Abstract:
A regional oximetry pod drives optical emitters on regional oximetry sensors and receives the corresponding detector signals in response. The sensor pod has a dual sensor connector configured to physically attach and electrically connect one or two regional oximetry sensors. The pod housing has a first housing end and a second housing end. The dual sensor connector is disposed proximate the first housing end. The housing at least partially encloses the dual sensor connector. A monitor connector is disposed proximate a second housing end. An analog board is disposed within the pod housing and is in communications with the dual sensor connector. A digital board is disposed within the pod housing in communications with the monitor connector.

Description:
PRIORITY CLAIM TO RELATED PROVISIONAL APPLICATIONS 
       [0001]    Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57. The present application claims priority benefit under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 62/012,170, filed Jun. 13, 2014, titled Peel-Off Resistant Regional Oximetry Sensor, U.S. Provisional Patent Application Ser. No. 61/887,878 filed Oct. 7, 2013, titled Regional Oximetry Pod; U.S. Provisional Patent Application Ser. No. 61/887,856 filed Oct. 7, 2013, titled Regional Oximetry Sensor; and U.S. Provisional Patent Application Ser. No. 61/887,883 filed Oct. 7, 2013, titled Regional Oximetry User Interface; all of the above-referenced provisional patent applications are hereby incorporated in their entireties by reference herein. 
     
    
     BACKGROUND 
       [0002]    Pulse oximetry is a widely accepted noninvasive procedure for measuring the oxygen saturation level of arterial blood, an indicator of a person&#39;s oxygen supply. A typical pulse oximetry system utilizes an optical sensor attached to a fingertip to measure the relative volume of oxygenated hemoglobin in pulsatile arterial blood flowing within the fingertip. Oxygen saturation (SpO 2 ), pulse rate and a plethysmograph waveform, which is a visualization of pulsatile blood flow over time, are displayed on a monitor accordingly. 
         [0003]    Conventional pulse oximetry assumes that arterial blood is the only pulsatile blood flow in the measurement site. During patient motion, venous blood also moves, which causes errors in conventional pulse oximetry. Advanced pulse oximetry processes the venous blood signal so as to report true arterial oxygen saturation and pulse rate under conditions of patient movement. Advanced pulse oximetry also functions under conditions of low perfusion (small signal amplitude), intense ambient light (artificial or sunlight) and electrosurgical instrument interference, which are scenarios where conventional pulse oximetry tends to fail. 
         [0004]    Advanced pulse oximetry is described in at least U.S. Pat. Nos. 6,770,028; 6,658,276; 6,157,850; 6,002,952; 5,769,785 and 5,758,644, which are assigned to Masimo Corporation (“Masimo”) of Irvine, Calif. and are incorporated in their entireties by reference herein. Corresponding low noise optical sensors are disclosed in at least U.S. Pat. Nos. 6,985,764; 6,813,511; 6,792,300; 6,256,523; 6,088,607; 5,782,757 and 5,638,818, which are also assigned to Masimo and are also incorporated in their entireties by reference herein. Advanced pulse oximetry systems including Masimo SET® low noise optical sensors and read through motion pulse oximetry monitors for measuring SpO 2 , pulse rate (PR) and perfusion index (PI) are available from Masimo. Optical sensors include any of Masimo LNOP®, LNCS®, SofTouch™ and Blue™ adhesive or reusable sensors. Pulse oximetry monitors include any of Masimo Rad-8®, Rad-5®, Rad®-5v or SatShare® monitors. 
