Measurements of piezoelectric properties in cancellous bone under ultrasound irradiation

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K06479
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Measurement engineering
• Research Institution: Akashi National College of Technology
• Principal Investigator: Hosokawa Atsushi 明石工業高等専門学校, 電気情報工学科, 准教授 (00321456)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 海綿骨 / 圧電特性 / 超音波 / 間隙流体 / 骨梁構造

Outline of Final Research Achievements

In this study, the piezoelectric properties of cancellous bone in the ultrasound (high-frequency) region were experimentally investigated. First, "a piezoelectric cell," which is an ultrasonic sensor using a cancellous bone specimen as a piezoelectric element was developed and improved,and a method for observing piezoelectric signals generated in cancellous bone by ultrasoound irradiation could be established. Next, using the piezoelectric cell, the piezoelectric signal in cancellous bone was measured, and the piezoelectric properties were investigated. Concretely, the difference in the piezoelectric signal owing to the fluid filling the pores in cancellous bone was shown with the relationship with the ultrasound signal propagating through the bone. Moreover, the effect of the trabecular orientation in cancellous bone on the piezoelectric signal were shown.

Free Research Field

超音波工学

Academic Significance and Societal Importance of the Research Achievements

現在、超音波照射による骨折治療が行われているが、その物理的（電気・機械的）メカニズムは不明なままである。骨の生成骨には骨が有する圧電特性が関係すると考えられているが、超音波（高周波）帯域における骨の圧電特性は十分に分かっていない。特に、多孔性構造を有する海綿骨における圧電特性については、ほとんど未知であると言える。本研究で明らかにした海綿骨の圧電特性は、海綿骨生成の物理メカニズムの解明の一助となることが期待できる。最終的には、海綿骨を多く含む関節骨における骨折の効率的な治癒方法の実現につながると考えられる。