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

Category Archives: Technologies

Technologies for implantable devices

Pacesetter’s 1973 Rechargeable Pacemaker

Posted on by Posted in Alfred E. Mann, Cardiac Pacing, Dr. Robert Fischell, History, Museum, Pacesetter, Power Sources, Rechargeable Batteries, Wireless Power Transmission

Demo of a rechargeable Pacesetter pacemaker at the Udvar-Hazy Center. www.implantable-device.com, David Prutchi PhD

Yesterday I visited the Udvar-Hazy Center of the Smithsonian Air & Space Museum in Chantilly, VA.  There I found this demo rechargeable pacemaker being displayed as a spinoff of NASA’s technology with the following explanation:

Demo of a rechargeable Pacesetter pacemaker at the Udvar-Hazy Center. www.implantable-device.com, David Prutchi PhD

Pacesetter model BD102 VVI rechargeable pacemaker www.implantable-devices.com David Prutchi PhDI can’t remember exactly where I found the picture of a Pacesetter model BD102 VVI, but the story behind it is documented by Kirk Jeffrey in “Machines in our Hearts”:

“In 1968, Robert Fischell, of the Applied Physics LOaboratory at Johns Hopkins University, and cardiologist Kenneth B. Lewis had begun a collaboration that led in 1973 to a new kind of Ni-Cad battery able to function more effectively at body temperature and hermetically sealable.  Alfred E. Mann, a California entrepreneur with background in the aerospace industry, had provided some financial support to the Hopkins group.  Eventually Mann founded a small company to develop a pacemaker for the rechargeable battery; this was the origin of Pacesetter Systems.  The rechargeable pacemaker reached the market in the summer of 1973, just as CPI introduced its lithium pacer.”

 

Sorin Announces CE Mark and Implant of its MRI-Compatible Kora 100 Pacemaker with Automatic MRI Mode

Posted on by Posted in Bradycardia, Cardiac Pacing, MRI-safe, Sorin

Sorin Kora 100 MRI pacemaker David Prutchi PhD www.implantable-device.com

Sorin announced the CE Mark approval and first implant of its KORA 100 pacing system.

According to the press release:

KORA 100 SR and DR pacemakers when implanted with the Sorin BEFLEX pacing lead enable implanted patients to undergo magnetic resonance imaging (MRI) safely.[1] Pacemaker patients are typically older than 65 years. This patient population is prone to other medical conditions such as arthritis, cancer or stroke that may require MRI examinations for optimal diagnosis and management.

The KORA 100 pacing system has been designed with both patients and physicians in mind. Device settings which allow safe operation during an MRI examination are automatically enabled when KORA 100 pacemakers detect the scanner’s magnetic field. Similarly the devices sense when a patient leaves the MRI field, and return to normal operation within five minutes. The Automatic MRI Mode feature, which is patented and available exclusively on Sorin Group pacemakers, limits the amount of time that KORA 100 pacemakers operate in MRI mode.

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AAMI Technical Information Report Gives Guidance to AIMD Designers Regarding MRI Compatibility

Posted on by Posted in MRI-safe, Tech Talk

AAMI Guidance Implantable Device Compatibility with MRI

A new technical information report (TIR) provides guidance to design active implantable medical device manufacturers for use in patients who may need magnetic resonance imaging (MRI) scans.

ANSI/AAMI/ISO TIR10974:2012, “Assessment of the safety of magnetic resonance imaging for patients with an active implantable medical device” was adopted and published by AAMI is meant to inform manufacturers about device behavior and patient risks so that MR-conditional AIMDs can be designed and labeled appropriately.  The introduction to the TIR explains:

Test methods described in this Technical Specification are primarily designed and intended as bench-top tests using equipment and techniques to simulate the fields (B0 static, gradient, and RF) found in MR 1.5 T scanners. Although, in a few cases, clinical scanner tests are implied, in all others, the AIMD manufacturer assumes the burden for development and validation of clinical scanner-based test methods.  Furthermore, the test signals and parameters specifically described within this Technical Specification for bench-top testing are not being encouraged or recommended for use on clinical scanners and to do so might result in scanner damage.

WISE s.r.l. Raises €1M to Develop Flexible Electrodes for Spinal Cord Stimulation

Posted on by Posted in Electrode Materials, Spinal Cord Stimulation

Supersonic Cluster Beam ImplantationWISE (Wiringless Implantable Stretchable Electronics), a Milan- and Berlin-based medical device companyraised a seed-round of € 1 M to advance the development of its first product aimed at the spinal cord stimulation market.

