antenna design for monitoring bone fracture healing

antenna design for monitoring bone fracture healing

1. A Trapezoidal Ground-based Truncated Rectangular Patch Antenna for Non-Invasive Monitoring of Bone Fracture Healing Tilakdhari Singh ECED,MNNIT Allahabad, Prayagraj Anupriya Verma ECED,MNNIT Allahabad, Prayagraj Piyush Kumar Mishra ECED,MNNIT Allahabad, Prayagraj Shalini Siddhi ECED,MNNIT Allahabad, Prayagraj Pooja Sharma ECED,MNNIT Allahabad, Prayagraj Vijay Shanker Tripathi Professor ECED,MNNIT Allahabad, Prayagraj

2. Outline Introduction Methodology Antenna Design and Specification Results and Discussion Comparison Conclusion References

3. Introduction In recent years, RF/microwave based non-invasive devices for monitoring bone fracture have paid much attention due to increasing numbers of bone fractures in the world. Bone fractures are a public health issue around the world and pose a serious economic burden [1]. The bone fractures are common in children, old age people, people having weak bone due to lack of calcium. The majority of bone fractures are caused by accidents in metropolitan cities. The treatment of bone fractures is a time-consuming process and needs more care, continuous monitoring by doctors during the first four weeks. Figure 1: Burden of bone fractures in 204 countries [2019] [1]. The Lancet Global Burden on Disease resource centre

4. Introduction contd.. Time taken in recovery of bone fracture depends on age, gender, and type of physical condition. This can be varied between 4 to 40 weeks [2]. Recently there is no standard procedure for predicting bone fracture. People generally rely on X-ray. In general, the X-ray is the first screening test performed when the patient arrives at the hospital. Due to the high cost, CT and MRI are indicated only in cases where X-rays do not provide the necessary detail. MRI provides better contrast between cortical bone, bone marrow, muscle, and soft tissues in the body, yet it is the most expensive and slower technique [3]. Figure 2. Recovery of bone fracture [2] (b) CT-Scan (c) MRI (d) Comparison (a) X-ray Figure 3. Comparison of X-ray, CT and MRI [google source]

5. Introduction contd.. Previously mentioned techniques use high levels of ionised radiation to monitor the bone fractures in the human body. According to the World Health Organization (WHO), the continuous radiation exposure to the human body may cause cancer. Hence there is need of antenna based microwave sensors because it is potentially inexpensive, compact, portable and able to provide hard and soft tissue information in real time [4].

6. Methodology The human bone is divided into 5 categories as large, small, flat, sesamoid, and random shape based on size, position, and tissue characteristics. The largest bone observed in the human body is Tibia. The tibia is found at the bottom side of the legs. During bone fracture, there arises a small gap (fracture area) between two ends in the injured area that needs to be filled by new generating bones to make it normal as before. Figure 3. Different stage of healing during bone fracture recovery [5]. The process of the formation of blood clots and calluses to feel the gap in a fractured area by bones is called healing. The normal healing process takes 6 to 8 weeks even though this time frame is highly variable for example, a tibia fracture can take up to 20 weeks to heal while hand and wrist fracture Heals rapidly and takes only up to 6 weeks [5].

7. Methodology contd.. When the antenna comes in contact with a phantom, its frequency is shifted in terms of S 11 as per varying values of relative permittivity from blood (55) to remodelling bone (4). By analysing the average linearity graph between changes in frequency and relative permittivity, we can monitor the healing of bone fractures. Figure 4. Block Diagram for Measurements of Bone Fracture Healing

8. Methodology contd.. The monitoring of the formation of blood clots to callus in the fractured area helps us in predicting the rate of recovery. Normally callus is divided into two parts soft and hard callus phases. In the soft callus phase, stem cells in fractured area changes into chondrocytes which results in cartilages to fill the gap. In the hard callus phase, endochondral ossification occurs Where cartilage is replaced by bone as shown in Figure 3. To monitor bone fracture healing, a Phantom is created using tissue layers of muscles, bone marrow, bone cortical, and blood. The dielectric properties of above mention tissues varied from blood to bones and were highly affected by electromagnetic wave radiation when the antenna came closer to the phantom as shown in Figure 5. Figure 5. Antenna in contact with phantom [6]

9. 9 Design of microwave sensor Proposed antenna is designed on Rogers RT Duroid 5880 substrate with height 0.25 mm. Tissue Conductivity (S/M) Relative permittivity Loss tangent Muscle 3.8279 49.8 0.28785 Blood 5.1306 54.299 0.35384 Bone Cortical 0.91468 10.135 0.33798 Bone Marrow 0.22144 5.0572 0.16398 Figure 6. (a) Simulated Antenna (b) Antenna with human bone phantom (c) Fabricated Antenna in anechoic chambre (d) Fabricated Antenna Table 1. Electrical properties of tissue layers at 4.8 GHz [8].

