A blog about what is new (and old) in the world of active implantable medical devices

Radiation-Hardened ICs for Implantable Medical Devices

Posted on by Posted in Radiation Oncology, Ultra-Low-Power ICs

Radiation hardened integrated circuits for implantable medical devices

Lately I’ve received many inquiries about the paper on radiation-hardness testing of implantable integrated circuits that I published with Dr. Larry Stotts (now Executive VP R&D at Biotronik), and the late Dr. John Prince.  This is because the effects of medical diagnostic and therapeutic radiation are becoming an issue of concern to physicians who often encounter the need for radiotherapy in the growing population of patients implanted with pacemakers, defibrillators, neural stimulators, and drug-delivery pumps.

Although the paper reported mainly on the test of floating-gate EEPROMs, the modern interest is on the test methods that we developed to test ICs used in implantable devices for hardness to the type of radiation encountered in the medical field.

Click here for our paper: D. Prutchi, J.L. Prince and L.J. Stotts, “X- and Gamma-Ray Hardness of Floating-Gate EEPROM Technology as Applied to Implantable Medical Devices”, IEEE Transactions on Electronic Components and Packaging Technology, 22(3), 390-398, 1999.

InControl’s Metrix Atrioverter (1990-1998)

Posted on by Posted in Atrial Flutter/Fib, Boston Scientific, Cardioversion/Defibrillation, Guidant, History, InControl

InControl Metric Atrioverter InControl was founded in 1990 in Redmond, WA to develop an implantable device for treating atrial fibrillation.  In November 1995, InControl announced the first human implant of its Metrix atrioverter.

The implantable atrioverter system consisted of an implantable atrial defibrillator (model 3000 or 3020) connected to right atrial (perimeter right atrial model 7205) and coronary sinus (perimeter coronary sinus model 7109) defibrillation leads and a bipolar endocardial ventricular pacing lead, a programmer, and a defibrillation systems analyzer. The device had a volume of 53cc and weighed 79 g (model 3000) or 82 g (model 3020).

The device detected AF and delivers R-wave synchronous defibrillation shocks to convert AF to sinus rhythm. It was also able to pace the ventricle after shock delivery in case of bradycardia. Shocks could be delivered at a selected voltage up to 300V. The model 3000 defibrillator had an 80µF capacitor and could deliver a maximal shock of 3J with a biphasic waveform of 3 ms/3 ms. The model 3020 defibrillator had a 160-µF capacitor with a maximal shock of 6J with a biphasic waveform of 6 ms/6 ms. Continue reading→

Cactus/Freescale Semiconductor ICs for Implantable Medical Devices

Posted on by Posted in Ultra-Low-Power ICs
Freescale/Cactus Semiconductor SOC for AIMDs
Image Credit: Freescale Semiconductor, from “Integrated Circuits for Implantable Medical Devices”

 An article by Steve Taranovich in the December 15, 2011 issue of EDN discussed technologies that are expected to be hot in 2012. One of these is the implantable chipset being developed by a collaborative effort between Cactus Semiconductor of Chandler, AZ and semiconductor giant Freescale.

SOCs developed by the alliance are expected to accelerate the development of innovative AIMDs. Continue reading→

Victhom Human Bionics’ Neurostep Implantable Closed-Loop Stimulator for Foot Drop

Posted on by Posted in Foot Drop, Muscular Stimulation, Victhom Human Bionics
Neurostep stimulator for drop-foot
Image Credit: Victhom Human Bionics

Victhom Human Bionics was founded in 2002 in Saint-Augustin-de-Desmaures, Canada. The company’s Neurobionix business unit develops its implantable closed-loop system devices.

The Neurostep® is a neurostimulator designed to be implanted into the patient’s leg. Electrodes are attached to the peripheral nerves responsible for sensing and stimulating the muscles that lift the foot during normal walking. In operation, the device senses key physical events and stimulates the muscles of the ankle flexing the foot upward in patients suffering from foot drop.

Continue reading→

Spinal Modulation’s Neurostimulator for the Stimulation of the Dorsal Root Ganglion

Posted on by Posted in Mir A Imran (InCube), Pain, Spinal Cord Stimulation, Spinal Modulation
Spinal modulation for stimulation of dorsal root ganglion
Image Credit: Spinal Modulation

 

Spinal Modulation was founded by Mir Imran in Menlo Park, CA in 2004.  The company has developed an implantable neurostimulator to deliver signals to the primary sensory neurons located within the dorsal root ganglion (DRG).  The idea is that unlike dorsal column spinal cord stimulation, the Spinal Modulation system breaks the pain signal’s path before it enters the spinal cord. Continue reading→

Why Do So Many Novel Implantables Use a “Boxy” Enclosure?

