RTLS in Healthcare: Comparing Real-Time Location Systems


Real-Time Location Systems (RTLS) in Healthcare: Optimizing Operational Efficiency

Real-Time Location Systems (RTLS) have emerged as a valuable technological tool in healthcare. By providing real-time tracking of patients, staff, and assets, these systems contribute to workflow optimization and greater operational efficiency. Additionally, to enable even more valuable use cases, Real-Time Location Systems can be integrated with other healthcare systems such as Electronic Medical Records (EMR) systems, Enterprise Resource Planning (ERP) systems, Computerized Maintenance Management Systems (CMMS), Bed Management software, and Nurse Call systems. 

There are now many different enabling technologies that power RTLS and many different vendors. There are myriad combinations of technologies, integrations, and use cases. This has made it important for healthcare organizations to establish a basic understanding of the underlying technologies.  

Table of Contents


Understanding RTLS 

Definition and Purpose of RTLS 

What is RTLS? Real-Time Location Systems (RTLS) are technologies that enable the tracking of objects or people within a defined area in real time or near real time. This is useful in healthcare settings for monitoring patients, locating critical assets, and enhancing staff workflow. This is becoming especially useful as integrations between healthcare systems are becoming more possible and prevalent. 

Asset Orchestration Solution with Asset Map on Desktop and Mobile Device

Overview of Main Components 

A Real-Time Location System is typically comprised of three fundamental components.

Tags
Infrastructure Devices
RTLS Software

Tags

These are mobile specialized devices and/or labels that are attached to objects or worn/carried by people. These are the devices that will be located and may include battery-powered RTLS tags, passive RFID labels, mobile computers/phones, and other similar devices. 

Fixed Infrastructure Devices

These are mobile specialized devices and/or labels that are attached to objects or worn/carried by people. These are the devices that will be located and may include battery-powered RTLS tags, passive RFID labels, mobile computers/phones, and other similar devices. 

RTLS Software

These are mobile specialized devices and/or labels that are attached to objects or worn/carried by people. These are the devices that will be located and may include battery-powered RTLS tags, passive RFID labels, mobile computers/phones, and other similar devices. 

Different RTLS technologies and vendors require different types of hardware components. While these various hardware components differ in functionality (and terminology), typically those various components can be categorized into one of the latter categories. 

The Right RTLS for the Right Job 

There are different technologies that enable Real-Time Location Systems (RTLS), and one size does not fit all. 

  • High Room-level Accuracy
    Some use cases require a high degree of room-level accuracy – certainty that a Tag is within a space bounded by four walls (such as an operating room or an inpatient room). 
  • High Free-space Accuracy
    Other use cases require a high degree of accuracy in free space – certainty that a Tag is in a specific position not bounded by four walls (such as a chair in an infusion center or a bed in a PACU). 
  • Minimal Cost
    Other use cases do not require a high level of accuracy and instead require a minimal optimal cost of ownership. 
  • Low Tag Cost
    Still other use cases demand a low Tag cost where tens or hundreds of thousands of assets & supplies need to be tracked.  

Sometimes these requirements may conflict with one another and sometimes not, which is why RTLS experts can help hospitals weigh these decisions. 


Different Types of RTLS Technologies 

In the following sections, we’ll delve into the diverse landscape of Real-Time Location Systems (RTLS) technologies, each offering unique advantages and limitations. We’ll explore the high-level basics of how these technologies function and how they can best be utilized in healthcare settings. 

The most widely deployed RTLS-enabling technologies include: 

  • Infrared (IR)  
  • Ultrasound 
  • Wi-Fi-based 
  • Ultra-Wideband (UWB)
  • RFID (Radio-Frequency Identification) 
  • Bluetooth/BLE(Bluetooth Low Energy)-based
  • Active vs. Passive RTLS Systems
  • Choosing the Right System for Healthcare

Infrared (IR) RTLS

Infrared (IR) systems use infrared signals to determine the location of a tagged object or person. They operate on the principle of line-of-sight (LoS), which makes them especially suited for high room-level accuracy in controlled environments. It is important to note that modern infrared systems do not have strict line-of-sight limitations.

Zone Coverage

  • Infrastructure Device
  • Tag
  • Coverage Zone
  • Active Coverage Zone

Infrared devices are fixed on the ceiling of a room and set to monitor different zones of a room. When a tag enters the monitored zone, the tag is reported in that zone.

Infrared RTLS Quick Facts

4

Cost

3

Device cost

3

Tag Cost

4

Accuracy

4

Precision

Advantages 

  • High room-level accuracy with line-of-sight (LoS) technology. 
  • Difficult to interfere with or to eavesdrop on. 

