This is a picture of the first pacemaker to be implanted in a human patient. It was developed by Dr. Rune Elmqvist (1906–1996), a physician by training, but working for the Swedish company Elema-Schonander as an engineer. Dr. Elmqvist developed the device in cooperation of Åke Senning, senior physician and cardiac surgeon at the Karolinska University Hospital in Solna, Sweden. Continue reading
Category Archives: AIMD Companies
“Data Block” Percutaneous Implantable Electrical Connector
The development of medical devices, drugs, and treatments depends on accurately retrieving clinical data from implanted animals. Implantable data collecting and sensing devices provide one way to retrieve these data. These device often include sensors or electrodes which must be implanted within the subject in order to provide clinicians with access to the sensed information.
Retrieving data from implanted sensors poses a potential problem since data frequently must be retrieved on numerous different occasions and over an extended period of time. If surgery is required each time data is retrieved, the subject may be overly exposed to stress, trauma, or risk of infection. In order to develop and test cardiac pacemakers and defibrillators, for example, clinicians need to monitor electrical activity of the subject’s heart. One way to monitor this activity is to surgically implant one end of a lead to the heart. The other end of the lead may be left subcutaneously (i.e., under the skin) or transcutaneously (i.e., through the skin). In the former instance, access to the electrode may require an invasive procedure, such as surgery. In the latter instance, prolonged and chronic exposure of the electrode through the skin may cause discomfort, lead to infection, or cause damaging stress on the electrode. Continue reading
MicroCHIPS’ Implantable Drug Delivery Device for the Treatment of Osteoporosis

Image Credit: MicroCHIPS
MicroCHIPS was founded in 1999 as an MIT spinoff to develop implantable sensors and drug-delivery devices.
MicroCHIPS’ drug-delivery technology is based on proprietary reservoir arrays that are used to store potent drugs within the body for long periods of time. Individual device reservoirs can be opened on demand or on a predetermined schedule to precisely control drug release or sensor activation. Continue reading
Neuromed’s TIME Battery- and RF-Powered Totally Implantable Multichannel Spinal Cord Stimulator (ca. 1988)

Neuromed TIME IPG on loan from Daniel Villamil's collection.
Neuromed was formed in 1980 with an initial capitalization of $150,000 by Bill Borkan through money obtained when Borkan`s parents took out a second mortgage on their home. Borkan’s desire to help his sister, Jennie, a cerebral palsy patient, got him started in neurostimulation technology. In the next few years, Neuromed developed and marketed a RF-powered implantable spinal cord stimulator, along with its external radio frequency transmitter.
Throughout the 1980s, development of more advanced devices was ongoing at Neuromed. My friend Daniel Villamil from CCC Medical has in his collection one of these more modern units, which he lent to me for photographing. The “Total Implantable Multichannel Electronics” (TIME) spinal cord stimulator shown in this picture went into clinical trials around 1988. This was a device that was internally powered by its own battery. However, it could also be RF-powered after the eventual battery failure. Continue reading
St. Jude’s (ANS) Rechargeable Spinal Cord Stimulators Eon and Eon Mini
In 2005, St. Jude Medical purchased Advanced Neuromodulation Systems (ANS) in Plano, Texas. ANS had developed a number of spinal cord stimulation IPGs that were either externally powered via inductive link, internally powered by a primary cell, or internally powered by a transcutaneously rechargeable lithium-ion cell.
Today, the most popular St. Jude spinal cord stimulators are the rechargeable 42 cc Eon and 18 cc Eon mini neurostimulators.
They are constant-current devices with a rated longevity of 10 years. Current through up to 16 electrodes is programmable between 0-25.5 mA with a pulse width of 50-500 µs and a frequency between 2-1200 Hz. Continue reading
Intermedics’ First Pacemakers (Mid 1970s)
In 1973, former Medtronic sales representative Albert Beutel founded Intermedics in Freeport, TX. The first product was a small, mercury-cell-powered pacemaker. In 1974 Intermedics introduced a lithium-powered version, and in 1976 it introduced InterLith which was hermetically sealed, and weighed just 65 grams. At the time, InterLith’s size was a breakthrough, and became a very popular device, solidifying Intermedics’ position in the industry.
Original Datasheet for Arco’s Nuclear Pacemakers (ca. 1974)
Some time ago, my friend and colleague Paul Spehr gave me a copy of Arco Medical’s product catalog. I scanned the original datasheets for Arco Medical’s nuclear fixed-rate and demand pacemakers models NU-5 and NU-6 and posted them here in pdf format: Arco_Nuclear_Datasheets
Click here for a color picture and more information on Arco Medical’s nuclear pacemakers.