WISE’s technology relies on Supersonic Cluster Beam Implantation (SCBI) for the metallization of polymers and elastomers. SCBI allows to fabricate complex microelectronic circuits and interconnects on stretchable and conformable supports that preserve their electrical performances after extensive cycles of stretching and bending of the substrates. The devices can be efficiently fabricated on biocompatible platforms, and are therefore suitable for the production of implantable biomedical devices.

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Interesting Article in Medical Design Briefs: Designing an ASIC Chip to Control an Implantable Glucose Measurement Device

Posted on by Posted in Diabetes, Drug Delivery, Senseonics, Sensors, Sensors for Medicine and Science, Telemetry, Ultra-Low-Power ICs

Senseonics implantable glucose sensor www.implantable-device.com David Prutchi PhDSenseonics implantable glucose sensor www.implantable-device.com David Prutchi PhD

The current issue of Medical Design Briefs carries an interesting article titled “Designing an ASIC Chip to Control an Implantable Glucose Measurement Device” by Uwe Guenther of ZMDI (Dresden, Germany) and Andrew DeHennis of Senseonics (formerly known as “Sensors for Medicine and Science, Inc.” in Germantown, MD).

Zentrum Mikroelektronik Dresden AG (ZMDI), Dresden, Germany, partnered with Senseonics and developed a new microchip for use in Senseionics’ fluorescence-based implantable glucose sensor. According to the article, “ZMDI’s design specifications for this application-specific integrated circuit (ASIC), which is implemented as a system- on-a-chip (SoC) for control and analysis had to meet the following main requirements: LED driver, measurement and analysis of reflected light, data pre-processing, memory, wireless interface for data transfer, no battery due to extremely low power and low voltage requirements, medical certification, and special form factor.”

Click here for the online article.  Click here for a local pdf printout.

Increase in Temperature from AIMDs Dissipating Endogenous Heat

Posted on by Posted in Impulse Dynamics, MetaCure, My Portfolio, Rechargeable Batteries, Wireless Power Transmission

Analysis of Temperature Increase at the Device/Tissue Interface for Implantable Medical Devices Dissipating Endogenous HeatActive Implantable Medical Devices generate heat as a result of resistive losses in their circuitry, exothermic reaction in their batteries, eddy-current heating due to inductive recharge, friction between mechanical components, etc.  The European Standard which regulates AIMDs limits the heating of the outer surface of an AIMD to 2ºC above normal body temperature.  Despite the rapid growth in the use of AIMDs, the relationship between AIMD endogenous heat generation and tissue temperature has not been quantified.   In the attached paper we aimed at determining the limit of endogenous heat that can be dissipated in-vivo by the surface area of an AIMD to remain compliant with the 2ºC temperature increase limit.  In our study, four Sinclair mini-pigs underwent implantation of AIMD simulants instrumented to dissipate heat and measure temperature internally, as well as the device/tissue interface temperature.

We found that for a device with the surface area and geometry that we used, approximately 1W can be dissipated before reaching the 2ºC temperature increase limit. 

Click here for a preprint of this paper

 

Cleveland FES Center’s Networked Neural Prosthesis

Posted on by Posted in Brain-Computer Interface, Cleveland FES Center, Muscular Stimulation, Paralysis, Spinal Cord Injury (SCI)

Cleveland FES - Networked Neural Prosthesis (NNP) system, www.implantable-device.com, David Prutchi, Ph.D.

The Cleveland FES Center was established in 1991 as a consortium between the Cleveland VA Medical Center (CVAMC), the private educational institution of Case Western Reserve University (CWRU), and the public hospital system of MetroHealth Medical Center (MHMC).

As part of this consortium, Dr. Hunter Peckham – biomedical engineering professor at Case Western Reserve University – and his group have developed the Networked Neuroprosthetic System (NNPS), which is based on a network of small implanted modules they call “neuroprosthetic building blocks”.  These modules are distributed throughout the body, and each is dedicated to a specific function.  Modules are linked to a centralized power source via a network cable through which they also communicate with each other.

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Medtronic SureScan Neurostimulators Cleared by FDA for Full-Body MRI

Posted on by Posted in Medtronic, MRI-safe, Pain, Spinal Cord Stimulation

Medtronic Restore Sensor MRI www.implantable-device.comFollowing Medtronic’s announcement in February of this year that it had introduced in Europe the first and only implantable neurostimulation systems indicated for use in the treatment of chronic back and/or leg pain that are designed for full-body Magnetic Resonance Imaging (MRI) scans under specific conditions, the Company announced today that FDA has approved the system for use in the US.  Medtronic SureScan neurostimulation systems include enhancements to existing devices as well as specially designed leads to reduce or eliminate the hazards produced by the MRI environment. The devices also include a proprietary SureScan programming feature, which sets the device into an appropriate mode for the MRI environment.