Disadvantages 

  • Best performance requires line-of-sight between the tag and the sensor. 
  • Infrastructure can be expensive due to the high density of sensors needed. 

Ideal Healthcare Use Cases 

  • Patient Tracking & Workflows (especially where room-level accuracy is important) 
  • Staff Tracking & Workflows, and Staff Safety/Duress 

Components 

  • Tags: Tags are battery-powered devices that are equipped with infrared (IR) sensors, wireless radios for communication, and any additional sensors that may augment location accuracy (in hybrid systems). 
  • Fixed Infrastructure Devices: Fixed-position devices are installed that have at least infrared (IR) sensors and may be either battery-powered or line-powered. 

Understanding Infrared RTLS: The Importance of Line-of-Sight and Controlled Environments  

Infrared (IR) systems use infrared signals—part of the electromagnetic spectrum with wavelengths longer than those of visible light but shorter than microwaves—to determine the location of a tagged object or person. These signals are emitted from tags and captured by receivers. An IR system may calculate the distance based on the time it takes for the infrared signal to travel from the tag to the receiver, thus providing the tagged object’s or person’s location. 

Infrared Real-time Location Systems are commonly deployed for patient tracking solutions.

The IR system operates at least in part on the principle of line-of-sight. This means that the tagged object must be visible to the sensor for a precise measurement. Because of this line-of-sight (LoS) requirement, infrared signals can be used to accurately and precisely locate a Tag within a given room, allowing for a high level of certainty that an object or person is located within a room – especially when compared to other, non-LoS technologies. 
 
IR systems thrive in a “controlled environment,” meaning spaces where the conditions are stable and predictable such as individual hospital rooms, as opposed to larger, more open areas with more variables that could impact signal integrity. In such controlled environments, the line-of-sight (LoS) requirement can be more reliably met, leading to higher accuracy in tracking. 

Obstructions to the line-of-sight in an infrared system can include a variety of physical and environmental barriers. Some examples are: 

  • Walls
    Traditional walls, partitions, or even temporary structures like screens can block the infrared signals. 
  • Furniture
    Large furniture items like cabinets, desks, and beds could potentially interfere with the direct path between the tag and the receiver. 
  • People
    In busy environments like hospitals, the movement of healthcare providers, patients, and visitors can momentarily obstruct the signal. 
  • Medical Equipment
    Large pieces of medical equipment like diagnostic machines, mobile workstations, or medical carts could also act as obstructions. 
  • Doors
    Closed or even partially open doors can impede the line-of-sight for infrared systems. 
  • Curtains or Drapes
    Soft obstructions like curtains, blinds, or other window coverings could also interfere with infrared signals if they are positioned between the tag and the receiver. 
  • Plants
    Although less common in healthcare settings, large potted plants could potentially obstruct the line-of-sight. 

Understanding these potential obstructions is essential for the effective deployment of infrared RTLS, especially in a complex and dynamic environment like healthcare facilities.  Obstructions are not necessarily bad and can in fact help bound spaces (e.g., walls bounding a room); however, system design must be intentional and thoughtful by considering how the environment may change. 


Ultrasound RTLS 

Ultrasound systems utilize sound waves to measure the time it takes for a signal to travel between the tag and the receiver. Because they rely on sound rather than light or radio waves, they offer unique advantages in accuracy and resistance to electronic interference but also come with their own set of environmental constraints. 

Room Level Location with Sound

  • Infrastructure Device
  • Tag
  • Sound Waves
  • Calculated Position

Ultrasound uses sound waves to find position of a tag. Sound is unique in that it can penetrate objects that other signals cannot.

Ultrasound RTLS Quick Facts

3

Cost

3

Device cost

4

Tag Cost

4

Accuracy

4

Precision

Advantages 

  • Provides precise location information. 
  • Not impacted by electronic interference. 

Disadvantages 

  • Can interfere with lighting control systems when ultrasound motion sensors are used 
  • Infrastructure can be expensive due to the high density of sensors needed (similar but often less than infrared) 

Ideal Healthcare Use Cases 

  • Patient Tracking and Workflows 
  • Staff Tracking, Safety/Duress, and Workflows 

Ultrasound RTLS Systems: The Power and Limitations of Sound-Based Tracking 

Ultrasound RTLS systems function by emitting sound waves from a tagged object, which are then picked up by a receiver. The time it takes for the sound wave to travel from the tag to the receiver allows the system to calculate the distance between them. Unlike systems that use light or radio waves, sound waves offer some distinct advantages but also come with unique environmental constraints. 

Triangulation

Finding the triangulated location of a tag involves measuring the time a signal response takes to return from at least three different sensors. This image depicts location using ultrasound based signals, however the concept is consistent independent of signal type.

