The HeartWare controller manages HVAD pump by sending power and operating signals to the pump while also providing information to the patient and physician via visual and audio feedback. The controller incorporates a three-tier alarm redundancy comprising a sound i.e. an audible alarm, together with a color-coded visual display and written text on a screen.

According to HeartWare, the visual text and color-coding are visible to the patient and caregivers at all times. Each of the three alarms is tested multiple times each day when the patient or the caregiver replaces the patient’s batteries in the normal course of use.

HeartWare said that although a small number of controllers have exhibited reduced levels of speaker volume, no patient has experienced any form of resultant medical complications due to the above mentioned alarm redundancies and daily testing.

Reportedly, in July 2009, HeartWare implemented a new revision of its controller to incorporate waterproofing. Unfortunately, during air transportation of the new revision of controllers to clinics, a small number of controllers developed excess air vacuum that subsequently reduced levels of speaker volume.

As a result, HeartWare expanded its standard product testing processes to include an air pressure simulation so as to screen-out susceptible units and, commencing in December 2009, implemented a further revision of the controller which added a small Teflon vent to the underside of the controllers so as to prevent the occurrence of excessive air vacuums during transportation to the clinic.

Doug Godshall, president and CEO of HeartWare, said: “The implementation of the waterproof controllers in July 2009 unfortunately generated an air-tight vacuum within our controller with the result that our speaker may be quieter than expected in a small number of cases, including just one occurrence in the US since the commencement of implanting in our IDE trial in August 2008.

“We have since rectified this issue but there are still patients being supported by our now waterproof controllers that do not have the current ‘vented’ controller. This field program will enable these older versions to be upgraded to the current vented configuration. We will also take this opportunity to replace approximately 80 controllers which were introduced since we received our IDE for our US bridge-to-transplant trial.”