Ultrasensitive pressure sensors and applications. April 2018

Transcription

1 Ultrasensitive pressure sensors and applications April 2018

2 We started working on artificial e-skin Sensing elements: pressure, temperature, chemical Skin + Circuits Tee, Chortos, Deisseroth, Bao et al., Science, Oct. 16, 2015 Flexible Stretchable Biodegradable Self healing Sensing Functions: Touch Temperature Humidity Chemical 2016

3 Which led to.. Ultra-sensitive thin film pressure sensors Microstructured dielectric layer greatly increases sensitivity Conductor Conductor Conductor Conductor Dielectric 5 µm Advantages: Fast response time: ~10 msec No hysteresis Ultra-sensitive: down to Pa Thin: ~30 µm Bendable Conformal to skin Human hair Minimum thickness of our sensor 20 µm /spr06/xue/need/cross-section/0425a1.jpg S.C.B. Mannsfeld, B.C.K. Tee et al. Nature Materials, 2010 Bao, et al Science,

4 Which enabled.. a new way of pulse wave monitoring Measured P 2 /P 1 µ blood pressure Issues Wired Hand crafted Sensitive to placement accuracy Sensitive to environmental conditions C. Pang, Bao et al., Adv. Mater Schwartz, Tee, Bao et al. Nature Communications,

5 We care because hypertension is a huge problem 1 out of 4 adults worldwide (1.4B people) $370B - $3.6T economic burden 1.2B hypertensives do not have their blood pressure under control despite many effective hypertension medications why? because of issues with BP measurements!

6 Here s what s wrong with today s BP measurements Inflatable cuffs are widely used, but... just provide a snapshot value and do not capture BP variability and trends Arterial lines (A-lines) provide rich information, but... are highly invasive carry risk of complications and only used in ICUs BP [mm Hg] Both are inconvenient and uncomfortable.

7 We solve the problems with BP measurements PyrAmes - lightweight, comfortable, non-invasive, continuous monitoring, easy to use Patented technology from Stanford Professor Zhenan Bao s research lab Arterial line quality data 500 hours of clinical data, 220 patients, 100 F&Fs BP model predictions approaching FDA specifications Sensor data Arterial line data

8 Arterial line-like data can predict blood pressure Test of A-line data in ML model Test of sensor data in ML model Predicted Systolic BP [mm Hg] MAE = 5.9 Stdev = 9.3 MAE = 5.0 Stdev = 4.7 Predicted Diastolic BP [mm Hg] MAE = 3.5 Stdev = 5.4 MAE = 7.5 Stdev = 3.5 Measured a-line BP [mm Hg] FDA spec MAE < 5 mm Hg Stdev < 8 mm Hg Ground Truth (one minute average a-line BP)

9 Better data, smaller, lighter, lower power, easy to use Technology Companies Information content Continuous Comfort Power Ultra-sensitive capacitive PyrAmes (exclusive license) Very high Yes Thin, flat, flexible Low Inflatable cuff Many, e.g. Omron, Withings, Panasonic Low No Arm compression Medium/High Pulse transit time Pulse wave velocity (PPG/EKG, radar) Many, e.g. Google, Scanadu, Blumio, Salu, Quanttus, Spry, Sensifree, Samsung High Limited Multiple contact points Medium/High Tonometer Atcor, H2, Microsoft Very High No Artery compression Medium

10 This enables a big vision, with at least 3 stages Inpatient: Non-invasive arterial line Daily use Outpatient: Comfortable ABPM 1-2 week use Home digital therapeutic: Medication management 1-2 year use CONFIDENTIAL 10

11 Starting with an inpatient product Single use band: integrated sensor array, fasteners, and interconnects hypoallergenic, sterile packaging, flexible, stretchable, comfortable, adjustable sizing Reusable electronics module: wireless communications, on-board processor and memory rechargeable, water resistant, minimal footprint and thickness, can be easily cleaned or sterilized

12 Basic component & materials requirements Component Sub-components Primary concerns Wishlist Sensors Electrodes Flexibility, processability, stretchability Printable, R2R Dielectrics Dielectric constant, processability Printable, R2R Packaging materials Thickness, biocompatibility, processability R2R Electronics Discretes Size, assembly Single chip PWB/Flex circuits Thickness, size Chip on flex Interconnections Reliability, size Printable Packaging Biocompatibility, sterilization, moisture resistance IP67 Power supplies Power density, safety Thin film Wristbands Band materials Biocompatibility, comfort, stability R2R Fasteners Robustness Printable

13 Can you help us get there? Our sensor has the potential to become the standard of care for BP measurements We need to choose materials and processes that meet a complex set of requirements, including FDA, TSCA, and ROHS compliance We have a product roadmap that will require continuous performance and cost improvements

14 Thank you! For more information: Xina Quan CTO & Co-founder CONFIDENTIAL

15 Note: abstract With a greying populace in many parts of the world, there is fast growing demand for health monitoring systems that are low-cost, discreet, comfortable, and easy to use. Advances in data analysis and electronics have fueled the development of wearable, digital health technologies. Given the importance of the cardiovascular system to overall health, and our increasing understanding of its physiology, it is natural to start here in our efforts to create devices that provide useful, high-content data in a low-cost form factor that people are willing to use. In this talk, I will cover some concepts and trade-offs we are considering for a cardiovascular monitoring device we are developing at PyrAmes, a start-up spun out of Stanford with thin film sensor technology based on Prof. Zhenan Bao's research on artificial skin.