Abstract:
The present invention features a wireless, remote monitor system for multiple, diverse sensors. A remote transceiver is equipped with one or more interchangeable sensors, each type of sensor being capable of providing a unique identity code to the base monitoring station. Multiple sensors may be piggybacked so as to monitor more than one condition substantially simultaneously. The inventive system includes routines which automatically recognize the sensors and then upload and execute one or more sensor-specific software routines. This quasi “plug and play” approach overcomes problems where improper sensor inputs are made to a particular data analysis routine resulting in erroneous results. The inventive system is applicable to a wide variety of fields such as biomedical, athletics, security, etc. Each remote sensor included provisions for signal conditioning and data analysis. In addition, storage is provided at each remote mobile unit so that, in the event that the RF link is unavailable, the sensor data may be stored for later transmission once the communication link is reestablished.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to wireless sensors. More particularly, the invention comprises a reconfigurable wireless sensor system for use with multiple, interchangeable sensors. 
     2. Description of the Prior Art 
     For many years, the need to remotely monitor the status of an electrical/mechanical system, an animal, or a human being has been recognized. Under some circumstances, such as when the person or thing to be monitored is stationary, data may be communicated by means of a hard connection such as a telephone line, dedicated line, fibre channel, or the like. Often, however, the device, animal, or person to be monitored is mobile and the use of such a hard connection is impossible. For this reason, the field of wireless telemetry has developed. By using a radio frequency (RF) link, one-way or, sometimes, two-way data links can be established between a base monitoring/controlling station and a remote mobile unit supporting a remote sensor. 
     One such hard wired system is described in U.S. Pat. No. 4,455,453, issued to Theodoros G. Parasekvakos, et al. on Jun. 19, 1984. PARASEKVAKOS, et al. utilize a telephone-based system wherein a remote meter (e.g., a gas or electric utility meter) is selectively connected to a telephone line. The remote meter initiates a telephone call to a central complex at a predetermined time. The central complex initiates a hand shaking authentication routine after which, the remote meter transmits identification information along with its collected data. In addition, the central complex uploads the next call back time as well as any other required operating parameter change. 
     In contradistinction, the multi-sensor, reconfigurable system of the present invention utilizes an RF link, not a telephone connection. A multiplicity of interchangeable sensors are usable with the inventive system unlike the single, dedicated sensor of PARASEKAVOKOS, et al. Multiple, diverse sensors may be piggybacked in the inventive system. The inventive system also includes data storage capability to save monitored data during any lapse in the RF communications link. 
     Another hard wired system is taught in U.S. Pat. No. 5,200,743, issued Apr. 6, 1993 to Michael J. St. Martin, et al. St. MARTIN, et al. utilize a four-wire communications like to which multiple remote mobile units are connected, each station having a transducer. One pair of the four-wire system is used to communicate individually with the remote mobile units while the second pair is used to receive data from the stations. Each station may be individually addressed by the host and, upon command, each remote mobile unit transmits real-time, analog data to the host. 
     The inventive multi-sensor, reconfigurable system however, utilizes an RF link, and, unlike St. MARTIN, et al., may have reconfigurable, interchangeable sensor combinations. Each sensor identifies itself to the base station so that appropriate signal conditioning or signal processing and/or data reduction algorithms may be used. The multiple, piggybacked remote sensors of the inventive system utilize backup memory to store data while the data transceiver is, for example, out-of-range with the base station. 
     U.S. Pat. No. 5,687,175, issued Nov. 11, 1997 to Virgil Maurice Rochester, Jr., et al. teaches an adaptive, time-division multiplexing communication protocol for collecting data from remote sensors equipped with RF transceivers. All remote units “listen” for a command from the host, upon which they transmit a unique ID. These unique IDs are used by the host to individually poll each remote unit. When polled, each remote unit a packet of data. Upon receipt of the data packet from the remote unit, the host transmits an acknowledgement packet indicating that the data has been received. Upon receipt of the acknowledgement from the host, the remote unit is set to a stand-by state whereby it will not respond to the host for a predetermined length of time. 
     The inventive sensor system uses a packet transmission system for essentially continuous communication between a remote transceiver with its multiple, reconfigurable, self-identifying sensors and a base station. No command from the base host station is required to initiate periodic communication between the remote sensors and the base. Each type of sensor connected to the remote unit uniquely identifies itself to the base station and multiple, diverse sensor types may coexist on the same remote unit. 
