Dept. Biomedical Measurements
Department of Biomedical Aging Measurements
The Department of Biomedical Aging Measurements aims to develop and to validate imaging and sensor technologies for measurements of aging-related physiological, morphological and/or biochemical changes which can help to elucidate the processes and mechanisms of human aging.
Development of High Precision Imaging and Sensor Technologies
Ultrasound is well recognized as a safe and portable device for clinical imaging. Not only that, high frequency ultrasound has realized high precision imaging with the resolution of 10 microns. We have developed scanning acoustic microscopy to visualize acoustical properties that is closely correlated with biomechanical properties of the excised tissues or cultured cells. Recently, we applied the technology for assessing biomechanics of cartilage in order to clarify the development and regeneration of cartilage. We have newly developed acoustic impedance microscopy and 3D acoustic microscopy for in vivo imaging and clinical applications.
Instead of mechanical scan transducer, we have currently started the fabrication of high frequency ultrasound array transducer with international collaborations of universities and industries.
Biomedical Engineering Evaluation of Skin Conditions
Human skin consists of three layers such as epidermis, dermis and subcutis. Among these layers, dermis is most important to maintain elasticity and flexibility of the skin. We have applied 3D acoustic microscopy to visualize fine structure of dermis such as microvessel, hair follicle and skin texture. Elastic properties of dermis depend on quality of collagen and elastin. With ultrasonic analysis of the very small vibration induced on the dermis, the elasticity of the dermis is quantitatively measured. We compared our imaging-based measurements with existing skin analysis methods such as water content, oil content, normal light / UV CCD camera and biomechanical measurement with analysis of force-displacement relation.
We are developing novel measurement devices for skin analysis. Ultrasound impedance meter based on ultrasound impedance microscopy is a compact small probe that measures the acoustic impedance of the skin which is strongly correlated with skin elasticity. We will start collaboration with plastic and aesthetic surgeons and cosmetic industries to achieve scientific base on the smart aging of the skin.
Evaluation of Atherosclerosis in Large Population
Today, atherosclerosis is defined as the condition in which an artery wall thickens as the result of chronic inflammatory responses against low-density lipoproteins in the arterial wall. Classically, atherosclerosis is developed with human aging, thus easy diagnosis for large population is important for public health and welfare of the aging society. Popularization of clinically approved examinations such as carotid artery ultrasound or pulsed wave velocity measurement, we have developed an in-expensive mobile ultrasound device for refugee medicine or public health care. We have confirmed the ability for screening of deep vein thrombosis in Miyagi-Iwate inland earthquake. We have also confirmed the utility and image quality for carotid artery scan in screening of atherosclerosis in large population. We believe that the mission of the university is not only research and education, but also social contribution. For that purpose, we will start the screening of the atherosclerosis as a part of the social health examination in Miyagi area in 2010.
Collaborations of Aging Research and Imaging and Sensor Research
The development of the best measurements for aging-related physiological and functional changes requires development of a relationship among the aging research and imaging and sensor communities. As the researchers in this department also belong to Division of Biomedical Measurements and Diagnostics, Graduate School of Biomedical Engineering, Tohoku University, we would like to contribute to collaboration by introducing advanced measurement technologies in the engineering field to clinicians, aging researchers and industries. The imaging and sensor technologies are not only important for diagnosis but also facilitate an opportunity to test an intervention for a disease and stimulate a field of pharmacology and therapeutics.
- Saijo Y, Jorgensen CS, Falk E. Ultrasonic tissue characterization of collagen in lipid-rich plaques in apoE-deficient mice. Atherosclerosis Vol. 158, No. 2: 289-295, 2001.
- Saijo Y, Ohashi T, Sasaki H, Sato M, Jorgensen CS, Nitta S. Application of scanning acoustic microscopy for assessing stress distribution in atherosclerotic plaque. Ann Biomed Eng, Vol. 29, No. 12: 1048-53, 2001.
- Saijo Y, Jorgensen CS, Mondek P, Sefranek V, Paaske W. Acoustic inhomogeneity of carotid arterial plaques determined by GHz frequency range acoustic microscopy. Ultrasound Med Biol, Vol. 28, No. 7: 933-937, 2002.