Sound waves are mechanical waves that travel through a medium like air or water, whereas light and radio waves are electromagnetic and can travel through a vacuum. This fundamental difference makes sound waves less susceptible to electronic interference. Sound waves can offer more precise location tracking in certain environments because they are not easily interfered with by electronic devices or Wi-Fi signals. However, this precision can come at a cost, as sound waves are also more affected by environmental factors. 

It is also important to note that ultrasound RTLS can interfere with lighting control systems when ultrasound motion sensors are used. 

Understanding environmental considerations is essential for the effective deployment of ultrasound RTLS, especially in a complex and dynamic environment like healthcare facilities.  As with infrared RTLS, system design must be intentional and thoughtful by considering how the environment may change. 


Wi-Fi-based RTLS 

Wi-Fi-based RTLS systems leverage existing and additional Wi-Fi infrastructure to locate and track assets or individuals. These systems can be beneficial for large healthcare facilities due to their scalability and compatibility with existing networking equipment. To benefit from existing equipment, the Wi-Fi network needs to have capacity to handle the additional RTLS systems. 

Wi-Fi Calculated Position

  • Infrastructure Device
  • Wi-Fi Signal
  • Tag
  • Wi-Fi Response Signal
  • Calculated Position

Wi-Fi access points are used to triangulate a tag position. Calculated position is usually accurate to 6 to 12 feet. Existing Wi-Fi infrastructure can sometimes be used.

Wi-Fi-based RTLS Quick Facts

2

Cost

3

Device cost

3

Tag Cost

2

Accuracy

2

Precision

Advantages 

  • Potentially cost-effective due to leveraging existing Wi-Fi infrastructure. 
  • Good coverage across larger areas. 
  • Can be augmented with other RTLS technologies to achieve better accuracy (e.g., infrared and ultrasound) 

Disadvantages 

  • Less accurate compared to other RTLS types when not augmented. 
  • Dependent on the reliability and coverage of the Wi-Fi network. 
  • Frequently requires new licenses and often new access points. 

Ideal Healthcare Use Cases 

  • Asset Tracking and Management 

Wi-Fi-Based RTLS Systems: Bridging Scalability and Compatibility in Healthcare Settings 

Wi-Fi-based systems utilize existing Wi-Fi networks within healthcare facilities to locate and track assets or individuals. Generally, Wi-Fi-based RTLS systems measure the signal strength of Wi-Fi signals sent between access points and tags. The received signal strength indicator (RSSI) values are used in a multiliterate calculation to approximate the location of tags. Wi-Fi-Based systems hold the advantage of leveraging existing infrastructure, making them particularly appealing for large healthcare environments in terms of scalability and compatibility with network access points already in place. 

It is important to note that while many RTLS vendors promise their systems will use “existing WiFi networks,” systems often require additional software licenses, access point upgrades, and/or additional access points. 

Wi-Fi-based RTLS systems can cover large areas effectively when access points are strategically placed.  They often use high transmission power and advanced antenna designs. The use of repeaters and mesh networks can further extend this coverage, which can increase the effectiveness of Wi-Fi-based solutions. 

Wi-Fi signal strength can fluctuate widely and unevenly due to physical obstacles like walls and furniture, as well as electronic interference from other devices. Additionally, certain building materials such as metal and concrete can weaken or block the signals. Locating tags using signal strength based multiliterate algorithms can be subject to wide variations in accuracy and precision.  Often, when better accuracy or precision is required, Wi-Fi-based RTLS is augmented with other RTLS technologies (e.g., ultrasound and infrared). 

Additional Information About Wi-Fi-based RTLS

Challenges with WiFi Integration 

  • Network Capacity
    Not all existing Wi-Fi systems have the bandwidth to handle the added load of an RTLS system, which may require an upgrade to the network infrastructure. 
  • Security Concerns
    Merging RTLS with existing Wi-Fi systems could potentially expose vulnerabilities, necessitating additional security measures. 
  • Software Compatibility
    RTLS software must be compatible with the existing network management software to function correctly. 

Utilizing Existing WiFi Coverage 

  • Use of Existing Access Points
    The system can utilize current Wi-Fi access points, avoiding the need for specialized infrastructure. 
  • Wide Range
    Wi-Fi signals can cover a large area, making them suitable for expansive healthcare facilities. 

WiFi Accuracy Limitations 

  • Signal Fluctuations
    Wi-Fi signals can fluctuate due to environmental factors or electronic interference, affecting accuracy. 
  • High Traffic
    Wi-Fi networks often serve many functions; the added traffic can introduce latency, affecting real-time tracking capabilities. 
  • Multiple Devices
    Wi-Fi networks generally support multiple devices. This multiplicity can cause ‘noise,’ making it harder to isolate the specific signal from an RTLS tag, thereby affecting accuracy. 

