Neural Facilitation in MRI via Pneumatically Driven, Tele-Operated Systems

Transcription

1 Neural Facilitation in MRI via Pneumatically Driven, Tele-Operated Systems Georgia Institute of Technology Milwaukee School of Engineering North Carolina A&T State University Purdue University University of Illinois, Urbana-Champaign University of Minnesota Vanderbilt University Presenter Melih Turkseven (GT) Faculty Robert Webster (VU), Jun Ueda (GT), Vito Gervasi (MSOE), Eric Barth (VU) FPIRC October 15, 2015 Universities Vanderbilt University, Georgia Institute of Technology, Milwaukee School of Engineering

2 FLUID POWERED SURGERY AND REHABILITATION VU: MRI compatible surgery robot Linear and rotary actuators Design of integrated systems Surgical applications GT: functional MRI compatible haptic interface Novel manufacturing processes Novel AM-based FFA s Force and displacement sensors Control with long pneumatic lines 2

3 Difficulties in utilizing this technology: REHABILITATION IN MRI USING ROBOTS Limited access to the patient A practitioner has to spend hours in MRI Hard to apply the exercise and monitor its efficacy simultaneously A tele-operated platform can improve the quality of rehabilitation A more standardized therapy A wider range of statistical information on the patient Has gained popularity in neuroscience Investigation of brain functioning in fine motor skills 15 million individuals suffer hemiplegia each year worldwide, in the U.S. 3

4 Pressure (Pa) Pressure (Pa) MAJOR CHALLENGE IN DEVICE CONTROL 4.8 x Transmission line and the cylinder geometry affect the pressure dynamics of the system Actual pressure in the cylinder chamber cannot be measured on the transmission line x Time (sec) Valve Line 3 V 7.25 m Actuator Time (sec) 4

5 FACILITATION EXERCISE USING A PNEUMATIC DEVICE Targeted for Repetitive Facilitation Exercise (RFE) of Hemiplegic Limbs 5-7 m. MRI Control Room Pressure Sensor Valve 5

6 FACILITATION EXERCISE USING A PNEUMATIC DEVICE Targeted for Repetitive Facilitation Exercise (RFE) of Hemiplegic Limbs Goal: To superpose voluntary muscle activation with involuntary stretch reflex Augmented feedback instruction Reaction time Receiving and processing sensory stimulus Voluntary response Command Mechanical stimulus (Tendon tapping) Signal going out from motor cortex Robotic Mechanism Long latency response Signal overlapping 6

7 FACILITATION EXERCISE USING A PNEUMATIC DEVICE Targeted for Repetitive Facilitation Exercise (RFE) of Hemiplegic Limbs Goal: To superpose voluntary muscle activation with involuntary stretch reflex Transcranial Magnetic Stimulus Augmented feedback instruction Receiving and processing sensory stimulus Voluntary response Command Pneumatic transmission line delay Pneumatic System Long latency response Signal overlapping 7

8 DESIGN SPECIFICATIONS An fmri compatible device, capable of replicating RFE procedures. Designed for consistent mechanical impulses with a certain timing precision. Confirmed fmri compatibility 8

9 TESTS FOR INVESTIGATING THE REQUIRED TIMING PRECISION The time delay between two stimuli was varied to observe the time range of successful superposition Pneumatic transmission meets initially targeted precision requirements Hose Length (m) Mean Delay (s) STD (s) Range (s)

10 ROBOTIC RFE EXPERIMENTS ON HUMAN SUBJECTS Tests on human subjects revealed the required precision for a successful facilitation exercise with mechanical stimulus 10

11 ADDED MECHANISM FOR WRIST ROTATION Plastic Vane Actuator Designed a fmri compatible pneumatic vane actuator. The prototype satisfied required timing precision Provides rotary actuation in a compact and efficient way Input pressure [psi] Start time mean (STD) [ms] (1.03) (0.84) (1.41) (2.16) Compressed air (red) Atmospheric air (blue) 11

12 MODEL OF A PNEUMATIC SYSTEM WITH LONG TRANSMISSION LINES Reservoir Actuator P reservoir Transmission Line P actuator V actuator F Force Sensor m v P line V line m f Valve An inhomogeneous pressure distribution between the transmission line and the actuator is assumed The transmission line is treated as an intermediate chamber between the reservoir and the actuator Fitting Fitting is assumed as an orifice: m na P, P ) f f ( u d P, P, ) u ) ( P P line actuator ( d P actuator, P ) ( line if P line P otherwise actuator 12

13 PNEUMATIC VANE ACTUATION FOR fmri STUDIES The feasibility of using pneumatic vane actuation for wrist supination/pronation in RFE was checked 13

14 PNEUMATIC VANE ACTUATION FOR fmri STUDIES The feasibility of using pneumatic vane actuation for wrist supination/pronation in RFE was checked 14

15 ACKNOWLEDGEMENTS KYB Corporation Danish Technological Institute Enfield Technologies 15

16 THANK YOU! Questions? 16