Assessment of human bones encompassing physiological decay and damage using piezo sensors in non-bonded configuration

In the recent years, several biomedical applications of lead zirconate titanate piezo-electric ceramic patches based on the electro-mechanical impedance technique have been reported in the literature. However, practical application of the technique on live subjects is severely hampered due to the requirement of bonding the patch with bone or cartilage with an adhesive. In addition, live subjects have skin cover over the bone. This article proposes and evaluates the feasibility of employing lead zirconate titanate patches as biomedical sensors in non-bonded configuration for assessing the physiological conditions of bones. For this purpose, a special design is proposed where the lead zirconate titanate patch is first bonded on a thin aluminum strip, which is in turn clamped securely on the biomedical subject. The proposed configuration is investigated both in vitro and in vivo. The non-bonded piezo sensors are first investigated to identify dynamic parameters of the bone through lab-based experimental study involving artificial bones. Thereafter, physiological damage and decay conditions are artificially simulated in the experimental bones and the same are correlated with changes in conductance signatures from the non-bonded piezo sensor as well as the lead zirconate titanate patch in the conventional adhesively bonded (direct bonding to the subject) configuration. The trend of the conductance signatures in the healthy and the damaged conditions from the non-bonded piezo sensor is found to correlate well with the corresponding signatures from the directly bonded piezo sensor. At the same time, the repeatability of the signatures is also found to be satisfactory. After success in bare bones, the non-bonded piezo sensor configuration is extended to monitor the condition of bones covered with skin and tissue, simulated in the lab with the aid of silicone-based coating. Finally, a proof-of-concept experiment on a live human subject is successfully demonstrated. The overall results of the study demonstrate very good prospects of employing lead zirconate titanate patches in non-bonded piezo sensor mode for monitoring the condition of human bones and other related biomedical subjects.

[1]  Chee Kiong Soh,et al.  Effect of varying axial load under fixed boundary condition on admittance signatures of electromechanical impedance technique , 2012 .

[2]  Suresh Bhalla,et al.  Calibration of piezo-impedance transducers for strength prediction and damage assessment of concrete , 2005 .

[3]  Chung Bang Yun,et al.  PZT-based active damage detection techniques for steel bridge components , 2006 .

[4]  Suresh Bhalla,et al.  Performance of smart piezoceramic patches in health monitoring of a RC bridge , 2000 .

[5]  Piervincenzo Rizzo,et al.  Assessment of dental implant stability by means of the electromechanical impedance method , 2011 .

[6]  Yaowen Yang,et al.  Practical issues related to the application of the electromechanical impedance technique in the structural health monitoring of civil structures: I. Experiment , 2008 .

[7]  Suresh Bhalla,et al.  Structural impedance based damage diagnosis by piezo‐transducers , 2003 .

[8]  T. Keaveny,et al.  Evolution of the biomechanical material properties of the femur , 2002, The Anatomical record.

[9]  Suresh Bhalla,et al.  Ultra Low-cost Adaptations of Electro-mechanical Impedance Technique for Structural Health Monitoring , 2009 .

[10]  Piervincenzo Rizzo,et al.  On the use of the electromechanical impedance technique for the assessment of dental implant stability: Modeling and experimentation , 2015 .

[11]  M Fitzmaurice,et al.  The Use of Biomedical Sensors to Monitor Capsule Formation Around Soft Tissue Implants , 2006, Annals of Plastic Surgery.

[12]  Chee Kiong Soh,et al.  Damage detction and characterization using EMI technique under varying axial load , 2013 .

[13]  Anil K. Chopra,et al.  Dynamics of Structures: Theory and Applications to Earthquake Engineering , 1995 .

[14]  Victor Giurgiutiu,et al.  Recent advancements in the electromechanical (E/M) impedance method for structural health monitoring and NDE , 1998, Smart Structures.

[15]  Suresh Bhalla,et al.  Bone Characterization using Piezotransducers as Biomedical Sensors , 2008 .

[16]  S. Bhalla,et al.  Condition monitoring of bones using piezo-transducers , 2013 .

[17]  Victor Giurgiutiu,et al.  Embedded Self-Sensing Piezoelectric Active Sensors for On-Line Structural Identification , 2002 .

[18]  Joel W. Ager,et al.  Fracture and Ageing in Bone: Toughness and Structural Characterization , 2006 .

[19]  E Panagiotopoulos,et al.  Evaluation of modal damping factor as a diagnostic tool for osteoporosis and its relation with serum osteocalcin and collagen I N-telopeptide for monitoring the efficacy of alendronate in ovariectomized rats. , 2006, Journal of pharmaceutical and biomedical analysis.