Ultra-Wideband (UWB) 

Ultra-Wideband (UWB) RTLS systems use low-power digital radio signals for precise location tracking. These systems are known for their high accuracy and low latency, but they require dedicated infrastructure that can be costly. 

Very Accurate Location

  • Infrastructure Device
  • UWB Signal
  • Tag
  • UWB Response Signal
  • Calculated Position

UWB access points are used to triangulate a tag position. Calculated position is usually accurate to the centimeter. UWB waves can penetrate objects that other signals cannot. UWB infrastructure usually demands a larger budget.

Ultra-Wideband RTLS Quick Facts

5

Cost

5

Device cost

3

Tag Cost

5

Accuracy

5

Precision

Advantages 

  • Very high accuracy and precision. 
  • Penetrates walls and floors well without losing accuracy. 

Disadvantages 

  • Requires the installation of dedicated infrastructure. 
  • Typically much more expensive compared to other systems. 

Ideal Healthcare Use Cases 

  • Not widely deployed in healthcare due to the high cost. 

Ultra-Wideband (UWB) RTLS Systems: A Detailed Overview 

Understanding Signal Types and Positioning Techniques 

Ultra-Wideband (UWB) RTLS systems employ low-power digital radio signals, operating in the frequency range between 3.1 and 10.6 GHz for precise location tracking. Unlike infrared or ultrasonic systems, which operate on the principles of line-of-sight or sound wave propagation, these digital radio signals use Time-of-Arrival (ToA) and/or Time Difference of Arrival (TDoA) techniques to calculate position. These methods contribute to high accuracy and precision. 

Signal Penetration and Environmental Constraints 

Ultra-Wideband (UWB) systems generally do not suffer from obstructions to the same degree as infrared systems. Unlike infrared, which requires a direct line-of-sight (or at least near line-of-site) between the tag and the sensor, UWB radio signals can penetrate walls and other solid objects to some extent. While they are less susceptible to physical barriers, the signals can still be attenuated or weakened by certain materials like metal or concrete. Thus, while UWB systems offer more flexibility in terms of placement and are less hindered by physical obstructions, their performance may still be affected by the composition of the environment they are deployed in. 

The Importance of Low Latency 

The term ‘low latency’ refers to the minimal time delay in the transmission of data between the tag and the reader, which is typically in the range of microseconds to milliseconds for UWB systems. This low latency makes the system responsive and real-time, allowing for immediate action based on the location data. 

Cost Considerations for UWB Systems 

In terms of cost, UWB systems generally require the installation of dedicated infrastructure, including multiple fixed infrastructure devices and specialized software, which can make them more expensive than other RTLS systems that leverage existing infrastructure like Wi-Fi-based systems. Costs can range from a few thousand dollars for smaller deployments to hundreds of thousands for larger, more complex environments. 


RFID (Radio-Frequency Identification) 

Passive RFID systems utilize electromagnetic fields to identify and track tags attached to objects or individuals. These systems are versatile and can be easily integrated into existing healthcare processes like inventory management and patient check-in where users are likely already printing tags/labels which can be easily upgraded to RFID-enabled tags/labels. 

Zone Coverage with Direction

  • Infrastructure Device
  • RFID Signal
  • Tag
  • Coverage Zone
  • Active Coverage Zone

RFID access points are mounted in fixed positions at key points to calculate when tags enter and exit a zone. Direction in which a tag moves can be tracked as well. RFID infrastructure usually demands a larger upfront budget. Tags can be very inexpensive allowing for large quantity item tracking.

RFID in RTLS Quick Facts

4

Cost

5

Device cost

1

Tag Cost

3

Accuracy

5

Precision

Advantages 

  • Passive tags do not require a power source. 
  • Easily integrated with other systems like barcode printers. 
  • Low-cost passive tags (many less than $1/tag). 

Disadvantages 

  • Line-of-sight may be needed for certain types. 
  • Variable accuracy and range based on tag type. 
  • Higher cost for retrofitting infrastructure. 

Ideal Healthcare Use Cases 

  • Asset Tracking and Management 
  • Inventory Management 
  • Specimen Tracking 
  • Patient Tracking and Workflows 

Radio-Frequency Identification in RTLS: A Comprehensive Look 

Battery-Free Tags 

In RFID systems, RFID readers and their attached RFID antennas (the fixed infrastructure) emits an electromagnetic field that powers battery-free passive tags when the tags comes into range, allowing tags to transmit identification information back to the reader. This makes passive tags more cost-effective and easier to manage, as they can last indefinitely without requiring a battery change. Additionally, these tags can be printed by the user from similar printers (and sometimes even the same printers) that may already be used in their workflow to create barcode labels or patient wristbands. 

