Apr 20, 2015Real-time location system (RTLS) solutions deployed at hospitals allow health-care workers and management to locate equipment, patients or other personnel in real time. However, one shortcoming of most RTLS solutions is the limited lifetime of batteries. Because active RFID tags require battery power, hospitals face a challenge in ensuring that all tags are working properly, especially if there are a large number of items tagged throughout a facility.
Ohio startup Emanate Wireless has developed a solution to that problem, the company reports, with its PowerPath RTLS. The system consists of a tag that plugs into a hospital device's AC power cord, using that AC to recharge the tag's batteries when the tagged device is plugged in.
The PowerPath tag not only transmits its identifier, but also indicates whether a piece of equipment to which it is attached is being used, based on the current flow at that time. The device comes with a Bluetooth Low Energy (BLE) radio so that it can communicate with a smartphone or tablet running a PowerPath app, and also includes infrared (IR), ultrasound and 40 kHz RF receivers that can capture data from RTLS beacons and other RTLS hardware employing those technologies (such as systems from AeroScout, CenTrak, Ekahau and Sonitor).
An Ohio hospital, which Emanate declines to name, plans to begin testing the PowerPath system. That facility will use both the Wi-Fi and BLE capabilities of the tag, and will employ PowerPath software to determine where tagged equipment is located, as well as whether and how often it is in use. The hospital's Wi-Fi system will be used to locate the tags within a 25-foot zone, and to track utilization rates. Workers will use the tag's BLE feature in conjunction with an Apple iPhone or iPad to locate a tagged device within that 25-foot zone, and to create an inventory of devices in proximity to the iPad or iPhone user.
Emanate was founded in 2014 by four former Cisco Wireless Networking Business Unit executives who had come to Cisco through its acquisition of another startup, Cognio. Emanate's goal was to develop a solution capitalizing on the trends of wireless and Internet of Things technology proliferation, as well as the need for greater efficiency in the health-care sector. The company discussed pain-points with hospitals and found that many had not adopted RTLS technology because of the perceived high cost of the infrastructure, as well as the need to replace a tag's depleted batteries. What's more, dead tag batteries were causing some existing RTLS solutions to fall far short of the planned objective of locating all high-value equipment in real time.
"It can be a big maintenance issue to replace batteries every six months to a year," says Neil Diener, one of Emanate Wireless' co-founders and its CEO. One hospital, he adds, indicated that it employed two full-time staff members to simply walk through the facility replacing RTLS tags' batteries.
Another problem was the fact that hospitals could not determine an asset's utilization rate simply based on its location. Although an infusion pump or other device may be in a patient's room, there was no way to know whether it was actually in use. That information not only enables personnel to retrieve a piece of equipment they need (assuming it is not being used), but also allows management to better determine how many of each asset are actually needed at the facility.
Lastly, Diener says, hospitals often felt that putting in place infrastructure to support a system including a secondary technology to better pinpoint location would be expensive. Wi-Fi can approximate a tag's location within a zone, but if a hospital wants room-by-room accuracy, it would also need to install IR or ultrasound emitters to create a hybrid system. Emanate's hybrid approach of using Wi-Fi plus the BLE functionality already within users' phones, however, can eliminate the need for this additional infrastructure.
The PowerPath tag connects to an electronic device, such as a ventilator, pump or monitor, between the power cord and the device itself, thereby enabling it to determine how much current that device is drawing. When it transmits its ID number at its configured intervals, the tag sends power-usage data as well, indicating that the device is turned on and in operation. If the device is plugged in and turned off, the tag still uses power from the cord to recharge its batteries and continues to transmit a signal that indicates the device is not in use. When the device is unplugged, the tag operates off its own battery and transmits a signal indicating that the device to which it attached is not plugged in.
The tag is certified by Underwriters Laboratories (UL) for inline use on the power cord of a medical device. Therefore, it is unlikely to fail and create a failure in the device itself.
"Most RTLS tags today just transmit an ID to be located," Diener explains. That's because the batteries have a limited lifespan, and the sending of more data would shorten the battery's operation life even further. "We don't have to be as judicious with power when it comes to PowerPath," he explains, since PowerPath tags can recharge their batteries whenever the devices to which they are attached are plugged into an AC power outlet. As such, they can perform extra functions, such as monitoring the device's usage. PowerPath software can also be used to periodically update the tag's configuration and firmware.
Typically, a single charge—occurring when a health-care device is plugged in and used once—is sufficient to power the tag's battery for approximately six months.
The PowerPath solution captures the current-flow data and, working with third-party location servers such as Cisco MSE, can determine a tag's location to within about 30 feet, based on the Wi-Fi access points that receive the transmission. When employees seek a specific item, they can access the PowerPath software, input that device's description or serial number, and view a map indicating where that item is located within that 30-foot area, as well as whether or not it is in use.
If workers find that the location information is not specific enough, they can use the BLE function. For this application, PowerPath includes an app for iOS devices, and the company soon plans to release an Android version as well. A health-care worker would proceed to a zone where an item is detected in the software, take out his or her phone or tablet running the PowerPath app, and input the item's ID or description. That person would then use the phone or tablet as a Geiger counter, walking through the area until it comes within BLE range of the tag, which subsequently flashes an LED light and makes an audible chirp. The BLE function also works for performing inventory checks in specific areas, Diener adds. If workers simply want to know which tagged items are in a particular room, for example, they can utilize the BLE app to view a display on their device, indicating what is in range of the phone or tablet.
For analytics, hospital management can view how often any particular device has been used during a particular time period—within one month, for example—and then decide whether a piece of equipment should be moved to another area, or if an additional unit should be ordered. The PowerPath system not only collects the usage data, but can be employed to create a variety of reports based on that information.
If a hospital wishes to use ultrasound or IR transmissions to further identify an asset's location in real time, the tag can read those transmissions and send the identifiers of those ultrasound or IR emitters, along with their own, to the server via a Wi-Fi connection.
If a hospital installs BLE beacons within its facility, the tag's BLE radio can both receive and send BLE transmissions, and this information can be used to improve location accuracy. BLE beacons could be installed to provide way-finding features for smartphone applications, or for other applications, such as monitoring hand hygiene.
In the future, PowerPath may also include tags that could be worn by personnel or patients, or be attached to non-electric items, such as wheelchairs. In this case, however, the tags would require a traditional battery. According to Diener, approximately 90 percent of mobile equipment that hospitals tend to track come with an electric cord.
The test at the Ohio hospital is slated to begin in May, says Dan Cusick, Emanate Wireless' VP of customer development. The hospital already uses an RTLS solution, and plans to compare data from the Emanate PowerPath tags, and thus determine how much value is gained from collecting usage data related to transmissions from tags reporting current flow to each device.
Emanate expects to release its PowerPath solution commercially during the early third quarter of this year. The company is presently in discussions with multiple hospitals regarding the technology, Diener says.
The PowerPath system could also be used in other markets—for instance, to track electric devices in an industrial setting, or servers within a data center. However, Cusick says, the initial focus is on the health-care market.
