Design and integration company Walker Engineering was asked to assess the paging and public address systems at the sprawling Houston Methodist Hospital. The integrator encountered an assortment of older analogue systems that were inadequate for the needs of a modern medical facility – including integration with the new Paula and Joseph C. “Rusty” Walter III Tower, a 22-storey, one million-square-foot building for cardiovascular and neurosurgery.
Efficient communications across all 10 of Houston Methodist’s
downtown buildings was critical. Walker recommended Bosch Praesideo digital public address and emergency sound system as a scalable, flexible enterprise solution to serve the new Walter Tower and unite it with the rest of the campus.
“We had previously upgraded several of the medical centre‘s suburban facilities, but the downtown campus was a different kind of challenge,” noted Matt Kenjura, manager of technology pre-construction for Walker. “Each existing building had its own legacy paging system, and the goal was to find an operational approach that could pull those patchwork analogue systems into a modern digital environment, and do it without downtime to critical communications. Bosch Praesideo has the flexibility and scalability to keep all these adjacent systems working throughout the transition.”
In a hospital environment, communications is a critical component of efficient care delivery, most notably when a patient requires immediate assistance. Houston Methodist’s goal was to allow system-wide call distribution while enabling floor-level and single-building traffic to function without losing any of the 1,700-plus daily PA calls.
Walker Engineering’s approach was to harness each outlying building’s system by converting the audio signal to digital with Bosch Praesideo, enabling the system’s control network to work with the existing analogue amplifiers and transducers. These systems, in turn, are chained together based on which side of the street the building is located, essentially creating two primary control loops. An additional Praesideo system then connects all the buildings together to enable campus-wide calls. This nested architecture functions as the core for the distribution network.
“All the mission-critical campus-wide paging resides on the network, backed up by two redundancy networks,” explained Kenjura. “There’s a Praesideo network controller and audio expander in each building. Calls are routed according to priority, and are routed locally on the floor, within a building, or across the campus. The key is reliability and intelligibility, because a Code Blue call is literally life-or-death.”
That mission-critical urgency was a driving force in the upgrade of the existing systems. The first phase was to create a network, replacing relay-based analogue signal routing by replacing existing signal processors with a Bosch Praesideo PRS-NCO3 network controllers and digital conversion hardware in each building.
Using Praesideo for networked digital distribution was an instant success. Missed calls were now getting through, solving the majority of problems with the system. Legacy amplifiers and loudspeakers could still be used, saving Houston Methodist considerable money while putting the infrastructure in place to convert failing components to Bosch Praesideo as the opportunity arose.
In the new Walter Tower facility, the entire public address system is an end-to-end Bosch Praesideo system from call station to loudspeakers, including all network control, signal processing, and amplification. This creates numerous operational advantages.
In addition to advanced call routing, each Praesideo system component can be monitored and controlled from a computer on the network, creating efficiency through visibility of each physical asset. Any operational fault, such as overloads, faults and short circuits, can be remotely identified and addressed, which simplifies troubleshooting and minimises downtime. These advantages are being realised in the satellite buildings by replacing outdated amplifiers with Praesideo power amplifiers, connecting them to the existing loudspeakers.
Overall, the downtown Houston Methodist Hospital campus is operating roughly 3,000 audio channels to nearly 7,000 speakers across 126 zones in its 10 buildings, all running through a total of 14 interconnected Praesideo systems. Beyond paging, the network handles data, intercom, access-controlled video surveillance, cable TV, and mass notification of life safety systems.