The press release states:

“With the first U.S. implants of its new RestoreSensor® SureScan® MRI neurostimulation systems, Medtronic, Inc. (NYSE: MDT) is introducing the first and only implantable neurostimulation (also known as spinal cord stimulation, or SCS) systems for use in the treatment of chronic, intractable back and/or limb pain that are approved by the U.S. Food and Drug Administration (FDA) for conditionally safe* full-body Magnetic Resonance Imaging (MRI) under specific conditions.

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WiTricity Developing Long-Range Transcutaneous Energy Transfer Solutions for AIMDs

Posted on by Posted in Rechargeable Batteries, Thoratec, WiTricity

WiTricity Logo www.implantable-device.comThis month’s Medical Device and Diagnostic Industry  (MD+DI) magazine carried an interesting article by David Schatz – WiTricity’s VP Sales – on their efforts to develop highly resonant wireless power transfer technology for use in AIMDs.  The article is available online at http://www.mddionline.com/article/wireless-power-medical-devices.

The article mentions the work that WiTricity has been doing with Thoratec to wirelessly power a HeartMate II® LVAD, and which was announced back in May 2011.  David told me that for this project, WiTricity has been able to transfer 20 Watts over 20 cm, with SAR and temperature-rise compliance, and without the use of resonant repeaters.

If these levels scale well to small receiver units, I believe that this technology would enable not only the development of deep-implant AIMDs that are currently outside the range of classical resonant-inductive TET, but would also allow the development of more patient-friendly rechargeable AIMDs that don’t require dedicated recharge sessions, but rather receive their charge from a WiTricity transmitter under the patient’s bed while the patient sleeps.  From the MD+DI article:

“A circulatory assist device like an LVAD is just one example of a medical device that can harness the benefits of highly resonant wireless power transfer. There is also promise for other implanted devices, including neurostimulators, implantable defibrillators and pacemakers, implantable drug-delivery pumps, electronic ophthalmic and cochlear implants, and rechargeable hearing aids.

In this broad range of implanted medical devices, high-resonance wireless power transfer can enable higher charge rates than would be possible with traditional magnetic induction. Higher charge rates allow for device implantation deeper within the body and enable more flexible charger configurations outside of the body.

For example, the wireless charger for ophthalmic or cochlear implants could be deployed in a pair of eyeglasses or a pillow. The wireless charger for a neurostimulator implanted in the lower back could be deployed in a chair or bed. Hearing aids could be recharged by simply placing them in a charging box on one’s nightstand, without requiring precise fixturing or galvanic contacts as do today’s rechargeable hearing aids.”

 

 

IEEE Summer School on Implantable Devices – Bogotá, Colombia (July 9 – 12, 2013)

Posted on by Posted in My Portfolio, Tech Talk, Technologies, Ultra-Low-Power ICs, Wireless Power Transmission

IEEE Summer School Implantable Devices David Prutchi PhD Bogota ColombiaI have been honored with an invitation to present at the  Fourth IEEE CASS Summer School on Wearable and Implantable Biomedical Circuits and Systems in Bogotá, Colombia (July 9 – 12, 2013).

I will be giving two 1 hour and 20 minute talks on “A Practical Perspective on Developing Novel Commercial Active Implantable Medical Devices”.  Unlike other commercial devices, developing medical implantable devices takes place in a heavily regulated environment which requires decisive proof of the devices’ safety and efficacy. Costs, schedules, and clinical strategies must be planned accordingly to achieve a successful exit. This two-part lecture will focus on the practical technical and business-oriented aspects of planning and executing the development of implantable medical devices intended for a commercial application.