Easy Integration with Existing Systems 

The versatility of RFID systems makes them easily integrable into existing healthcare processes, such as inventory management and patient check-in systems. This is in part because the RFID tags can share the same form factor as barcodes, making it easy to replace or augment barcode systems with RFID capabilities. Also, RFID readers can often be integrated into existing IT frameworks. 

Read Range in RFID Systems 

While RFID systems do not have strict line-of-sight constraints, they are subject to a similar constraint of read range. Dense materials like metal or water can interfere with the electromagnetic fields, preventing effective reading of tags. This can pose challenges in complex environments like hospitals, where numerous electronic devices, fluids, and metallic structures are present. 

High Infrastructure Costs 

One of the major drawbacks of RFID systems can be the initial cost of infrastructure, particularly if a high level of accuracy is required (which equates to more fixed infrastructure). While the total cost of ownership (on a long-term basis) is often lower than active RTLS systems (especially when a high volume of tags are tracked), the initial expense is typically higher than most other RTLS modalities (excluding UWB RTLS, which is often the most expensive option). 


Bluetooth (including BLE – Bluetooth Low Energy) 

Bluetooth RTLS, including its low-energy variant BLE, uses radio signals to determine the location of tagged objects or individuals. These systems are easily scalable and compatible with existing devices like smartphones and tablets, making them versatile for a range of healthcare applications. 

BLE Calculated Position

  • Infrastructure Device
  • BLE Signal
  • Tag
  • BLE Response Signal
  • Calculated Position

BLE access points are used to triangulate a tag position. Calculated position is usually accurate to 6 to 12 feet. BLE tags are low energy leading to lower tag costs.

Bluetooth and BLE in RTLS Quick Facts

3

Cost

3

Device cost

2

Tag Cost

3

Accuracy

2

Precision

Advantages 

  • Compatible with many existing devices like smartphones. 
  • BLE is more energy-efficient than other active RTLS solutions, leading to longer battery life for tags. 
  • Scalable and can cover larger areas without significant additional costs, particularly when BLE is in access points, lighting and other controls. 

Disadvantages 

  • Dependent on the density of Bluetooth beacons for accuracy. 
  • Susceptible to signal interference from other electronic devices. 
  • Less accurate compared to other RTLS types (without augmentation with other technologies) 

Ideal Healthcare Use Cases 

  • Asset Tracking and Management 

Bluetooth and BLE in RTLS: A Deep Dive into Scalability and Energy Efficiency 

BLE-based RTLS often is similar to Wi-Fi-based RTLS in that it measures the signal strength of BLE signals sent between fixed infrastructure and tags. The received signal strength indicator (RSSI) values are used in a multiliterate calculation to approximate the location of tags.  However, newer BLE-based systems are starting to incorporate other approaches such as angle of arrival (AoA) which is more accurate than RSSI-based calculations. 

Asset Management
BLE is commonly used for asset tracking in healthcare environments.

While simplistic, it is not unreasonable to consider BLE-based RTLS a newer, better version of Wi-Fi-based RTLS, which is why major access point vendors are adding the capability to their networking technology. 

The Energy Efficiency of BLE 

Bluetooth Low Energy (BLE) is designed to provide significantly lower power consumption compared to traditional Bluetooth technology. It achieves this by maintaining a sleep mode and only becoming active when a connection is initiated, thereby extending battery life. This makes it ideal for applications where constant, real-time tracking is not necessary, such as asset tracking in healthcare settings. BLE-based RTLS holds a distinct power advantage over its Wi-Fi-based RTLS counterpart. 

Scalability and Coverage 

BLE-based systems are highly scalable because they can easily integrate with existing devices like smartphones and tablets. This eliminates the need for specialized tracking devices or tags in many cases. BLE also uses a mesh networking topology, allowing devices to relay signals between each other, effectively extending the system’s range without requiring additional infrastructure.  It is important to note that mileage varies on the accuracy that can be achieved tracking devices not specifically designed as RTLS tags (e.g., smartphones). 

Density of Beacons: A Double-Edged Sword 

To achieve high accuracy, Bluetooth RTLS often requires a high density of beacons, which can be a disadvantage in terms of both cost and complexity. The more beacons you have, the more accurately you can pinpoint a device’s location. However, the need for multiple beacons can increase infrastructure costs and make the system more difficult to manage. 

Susceptibility to Signal Interference 

As with Wi-Fi-based RTLS, BLE-based RTLS is susceptible to signal interference from other and subject to environmental impacts to signal strength.  As with Wi-Fi-based RTLS, the BLE signals are prone to environmental factors like walls and human bodies, which can cause signal attenuation and multi-path effects. These factors result in a less precise location calculation compared to systems that use other technologies. 