10. 10 Results and Discussion Figure 7. (a) Design step to achieve final antenna. Reflection coefficient of simulated measured and with phantom (c) Surface current distribution (e) Gain and frequency graph (d) 3D polar gain -Resonance frequency ( fr ): 4.8 GHz. - Reflection coefficient (S 11 ): -43 dB - Impedance Bandwidth: 1.2 GHz (4.4-5.6 GHz) - S11 with phantom shows -25 dB at shifted resonance frequency 3.8 GHz at 0.2 mm separation

11. Results and Discussion contd.. Figure 8. Different stage of bone fracture healing To monitor bone fracture healing, the relative permittivity of bone marrow tissue is varied between 5 (bone marrow) to 55 (blood). In normal conditions at a relative permittivity of 5, bone marrow is assumed as 0% bone fracture, and in the worst condition of bone fracture, the gap filled with blood is assumed as 100% bone fracture. The formation of blood clots to callus during healing is divided into different fracture levels as 20%, 40%, 60%, and 80% based on varying relative permittivity between 15 to 45 at the intervals of 10 respectively as shown in Figure 8.

12. Results and Discussion contd.. Figure 9. Linearity graph for predicting sensitivity . For developing linearity graph, total 11 samples are collected with the help of VNA by varying relative permittivity in the range of 5 to 55 at intervals of 5. The observed change in frequencies is found between 3.925 to 4.125 GHz with a minimum error of 4.5 MHz to maximum error of 18 MHz Percentage error becomes a minimum of 2.25% to a maximum of 9% to provide an average sensitivity of 4MHz/ ε r . Linearity graph is shown in figure 9.

13. Reference Substrate/ Size (mm 3 ) Fr/ B.W. [GHz] Technique used Measured value [7] FR-4/ 18×19×0.8 3.76, 6.7, 9.8/ 3.14-11.7 S 11, SAR 1.6 w/kg for 1g at 18 dBm I/P power [8] FR-4 Glass Epoxy / 114×80 2.45/ 0.292 S 11 / S 21 Accuracy 98.86 by using the Lanczos method [10] Rogers RT duriod 5880/ 30×40×1.016 3.4/0.5 S 11 Propagation delay (ns) [11] FR-4/ 32× 30×1.6 2.45/ 0.027 S 11 Shift in frequency   Proposed sensor Rogers RT droid/ 25×25×0.25 4.8/ 1.2 S 11 The shift in frequency/ sensitivity of 4 MHz/ ε r TABLE II. COMPARISON OF PROPOSED ANTENNA DESIGN WITH OTHER WORK FOR MONITORING BONE FRACTURE HEALING. Comparison

14. Conclusion This paper explains the study of trapezoidal shape based patch antenna for non-invasive monitoring of bone fracture healing. The antenna is designed on RT Rogers 5880 substrate with 0.25 mm thickness with a compact size of 25×25 mm 2 . The measured antenna shows 1.2 GHz Impedance bandwidth with 3.4 dBi measured gain at the resonance frequency of 4.8 GHz. The fabricated antenna is simulated for bone fracture monitoring with Phantom by using a vector network analyzer (VNA). Different samples are collected by VNA and their sensitivity is calculated by linearity graph. The observed sensitivity is 4 MHz/ ε r with minimum to maximum error of 2.25% to 9% respectively. Hence, we can conclude that the proposed antenna is suitable for monitoring bone fracture healing.

