An Implanted Antenna System for the Monitoring of Bioresorbability of a Biocompatible Scaffold Embedded into a Bone Fracture

Abstract

In this paper the dielectric properties of an implanted bioresorbable scaffold that is being used for the acceleration of the healing process of a fractured bone have been investigated. An implanted antenna system is presented for the monitoring of the resorption rate of the scaffold, which gives an indication on the healing process of the bone fracture. A simulation model of a three layer body phantom was used for the evaluation of the response of the system as the introduced fracture gradually healed, turning from blood to bone marrow and bone cortical in five steps.

Bone fracture monitoring using implanted antennas in the radius, tibia and phalange heterogeneous bone phantoms

“…) where ω is the angular frequency and μ 0 , ε 0 are the permeability and permittivity of vacuum respectively. The relative permittivity and conductivity of blood are higher than that of bone over the frequency range 1 to 4 GHz [17,18,39], i.e. ε rblood =61, σ blood =1.58 and ε rbone =12, σ bone =0.15 at 1 GHz.…”

Design and characterization of a three material anatomical bone phantom for implanted antenna applications

“…An antenna test bed consisting of two monopoles was created for the investigation of the electromagnetic wave propagation inside the phantom. It is envisioned that the proposed test bed will re-enact the metal pins of an external medical metal plate for bone fracture monitoring applications, as presented in our previous work [15]. The conducting parts of the monopoles were implanted into the bone and muscle layers of the simulated three layer phantom.…”

“…A gap of 4mm between the groundplanes was selected in order to ensure separation between them. The monopoles and groundplanes were coated with biocompatible PLA insulator and the distance between them was 2cm as it was found in previous research to be a good trade-off between distance and wave attenuation [15] inside the phantom. Achieving a 2cm distance between the conductors required the monopoles to be placed 0.…”

Characterisation of an antenna system implanted into a limb phantom for monitoring of bone fracture healing

“…The biological process of fracture healing is a complicated process that if not monitored and evaluated continuously the first 4 weeks after the trauma, often leads to failure of bone restoration to its pre fractured state [19]. Healing depends, amongst others, on the number of discrete fractures, the type of bone and the patient's age and gender [20], [21]. The proposed antenna system could provide doctors with continuous information regarding the state of the fractured bone, reducing the required x-rays and CT scanning.…”