Posted on by Posted in Enclosures, Greatbatch Medical (Power), Heraeus Medical Components, Hudson Technologies, National Manufacturing, Okay Industries

Deep drawn can for implantable medical devices

 

Active implantable medical devices are typically enclosed in a hermetically-sealed titanium housing which provides protection of the circuitry and other components.

Commonly, Grade 1 titanium is formed into the enclosure using stamping. The pretty, rounded shapes of modern pacemakers and ICDs are achieved by having two enclosure halves shallowly stamped from sheet stock material, and are then welded together to form the enclosure.

On the other hand, “boxy” enclosures that were popular in the 1970s are made by deeply drawing the titanium into a seamless can that is then capped by an ellipsoidal lid.  However, many modern start-up companies still develop their early-generation implantable devices in this format because a number of off-the-shelf  implantable-grade cells are available to fit in these deep-drawn enclosures, and the housings can be purchased off-the-shelf from various manufacturers.  In addition, these enclosures provide sufficient volume for electronic assemblies manufactured using off-the-shelf packaged components and printed-circuit-board technology instead of more aggressive manufacturing methods (e.g. bare IC die on ceramic substrates) used by more established companies to miniaturize their mature implantable devices. Continue reading→

Nevro’s Senza Rechargeable Spinal Cord Stimulator for Back and Leg Pain

Posted on by Posted in Nevro, Pain, Spinal Cord Stimulation, Wireless Power Transmission
Nevro Senza Implantable Spinal Cord Stimulator for Back and Leg Pain
Image Source: Nevro’s Website

Nevro Corporation (formerly NBI Development) was founded in 2006 by Dr. Konstantinos Alataris.  The Menlo Park, CA company developed a pain management concept that originated at the Mayo Clinic into a spinal cord stimulation system for back and leg pain.

According to Nevro, their unique stimulation waveform achieves pain relief without paresthesia or uncomfortable stimulation.  Few details are available about the waveform, but Nevro’s Spanish distributor’s brochure specifies it as high-frequency stimulation at 10,000 Hz.  This is consistent with Nevro’s patent applications which teach that “high-frequency modulation in the range of from about 1.5 KHz to about 50 KHz may be applied to the patient’s spinal cord region to address low back pain without creating unwanted sensory and/or motor side affects.” Continue reading→

TransWorld’s Soul Mate Implantable Heart Transplant Rejection Monitor

Posted on by Posted in Telemetry, Transplant Rejection, TransWorld Heart
TransWorld Medical's Soul Mate Implantable Heart Transplant Rejection Monitor
Image Source: TransWorld Heart Corporation’s Website

TransWorld Heart Corporation of Charlotte, NC, was founded by Dr. Charles Richardson in 2004.  The company developed an implantable device intended to replace routine post-transplant heart biopsies.

TransWorld’s Soul Mate implantable system analyzes 9 intramyocardial electrogram parameters recorded from 4 or 6 configurations of 2 or 3 epicardial leads to detect allograft rejection. Continue reading→

Biomet EBI’s OsteoGen™ Implantable Bone-Growth Stimulator

Posted on by Posted in Bone Fracture/Fusion, Bone Growth Stimulation, Electro Biology Inc (EBI)

Electrobiology Inc (EBI) Osteogen Implantable Bone-Growth StimulatorIt has been known for quite some time that bone growth is stimulated by DC electrical currents.  However, only relatively recently implantable stimulators have been developed for the application.

In 1988 Biomet acquired Electrobiology Inc. (EBI) in Parsippany, NJ, a leader in bone-growth electrical stimulation and bone external fixation markets.

