Integrating sensors into health diagnostic systems

Transcription

1 Integrating sensors into health diagnostic systems May NanoEXPO Conference Prepared by Diana Hodgins, Managing Director ETB SIXTH FRAMEWORK PROGRAMME Information Society Technologies

2 Overview ETB is microsystem design company,specialising in physical sensor systems and is the project co-ordinator for Healthy Aims. Healthy Aims is a 23M, four year EU FP6 project with the goal to develop a number of intelligent medical implants and diagnostic systems, integrating a range of underpinning micro- and nano- technologies. The medical diagnostic equipment undergoing patient trials within the Healthy Aims project provide a benchmark of today s state-of-the-art worldwide. There are 25 partners from 10 EU countries, six of which are clinical partners. Their role is to help develop the system specifications, guide the development work and carry out clinical trials on prototypes. Page 1 of 27

3 Products being developed within Healthy Aims passive gauge telemetry chip antenna active gauge Glaucoma sensor Intra-cranial pressure sensor Retina implant Cochlear implant Electrical stimulation (FES) for limb motion Bladder and bowel electrical stimulators Sphincter sensor Activity monitor Page 2 of 27

4 How nanotechnology is applied to the products Each of the system products integrate nanotechnology, for example: Coating materials Features on sensors Surface treatments Joining technologies In the Healthy Aims project only those nanotechnologies that were ready for product integration have been incorporated. Some examples of the use of nanotechnology in the glaucoma sensor, activity monitor, intra-cranial pressure sensor (ICP) and the retinal implant are now discussed. Page 3 of 27

5 Glaucoma sensor integrated into a contact lens 50µm ASIC Ref sensor ASIC Antenna Flexible substrate Gold stud bump Active sensor Page 4 of 27

6 Complete glaucoma sensor system [Page 5 of 15] 27

7 Signal measured with the Glaucoma Sensor Continuous IOP monitoring on human Contact Lens output [mv] Ocular Pulse Amplitude eye blinking time [s] Signal measured with the first version (with wires) of the glaucoma sensor, during clinical trials on healthy patients. The ocular pulsation has been measured, which corresponds to a deformation of the eyeball 10 to 15 times smaller than in the case of glaucoma patients. Page 6 of 27

8 Human body motion system Combs on a single gyro sensor Wafer of planar 3-axis gyro Page 7 of 27

9 Activity and human gait monitoring Activity monitor integrating inertial sensors Storage 6 degree of freedom IMU ( out of the gait lab system) Page 8 of 27

10 Applications for activity monitoring Monitoring people undergoing a range of activities Training athletes Page 9 of 27

11 Example of an equine application Page 10 of 27

12 Stride characteristics from Activity monitor AVE S.D. Time to 90% (s) Speed (m/s) Length (m) Stride Rate (Hz) Horse 1 14m/s Gallop 4 April 7:10am 6 furlong all weather track sec = 684m Speed (m/s) and stride length (m) Stride Rate (Hz) :11:00 07:12:00 07:13:00 0 Page 11 of 27

13 Intra-cranial pressure sensor system Inductive coupling (< 10cm) External transmitting coil RF communication (1m - 100m) Page 12 of 27

14 ICP application Long term applications include shunt monitoring in hydrocephalus patients over a lifetime Pressure sensor head is inserted into the brain and hence the coatings must be biocompatible and thin in order not to affect the stability of the pressure reading Page 13 of 27

15 Retina implant system Retinal Stimulator (RS) Retina Stimulator (RS) IRIS Retinal ganglion cells Environment Visual Interface (VI) Cable Pocket Processor (PP) PC / Notebook with Fitting Software Battery Charger Page 14 of 27

16 Retina implant Electrode array attached to the retina Page 15 of 27

17 Retinal electrodes under development Individually addressable electrode array which is fixed to the back of the retina 3D electrodes to maximum charge density Page 16 of 27

18 Current implants have the electrodes in the cochlear Cochlear implant New electrodes are being developed which fit into the modiolus, to reduce damage to residual hearing Page 17 of 27

19 Functional Electrical Stimulation (FES) Controller Motion Sensor Motion Sensor Implant Sensor system used to determine when the implant should be triggered Wireless communication sends signal to trigger the implant Implanted, encapsulated electronics generate the electric pulse Electric pulse passed into the electrodes which excites the nerve Nerve causes muscle movement in the arm Electrode pair placed close to the nerve Electromagnetic field Evoked Action Potentials Epineurium 1mm Page 18 of 27

20 Upper arm FES application X Y X Y sensors sensors Reflective Position Markers FES for upper arm OFF Wrist Extended OFF Stroke Patient with 2 channel stimulator OFF Hand Open Hand Grasp/Closed Hand Open OFF Trigger Trigger Trigger Trigger/Timeout Page 19 of 27

21 Implant components for FES application MICS communications Implant battery to provide the power Implant electronics to stimulate electrodes Page 20 of 27

22 MICS - Communicating data through the body Implant communications Page 21 of 27

23 Implantable Rechargeable Battery Implantable power source for the Cochlear & FES systems First prototypes now available and undergoing life trials Parameter No. of charges Life time Dimensions Minimum voltage Average current Specification years 5 x 10 x 22 mm 3V 5mA Page 22 of 27

24 Encapsulating Biomaterials and functional interface between electrodes and nerves in the body Means of improving the connection between the electrode and the nerve cells to optimise charge transfer. Aligning electrically active neurons to the electrode surface Preventing adhesion of non electrically active cells. Biocompatible encapsulating materials to stop water ingress into the implant and prevent leeching of materials from the implant into the body. Silicone rubber Silicone rubber coated with diamond-like carbon (DLC) Page 23 of 27

25 Isopropyl myristate (IPM) modified silicones Retina implant before coating Retina implant coated with modified silicone WP12 sensor before coating WP12 sensor coated with modified silicone Page 24 of 27

26 Biofuel cell to meet future implant challenges The material of a biofuel cell needs to be: Biocompatible Stable Formed onto the surface of the implant Prototype biofuel cell Page 25 of 27

27 Summary and acknowledgements Some nanotechnologies that are at a suitable stage of development have been integrated into new medical products, for example material coatings and surface treatments. Nanotechnology forms one of the key building blocks for future medical systems and advancements will help to improve the viability and performance of new medical implants and diagnostic equipment. The financial support of the EU FP6 programme is greatly appreciated by the Healthy Aims consortium. Page 26 of 27

28 Healthy Aims partners Page 27 of 27