     U.S. Pat. No. 5,959,529, issued Sep. 28, 1999 to Karl A. Kail, IV teaches another system for monitoring remote sensors. KAIL&#39;s sensors are carried or worn by a person or animal to be monitored or affixed to an inanimate object. Unlike the inventive system, the KAIL system teaches dedicated, non-interchangeable sensors having a single function, (i.e., to track the location of the person, animal or object to which the remote sensor is attached). The sensors of the inventive system may be varied and may also be piggybacked to allow monitoring more than one condition, substantially simultaneously. KAIL provides no teaching of any backup memory to store data when the remote sensor is out-of-range. Such backup memory is present in the remote sensor system of the instant invention so that data may be stored for later transmission when the communications link is unavailable. 
     In each one of these prior art inventions, some aspect of remote monitoring is taught, either utilizing a hard (i.e., wired) connection or an RF link. Unlike the prior art, the inventive system supports multiple remote mobile units on the same system, each remote mobile unit being capable of supporting multiple, diverse sensors. 
     None of the above inventions and patents, taken either singly or in combination, is seen to describe or render obvious the instant invention as claimed. 
     SUMMARY OF THE INVENTION 
     The present invention features a remote monitor system for a plurality of sensors. A remote mobile unit is equipped with one or more interchangeable sensors, each sensor being capable of providing a unique identity code to the base monitoring station. Multiple sensors may be piggybacked to simultaneously monitor more than one condition or parameter. The inventive system includes routines which automatically recognize each sensor type and invokes specific software routines applicable only to the sensors. This quasi “plug and play” approach overcomes problems where improper sensor inputs are made to a particular data analysis routine which often results in apparent sensor data errors. The inventive system is applicable to a wide variety of fields such as biomedical, athletics, security, etc. Each remote mobile unit has provision for both signal conditioning and data processing (i.e., data analysis, data reduction, etc.). In addition, storage is provided at each remote mobile unit so that, in the event that the RF link is unavailable, the sensor data may be stored for later transmission once the RF link is reestablished. In that event that data is being collected at a rate faster than it can be transmitted (i.e., a burst rate), the data may also be stored and transmitted at the slower data link rate. 
     Accordingly, it is a principal object of the invention to provide a wireless remote sensing apparatus. 
     It is another object of the invention to provide a wireless remote sensing apparatus which may accommodate a variety of diverse, interchangeable sensors. 
     It is a further object of the invention to provide a wireless remote sensing apparatus incorporating built-in signal conditioning and signal processing. 
     Still another object of the invention is to provide a wireless remote sensing apparatus having built-in storage which accumulates data during times when an RF link is unavailable to transmit data to a base station. 
     It is yet another object of the invention to provide data storage to buffer data being collected at a rate faster than the data can be transmitted to a base station. 
     An additional object of the invention is to provide a wireless remote sensing apparatus having automatic recognition of the sensor mix present. 
     It is again an object of the invention to provide a wireless remote sensing apparatus wherein a base station can upload appropriate software modules to the remote based upon the detected mix of sensors. 
     Yet another object of the invention is to provide a wireless remote sensing apparatus having remote programmability. 
     It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
    
    
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various other objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
     FIG. 1 is an overall system block diagram of the remote, mobile sensor system of the invention; 
     FIG. 2 is a schematic block diagram of the remote portion of the system of FIG. 1; 
     FIG. 3 is a flow chart of a remote mobile unit reporting to a base station; 
     FIG. 4 is a flow chart of a base station gathering data from a remote mobile unit; 
     FIG. 5 is a flow chart of a base station uploading instructions to a remote mobile unit; 
     FIG. 6 is a flow chart of a remote mobile unit receiving a transmission from a base station; 
     FIG. 7 is a flow chart showing how an end user programs a remote mobile unit; 
     FIG. 8 is a flow chart of the data analysis process. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention features a remote, mobile, programmable monitor system supporting a plurality of diverse sensors. Referring first to FIG. 1, there is shown an overall block diagram of the inventive system, generally at reference number  100 . A remote mobile unit  102  consists of a number of sensors  104   a ,  104   b    104   n  connected to the inputs of a signal collection device  106 , typically an analog-to-digital (A/D) converter in conjunction with a multiplexor (MUX). The output of signal collection device  106  is connected to an appropriate input port of a processor/controller  108 . A memory module  110  is connected to processor/controller  108 . Processor/controller  108  is connected to a transceiver  112  by means of a two-way interface  114 . An antenna  116  is connected to a radio frequency (RF) input/output connection on transceiver  112 . 