         [0005]    Advanced blood parameter measurement systems are described in at least U.S. Pat. No. 7,647,083, filed Mar. 1, 2006, titled Multiple Wavelength Sensor Equalization; U.S. Pat. No. 7,729,733, filed Mar. 1, 2006, titled Configurable Physiological Measurement System; U.S. Pat. Pub. No. 2006/0211925, filed Mar. 1, 2006, titled Physiological Parameter Confidence Measure and U.S. Pat. Pub. No. 2006/0238358, filed Mar. 1, 2006, titled Noninvasive Multi-Parameter Patient Monitor, all assigned to Cercacor Laboratories, Inc., Irvine, Calif. (Cercacor) and all incorporated in their entireties by reference herein. Advanced blood parameter measurement systems include Masimo Rainbow® SET, which provides measurements in addition to SpO 2 , such as total hemoglobin (SpHb™), oxygen content (SpOC™), methemoglobin (SpMet®), carboxyhemoglobin (SpCO®) and PVI®. Advanced blood parameter sensors include Masimo Rainbow® adhesive, ReSposable™ and reusable sensors. Advanced blood parameter monitors include Masimo Radical-7™, Rad87™ and Rad57™ monitors, all available from Masimo. Such advanced pulse oximeters, low noise sensors and advanced blood parameter systems have gained rapid acceptance in a wide variety of medical applications, including surgical wards, intensive care and neonatal units, general wards, home care, physical training, and virtually all types of monitoring scenarios. 
       SUMMARY 
       [0006]    Regional oximetry, also referred to as tissue oximetry and cerebral oximetry, enables the continuous assessment of tissue oxygenation beneath a regional oximetry optical sensor. Regional oximetry helps clinicians detect regional hypoxemia that pulse oximetry alone can miss. In addition, the pulse oximetry capability in regional oximetry sensors can automate a differential analysis of regional to central oxygen saturation. Regional oximetry monitoring is as simple as applying regional oximetry sensors to any of various body sites including the forehead, forearms, chest, upper thigh, upper calf or calf, to name a few. Up to four sensors are connected to a conventional patient monitor via one or two regional oximetry pods. The pods advantageously drive the sensor optics, receive the detected optical signals, perform signal processing on the detected signals to derive regional oximetry parameters and communicate those parameters to a conventional patient monitor through, for example, standard USB ports. 
         [0007]    One aspect of a regional oximetry pod drives the optical emitters of one or two regional oximetry sensors and receives the corresponding detector signals in response. The sensor pod has a dual sensor connector configured to physically attach and electrically connect one or two regional oximetry sensors. The pod housing has a first housing end and a second housing end. The dual sensor connector is disposed proximate the first housing end. The housing at least partially encloses the dual sensor connector. A monitor connector disposed proximate a second housing end. An analog board is disposed within the pod housing in communications with the dual sensor connector, and a digital board is disposed within the pod housing in communications with the monitor connector. 
         [0008]    In various embodiments, the dual sensor connector has a pair of pod cables partially disposed within the pod housing. A first end of the pod cables is electrically connected to and mechanically attached to the analog board. A second end of the pod cables extends from the pod housing and terminates at a pair of sensor connectors. The sensor connectors are configured to physically attach and electrically connect up to two regional oximetry sensors. The dual sensor has a socket block at least partially disposed within the pod housing, and the socket block has socket contacts configured to electrically connect to a pair of regional oximetry sensors. The socket contacts are in electrical communications with the analog board. The monitor connector has a pod cable extending from the digital board and terminates at a monitor connector. The analog board has an analog board connector disposed on the analog board surface. The digital board has a digital board connector disposed on the digital board surface, and the analog board connector is physically and electrically connected to the digital board connector. 
         [0009]    In further embodiments, the analog board mounts emitter drivers that activate the regional oximetry sensor emitters, the analog board has detector amplifiers that receive sensor signals from the regional oximetry detectors, and the analog board digitizes the sensor signals. The digital board has a digital signal processor (DSP) that inputs the digitized sensor signals. The DSP derives regional oximetry parameters from the sensor signals, and the regional oximetry parameters are communicated to a patient monitor via the pod cable and the monitor connector. 
         [0010]    Another aspect of a regional oximetry pod is defining a pod having a first pod end and a second pod end, disposing a signal processor within the pod, extending a sensor connector from the first pod end and extending a monitor connector from the second pod end. Sensor signals are received from the first pod end. Signal processing on the sensor signals calculates a regional oximetry parameter, and the parameter is transmitted to the monitor connector for display on a standard patient monitor. 
