Medical MEMS, BioMEMS and Sensor Applications
Curator and Reporter: Aviva Lev-Ari, PhD, RN
Contents for Chapter 11
Medical MEMS, BioMEMS and Sensors Applications
Curators: Justin D. Pearlman, MD, PhD, FACC, LPBI Group, Danut Dragoi, PhD, LPBI Group and William H. Zurn, Alpha IP
FOR
Series E: Patient-centered Medicine
Volume 4: Medical 3D BioPrinting – The Revolution in Medicine
Editors: Larry H Bernstein, MD FCAP and Aviva Lev-Ari, PhD, RN
Work-in-Progress
Image Source
http://www.memsjournal.com/2010/05/medical-applications-herald-third-wave-of-mems.html
Image is courtesy of Google Images
Image Source
Stanford Engineering Team Invents Pressure Sensor That Uses Radio Waves | CytoFluidix
Image is courtesy of Google Images
Introduction by Dr. Pearlman
Chapter 1: Blood Glucose Sensors
1.1 MINIATURIZED GLUCOSE SENSOR – Google
- Tiny wireless chip and miniaturized glucose sensor
- Embedded between two layers of soft contact lens material
- Accurate glucose monitoring for diabetics
- Using bodily fluids, i.e. tears
- Prototypes can generate one reading per second
- Experimenting with LEDs
- Early warning for the wearer
Chapter 2: Blood Chemistry Tests – up to 100 Samples
2.1 NON-INVASIVE BLOOD MONITOR- UCSD
- Digital tattoo monitors blood below the skin
- Tattoos are needle-less
- Sensor-laden transdermal patch
- Painless for the user Tiny sensors “ink”
- Can read blood levels of:
- Sodium, glucose, kidney function
- Prototypes contain probes
- Wireless, battery-powered chip
- Continually test up to a hundred different samples
2.3 CELLPHONE-BASED RAPID-DIAGNOSTIC-TEST (RDT) READER – UCLA
- Lateral flow immuno-chromatographic assays
- Sense the presence of a target analyte in a sample
- Device connects to the camera on a cell phone
- Weighs only 65 grams
2.4 IMPLANTABLE BLOOD ANALYZER CHIP – EPFL
- Implantable device for instantaneous blood analysis
- Wireless data transmission to a doctor
- Applications include monitoring general health
- Tailor drug delivery to a patient’s unique needs
- Includes five sensors and a radio transmitter
- Powered via inductive coupling from a battery patch
- Worn outside the body
Chapter 3: Motion Sensors for Head-Impact
3.1 HEAD-IMPACT MONITORING PATCH – STMicro & X2Biosystems
- Wearable electronic contains MEMS motion sensors
- Microcontroller, low-power radio transmitter, and power management circuitry
- Cloud-based system combines athlete concussion history
- Pre-season neurocognitive function, balance, and coordinate-performance data
- Creates a baseline for comparison after a suspected injury event
Chapter 4: Drug Delivery & Drug Compliance Monitoring Systems
4.1 Smart Pill delivers Therapeutic Agent Load to target – ELECTRONIC PILL – Phillips
- Electronic pill to treat gastrointestinal cancer
- An ingestible pill is swallowed by the patient, finds its way to the tumor, dispenses the drugs and passes harmlessly from the body
- Smart pill contains reservoir for drug supply, fluid pump for drug delivery, pH sensor (for navigation), thermometer, microprocessor, communication
4.2 Drug Compliance Monitoring Systems
4.2.1 INGESTIBLE BIOMEDICAL SENSOR – Proteus Digital Health
- Biomedical sensor that monitors medication adherence
- Embedded into a pill, the sensor is activated by stomach fluid
- Transmits a signal through the body to a skin patch
- Indicates whether a patient has ingested material
4.2.2 MICROPUMP DEVICES – Purdue University
- Device based on skin contact actuation for drug delivery
- Actuation mechanism only requires body heat
- Induced actuation can result to a gradient of 100 Pa/oC
- Sufficient to drive liquid drug through micro-needle arrays
- Prototypes exhibit low fabrication costs, employment of biocompatible materials and battery-less operation Suitable for single- or multiple-use transdermal drug dispensers
4.2.3 IMPLANTABLE MEMS DRUG DELIVERY SYSTEM – MIT
- Device can deliver a vasoconstrictor agent
- On demand to injured soldiers to prevent hemorrhagic shock
- Other applications include medical implants
- For cancer detection and monitoring
- Implant can provide physicians and patients
- Real-time information on the efficacy of treatment
Chapter 5: Remove Monitoring of Food-related Diseases