- Saijo Y, Akimoto H, Saiki Y, Tabayashi K, Horinouchi T, Kobayashi T, Nitta S.I. Proximal (entry) tear of dissecting aortic aneurysm visualized by three-dimensional echocardiography. J Thorac Cardiovasc Surg Vol. 124, No. 6: 1245-1246, 2002.
- Saijo Y, Miyakawa T, Sasaki H, Tanaka M, Nitta S. Acoustic properties of aortic aneurysm obtained with scanning acoustic microscopy. Ultrasonics, Vol. 42, No. 1-9: 695-698, 2004.
- Saijo Y, Nitta S, Kobayashi K, Arai H, Nemoto Y. Development of an ultra-portable echo device connected to USB port. Ultrasonics, Vol. 42, No. 1-9: 699-703, 2004.
- Saijo Y, Tanaka A, Owada N, Akino Y, Nitta S. Tissue velocity imaging of coronary artery by rotating-type intravascular ultrasound. Ultrasonics, Vol. 42, No. 1-9: 753-757, 2004.
- Saijo Y, Sasaki H, Hozumi N, Kobayashi K, Tanaka M, Yambe T. Sound speed scanning acoustic microscopy for biomedical applications. Technol Health Care. Vol. 13, No. 4: 261-7, 2005.
- Watanabe S, Suzuki N, Kudo A, Suzuki T, Abe S, Suzuki M, Komatsu S, Saijo Y, Murayama N. Influence of aging on cardiac function examined by echocardiography. Tohoku J Exp Med. Vol. 207, No.1: 13-9, 2005.
- Santos Filho E, Yoshizawa M, Tanaka A, Saijo Y, Iwamoto T. Moment based texture segmentation of intravascular ultrasound images. J Med Ultrasonics. Vol. 32, No. 3: 91-99, 2005.
- Sano H, Hattori K, Saijo Y, Kokubun S. Does decalcification alter the tissue sound speed of rabbit supraspinatus tendon insertion? In vitro measurement using scanning acoustic microscopy. Ultrasonics, Vol. 44, No. 3: 297-301, 2006.
- Saijo Y, Hozumi N, Lee C, Nagao M, Kobayashi K, Oakada N, Tanaka N, Santos Filho ED, Sasaki H, Tanaka M, Yambe T. Ultrasonic speed microscopy for imaging of coronary artery. Ultrasonics, Vol. 44; Suppl. 1: e51-55, 2006.
- Saijo Y, Tanaka A, Iwamoto T, Dos Santos Filho E, Yoshizawa M, Hirosaka A, Kijima M, Akino Y, Hanadate Y, Yambe T. Intravascular two-dimensional tissue strain imaging. Ultrasonics, Vol. 44; Suppl. 1: e147-151, 2006.
- Saijo Y, Hozumi N, Kobayashi K, OkadaN, Santos Filho ED, Sasaki H, Yambe T, Tanaka M. Ultrasonic tissue characterization of atherosclerosis by a speed-of-sound microscanning system. IEEE Trans Ultrason Ferroelectr Freq Control. Vol. 54, No. 8: 1571-1577, 2007.
- Santos Filho E, Saijo Y, Tanaka A, Yambe T, Yoshizawa M. Fractal dimension of 40 MHz intravascular ultrasound radio frequency signals. Ultrasonics, Vol. 48, No. 1, 35-39, 2008.
- Santos Filho E, Saijo Y, Tanaka A, Yoshizawa M. Detection and quantification of calcifications in intravascular ultrasound images by automatic thresholding. Ultrasound Med Biol. Vol. 34, No. 1: 160-165, 2008.
- Hagiwara Y, Ando A, Chimoto E, Saijo Y, Ohmori-Matsuda K, Itoi E. Changes of articular cartilage after immobilization in a rat knee contracture model. J Orthop Res. Vol. 27, No. 2: 236-242, 2009.
- Hagiwara Y, Saijo Y, Ando A, Chimoto E, Suda H, Onoda Y, Itoi E. Ultrasonic intensity microscopy for imaging of living cells. Ultrasonics Vol. 49, No. 3: 386-388, 2009.
- Saijo Y. Acoustic microscopy: latest developments and applications. Imaging in Medicine, Vol. 1, No. 1, 47-63, 2009.