Active vs. Passive RTLS Systems 

Active and passive RTLS systems differ mainly in the type of tags they use and how those tags interact with the rest of the system. Active RTLS systems use battery-powered tags to transmit real-time location and additional data, making them ideal for complex tracking needs. Passive RTLS systems rely on unpowered tags that draw energy from the reader’s field, offering a cost-effective solution for simpler tracking applications. 

Active RTLS Systems

Active Systems 

These systems use battery-powered tags that emit signals regularly. 

Advantages 

  • Offers real-time tracking. 
  • Higher accuracy can be achieved with less infrastructure than passive. 
  • Can cover larger distances with fewer infrastructural needs. 
  • Tags can store and transmit additional data, such as sensor data and button-presses. 

Disadvantages 

  • Tags are generally larger due to the battery. 
  • Higher cost due to complexity and battery replacements. 
  • Systems require specialized maintenance. 
Passive RTLS Systems

Passive Systems

Tags do not have their own power source; they reflect or absorb and re-emit signals from a reader. 

Advantages 

  • Tags are cheaper and smaller. 
  • Long-lasting due to no battery requirements. 
  • Many tags available with interoperable standards. 

Disadvantages 

  • Lower range compared to active tags, requiring more infrastructure. 
  • Less accurate, and may be unsuitable for real-time tracking without higher-density infrastructure. 
  • Infrastructure is more expensive (especially for retrofit) 

Choosing the Right RTLS for Healthcare 

Selecting an RTLS for healthcare involves balancing several factors. It is important to consider your facility’s specific needs, size, and existing infrastructure. There are various RTLS technologies available—each with its own set of advantages, limitations, and ideal use-cases. 

Factors to Consider When Choosing an RTLS System 

  • Use Cases: Specific needs and use cases. 
  • Amount of Tracking: Number of people and/or assets to track. 
  • Facility Size: Size of the facility(ies). 
  • New or Existing Deployment: Whether RTLS will be added to an existing facility(ies) (retrofit) or whether it will be incorporated into a new facility(ies). 
  • Current Infrastructure: Existing RTLS-relevant infrastructure (e.g., existing Wi-Fi access points, lighting controls, legacy RTLS systems, existing RFID infrastructure, etc.). 
  • Budget: Budget constraints. 
  • System Integration: Integration capabilities with existing systems. 

Hybrid RTLS Technology Solutions 

When it comes to real-time location systems (RTLS), there is no one-size-fits-all solution. Different technologies come with their own sets of advantages and disadvantages. However, combining different types of RTLS can potentially mitigate the weaknesses of each, while maximizing their strengths.  This is becoming increasingly common. 

The Synergy of Combining Technologies 

When you merge two or more RTLS technologies, the resulting system can offer more than the sum of its parts. For example, Wi-Fi might provide extensive coverage but lacks in pinpoint accuracy. Pairing it with ultrasound can remedy this issue by adding a layer of high room-level accuracy where needed. 

The ideal use cases for multi RTLS solutions depend on the specific challenges your facility faces. If you need high accuracy in certain sensitive areas (like surgical suites or intensive care units) but also need to cover a large campus, a combined solution could be your best bet. It allows you to customize your tracking capabilities according to the diverse needs of different hospital zones, thus offering a tailored solution. 

Common RTLS Combinations 

Infrared + WiFi RTLS Combination

Infrared offers high room-level accuracy but can be obstructed easily. Wi-Fi, on the other hand, provides a broader range. By combining these two, you can achieve comprehensive coverage and high accuracy where you most need it. 

Integrating Wi-Fi with IR brings the advantage of enhanced location accuracy, particularly valuable in sensitive areas like operating rooms or intensive care units. While Wi-Fi offers a solid foundation for tracking, the addition of IR allows for precise room-level location data. This precision is crucial for monitoring high-value equipment and patient flow. However, the installation of IR emitters requires additional investment, and the system’s effectiveness is contingent on unobstructed line-of-sight between IR tags and sensors.

Benefits
  • Enhanced location accuracy to room level.
  • Ideal for monitoring sensitive areas like operating rooms.
  • Complements Wi-Fi’s broad coverage with IR’s precision.
Drawbacks
  • Additional investment for IR sensor installation.
  • Line-of-sight requirement limits flexibility.
Example Case Study: Wi-Fi and IR in a Neonatal Unit

For a neonatal unit, where precision in monitoring infant locations is crucial, the Wi-Fi and IR combination excels. This system provides exact room-level tracking, ensuring the safety and proper placement of newborns, an essential feature in sensitive and high-risk areas. Wi-Fi provides a stable and extensive network foundation, ensuring coverage throughout the unit. This ensures that tracking is not limited to just the immediate vicinity of the IR sensors. On the other hand, Infrared (IR) technology offers the precision of room-level tracking. It does this by using IR sensors placed in each room, which interact with IR tags on equipment or ID badges, allowing for very accurate location data within a specific room. This combination of Wi-Fi’s extensive coverage and IR’s pinpoint accuracy is particularly beneficial in the sensitive and precise environment of a neonatal unit.