         [0011]    In various embodiments, disposing a signal processor within the pod comprises stacking an analog board to a digital board, extending a sensor cable from the analog board to the sensor connector and extending a monitor cable from the digital board to the monitor connector. This also comprises mounting and electrically connecting a DSP to the digital board and calculating the regional oximetry parameter within the DSP. This also comprises driving sensor emitters and receiving detector signals on the analog board, wherein extending a monitor connector includes attaching a monitor cable first end to the signal processor and attaching the monitor connector to a monitor cable second end. Extending a sensor connector comprises extending sensor connector cables from the first pod end, and attaching the sensor connector to the sensor connector cable distal the pod. Extending a sensor connector comprises attaching a socket block partially within the pod at the first pod end. 
         [0012]    An additional aspect of a regional oximetry pod is a driver means for transmitting a drive signal to a plurality of emitters, and an amplifier means for receiving a response signal from at least one detector in optical communications with the emitters. A dual connector means is for communicating the drive signal and the response signal to the drive means and the amplifier means. A housing means is for enclosing the driver means and the amplifier means and for at least partially enclosing the dual connector means. An analysis means is for deriving physiological parameters from the response signal, and a monitoring means is for communicating the physiological parameters to a display. The driver means and the amplifier means comprise an analog board means disposed within the housing means. 
         [0013]    For various embodiments, the analysis means comprises a digital board means disposed within the housing means. Board connectors interconnect the analog board means and the digital board means. A frame means is for mechanically stabilizing the analog board means connected to the digital board means. The dual connector means has connector cables extending from the housing means between the analog board means and a plurality of sensor connectors. The dual connector means has a socket block partially disposed within the housing means and is configured to receive dual sensor plugs. A monitoring means comprises a pod cable extending from the digital board means and the housing means and terminating at a USB connector. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a general block diagram of a pod-based regional oximeter that interconnects with regional oximetry sensors so as to derive regional oximetry parameters and communicate those parameters to a patient monitor; 
           [0015]      FIGS. 2A-B  are perspective views of an internal-connector regional oximetry pod and an external-connector regional oximetry pod, respectively; 
           [0016]      FIG. 3  is a cross-sectional view of a regional oximetry sensor attached to a tissue site, illustrating corresponding near-field and far-field emitter-to-detector optical paths; 
           [0017]      FIG. 4  is a general block diagram of a regional oximetry pod housing a regional oximetry analog board, digital board and signal processor; 
           [0018]      FIG. 5  is a general block diagram of regional oximetry signal processing; 
           [0019]      FIGS. 6A-D  are top perspective, bottom perspective, sensor connector and monitor connector views, respectively, of an internal-connector regional oximetry pod; 
           [0020]      FIGS. 7A-D  are top perspective, bottom perspective, detailed sensor connector and detailed monitor connector views, respectively, of an external-connector regional oximetry pod; 
           [0021]      FIG. 8  is a detailed block diagram of the emitter drive for dual, regional oximetry sensors; 
           [0022]      FIG. 9  is a detailed block diagram of the detector interface for dual regional oximetry sensors; 
           [0023]      FIG. 10  is a regional oximetry monitor display that provides user I/O showing placement of up to four sensors on a patient; and 
           [0024]      FIG. 11  is a regional oximetry parameter display for up to four regional oximetry sensors; 
           [0025]      FIGS. 12A-E  are various exploded views of an internal-connector regional oximetry pod; 
           [0026]      FIGS. 13A-D  are side, back, back perspective and exploded views, respectively, of a dual sensor connector for an internal-connector pod; 
           [0027]      FIGS. 14A-C  are front, front perspective and folded front perspective views, respectively, of an internal-connector flex-circuit assembly for an internal-connector pod; and 
           [0028]      FIGS. 15A-C  are various exploded views of an external-connector regional oximetry pod; 
       
    
    
     DETAILED DESCRIPTION 
       [0029]      FIG. 1  generally illustrates a pod-based regional oximeter  100  including pod assemblies  101 ,  102  each communicating with an array of regional oximetry sensors  110  via sensor cables  120 . The sensors  110  are attached to various patient  1  locations. One or two regional oximetry pods  130  and a corresponding number of pod cables  140  advantageously provide communications between the sensors  110  and a patient monitor  170 . Regional oximetry (rSO 2 ) signal processors  150  housed in each of the pods  130  perform the algorithmic processing normally associated with patient monitors and/or corresponding monitor plug-ins so as to derive various regional oximetry parameters. The pods  130  communicate these parameters to the patient monitor  170  for display and analysis by medical staff. Further, in an embodiment, each pod  130  utilizes USB communication protocols and connectors  142  to easily integrate with a third party monitor  170 . A monitor  170  may range from a relatively “dumb” display device to a relatively “intelligent” multi-parameter patient monitor so as to display physiological parameters indicative of health and wellness. 
