Abstract:
A system and method for sensing environmental conditions within a conventional orthopedic device, such as a cast or splint, which may lead to serious medical complications from that form of treatment and to provide a notification of adverse conditions. An implantable node includes sensors for pressure, moisture and temperature, which, when combined with a power source, monitoring circuitry, communication hardware, and companion software can provide sensor data to a remote application and thus alert health care professionals to potentially dangerous environmental conditions developing within the cast.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority to U.S. Provisional No. 62/309,894, filed on Mar. 17, 2016. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to orthopedic devices and, more specifically, to a system and method for monitoring conditions within an orthopedic cast or splint. 
         [0004]    2. Description of the Related Art 
         [0005]    Plaster and fiberglass casts and splints are commonly used by orthopedic specialists to treat a variety of traumatic injuries, with bone fractures being the most common indication. Casting allows both anatomical alignment of the fractured bone fragments and stability. Both conditions are critical for successful healing and restoration of function. While other treatment options exist, only casting is non-invasive, inexpensive and available to use without advanced medical facilities present. Therefore this treatment has evolved over time to be the gold standard for fracture care. 
         [0006]    Due to the prolonged length of time casts are required, typically eight to twelve weeks, use of casts and splints can be associated with iatrogenic injury to the affected limb and patient. Feared complications include compartment syndrome, infections and skin ulceration. These complications are usually associated with detectable environmental conditions within the cast. 
         [0007]    For example, in the case of external compartment syndrome, excess soft tissue swelling within the rigid cast can impair proper blood circulation and lead to ischemic death of tissues. Frequent measuring the skin pressure can prevent this form of compartment syndrome. Internal compartment syndrome caused by tissue swelling within the limb&#39;s fascial compartments would require the use of invasive pressure sensors inserted directly into muscle. 
         [0008]    Infections are often heralded by fever. Temperature within the cast can be monitored and analyzed to predict possible infection. Skin ulceration or bleeding are associated with increased moisture within the cast, another detectable and correctable environmental condition. 
         [0009]    For the alert patient who has the ability to communicate with their health care provider these complications rarely present a clinical problem. However, for the patient who is for some reason rendered unable to communicate, these complications are more frequent and often devastating. A common clinical situation is the poly-trauma with multiple injuries. They can be comatose for prolonged periods of time or sedated and intubated in an ICU setting. They often have more serious injuries than their fracture and “checking the cast” can be overlooked. In addition to comatose patients, small children often cannot communicate problems inside their cast. A few conventional systems have incorporated pressure sensors into orthopedic casts. However, none of these systems have combined the pressure sensors with other sensors and monitoring software to provide a larger spectrum of sensing capabilities, such as temperature and moisture. 
         [0010]    Thus, an intelligent system with the ability to detect and notify the wearer, as well as physician and other medical professionals, of the onset of adverse conditions and the ability to predict harmful changes based on historical data would mitigate many of the complications that arise from wearing orthopedic casts and splints. 
       BRIEF SUMMARY OF THE INVENTION 
       [0011]    The present invention is a system and method designed to sense environmental conditions within a conventional orthopedic device, such as a cast or splint, which may lead to serious medical complications from that form of treatment and to provide a notification of adverse conditions. The device of the present invention houses sensors for pressure, moisture and temperature, which, when combined with a power source, monitoring circuitry, communication hardware, and companion software can alert health care professionals to potentially dangerous environmental conditions developing within the cast. The alert provided by the sensor may be wirelessly communicated to a health care professional via a companion mobile application preloaded and running on a portable computing device or smartphone. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0012]    The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which: 
           [0013]      FIG. 1  is a schematic of a system for monitoring orthopedic device conditions according to the present invention; 
           [0014]      FIG. 2  is a flowchart the interconnection between a monitoring device and associated monitoring software according to the present invention; 
           [0015]      FIG. 3  is an example of a display screen for a mobile computing device programmed according to the present invention; and 
           [0016]      FIG. 4  is a flowchart of a method for monitoring orthopedic device conditions according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    Referring to the figures, wherein like numerals refer to like parts throughout, there is seen in  FIG. 1  an orthopedic monitoring node  10  for collecting data from within an orthopedic device, such as a cast or splint. Node  10  includes one or more sensors  12  mounted to a printer circuit board  14 . Sensors  12  may include a force-sensing resistor or other pressure monitoring device, a resistance-based moisture sensor, a temperature sensor, and the like. A microprocessor  16 , such as an ATmega or ATtiny device, is used to operate and collect data from sensors  12  and prepare collected data for transmission to a remote device  18  via a wireless communication chip  20 , such as a Punch Through Design LBM313, or an NRF24L01 module. Remote device  18  may comprise a mobile phone, tablet, computer, or other receiver running an associated software application for interpreting the data and provided user notifications. A local power source  22 , such as a coin cell battery or lithium ion battery, may be used to supplying power to all these components. It should be recognized that monitor may include various electronic components  24  for managing sensors  12 , regulating power, etc. Multiple nodes  10  may be installed in combination with a particular orthopedic device with a single remote device  18  programmed to communicate with each node  10 . 
         [0018]    Referring to  FIG. 2 , remote device  18  is programmed to receive data from node  10 , such as by a wireless communications chip  30  that receives an XML string object for processing by an XML processor application  32 . XML processor application  32  processes the XML string to obtain all of the relevant sensor and device state data. For example, relevant data could include the readings of sensors  12 , battery voltage, and other system status messages. The parsed data is passed to a prediction algorithm  34  that compares historical data and newly received data according to predetermined baselines to determine future cast conditions. For example, if the average pressure has risen in a cast by a certain number of pounds per square inch over the past few days, and this certain number is above the tolerance for such an event, algorithm  34  would mark this condition as an abnormality. As another example, if the average amount of moisture present in the cast is above the tolerance for such an event, the algorithm would mark this as another abnormality. Once algorithm  34  has determined the presence of an abnormality, or has determined that a patient is at risk of developing a future abnormality, the algorithm notifies a physician, nurse, or other medical professional via local and remote notifications. Notifications could include vibrations, messages on the screen of the receiving device, text messages, or messages on the device of a medical professional. 
         [0019]    While algorithm  34  is processing new and historical data, XML processor application  32  may also pass the data to a user interface manager  36  that cooperates with onscreen graphics engine  38  to display the current status of conditions within the orthopedic device. For example, as seen in  FIG. 3 , onscreen graphics engine  38  may provide the sensed data as a series of gauges to provide a detailed, visual representation of current conditions inside the medical device based on all the sensor readings and state of every connected sensor node  10 . Another part of the display may be devoted to displaying future projected conditions inside the cast, as predicted by algorithm  34  and discussed above. For hospital and medical offices, nodes  10  from multiple different patients may be combined into a single monitoring screen at, for example, a nursing station. 
         [0020]    Referring to  FIG. 4 , node  10  may be programmed to implement a monitoring process  40  that begins with a test for an active wireless connection  42 . If there is a connection, node  10  triggers sensors  12  to collect information from within orthopedic device  44 . Sensors  12  then collect the associated data  46  and output signals to an analog to digital converter  48  that converts the sensor signals into digital. A local XML processor packages the digital sensor data  50  and provides the packaged data to a wireless communication chip for transmittal to the remote device  52 . To conserve power, process  40  may conclude by moving into an ultra-low power sleep mode  54 . 
         [0021]    Node  10  may be programmed to execute the following high level functions:
       Global Variables:
           Boolean: ConnectionState   Integer: NodeNumber   Integer: PressureValue   Integer: MoistureValue   Integer: TemperatureValue   Integer: BatteryValue   
           Setup Function:
           Set sensor node name to “CastMinder”+Node Number   
           Looping Function:
           Get connection state of external application   Set boolean ConnectionState to connection state of external application   If connected to external application:   Read sensor value for pressure sensor   Set integer PressureValue to read value of pressure sensor   Read sensor value for moisture sensor   Set integer MoistureValue to read value of moisture sensor   Read sensor value for temperature sensor   Set integer TemperatureValue to read value of temperature sensor   Read sensor value for battery voltage sensor   Set integer BatteryValue to read value of battery sensor   Create String DataString to send to external application   Set DataString equal to the following, substituting variable names as necessary:   
               