EBI’s OsteoGen™ Bone Growth Stimulator is marketed by Biomet Inc. It is designed for adjunctive use in the treatment of nonunions when surgery is required or when patient compliance is expected to be inadequate. The device is appropriate for any form of fracture. It is most often used on long bones and the clavicle. Variations of the OsteoGen device are available for high-risk fractures (OsteoGen™ Dual Lead Bone Growth Stimulator) and with mesh cathodes designed to provide scaffolding (OsteoGen™-M Bone Growth Stimulator). Continue reading→

BioControl’s MiniatURO Muscle Stimulator to Alleviate Incontinence (1999-2006)

Posted on by Posted in BioControl, Incontinence, Muscular Stimulation, Yossi Gross (Rainbow Medical)

BioControl's MiniatURO implantable muscle stimulator for the treatment of incontinenceBioControl Medical, Ltd. was founded in 1999 by Yossi Gross, and is based in Yehud, Israel.  BioControl’s first devices were developed to treat incontinence due to overactive bladder, stress, and interstitial cystitis.  In 2006 American Medical Sytems acquired an exclusive license for the use of the technology in urology, gynaecology and other pelvic health applications.

The BioControl MiniatURO was an implantable muscle and nerve stimulator designed for subcutaneous implantation on an outpatient basis. Its purpose was to alleviate some types of urinary incontinence.

For patients suffering from stress incontinence, whenever the device detected an increase in abdominal pressure through its pressure-sensing catheter, it applied mild electrical pulses to the pelvic floor muscles. The intention was to activate the muscles and prevent inadvertent urine loss. In the urge incontinence mode of operation, the unit applied mild electrical pulses to the pelvic diaphragm nerve, using the sphincter detrusor muscle reflex to inhibit bladder contractions. For those with both types of incontinence, the two modes of operation were combined.  In operation, the unit was intended to mimic natural physiology, activating the muscle upon demand, and strengthening the pelvic floor muscle. Continue reading→

BioControl’s CardioFit System for the Treatment of Heart Failure via Vagus Nerve Stimulation

Posted on by Posted in BioControl, CerebralRx, Heart Failure (CHF), Hypertension, Muscular Stimulation, Vagus Nerve Stimulation, Yossi Gross (Rainbow Medical)
Biocontrol's Cardiofit Vagus Nerve Stimulator for Heart Failure Treatment

BioControl Medical, Ltd. was founded in 1999 by Yossi Gross, and is based in Yehud, Israel.  BioControl’s first devices were developed to treat incontinence due to overactive bladder, stress, and interstitial cystitis.  In 2006 American Medical Sytems acquired an exclusive license for the use of the technology in urology, gynecology and other pelvic health applications. Continue reading→

Cameron Health’s Leadless Implantable Defibrillator

Posted on by Posted in Cameron Health, Cardioversion/Defibrillation, Tachycardia

Cameron Health's subcutaneous defibrillatorCameron Health was founded in 2000 in San Clemente, CA to develop a leadless implantable defibrillator.

The device does not require a lead to be implanted into the heart. Instead, the device has a lead that is tunneled beneath the skin from the upper left chest below the level of the clavicle to the level of about the breast, then tunneled laterally to the side of the chest beneath the arm. The device uses the subcutaneous lead to sense the heart rhythm and can detect rapid arrhythmias from the surface ECG created between the lead electrode and the can of the device. Its maximum shocking output is 80 joules. Continue reading→

EBR System’s Wireless Pacemaker

Posted on by Posted in Bradycardia, Cambridge Consultants, Cardiac Pacing, EBR Systems, Heart Failure (CHF), Ultra-Low-Power ICs, Ultrasonic Transducers, Wireless Power Transmission

EBR Systems, Inc., founded in 2003 and headquartered in Sunnyvale, CA, is developing the WiCS® Wireless Cardiac Stimulation technology to eliminate cardiac pacing leads, historically a major source of complications and reliability issues.  The startup was spun out of research by founder Debra Echt, a former professor of medicine and a cardiologist at Vanderbilt University. Continue reading→

Nanostim’s Leadless Pacemaker

Posted on by Posted in BetaBatt, Bradycardia, Cardiac Pacing, EBR Systems, Medtronic, Nanostim, Nuclear Batteries

Nanostim's leadless pacemakerNanostim is an early-stage AIMD company in Milpitas, CA that is developing a pacemaker that can be implanted inside the heart through a catheter.  The tiny device is attached directly to the heart, eliminating the need for leads.

In May 2011 Nanostim announced that St. Jude Medical had made a substantial investment in the company.

The company is operating in stealth mode, but some details about the leadless pacemaker have emerged from Nanostim’s patents and patent applications.  An interesting detail is about the possible use of a betavoltaic power source: Continue reading→