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.
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
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
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
The Medtronic Chronicle implantable hemodynamic monitor used a specialized RV lead/sensor. The device was able to monitor and telemeter:
Medcor was established in Hollywood, FL in 1969, and began developing pacemakers, lead and accessories in 1971. By 1975 it had a series of lithium-powered pacemaker in the market, but they never became popular with physicians.
On July 1980, Daig Corporation of Minnetonka, MN acquired Medcor with the expectation that Medcor pacemaker technology could be profitably marketed.
Daig had hoped to market a new line of Medcor pacemakers, but significant electronic malfunctions were encountered which foreclosed further development Medcor’s pacemaker product line. As a result of malfunctions in the first pacemaker line, FDA approval was withheld on a second Medcor line of pacemakers due to similarities in product design.
In 1981, amidst a very serious financial condition, Daig closed its doors. The remaining assets were acquired by Daig’s largest customer – Pacesetter (now part of St. Jude Medical).
UPDATE, May 20, 2013:
Mark Christensen – who worked at Daig Corporation from 1980 to 1986 – sent me a kind note with some additional information: “As you note in your comments on Medcor, it was purchased by Daig in 1980 but remained as a separate business. Daig’s financial crisis in 1981 caused Daig to go into Chapter 11 Bankruptcy and Medcor went to Chapter 7 – liquidation and was sold at auction in late 1981. No pacemaker company bought any of the assets. Daig reorganized, diversified into EP catheters and was bought by St Jude Medical in 1996 (15 years later).” Thanks Mark!
Image Credit: VeriMed
VeriMed’s VeriChip is the only RFID tag that has been cleared by FDA for human implant. The concept behind the medical use of the VeriChip is that patients would have the tiny chip implanted just under the skin, in the back of the arm. Each VeriMed microchip contains a unique identification number that emergency personnel may scan to immediately identify the patient and access his/her personal health information, thus facilitating appropriate treatment without delay. This is especially important for patients who suffer from conditions that may render them unconscious, confused, or unable to communicate. Although the FDA approved the use of the device for anyone 12 years of age or older, it would mostly be recommended for patients with diabetes, stroke, seizure disorders, dementia, Alzheimer’s, developmental disorders, and organ transplants.
CardioMEMS was founded by Dr. Jay S. Yadav and Dr. Mark G. Allen in Atlanta, GA in 2000 to develop implantable micro-electromechanical sensors to improve the management of severe chronic cardiovascular diseases such as heart failure and aneurysms.
The miniature wireless sensors can be delivered through a catheter. Once in place, they transmit cardiac output, blood pressure and heart rate data that are critical to the management of patients. Due to their small size, durability, and lack of wires and batteries, CardioMEMS’ sensors are designed to be permanently implanted into the cardiovascular system. An external reader is used to interrogate the sensors. Continue reading
NDI Medical was founded in 2002 by Geoffrey B. Thrope to develop and commercialize neurodevice products. NDI Medical developed the MicroPulse neurostimulator, a thumb-sized, rechargeable pulse generator, that has been used for the treatment of incontinence and pain, as well as an implantable device for the restoration of function of paralyzed limbs.
According to a 2006 news release by the electronics assembly manufacturer for the MicroPulse:
“Using minimally-invasive surgery, the Micropulse is implanted into a patient, usually in the lower abdomen or buttock, where the device is most comfortable and least visible. After implantation, a clinician uses a wireless programmer to set the Micropulse’s stimulus parameter and timing patterns. The programmer, as well as the patient’s controller for the device, has a range of about three feet.
To recharge the device’s lithium-ion battery, the patient applies a recharging patch for several hours to the vicinity of the implant. The battery needs recharging from once a month to every few weeks.” Continue reading
Leptos Biomedical was founded in Fridley, MN in 2002 by Dr. John D. Dobak. Leptos intended to develop an implantable device to stimulate the greater splanchnic nerve, that was hoped would result in reduced food intake and increased energy expenditure.
In February 2010 Leptos announced its closure. Reasons were not provided, but it has been suggested that the decision was prompted by the 2009 announcement by competitor EnteroMedics’ that it had failed to meet the primary goals of its pivotal study. EnteroMedics’ Maestro device didn’t perform any better than a sham device. EnteroMedics is now conducting a new study with the device.
Click here for Leptos Biomedical’s patents.
Palyon Medical Corporation was founded in 2004 in New York, NY, but recently moved its operations to Santa Clarita, CA. Palyon is still operating stealthily.
Palyon is developing a programmable implantable drug delivery system (IDDS) which delivers targeted doses of pain medication directly to the spinal area for the treatment of chronic pain, spasticity and other neurological diseases. According to Luis Malave, the company’s CEO, “Due to its inherent flexibility as a delivery platform, the IDDS can be used to deliver therapeutics to treat both acute diseases, such as cancer, and chronic diseases including diabetes and multiple sclerosis.” Continue reading
Neuros Medical was founded by Jon J. Snyder in Cleveland, OH in 2008 to develop a neurostimulation therapy to alleviate chronic pain. The company’s Electrical Nerve Block™ technology is based on research done at Case Western Reserve University.
The company’s Nerve Block is an implantable device that delivers high-frequency stimulation to sensory nerves in the peripheral nervous system. Neuros’ aim is to stop a wide variety of chronic pain, including residual limb pain, chronic post surgical pain, and chronic migraine.
In November 2011 Neuros Medical announced that it has received IDE approval from the FDA to evaluate its technology for use in acute treatment of pain in the residual limb of amputees.
Company website: http://www.neurosmedical.com/
Click here for patents on Case Western University’s nerve blocking technology
We conduct reliability analyses for our implantable devices on a continued basis. I’ve spent the last few days readying the data for this period’s analysis, and thought that a short primer on how this is actually done would be of interest to fellow engineers who may need it at some point.
You surely have heard of MTBF = Mean Time Between Failures. This is a key reliability metric. However, since our implantable devices are single-use, the first failure is the final failure, so MTTF = Mean Time To Failure. As such, for a device with no possibility of repair (e.g. implantables, satellites), MTBF=MTTF. Continue reading
Image Credit: NeuroVista
Seattle-based NeuroVista was founded in 2002 by Dr. Daniel DiLorenzo to develop an implantable device for the early detection of epileptic seizures.
The NeuroVista seizure advisory system is based on an implantable device that senses EEG irregularities that precede a seizure. Early warning allows patients to take medicine and find a safe place to lie down. Although some epilepsy sufferers can feel seizures coming, many cannot.
In NeuroVista’s Seizure Advisory System (SAS), intracranial EEG signals are recorded through electrodes implanted between the skull and the brain surface. Data storage and signal telemetry takes place within the pectorally-implanted can that transmits signals wirelessly to an external handheld device that processes the data and transmits visual and audible signals to the patient. The external pager-like receiver displays a blue light when there is a low likelihood of seizures, white indicates medium susceptibility, and red alerts to a high likelihood of impending seizure. Continue reading
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.