 
         [0000]    
       
         
               
               
             
               
               
             
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 “&lt;CastMinder Data&gt; 
               
             
          
           
               
                   
                 &lt;pressure&gt;BatteryValue&lt;/pressure&gt; 
               
               
                   
                 &lt;moisture&gt;MoistureValue&lt;/moisture&gt; 
               
               
                   
                 &lt;temperature&gt;TemperatureValue&lt;/temperature&gt; 
               
               
                   
                 &lt;battery&gt;BatteryValue&lt;/battery&gt; 
               
               
                   
                 &lt;nodeID&gt;NodeNumber&lt;/nodeID&gt; 
               
             
          
           
               
                   
                 &lt;/CastMinder Data&gt;” 
               
               
                   
                   
               
             
          
         
       
       
         
           
             
               
                 Encode DataString into binary using UTF-8 encoding 
                 Send binary over Bluetooth to connected external application 
               
             
             Sleep for one second 
             Loop program back to beginning of “Looping Function” 
           
         
       
     
         [0049]    Remote device  18  may be programmed to execute the following high level functions:
       Received Data:
           Convert binary data into string with UTF-8 encoding   Separate XML string into component XML data parts   If data contains pressure, moisture, temperature, and battery values:
               Set Integer DateReceived to current date value   Set String SensorName to the name of the sending sensor node   Append data with DateReceived and SensorName   Add new sensor data to SQL database   Post New Data Notification to rest of application   
               
           New Data Notification Received—User Interface Manager:
           Parse SQL database for most recent sensor data reading   Split sensor reading into component sensor values   Display each sensor reading on an on-screen gauge   
               
 
         [0063]    As described above, the present invention may be a system, a method, and/or a computer program associated therewith and is described herein with reference to flowcharts and block diagrams of methods and systems. The flowchart and block diagrams illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer programs of the present invention. It should be understood that each block of the flowcharts and block diagrams can be implemented by computer readable program instructions in software, firmware, or dedicated analog or digital circuits. These computer readable program instructions may be implemented on the processor of a general purpose computer, a special purpose computer, or other programmable data processing apparatus to produce a machine that implements a part or all of any of the blocks in the flowcharts and block diagrams. Each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical functions. It should also be noted that each block of the block diagrams and flowchart illustrations, or combinations of blocks in the block diagrams and flowcharts, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.