Ultrasound + Wi-Fi RTLS Combination

Ultrasound excels in accuracy and resistance to electronic interference. When paired with Wi-Fi’s extensive range and existing infrastructure, you get a system that is both precise and expansive. 

Combining Wi-Fi with ultrasound technology offers an advanced solution where precision tracking is paramount. Ultrasound’s strength lies in its ability to provide pinpoint accuracy, essential in environments where even minor location discrepancies matter. This combination is particularly effective in densely built environments where Wi-Fi signals may be obstructed. However, the deployment of ultrasound technology can be complex, potentially interfering with other ultrasound-based equipment, and requires a well-planned infrastructure to ensure seamless integration.

Benefits
  • High-precision tracking, especially through obstructions.
  • Effective in densely built environments.
  • Ideal for environments where accuracy is critical.
Drawbacks
  • Complex deployment and potential interference with other ultrasound equipment.
  • Requires carefully planned infrastructure.
Example Case Study: Wi-Fi and Ultrasound in a Multi-Story Clinic

In a multi-story clinic with dense structures, Wi-Fi and ultrasound provide an effective solution. The ultrasound component ensures accurate tracking through floors and walls, essential for locating critical equipment quickly in emergency situations. In this setting, Wi-Fi’s extensive coverage complements the precision of ultrasound. It ensures that tracking capabilities are not limited to specific areas and provides a reliable network that spans the entire clinic. This wide coverage is crucial in a multi-story building, where it’s essential to track assets or personnel across different levels efficiently. The combination of Wi-Fi’s broad reach and ultrasound’s detailed accuracy makes this an ideal solution for large, complex healthcare environments.

Infrared + Bluetooth RTLS Combination

This combination harnesses infrared’s high room-level accuracy and Bluetooth’s flexibility and scalability. Bluetooth can fill in the gaps when line-of-sight for infrared is obstructed, providing a more robust system. 

This combination leverages the precision of Infrared (IR) technology for room-level tracking and Bluetooth for its wider coverage. It’s particularly effective in environments where you need both detailed tracking within specific rooms and the ability to monitor movement in larger areas. For instance, in a hospital, IR can track equipment in specific wards, while Bluetooth provides a broader overview across different departments.

Benefits

Infrared provides highly accurate, room-level tracking, essential in settings where precise location data is needed.
Bluetooth extends the tracking range beyond individual rooms, allowing for wider area coverage.
This combination is ideal for environments where both precision and extended range are required.

Drawbacks

Infrared requires line-of-sight, which can be limited in cluttered or densely populated areas.
Bluetooth’s range, although extensive, may vary based on environmental factors, potentially affecting consistency.

Example Case Study: Infrared + Bluetooth in a Large Hospital

In a large hospital, this combination can be used for patient tracking and equipment management. Infrared technology is deployed in critical areas such as Intensive Care Units (ICUs) and emergency rooms. Here, its precision in room-level tracking is invaluable. It allows staff to monitor the exact location of patients and essential equipment within these areas, which is crucial for rapid response in critical situations and effective management of high-value assets.

Bluetooth technology supplements infrared by providing a comprehensive tracking system throughout the hospital. Its wider coverage is ideal for overseeing the general movement of patients and staff, as well as ensuring the availability of mobile medical equipment across various departments. This broader tracking capability is vital for efficient resource allocation and improving the overall workflow in patient care.

Together, infrared and Bluetooth create a robust tracking system in a large hospital, ensuring both precision in critical areas and expansive coverage across the entire facility, thus enhancing resource management and patient care efficiency.

Ultrasound + Bluetooth RTLS Combination

The high accuracy of ultrasound and the scalability of Bluetooth make this combination ideal for facilities that need precise tracking but also require a system that can easily expand as needs evolve. 

Combining Ultrasound with Bluetooth creates a powerful tracking system, ideal for environments with complex layouts. Ultrasound’s high accuracy in dense or obstructed areas ensures detailed tracking in specific zones, such as storage rooms or crowded warehouses. Bluetooth extends this capability to larger areas, providing a comprehensive overview of asset locations throughout the facility.