         [0030]      FIGS. 2A-B  illustrate an internal-connector regional oximetry pod  201  ( FIG. 2A ) and an external-connector regional oximetry pod  202  ( FIG. 2B ). As shown in  FIG. 2A , in the internal-connector embodiment  201 , pod sockets (not visible) are recessed into the pod housing  210 . RSO 2  sensors  60  have sensor cables  62  extending between the sensors  60  and sensor plugs  64 . The sensor plugs  64  insert into the pod sockets so as communicate sensor signals between the sensors  60  and pod analog and digital boards (not visible) within the pod housing  210 . Pod boards derive regional oximetry parameters, which are communicated to a monitor  170  ( FIG. 1 ) via a monitor cable  220  and a corresponding USB connector  230 . Pod boards are described with respect to  FIG. 4 , below. Sensor optics and corresponding sensor signals are described with respect to  FIG. 3 , below. 
         [0031]    As shown in  FIG. 2B , in the external-connector embodiment  202 , pod cables  260  extend from the pod housing  250 , providing external pod sockets  270 . Sensor plugs  64  insert into the external pod sockets  270  so as communicate sensor signals between the sensors  60  and the analog and digital boards within the pod housing  250 . As generally described above and in further detail below, pod boards  410 ,  420  ( FIG. 4 ) derive regional oximetry parameters from the sensor signals, and the parameters are communicated to a monitor  170  ( FIG. 1 ) via the monitor cable  220  and corresponding USB connector  230 . 
         [0032]      FIG. 3  illustrates a regional oximetry sensor  300  attached to a tissue site  10  so as to generate near-field  360  and far-field  370  emitter-to-detector optical paths through the tissue site  10 . The resulting detector signals are processed so as to calculate and display oxygen saturation (SpO 2 ), delta oxygen saturation (ASpO 2 ) and regional oxygen saturation (rSO 2 ), as shown in  FIG. 11 , below. The regional oximetry sensor  300  has a flex circuit layer  310 , a tape layer  320 , an emitter  330 , a near-field detector  340  and a far-field detector  350 . The emitter  330  and detectors  340 ,  350  are mechanically and electrically connected to the flex circuit  310 . The tape layer  320  is disposed over and adheres to the flex circuit  310 . Further, the tape layer  320  attaches the sensor  300  to the skin  10  surface. 
         [0033]    As shown in  FIG. 3 , the emitter  330  has a substrate  332  mechanically and electrically connected to the flex circuit  310  and a lens  334  that extends from the tape layer  320 . Similarly, each detector  340 ,  350  has a substrate  342 ,  352  and each has a lens  344 ,  354  that extends from the tape layer. In this manner, the lenses  334 ,  344 ,  354  press against the skin  10 , advantageously maximizing the optical transmission and reception of the emitter  330  and detectors  340 ,  350 . 
         [0034]      FIG. 4  generally illustrates a regional oximetry pod  401  that houses a regional oximetry analog board  410  and a regional oximetry digital board  420 . A regional oximetry signal processor  430  executes on a digital signal processor (DSP) residing on the digital board  420 . The regional oximetry signal processor  430  is described with respect to  FIG. 5 , below. The regional oximetry analog board  410  and digital board  420  are described in detail with respect to  FIGS. 8-9 , below. 