5.1 LASER-DRIVEN, HANDHELD SPECTROMETER
- For analyzing food scanned
- Information to a cloud-based application
- Examines the results Data is accumulated from many users
- Used to develop warning algorithms
- For Allergies, Bacteria
Chapter 6: Skin Protection and Photo-Sensitivity Management
6.1 WEARABLE-UVEXPOSURESENSOR – Gizmag
- Wristband for monitoring UV exposure
- Allows user to maximize vitamin D production
- Reducing the risk of sun
- Over-exposure and skin cancer
- LED indicators light up as UV exposure accumulates
- Flashes once the safe UV limit has been reached
6.2 WEARABLE SKIN SENSOR KTH – Chemistry 2011
- Bio-patch for measuring and collecting vital information through the skin
- Inexpensive, versatile and comfortable to wear
- User Data being gathered depends on where it is placed on the body
Chapter 7: Ophthalmic Applications
7.1 INTRAOCULAR PRESSURE SENSOR – Sensimed & ST Microelectronics
- Smart contact lens called Triggerfish
- Contact lens can measure, monitor, and control
- Intra-ocular pressure levels for patients
- Catch early cases of glaucoma
- MEMS strain gage pressure sensor
- Mounted on a flexible substrate MEMS
7.2 MICRO-MIRRORS ENABLING HANDHELD OPHTHALMIC – OCT News
- Swept source OCT model for retinal 3D imaging
- Replaces bulky galvanometer scanners in a handheld OCT probe for primary care physicians
- Ultrahigh-speed two-axis optical beam steering gimbal-less MEMS mirrors
- MEMS Actuator with a 2.4 mm bonded mirror and an angular reach of +6°
- Low power consumption of <100mW including the MEMS actuator driver Retinal 3D Imaging
Chapter 8: Hearing Assist Technologies
8.1 MEMS TECHNOLOGY FOR HEARING RESTORATION – University of Utah
- Eliminates electronics outside the ear
- Associated with reliability issues and social stigma
- Accelerometer-based microphone
- Successfully tested in cadaver ear canals
- Prototype measures 2.5 x 6.2mm, weighs 25mg
Chapter 9: Lab-on-a-Chip
9.1 ORGAN-ON-A-CHIP – Johns Hopkins University
- Silicon substrate for living human cells
- Controlled environment
- Emulate how cells function inside a living human body
- Replace controversial and costly animal testing
- Lab-on-a-chip: a cost effective end to animal testing
Chapter 10: Intra-Cranial Studies: Pressure Measurement, Monitoring and Adaptation
10.1: CEREBRAL PRESSURE SENSOR – Fraunhofer Institute
- Sensor to monitor cerebral pressure that can lead to dementia
- Pressure changes in the brain can be measured and transmitted
- Reading device outside the patient’s body
- Operating at very low power, the sensor module
- Powered wirelessly by the reading device
10.2 WIRELESS, IMPLANTABLE BRAIN SENSOR – National Institute of Biomedical Imaging and Bioengineering
- Fully implantable within the brain
- Allow natural studies of brain activity
- Cord-free control of advanced prosthetics
Wireless charging Prototypes transmitted brain activity data
Chapter 11: Cardiac and Cardiovascular Monitoring System
11.1 IMPLANTABLE MICRO DEVICE FOR MONITORING AND TREATING ANEURISMS – Electronic Design
- RF-addressed wireless pressure sensor are powered by inductive coupling
- Do not need batteries MEMS pressure sensor
- Wireless antenna are inserted near the heart
- With a catheter, Blood-pressure readings
- Are sent to a wireless scanner for monitoring Pressure changes
- Deflect the transducer’s diaphragm
- Change the LC circuit’s resonant
11.2 CUSTOM- FITTED, IMPLANTABLE DEVICE FOR TREATMENT AND PREDICTION OF CARDIAC DISORDERS – Washington University
- Working prototypes were developed on inexpensive 3D printers
- The 3D elastic membrane is made of a soft, flexible, silicon material
- Precisely shaped to match the outer layer of the heart
Chapter 12: microfluidic chips
12.1 MICROFLUIDIC MEMS FOR DIABETES TREATMENT – Micronews
- Watertight pump mounted on a disposable skin patch
- Provides continuous insulin infusion
- Controlled by a dedicated smart phone device
- Incorporating a BGM (blood- glucose meter)
12.2 ACOUSTIC RECEIVER ANTENNA/SENSOR PDMS MEMBRANE – Purdue
POLY-DI-METHYL-SILOXANE (PDMS)
Polydimethylsiloxane called PDMS or dimethicone is a polymer widely used for the fabrication and prototyping of microfluidic chips.
