The First Holter Monitor
The Holter monitor was developed in Helena, Montana, USA by experimental physicist Norman “Jeff” Holter and lab partner Bill Glasscole.
Jeff Holter’s original goal was to radio-broadcast and record electrophysiological activity in humans as they were going about their daily activities. The current electrographical monitoring at this time required subjects to remain supine and inactive therefore giving a very limited insight into cardiac activity.
In 1947, Jeff Holter undertook the first Holter recording via radioelectrogram technology. This involved wearing around 38kg strapped on his back whilst riding a stationary bike. This seemingly cumbersome method went on to form the basis of a major breakthrough for both cardiology but also the diagnostic industry.
From Backpacks to Pockets
Luckily, the first prototype was short-lived as transistors were developed. With this new advent of technology, radioelectrograms became obsolete and the Holter monitor became streamlined into a format that could be carried in a patient’s pocket.
As demand for his technology increased, Jeff Holter needed to look into solutions to help him take the Holter to new heights. To achieve this, Jeff Holter sold the exclusive rights of his technology to Bruce Del Mar, founder of Del Mar Avionics Corporation. This partnership became a catalyst for the creation of the diagnostic industry and both Holter and Del Mar are considered the ‘founding fathers’ of ambulatory ECG monitoring.
Del Mar and his team moved their focus from military equipment to improving the speed and diagnostic accuracy of the Holter monitor, a process that continued for 40 years.
Analogue to Digital
The initial ‘mass market’ Holter monitor in 1963 had the capacity to record 6-8 hours of ECG activity using an analogue signal.
In the 1980s, the conversion of analogue to digital opened up a world of new possibilities within the med-tech industry. Del Mar Avionics applied this breakthrough to develop a Holter monitoring system with a channel of amplified pacemaker signal accompanied by 1 or 2 channels of ECG in order to aid the interpretation of pacemaker waveforms.
Whilst this idea didn’t take off within the cardiology market, the technology went on to form the basis of the electrograms recorded by modern pacemakers and other implantable cardiac devices.
The advances in Holter monitoring technology not only helped to advance pacemaker technology but also led to the invention of ambulatory blood pressure monitoring, another important cardiac diagnostic tool.
Small But Mighty
In the current era, Holter monitoring has developed exponentially from the large, cumbersome backpack monitor to small, adhesive patch monitors and equally small traditional Holter monitors.
ECG On-Demand provides Holter monitoring with both patch and traditional electrode devices, including paediatric configurations to suit a wide range of patient and clinician needs. All options provide a sleek and compact solution that stands in stark contrast to the bulky Holter monitors that patients are familiar with.
Option 1 – Traditional Electrode
This Holter device delivers high-quality, single-channel recordings via two electrodes (we recommend Ambu VLC) and a short wire connection. This sits on the chest in a small, flexible form factor. Recording is up to 14 days, and the device is showerproof with an IP67 rating.
Additional configurations of this device are available for custom and bespoke requirements, for example, clinical trials. These include features such as 3-channel, high sample rates up to 1000 Hz, and 3D accelerometer data. All of which can be programmed and customised within the ECG On-Demand workflow and system integrations by our in-house software development team.
Option 2 – Patch
Our alternative to traditional electrodes is a patch device that provides multi-channel recordings via a replaceable and cost-effective patch. Again, this device sits on the chest and can record up to 14 days continuously. It is also showerproof with an IP68 rating.
Both devices are reusable and rechargeable, aligning with ECG On-Demand environmental values and ISO 14001 credentials.
The era of cumbersome Holter monitors with multiple leads and inconvenient setups, such as wearing a neck strap, is over.
As the industry continues to flourish, everything circles back to the two incredible minds, Jeff Holter and Bruce Del Mar.
References:
https://americanhistory.si.edu/explore/stories/heart-invention-development-holter-monitor
https://pmc.ncbi.nlm.nih.gov/articles/PMC6932486/
Norman Holter on bike https://en.ecgpedia.org/wiki/File:De-Norman_Holter.jpg