St. Jude’s DBS Study Confirms Benefit of Constant Current System for Parkinson’s Disease
- Image Credit: St. Jude Medical
Today St. Jude announced that its first controlled study of Deep Brain Stimulation (DBS) confirms benefit of constant current system for patients with Parkinson’s Disease.
Results were published online today by The Lancet Neurology journal. The aim of the study was to evaluate the Libra(TM) and LibraXP(TM) DBS constant current systems to determine the devices’ safety and effectiveness in managing the symptoms of PD. Continue reading
St. Jude 4Q IPG Sales: CRM Down 4%, Neuromodulation 12% Up vs. Q4 2010
Yesterday, Jan 9, 2011, St. Jude Medical announced preliminary revenue results for the fourth quarter ended December 31, 2011:
“Fourth quarter cardiac rhythm management sales were approximately $728 million, a 4 percent decrease compared with the fourth quarter of 2010. Fourth quarter sales of implantable cardiac defibrillators were approximately $436 million, a 5 percent decrease from the comparable quarter in 2010. Pacemaker sales during the quarter were approximately $292 million, a 4 percent decrease compared with the fourth quarter of 2010.
…
Fourth quarter sales of neuromodulation products were approximately $121 million, a 12 percent increase compared to the fourth quarter of 2010.”
Company website: www.sjm.com
American Optical Cardio-Care II Demand Pacemaker (ca. 1971)
The Cardio Care II Pacemaker was American Optical’s second implantable device. It was an improved version of the Cardio Care pacemaker. Besides improvements to the circuitry, the circuit board was enclosed separately inside a hermetic can within the epoxy encapsulation. Continue reading
American Optical Cardio-Care Demand Pacemaker (1968)
Barouh Berkovits at American Optical Co of Boston, MA designed the first “Demand Pacemaker” – what we now know as a VVI pacemaker. The Cardio-Care Demand Pacemaker, introduced in 1968, was American Optical’s first implantable device.
From Kirk Jeffrey’s Machines in our Hearts(2001):
“Berkovits in 1963 designed a sensing capability into the pacemaker. His invention behaved exactly like an asynchronous pacer until it detected a naturally occurring R wave, the indication of a ventricular contraction. This event would reset the timing circuit of the pacemaker, and the countdown to the next stimulus would begin anew. Thus the pacer stimulated the heart only when the ventricles failed to contract. It worked only ‘‘on demand.’’ As an added benefit, noncompetitive pacing extended the life of the battery. Continue reading
A Challenge to History Buffs: Who Was Digikon?
I took this picture a very long time ago at the office of one of my implanter friends in Europe. Ever since then, I’ve tried to find out about “Digikon,” but have had no luck so far. All that I have been able to find from the St. Jude legacy device database is that Digikon had produced a number of pacemaker models, including the one shown in this picture.
Do you know anything about Digikon? Please let me know!
Cook Pacemaker’s Sensor Kelvin 504 Central-Venous-Temperature-Sensing Pacemaker (ca. 1992)
In 1983, Bill Cook and Dr. Neal Fearnot began to work under the Cook Pacemaker Company in Leechburg, PA on developing the technology developed by Dr. Fearnot at Purdue University into an improved prototype for a temperature-based exercise responsive pacemaker that was released in 1988 as the Kelvin Sensor rate-responsive pacemaker. One of the first CVT rate-adaptive pacemakers was the Cook Model Kelvin 500 series. Continue reading
Intermedics’ Circadia Central Venous Temperature-Sensing Pacemaker (ca. 1993)
The Circadia pacemaker was one of the very few devices that had a lead-borne thermistor to measure cental venous temperature (CVT) as a sensor for rate-response.
A unique feature of this pacemaker was an iridium-oxide (IrOx)-coated button welded to the can. It was believed that this button would improve unipolar IEGM sensing and reduce unipolar pacing thresholds (it didn’t). Continue reading
Cook’s Sensor Kelvin and Intermedics’ Circadia Temperature-Sensing Rate-Responsive Pacemakers
One of the indicators of metabolic demand that has been used for controlling the rate of pacemakers is central venous blood temperature (CVT).
In 1983, Bill Cook and Dr. Neal Fearnot began to work under the Cook Pacemaker Company on developing the technology developed by Dr. Fearnot at Purdue University into an improved prototype for a temperature-based exercise responsive pacemaker that was released in 1988 as the Kelvin Sensor rate-responsive pacemaker. One of the first CVT rate-adaptive pacemakers was the Cook Model Kelvin 500 series.
Another one of the first CVT rate-adaptive pacemakers was the Intermedics Nova MR, which differs from the Kelvin 500 series in that its pacing algorithm had a more dynamic HR response. Continue reading