     A base station  120  consists of an antenna  122  connected to an RF input/output port of a transceiver  124 . Transceiver  124  is connected to a computer/processor  126  by means of a two-way interface  128 . Also connected to computer/processor  126  are mass storage device  130  adapted to store data and mass storage device  132  where a library of software routines is stored. Computer/processor  126  is equipped with an interface designed to allow connection to a variety of external connections (not shown). Some possible connections include dial-up telephone, leased line, private RF or microwave link or the Internet. It will be obvious to those skilled in the data communications art that other possible communications strategies and transport mechanisms could also be used. 
     Referring now to FIG. 2, there is shown a detailed schematic block diagram of a remote mobile unit  102 . A sensor  104 , representative of a plurality of different sensors of diverse types, is shown connected to a sensor interface module  140  via a sensor cable  142 . Typical sensors such as Burdick EKG patient cables and sensing pads could be used for biomedical applications. A sensor Scientific Model CB08-502T has been found suitable for temperature measuring applications. A Matsushita Model WM-063X microphone may be used for acoustical noise measurement applications. Virtually any sensor may be adapted for use in the inventive system by using appropriate circuitry in sensor interface module  140 . 
     The remote mobile unit  102  or the base station  120  are adapted to interrogate the sensor identification means  144  and perform a configuring operation responsive to a sensor identification retrieved therefrom. 
     Sensor interface module  140  contains signal conditioning circuitry  143  which is sensor-specific and designed to perform a combination of operations such as buffering, amplifying, attenuating, filtering, integrating, differentiating and level converting. Signal conditioning may be provided using any combination of electrical, electronic, mechanical, optical or other devices. These signal conditioning devices may be either active or passive. In the embodiment chosen for purposes of disclosure, the signal collection function  106  is performed using an analog-to-digital (A/D) converter and a multiplexor (mux). The output of signal conditioning circuitry  143  is a normalized analog signal in the 0-3.3 volt range. While 0-3.3 volts has been chosen for purposes of disclosure, it will be obvious to those skilled in the art that other voltage ranges or signal measurement methods could be chosen to meet other operating requirements or environments. 
     In addition to signal conditioning circuitry  143 , sensor interface module  140  contains sensor identification means  144 , typically a sensor ID chip. Each sensor identification means  144  is programmed with a code unique to the particular type of sensor  104  with which it is associated. All sensors of a particular type are given identical sensor ID codes. In the preferred embodiment, an EPROM such as Catalog No. NM24C02U manufactured by Fairchild Semiconductor has been used to perform the sensor ID function. These sensor ID codes can be stored in any of the many non-volatile memory devices well know to those skilled in the art. In alternate embodiments, volatile memory and a internal power source could also be used to store the sensor ID code. A standard connector  146   a  terminates each sensor interface module  140 . 
     A plurality of sockets  146   b  are provided to accept connectors  146   a  from sensor interface modules  140 . In a typical embodiment where signal collection device  106  consists of an analog-to-digital (A/D) converter and multiplexor, sockets  146   b  are connected to an analog signal bus  148  as well as a digital signal bus  150 . Analog signal bus  148  is connected to the analog-to-digital (A/D) converter and multiplexor. In the embodiment chosen for purposes of disclosure, signal collection device  106  is a type ADC12L038 3.3 Volt Self Calibrating 12-bit Plus Sign Serial I/O A/D converter with MUX and Sample/hold provisions manufactured by National Semiconductor. It should be obvious that other commercially available A/D-MUX chips could also be used. 
     Signal collection device  106  is connected to a microprocessor/controller  108 . Any of a wide variety of microprocessors (μPs) or controllers well know to those skilled in the art may be used in the inventive system. Microprocessor/controller  108  is connected to digital signal bus  150 . Memory  110  for data storage is also attached to microprocessor/controller  108 . Microprocessor/controller  108  is also connected to a wireless data transceiver  112  which is connected to an antenna  116 . Transceiver  112  is a commercial “radio” modem such as the Model 3090 Modem manufactured by Ericsson. The Ericsson 3090 combines microprocessor/controller  108  with transceiver  112  in a single compact package. Other manufacturers, such as Research in Motion (RIM), make similar equipment. A RIM model 902M has also been found suitable for use in the inventive application. In alternate embodiments, the functions of microprocessor/controller  108  and transceiver  112  could, of course, be performed by separate devices. 
     An optional user interface  152  and a indicator panel  154  having a power indicator and other such indicators as may perform useful functions in different embodiments of the inventive system. 