         [0035]    As shown in  FIG. 4 , on the patient side  402 , the regional oximetry analog board  410  communicates with one or more regional oximetry (rSO 2 ) sensors  440 ,  450  via one or more sensor cables  445 ,  455 . On the caregiver side  403 , a pod cable  425  has a USB connector  427  so as to provide a standard interface between the digital board  420  and a monitor  170  ( FIG. 1 ). 
         [0036]    Also shown in  FIG. 4 , the analog board  410  and the digital board  420  enable the pod  401  itself to perform the sensor communications and signal processing functions of a conventional patient monitor. This advantageously allows pod-derived regional oximetry parameters to be displayed on a variety of monitors ranging from simple display devices to complex multiple parameter patient monitoring systems via the simple USB interface  427 . 
         [0037]      FIG. 5  generally illustrates a regional oximetry signal processor  500  having a front-end signal processor  540 , a back-end signal processor  550  and diagnostics  530 . The front end  540  controls LED modulation, detector demodulation and data decimation. The back-end  550  computes sensor parameters from the decimated data. The diagnostics  530  analyze data corresponding to various diagnostic voltages within or external to the digital board so as to verify system integrity. 
         [0038]      FIGS. 6-7  generally illustrate regional oximetry pod  600 ,  700  embodiments, each having a pod end  601 ,  701 ; a monitor end  602 ,  702  and an interconnecting pod cable  603 ,  703 . The pod end  601 ,  701  has dual sensor connectors  610 ,  710 . The monitor end  602 ,  702  has a monitor connector  620 ,  720 . In a particular embodiment, the monitor connector  620 ,  720  is a USB connector. 
         [0039]    As shown in  FIGS. 6A-D , in an internal sensor connector embodiment  600 , the sensor connectors  610  are integrated within the pod housing  1200 . Advantageously, this configuration provides a relatively compact sensor/monitor interconnection having sensor connectors  610 , a monitor connector  620  and an interconnecting pod cable  603 . The pod  1200  internals, including the housed portion of the sensor connectors  610 , are described in detail with respect to  FIGS. 12-14 , below. 
         [0040]    As shown in  FIGS. 7A-D , in an external sensor connector embodiment  700 , sensor connector cables  705  extend from the pod housing  1500 . Advantageously, by removing the dual sensor connectors from within the pod housing  1500 , the pod internal complexity is reduced, which reduces manufacturing costs and increases pod reliability. The pod  1500  internals are described in detail with respect to  FIG. 15 , below. 
         [0041]      FIGS. 8-9  illustrate a regional oximetry signal processor embodiment  800 ,  900  having a digital board  803  ( FIG. 8 ) and an analog board  903  ( FIGS. 8-9 ) in communications with up to two regional oximetry sensors  801 ,  802  ( FIG. 8 );  901 ,  902  ( FIG. 9 ). The digital board  803  ( FIG. 8 ) has a DSP  850  in communications with an external monitor via a USB cable  882  and corresponding UART communications  884 . The DSP  850  is also in communications with the sensors  801 - 802 ,  901 - 902  via DACs  830  and ADCs  910  on the analog board  903 . 
         [0042]    As shown in  FIG. 8-9 , sensor emitters  801 ,  802  are driven from the analog board  903  under the control of the digital board DSP  850  via a shift register  870 . Each regional sensor  801 - 802 ,  901 - 902  has a shallow detector and a deep detector. Further, each sensor  801 - 802 ,  901 - 902  may have a reference detector and an emitter temperature sensor. In a cerebral regional oximetry embodiment, the sensor(s) may have a body temperature sensor  930  and corresponding analog board ADC  910  interface. 
         [0043]      FIG. 10  illustrates a user I/O display  1000  for indicating the placement of up to four sensors on a patient. An adult form  1001  is generated on the display. Between one and four sensor sites can be designated on the adult form  1001 , including left and right forehead  1010 , forearm  1020 , chest  1030 , upper leg  1040 , upper calf  1050  and right calf  1060  sites. Accordingly, between one and four sensors  110  ( FIG. 1 ) can be located on these sites. A monitor in communication with these sensors then displays between one and four corresponding regional oximetry graphs and readouts, as described with respect to  FIG. 11 , below. 