15. References [1] Wu, Ai-Min et al., “Global, regional, and national burden of bone fractures in 204 countries and territories, 1990–2019: a systematic analysis from the Global Burden of Disease Study 2019”, The Lancet Healthy Longevity, Volume 2, Issue 9, e580 - e592, August, 2021. [2] B. Khalesi , B. Sohani , N. Ghavami, M. Ghavami, S. Dudley and G. Tiberi , "Free-Space Operating Microwave Imaging Device for Bone Lesion Detection: A Phantom Investigation," in IEEE Antennas and Wireless Propagation Letters, vol. 19, no. 12, pp. 2393-2397, Dec. 2020, doi : 10.1109/LAWP.2020.3034039. [3] Augat , P., Faschingbauer , M., Seide , K., Tobita , K., Callary , S. A., Solomon, L. B., & Holstein, J. H. (2014). Biomechanical methods for the assessment of fracture repair. Injury, 45, S32-S38. [4] S. Symeon , G. W. William, Z. Massimiliano, and P Chinthana , “Bone fracture monitoring using implanted antennas in the radius, tibia and phalange heterogeneous bone phantoms” Biomed. Phys. Eng. Express 4- 045006, May,2018. [5] Kamlesh Kumar Gupta and P Gupta and Ganesh Singh and S. Kumar and RK Singh and R. N. Srivastava, “Changes in electrical properties of bones as a diagnostic tool for measurement of fracture healing” Hard Tissue, 3:2(1), 21 Jan 2013. [6] Symeon Symeonidis , Carmen Torres-Sanchez, Chinthana Panagamuwa and William Whittow , “An Implanted Antenna System for the Monitoring of Bioresorbability of a Biocompatible Scaffold Embedded into a Bone Fracture" Mobihealth , London, Great Britain, 14-16 Oct, 2015. DOI:10.4108/eai.14-10-2015.2262206. [7] Shaik Rizwan, Kanaparthi V. Phani Kumar, Sandeep Kumar Palaniswamy , "On the Experimental Investigation of Bone Fracture Recovery Process Using an Ultra-Wideband Planar Monopole Antenna", International Journal of Antennas and Propagation, vol. 2023, Article ID 8825446, 13 pages, 2023. [8] V. S. Ramalingam, M. Kanagasabai and E. F. Sundarsingh , "A Compact Microwave Device for Fracture Diagnosis of the Human Tibia," in IEEE Transactions on Components, Packaging and Manufacturing Technology, vol. 9, no. 4, pp. 661-668, April 2019. [9] K. C. Santos, C. A. Fernandes, and J. R. Costa, "Feasibility of Bone Fracture Detection Using Microwave Imaging," in IEEE Open Journal of Antennas and Propagation, vol. 3, pp. 836-847, 2022. [10] Shilpi Ruchi Kerketta and Debalina Ghosh, “Microwave sensing for human bone health evaluation” AEU - International Journal of Electronics and Communications, Volume 127, 153469, 2020. ISSN 1434-8411. [11] Ananda Venkatesan Boologam , Kalimuthu Krishnan, Sandeep Kumar Palaniswamy , Sachin Kumar, Shreya Bhowmik, Nivesh Sharma, Deepesh Vaish,Sourish Chatterjee, "On the Design and Development of Planar Monopole Antenna for Bone Crack/Void Detection", International Journal of Antennas and Propagation, vol. 2022, Article ID 4663488, 12 pages, 2022.

16. 16 Contd.. [12] Amin B, Elahi MA, Shahzad A, Porter E, McDermott B, O'Halloran M. Dielectric properties of bones for the monitoring of osteoporosis. Med Biol Eng Comput . 2019 Jan;57(1):1-13. doi : 10.1007/s11517-018-1887-z. Epub 2018 Aug 29. PMID: 30159660. [13] Singh, T., Mishra, P. K., Pal, A., & Tripathi, V. S. (2023). A planar microwave sensor for noninvasive detection of glucose concentration using regression analysis. International Journal of Microwave and Wireless Technologies, 1-11, https://doi.org/10.1017/S175907872300 0545. [14] S. S. Dhanabalan , Sitharthan R, K Madurakavi , A Thirumurugan , Rajesh M, S. R. Avaninathan and Marcos Flores Carrasco, “Flexible compact system for wearable health monitoring applications” Computers and Electrical Engineering, Volume 102, 108130, 2022, ISSN 0045-7906. [15] T. Singh, P. K. Mishra, A. Pal and V. S. Tripathi, "A Defected Ground Comb Shape Microwave Sensor for Non-Invasive Measurement of Blood Glucose," 2022 IEEE Microwaves, Antennas, and Propagation Conference (MAPCON), Bangalore, India, 2022, pp. 1783-1787, doi : 10.1109/MAPCON56011.2022.10046895.

17. 17 Thank You…