1. Tanvi Kalra 1, Deepak Joshi 2 and Sneh Anand 2 1- Department of Biomedical Engineering, Rayat & Bahra Institute of Engineering & Bio-Technology, Punjab 2 - Centre for Biomedical Engineering, Indian Institute of Technology – Delhi

2. Introduction Block diagram Transmitter module Receiver module Results Snapshots Conclusion References

3. Previous study (Deepak Joshi, et. al.; IJBBR) has proved the knee angle to be a potential parameter to develop Echo Control Prosthesis. Knee Angle measurement system (Deepak Joshi, et. al.; JMET) was found to be quite accurate at the lower range of knee angle (0° - 50°). Normal range of walking pattern. Wireless RF Transmission System ( reduce discomfort) Data – above knee amputee Low cost system Uses minimal number of electronic components

4. ADCENCODERTRANSMITTERRECEIVERDECODERDAC

5. ADC: # Data- Knee angle measurement system # ADC 0804 (20 pin) # 8 bit data transfer(D0-D7) ENCODER: # Parallel data (8 bit) into serial data # HT 640 (24 pin) # DATA OUT (pin 8) – serial data out TRANSMITTER: # TWS-434 module # OUTPUT - 433.92MHz # Wireless transmission - ANTENNA

6. RWS-434 Wireless reception - ANTENNA RECEIVER HT 648(24 pin) Serial data into parallel data(D0-D7) DECODER DAC 0800 (16 pin) analog data - IC 741 (current to voltage converter) DAC

7. Figure 1: Knee-Angle Measurement System (developed in lab, CBME, IITD) Figure 2(a)-(e): These snap shots shows the orderly change in the data at both the ends (channel 1- transmitter end, channel 2 – receiver end) (a)

8. (b)(c) (d)(e)

9.  Results (CRO) - Faithful signal transmission  Knee angle changes at the transmitter end & the same change is observed at the receiver end. i.e. ch1 & ch2 resp.  Direct application in Echo Control Lower Limb Prosthesis  And other wireless medical devices

10.  Deepak Joshi, Sneh Anand. Study of circular cross correlation and phase lag to estimate knee angle: an application to prosthesis; Int. J. Biomechatronics and Biomedical Robotics [in press]  Roozbeh Borjain, Mir Behrad Khamesee, William Melek. Feasibility study on echo control of a prosthetic knee: sensor and wireless communication; Microsyst Technol, Vol.16, No.257-265 [2010]  Deepak Joshi et.al. kinematics-coordinated walking pattern based on embedded controls; journal of medical engineering & technology [in press]  http://www.rentron.com/rf_remote_control.htm http://www.rentron.com/rf_remote_control.htm  http://pdf1.alldatasheet.com/datasheet-pdf/view/82103/HOLTEK/HT640.html http://pdf1.alldatasheet.com/datasheet-pdf/view/82103/HOLTEK/HT640.html  http://pdf1.alldatasheet.com/datasheet-pdf/view/64465/HOLTEK/HT648L.html http://pdf1.alldatasheet.com/datasheet-pdf/view/64465/HOLTEK/HT648L.html

11. Any Questions ? THANK YOU