvelin JS & Saarakkala S (2012) Fourier transform infrared spectroscopic imaging and multivariate regression for prediction of proteoglycan content of articular cartilage. PLoS One. 7(2): e32344.

Rieppo L, Saarakkala S, Närhi T, Helminen HJ, Jurvelin JS & Rieppo J (2012) Application of second derivative spectroscopy for increasing molecular specificity of fourier transform infrared spectroscopic imaging of articular cartilage. Osteoarthr Cart 20(5): 451-459.

Saarakkala S, Waris P, Waris V, Tarkiainen I, Karvanen E, Aarnio J & Koski JM (2012) Diagnostic performance of knee ultrasonography for detecting degenerative changes of articular cartilage. Osteoarthr Cart 20(5): 376-381.

Salo EN, Nissi MJ, Kulmala KA, Tiitu V, Töyräs J & Nieminen MT (2012) Diffusion of Gd-DTPA2- into articular cartilage. Osteoarthr Cart 20(2): 117-126.

Silfverhuth M, Hintsala H, Kortelainen J & Seppänen T (2012) Experimental comparison of connectivity measures with simulated EEG signals. Med Biol Eng Comp 50: 683-688.

Toljamo PS, Lammentausta E, Pulkkinen P, Tervonen O, Jämsä T & Nieminen MT (2012) Dual-energy digital radiography in the assessment of bone mechanical properties. Physiol Meas 33(1): 29-37.

Turunen SM, Lammi MJ, Saarakkala S, Koistinen A & Korhonen RK (2012) Hypotonic challenge modulates cell volumes differently in the superficial zone of intact articular cartilage and cartilage explant. Biomech Model Mechanobiol 11(5): 665-675.

Turunen MJ, Saarakkala S, Helminen HJ, Jurvelin JS & Isaksson H (2012) Age-related changes in organization and content of the collagen matrix in rabbit cortical bone. J Orthop Res 30(3): 435-442.

Last updated: 15.4.2014