     In the preferred embodiment, the well-known Mobitex communications infrastructure has been used. Mobitex is a wireless data communications system developed in the early 1980s by Eritel for the Swedish Telecommunication Administration. It has become a defacto standard for applications such as the that of the instant invention. Mobitex networks are maintained in the United Stated by such communications providers as BellSouth Wireless Data. It should be obvious that other commercial or private, proprietary communications strategies could be used to perform the necessary data communications functions between remote, mobile unit  102  and a base station  120  (FIG.  1 ). 
     Refer now again to FIG.  1 . In the embodiment chosen for purposes of disclosure, a base station  120  utilizes a commercial data transceiver such as Base Radio Unit Model BRU3 manufactured by Ericsson. The remainder of the components making up base station  120  are all commercially available and readily understood by those skilled in the art. One external interface found suitable for the application is a Mobitex Main/Area Exchange unit Model MX, also manufactured by Ericsson. The functions of base station  120  will be described in detail hereinbelow. 
     Referring now to FIG. 3, there is shown a flowchart  200  showing the steps performed at a remote, mobile unit. It is assumed that multiple sensors  104  (FIG. 1) are in place. These sensors  104  are scanned in the sequence they are connected to connectors  146   b  (FIG.  2 ). For each slot (i.e., connectors  146   b ), the presence and ID of a sensor is checked, step  202 . If no sensor is present, an “open slot” is reported, step  204 . If the data link is available, step  220 , the “open slot” report is transmitted, step  216 . If the data link is not available, step  220 , the “open slot” message is stored for later transmission, step  218 . If a sensor is present, step  202 , the system is checked to see if application software associated with the sensor is running, step  206 . If no application software is running, the “sensor ID” is reported, step  208 . If application software associated with the sensor is, however, running, the remote, mobile unit attempts to report the data for the sensor, step  210 . If the data link is not available, step  220 , the data is stored for later transmission, step  218 . A set of rules associated with each sensor-specific application software is consulted, step  212 . A check is again made to see if the data link is available, step  214 . If the data link is available, step  214  (i.e., ready and the remote mobile unit is within radio range), the data is transmitted, step  216 . If, however, the data link is not available (i.e., off line, out of radio range, etc.) step  214 , control is again transferred to block  212 . This process is repeated until all the slots have been queried and reported. It is possible for data to be collected by a particular sensor more quickly than the data link can transfer it. In this case, the data is stored, step  218 , and transmitted, step  216 , at rate slower than the data collection rate. 
     Referring now to FIG. 4, there is shown a flowchart  230  showing the steps performed at a base station  120  (FIG. 1) for receiving data from remote, mobile unit  102  (FIG. 1) in accordance with the instant invention. Error checking and retransmission requests are handled by the data transmission protocols within commercial data transceivers  112 ,  124  (FIG.  1 ), step  232 . These routines are well know to those skilled in the data transmission arts and form no part of the present invention. Good data is received from the remote mobile unit  102 , step  234 . The data reception routines are performed for all sensor positions (i.e., slots”) in the remote, mobile unit  102 . If the received data is sensor configuration data, step  236 , the sensor ID is recorded, step  238 . If the data is not sensor configuration data, step  236 , then the data is tested to see if it is application data, step  240 . If the data is application data, it is accepted, step  242  and stored, step  244 . If however, the data is not application data, step  240 , appropriate variance routines are performed, step  246 . The steps are repeated for the remaining sensor slots  146   b  (FIG. 2) which are processed in an identical manner. 
     Referring now to FIG. 5, there is shown a flowchart  260  showing the steps required for a base station  120  (FIG. 1) to upload information to a remote mobile unit  102  (FIG.  1 ). For each defined sensor position on remote mobile unit  102 , presence of information to be uploaded for the specified sensor is checked, step  262 . If there is not pending information to be transmitted, the routine ends, step  278 . If, however, information is pending, the information is sent, step,  264 . If the datalink is available, step  266 , the data is transmitted, step  274 . Error checking routines are performed, step  276 , and after the data transmission has been properly accomplished, the routine exits, step  278 . If, however, the datalink is not available, step  266 , the information to be transmitted is queued, step  270 . After a programmed delay, step  272 , the datalink&#39;s availability is again checked, step  266 . This overall process  260  is repeated for all defined sensor positions at remote mobile unit  102 . 