It is a mineral-organic polymer (a structure containing carbon and silicon) of the siloxane family (word derived from silicon, oxygen and alkane). Apart from microfluidics, it is used as a food additive (E900), in shampoos, and as an anti-foaming agent in beverages or in lubricating oils.
For the fabrication of microfluidic devices, PDMS (liquid) mixed with a cross-linking agent is poured into a microstructured mold and heated to obtain a elastomeric replica of the mold (PDMS cross-linked).
Why Use PDMS for Microfluidic Device Fabrication?
PDMS was chosen to fabricate microfluidic chips primarily for those reasons:
Human alveolar epithelial and pulmonary microvascular endothelial cells cultured in a PDMS chip to mimick lung functions
- It is transparent at optical frequencies (240 nM – 1100 nM), which facilitates the observation of contents in micro-channels visually or through a microscope.
- It has a low autofluorescence [2]
- It is considered as bio-compatible (with some restrictions).
The PDMS bonds tightly to glass or another PDMS layer with asimple plasma treatment. This allows the production of multilayers PDMS devices and enables to take advantage of technological possibilities offered by glass substrates, such as the use of metal deposition, oxide deposition or surface functionalisation.
PDMS, during cross-linking, can be coated with a controlled thickness on a substrate using a simple spincoat. This allows the fabrication of multilayer devices and the integration of micro valves.
It is deformable, which allows the integration of microfluidic valves using the deformation of PDMS micro-channels, the easy connection of leak-proof fluidic connections and its use to detect very low forces like biomechanics interactions from cells.
SOURCE
- Ferrite RF radiation Acoustic wave Rectifier
- Buried in PDMS Implantable miniature pressure sensor
- Powered by an acoustically actuated cantilever
- No battery required
- Acoustic waves in the 200-500 hertz range
- Cause cantilever to vibrate
- Scavenging energy to power pressure sensor
Chapter 13: Peropheral Neuropathy Management
13.1 WIRELESS SHOE INSERT – Mobile Health News
- WIRELESS SHOE INSERT – Mobile Health News
- Help diabetics manage peripheral nerve damage
- Insole collects data of where wearers
- Putting pressure on their feet
- Transmits wirelessly to a wristwatch-type display
- Prevent amputations that often stem from diabetic foot ulcers
Chapter 14: Endoscopic Diagnostics Tools
14.1 ENDOSCOPE USING MEMS SCANNING MIRROR
- For gastrointestinal and urological imaging
- Alternative to biopsies in cancer detection
- A laser beam pointed at the mirror is precisely deflected
- Steered by the scanning mirror to reach a target
Chapter 15: MEMS guided Surgical Tools
15.1 MICROMACHINED SURGICAL TOOLS; SILICON MEMS TWEEZERS – ElectrolQ Used for minimally invasive surgical (MIS)
- Procedures where diagnosis, monitoring, or treatment of diseases are performed
- Performing with very small incisions MEMS
- Based microsurgical tools is a key enabling technology for angioplasty, catheterization, endoscopy, laparoscopy, and neurosurgery
Summary by Dr. Pearlman
- Multiple projects by Academia & Industry
- Multiple MEMS devices for measuring body activities.
- Many patch type devices attached to the skin
- Devices attached to the eye
- Smaller is better, lower footprint, lower power
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