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Micromagnetic Stimulation as an Alternative to Electrical Stimulation for Implantable Devices? I don’t think so…

Posted on by Posted in Magnetic Stimulation, Neural Stimulation, Tech Talk
Principle of micromagnetic stimulation

From: Microscopic magnetic stimulation of neural tissue, Giorgio Bonmassar, Seung Woo Lee, Daniel K. Freeman, Miloslav Polasek, Shelley I. Fried & John T. Gale, Nature Communications 3, Article number: 921

The following captured my attention in the announcement of the 11th World Congress of the International Neuromodulation Society, “Technology Transforming Chronic Illness Management.” From June 8 – 13, 2013:

“Micro-Magnetic Stimulation (Monday, June 10) – John T. Gale, Ph.D., has demonstrated for the first time that deep brain stimulation with micro-magnets can activate brain cells in a living organism. Dr. Gale’s research team has shown that placing a micro-magnet on the auditory pathway of hamsters triggers nerve signal transmission. Stimulation from uniquely designed magnetic fields could avoid unintentional activation of nearby brain areas and the associated side effects. Micro-magnets might one day provide stimulation for heart pacing, cochlear implants, Parkinson’s disease, or neural prosthetics.”

I have worked on TMS before, even home-brewed a TMS device (the design of which is detailed in my book “Design and Development of Medical Electronic Instrumentation: A Practical Perspective of the Design, Construction, and Test of Medical Devices”), but it takes a very large amount of energy to induce sufficient current in the tissue to stimulate excitable tissue, so it peaked my attention that to do so at the implantable level would be under consideration.

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Biotronik’s Iforia DF4 ICD/CRT-D CE-Approved as Compatible with MRI

Posted on by Posted in Biotronik, Cardiac Pacing, Cardioversion/Defibrillation, Heart Failure (CHF), MRI-safe, Tachycardia

Iforia MRI-compatible ICD/CRT CRT-D David Prutchi PhD www.implantable-device.comBiotronik announced that it had received CE-approval for the world’s first DF4 ICD/CRT-D series approved for MRI. In addition, this series contains one of the world’s smallest ICDs– the Iforia single chamber ICD.

Aside from featuring ProMRI®technology, which allows patients to undergo potentially life saving MRI scans, Iforia also includes the industry standard DF4 connector system, which is designed to simplify and shorten the implantation procedure. The DF4 connector combines the traditional three connectors into one, allowing for a more convenient implantation procedure without compromising safety.

Click here for the press release.

Brown University Develops Fully-Implantable Brain-Computer Interface

Posted on by Posted in Brain-Computer Interface, EEG Monitoring, Paralysis

Brown University's fully-implantable brain-computer interface www.implantable-device.com David Prutchi, PhD

From Brown University’s press release:

“In a significant advance for brain-machine interfaces, engineers at Brown University have developed a novel wireless, broadband, rechargeable, fully implantable brain sensor that has performed well in animal models for more than a year. They describe the result in the Journal of Neural Engineering and at a conference this week.

PROVIDENCE, R.I. [Brown University] — A team of neuroengineers based at Brown University has developed a fully implantable and rechargeable wireless brain sensor capable of relaying real-time broadband signals from up to 100 neurons in freely moving subjects. Several copies of the novel low-power device, described in the Journal of Neural Engineering, have been performing well in animal models for more than year, a first in the brain-computer interface field. Brain-computer interfaces could help people with severe paralysis control devices with their thoughts.

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Medtronic Introduces First Neuromodulation Systems Compatible with Full-Body MRI

Posted on by Posted in Brain Stimulation, Medtronic, MRI-safe, Pain, Spinal Cord Stimulation

Medtronic Restore Sensor MRI www.implantable-device.com

Medtronic has introduced in Europe the first and only implantable neurostimulation systems indicated for use in the treatment of chronic back and/or leg pain that are designed for full-body Magnetic Resonance Imaging (MRI) scans under specific conditions.  Medtronic SureScan neurostimulation systems include enhancements to existing devices as well as specially designed leads to reduce or eliminate the hazards produced by the MRI environment. The devices also include a proprietary SureScan programming feature, which sets the device into an appropriate mode for the MRI environment.

St. Jude Starts Trial of Accent MRI Pacemaker and Tendril MRI Lead

Posted on by Posted in Bradycardia, Cardiac Pacing, MRI-safe, St. Jude Medical
St Jude's ACCENT MRI MRI-compatible pacemaker. Report by David Prutchi PhD

Image Credit: St. Jude Medical

Today St. Jude announced the first implant in its Accent MRI(R) Pacemaker and Tendril MRI(R) Lead IDE Study (MRI Study). The ultimate goal of the study is to determine if patients with these devices can safely undergo full-body, high resolution Magnetic Resonance Imaging (MRI) scans to better accommodate their medical needs. The investigational Accent MRI Pacemaker system from St. Jude Medical offers an advanced pacing platform that provides wireless telemetry and algorithms to help address individual patient conditions.

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