     Referring now to FIG. 6, there is shown a flowchart  280  showing the steps performed by remote mobile unit  102  in receiving an upload from base station  120 . The incoming message is error-checked, step  282 . Once the error checking is complete, a verified message is received, step  284 . The message content is checked to determine if it contains a manual request for data download, step  286 . If it is a manual data download request, the step of flowchart  200  (FIG. 3) are performed, step  288 . If the message is not a manual data download request, step  286 , the message is checked to see if it contains application code, step  290 . If the message does not contain application code, it is checked to see if it contains new parameters for the particular sensor, step  292 . If the message does not contain new sensor parameters, step  292 , appropriate variance routines are performed, step  294 , and the routine is completed, step  296 . Referring again to block  290 , if the message does contain application code for the specific sensor, step  290 , the application code is received, step  300 . The embedded sensor code information in the application code is checked against the sensor ID code, step  302 . If the codes do not match, the application code is rejected, step  304  and the routine ends, step  296 . If, however, the codes match, step  302 , the application code is accepted, step  306  and the code is executed, step  308 . The routine is then ended, step  296 . Referring again to step  292 , if the message does contain new sensor parameters, they are received, step  298 , and the routine ends, step  296 . This routine is repeated for each defined sensor at remote mobile unit  102 . 
     A user interface is provided which allows uploading application software to a remote mobile unit. This process  310  is illustrated in the flow chart of FIG.  7 . The user may typically request three different operations. First, an application program (either new or replacement) may be uploaded to a remote mobile unit. Each application program is designed to operate with a specific sensor attached to the mobile unit. If the user desires an update to the application program, step  312 , an appropriate, predefined application program is selected, step  314 . An upload is initiated by the user, step  316  and the application program is uploaded to the remote mobile unit, step  318 . This uploading process has been described in detail hereinabove. Once uploaded, the selected application software is executed in accordance with the specifics of the uploaded software. Only application software suitable for and compatible with a particular remote sensor may be uploaded. 
     The following is a typical example of an application software upload. A particular sensor “n” is identified as having the capability to sample heart rate and to measure EKG activity. For this sensor “n”, application software which continuously samples heart rate of the wearer is selected. When the wearer&#39;s heart rate exceeds 150 beats per minute, the application software initiates a five second, high frequency EKG sample. Upon completion of the EKG trace, heart rate sampling is restarted. Data is transferred to the base unit every five minutes. 
     Another function of the user interface allows the end user to change the operating parameters of application software already executing with a specific sensor at the remote mobile unit. If parameter update is requested, step  320 , new parameters are entered, step  322 . The new parameters may be either directly entered or one of a predetermined set of parameters may be selected. Once parameters are entered, the user initiates an upload, step  316  and the new parameters are uploaded, step  318 . The application software accepts the new parameters and modifies its behavior accordingly. 
     In the previous example, a heart rate threshold of 150 beats per minute (bpm) was selected to trigger a five second EKG reading. Typical changes to the parameters could be to change the threshold to 120 bpm and/or change the EKG sample time from five seconds to ten seconds. It should be obvious that wide range of parameter changes suitable for each specific sensor type could be made. 
     A third function of the user interface allows an end user to request an immediate download of data from a selected remote sensor, step  324 . If immediate download is desired, step  324 , immediate sensor data download is requested, step  326 , generally over-riding the application software which is currently executing for the remote sensor. An upload operation is initiated, step  316  and the immediate data download request is uploaded to the remote mobile unit, step  318 . 
     Referring now to FIG. 8, there is shown a flow chart illustrating the data analysis and reporting capabilities of the inventive remote sensor system. Data is downloaded and stored, step  332  as has been described in detail hereinabove. Data  334  is then available for automated data analysis, step  336 , manually selected data analysis, step  338 , and/or viewing and reporting, step  340 . 
     An example of automated data analysis, step  336  may be applied to the previously provided example. If a particular sensor is measuring and reporting the heart rate of a wearer, the automated analysis routine could report statistics such as minimum heart rate, maximum heart rate as well as cumulative hourly, and/or daily heartbeats of the wearer. This type of data analysis is programmed into the user interface. 
     The user interface also allows the user to select from one or more predetermined data analysis routines, step  338 . For example, if data is available from a sensor capable of providing EKG traces, the user could select a data analysis routine to detect certain cardiac conditions from the EKG data. Upon completion of the analysis, the user interface reports the results to the user. 
     Finally, the user interface provide a facility to report and/or view the sensor data, step  340 . A user can select from a variety of data formats such as “raw data”, charts, tables, etc. The data may be selected from multiple sensors and/or multiple remote mobile units in accordance with predefined rules. 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.