         [0044]      FIG. 11  illustrates a regional oximetry parameter display  1100  embodiment for accommodating up to four regional oximetry sensor inputs. In this particular example, a first two sensor display  1101  is enabled for monitoring a forehead left site  1110  and a forehead right site  1120 . A second two sensor display  1102  is enabled for monitoring a chest left site  1150  and a chest right site  1160 . 
         [0045]      FIGS. 12A-E  further illustrate a regional oximetry pod  1200  embodiment. As shown in  FIG. 12A , the pod  1200  has a top shell  1201 , a bottom shell  1202 , a pod assembly  1203  enclosed between the shells  1201 ,  1202  and a cable  1241  extending from the pod assembly  1203  through a bend relief (not shown). As shown in  FIG. 12B , an analog board  1230  and a digital board  1240  are seated within a frame  1210 . 
         [0046]    As shown in  FIGS. 12C-E , an analog board  1230  is plugged into a dual sensor connector assembly  1300 . In particular, an analog board plug  1232  is inserted into a flex circuit assembly socket  1430 . With this arrangement, sensor connectors  64  ( FIG. 2A ) have electrical continuity with the analog board  1230  and the (USB) cable  220  has electrical continuity with the digital board  1240 , as described above with respect to  FIG. 4 . 
         [0047]      FIGS. 13A-D  illustrate a dual sensor connector assembly  1300  that provides communications between the analog board  1230  ( FIGS. 12A-E ) and the dual sensor connectors  610 . The dual sensor connector assembly  1300  has a socket block  1310 , a contact assembly  1320  and a flex-circuit assembly  1400 . The socket block  1310  retains the contact assembly  1320  so as to form the dual sensor connectors  610 . The flex-circuit assembly  1400  provides a socket connector  1430  that mechanically receives analog board plug  1232  ( FIG. 12D ) and electrically connects the analog board sensor inputs to the sensor connectors  610 . In this manner, the analog board  1230  ( FIGS. 12A-E ) receives sensor signals for signal processing, such as filtering and analog-to-digital conversion. 
         [0048]      FIGS. 14A-C  illustrate a connector flex-circuit assembly  1400  having flex circuit contacts  1410 , a flex cable  1420  and a flex circuit socket  1430 . The contacts  1410  receive the sensor connector pins  1320  ( FIG. 13D ), which are soldered in place. When installing the flex-circuit assembly  1400  within a pod  1200  ( FIGS. 12A-E ) the flex cable  1420  folds into a U-shape ( FIG. 14C ) so as to expose the flex circuit socket  1430  ( FIG. 12D ) to the analog board plug  1232  ( FIG. 12D ), which is then inserted into the socket  1430  ( FIG. 12D ). 
         [0049]      FIGS. 15A-C  illustrate an external-connector regional oximetry pod housing  1500  having an upper pod shell  1501  and a lower pod shell  1502  that enclose a board assembly  1503 . The board assembly  1503  has a board frame  1510 , a signal processing assembly  1520  and a wrap  1550 . The board frame  1510  and wrap  1550  mechanically stabilize the signal processing assembly  1520 . 
         [0050]    As shown in  FIGS. 15A-C , the signal processing assembly  1520  has an analog board  1530  and a digital board  1540  as described with respect to  FIG. 4 , above. The analog board  1530  and a digital board  1540  mechanically and electrically interconnect at board connectors  1531 ,  1541 . A sensor cable  705  ( FIGS. 7A-B ) threads through an outer sensor cable boot  1507  and an inner sensor cable boot  1508  so as to mechanically and electrically interconnect with an analog board sensor cable connector  1533  ( FIG. 15C ). 
         [0051]    A regional oximetry pod has been disclosed in detail in connection with various embodiments. These embodiments are disclosed by way of examples only and are not to limit the scope of the claims that follow. One of ordinary skill in art will appreciate many variations and modifications.