Benefits
  • Ultrasound offers superior accuracy in dense or obstructed environments, perfect for tracking in tightly packed spaces.
  • Bluetooth complements ultrasound by providing broader area coverage, essential in large facilities.
  • Ideal for scenarios where both detailed accuracy in specific zones and overall tracking within a large area are necessary.
Drawbacks
  • Ultrasound installation can be complex and may interfere with other ultrasound-based systems.
  • Bluetooth’s effectiveness can be influenced by physical obstructions and environmental conditions.
Example Case Study: Ultrasound + Bluetooth in a Multi-Level Healthcare Facility

This combination is ideal for tracking equipment and personnel in a multi-level healthcare facility with complex layouts. Within compact and equipment-dense areas like pharmacies or storage rooms, ultrasound technology provides exceptional precision. It can accurately track the movement and location of specific items, even in cramped and crowded spaces. This capability is vital for inventory management, ensuring that essential medications and equipment are tracked and located efficiently.

Bluetooth technology complements ultrasound by extending the tracking network over multiple floors and broader areas within the healthcare facility. It’s particularly effective for monitoring the movement of personnel and mobile equipment, like portable scanners or IV pumps, across different departments. This broader coverage is crucial in a multi-level facility, facilitating seamless coordination and faster response times in patient care.

The integration of ultrasound and Bluetooth technologies in a multi-level healthcare setting ensures a thorough and efficient tracking system, enhancing both logistical operations and the overall quality of patient care.

Passive RFID + Active RTLS RTLS Combination

Passive RFID has many advantages that stem from tags not having batteries to manage – however, the required infrastructure may be cost prohibitive to put in all areas, and it may be beneficial to pair with other active RTLS technologies such as Wi-Fi based RTLS. 

This mix unites the cost-efficiency of Passive RFID for tracking a high volume of items with the dynamic tracking capabilities of Active Real-Time Location Systems (RTLS). It’s highly suitable for logistics and supply chain management, where keeping track of numerous items in real-time is crucial for operational efficiency. Passive RFID tags monitor a large number of items cost-effectively, while Active RTLS provides real-time updates on their movements.

Benefits
  • Passive RFID is cost-effective for tracking a large number of items, making it suitable for logistics and inventory management.
  • Active RTLS provides real-time location data, enhancing visibility and control over asset movements.
  • This combination is highly effective in dynamic environments like logistic hubs, where both bulk tracking and real-time data are valuable.
Drawbacks
  • Passive RFID has limited range and lacks real-time tracking capabilities.
  • Active RTLS systems can be more expensive to implement and maintain, increasing the overall cost.
Example Case Study: Passive RFID + Active RTLS in a Hospital Logistics System

In a hospital logistics system, this combination is effective for managing a large inventory of medical supplies. Passive RFID tags are attached to a wide range of medical supplies. They are cost-effective, which is essential when tagging a large inventory. Passive RFID excels in basic tracking tasks, such as monitoring stock levels or identifying the location of lower-priority items. It streamlines inventory checks, reducing the time staff spend on manual counts.

Meanwhile Active RTLS provides real-time location data, crucial for managing high-priority medical equipment or pharmaceuticals. The real-time aspect ensures that these vital items are not only accounted for but also quickly locatable in urgent situations. This enhances the hospital’s ability to respond to patient needs promptly and efficiently.

Together, these systems create a layered approach to inventory management. Passive RFID handles the bulk of items cost-effectively, while Active RTLS focuses on high-priority items, ensuring their availability and accessibility in critical moments, thereby improving overall healthcare delivery and resource management.


The Future of RTLS in Healthcare 

Advancements in AI and machine learning are set to improve RTLS accuracy, while increased interoperability between different healthcare systems and RTLS technologies in a unified software system is a promising trend. 

Selecting the right RTLS is crucial for healthcare institutions aiming to improve efficiency and patient care. Keeping abreast of technological advancements will further enhance these objectives. 

About the Author

Kris Uy

Ensuring successful implementations

Since joining TAGNOS as the Senior Director of Field Operations in 2014, Kris has played a vital role in elevating the company to where it is today. Kris is an expert in RTLS in Healthcare and oversees all aspects of client success and fully understands the complex nature of integrating software and hardware infrastructure into the hospital environment. Having worked nearly every position at TAGNOS as one of its first employees, Kris is an integral member of the executive team and has an in-depth knowledge of TAGNOS’ ED, OR and Asset Orchestration Solutions. Kris brings a background in healthcare administration and management, with experience running his own healthcare IT consultancy for over two years. However, his most valuable addition to the team is his entrepreneurial mindset that drives him to do what needs to be done to ensure success for TAGNOS and its clients. Kris balances his often-eclectic to-do list by hiking with his family, playing with his quirky corgi Hudson, or getting shots up at his local basketball court.

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