Patent Publication Number: US-2022233101-A1

Title: Devices, systems and methods for monitoring neuromuscular blockage

Description:
RELATED APPLICATION 
     This application is a continuation of application Ser. No. 15/325,959 filed 12 Jan. 2017, which is a National Stage Application of PCT/US2015/040733, filed on 16 Jul. 2015, which claims benefit of U.S. Provisional Application No. 62/025,236, filed on 16 Jul. 2014, each of which is hereby fully incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     Embodiments relate generally to medical devices, and more particularly to medical devices comprising sensors for monitoring patient neuromuscular blockage status, e.g., during surgery or other procedures. 
     BACKGROUND 
     During general anesthesia, a patient is given two types of drugs, anesthetics and neuromuscular blocking agents (NMBAs), the latter also known as neuromuscular blocking drugs (NMBD). The anesthetics cause unconsciousness so there is no recollection of the surgery, while NMBAs paralyze skeletal muscles to suppress any involuntary movements the body might have. At the start of a surgery, quick-acting NMBAs are given, and there is a critical time when the patient will need to be intubated to allow for mechanical breathing. Once the patient is intubated, the surgeon starts the surgical procedure and more NMBAs are given as needed during the procedure. There is a fine line as to the amount of paralysis a patient can take: too much and there can be permanent nerve damage, too little and the surgeon cannot do his or her job properly. Once the surgery is close to finishing, an anesthesiologist will put reversal drugs into the body that counteract the NMBAs. There is a constant need to know how much block is in a patient at a given time, but first it is important to know what NMBAs actually do in the body. 
     A muscle movement occurs when an action potential from the brain travels through the nerve to the synapse where it meets the innervated muscle. Once the synapse gets the action potential, it releases a chemical called acetylcholine (ACh). The muscle has chemical receptors that will cause a muscle contraction once ACh binds to the receptor. NMBAs will also bind to the chemical receptors on the muscle. This will block the muscle from contracting even though ACh was released by the nerve. The level of block in a patient is determined by the percentage of receptors that the NMBA binds to. 
     A current method of determining the level of paralysis in a patient is to do the Train of Four (TOF) test using a peripheral nerve stimulator (PNS). TOF is four electrical pulses through the ulnar nerve, facial nerve, or the tibial nerve. Four muscle twitches are observed on the corresponding muscles, and if NMBAs are present a fade (i.e., a decreasing muscle response) can be observed. This fade is how the level of paralysis in a patient is often characterized. Looking at the number of twitches that are observable, and the ratio in strength of the fourth twitch over the first twitch (called the TOF ratio) will give a good indication of how much block is in the body. 
     Literature has shown it is safe to move a patient from the operating room to a recovery room when the TOF ratio is above 90%. A TOF ratio below 90% will increase the likelihood of a patient experiencing post operative residual paralysis (PORP). Symptoms of PORP include difficulty breathing and swallowing, and muscle weakness; in the worst-case scenario, re-intubation can be necessary. 
     There are approximately 17 million surgeries each year in which patients are given neuromuscular blocking agents to induce paralysis. The majority of these surgeries use a PNS to conduct the TOF on a patient. The biggest drawback of this measurement, however, is that the TOF ratio is evaluated qualitatively by the anesthesiologist, either visually or tactilely. That means the anesthesiologist will manually look or feel the muscle twitching to determine if the patient is ready to be extubated and leave the operating room. Other clinical cues are often used, such as if the patient can lift his or her head for a few seconds, but one can never truly know how much NMBAs are in a patient because the evaluation does not take into account the NMBAs that are in the vascular system waiting to bind to the muscle receptors. 
     Many current literature articles discuss that for an experienced anesthesiologist it is very difficult, if not impossible, to objectively determine a difference in the TOF ratio above 40%. That is an unacceptably large margin of error. While anesthesiologists have extensive training, it was estimated that patients had a TOF ratio of below 70% in 30% of surgeries. This can range from minor to major symptoms, but still supports the fact that a new solution to measure NMBAs is severely needed. 
     Other products have focused on meeting the need for a quantitative block monitoring system, though with marginal success. While these systems can be very accurate, they also can be cumbersome and difficult to use. For example, one system referred to as the TOF-watch requires two electrodes to be attached separately to the patient, in addition to an accelerometer on the thumb. Adding even more complexity and time consumption, the patient&#39;s fingers also need to be taped down, along with many of the wires, in order to secure the system. Furthermore, a rigid bar that holds the thumb in place is recommended when calibrating the TOF-watch. When comparing the TOF-watch with the previous system of just a PNS and quick application of two electrodes and connections, the TOF-watch setup is very cumbersome. 
     These encumbrances are critical because anesthesiologists are severely pressed for time when starting a surgery. If everything goes well the TOF-watch setup may only slightly delay the surgery, but every additional step is one more area that can potentially cause a longer delay, particularly if a surgeon is under time pressure and eager to begin the procedure. 
     Another drawback of the PNS and other conventional systems is that test application and results must be documented manually. Given that the tests may be administered frequently (e.g., every fifteen minutes for some drugs, and often more frequently toward the anticipated end of a procedure), the documentation can be time-consuming and take the anesthesiologist away from other important tasks. 
     SUMMARY 
     Embodiments relate to devices, systems and methods for monitoring neuromuscular blockage. In an embodiment, a neuromuscular blockage monitoring system comprises a patch device comprising a unitary patch body, at least two electrodes and at least one sensor, the at least one sensor arranged between the at least two electrodes on the unitary patch body; and a stimulator device operatively coupled to the patch device and configured to provide at least one electrical signal to the at least two electrodes to stimulate a muscle motor point and to receive a signal from the at least one sensor related to a result of the stimulation of the muscle motor point. 
     In an embodiment, a kit comprises at least one patch device comprising a unitary patch body, at least two electrodes and at least one sensor, the at least one sensor arranged between the at least two electrodes on the unitary patch body; a stimulator device operatively coupled to the patch device and configured to provide at least one electrical signal to the at least two electrodes to stimulate a muscle motor point and to receive a signal from the at least one sensor related to a result of the stimulation of the muscle motor point; and user instructions related to the at least one patch device and the stimulator device. 
     The above summary is not intended to describe each illustrated embodiment or every implementation of the present invention. The figures and the detailed description that follow more particularly exemplify these embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments may be more completely understood in consideration of the following detailed description in connection with the accompanying drawings, in which: 
         FIG. 1A  is a block diagram of a neuromuscular blockage monitoring system according to an embodiment. 
         FIG. 1B  is a block diagram of a neuromuscular blockage monitoring system according to an embodiment. 
         FIG. 2A  is a diagram of a patch device according to an embodiment. 
         FIG. 2B  is a depiction of a prototype patch device according to an embodiment. 
         FIG. 3A  is a diagram of an exterior of a stimulator device according to an embodiment. 
         FIG. 3B  is a diagram of interior components of the stimulator device of  FIG. 3A  according to an embodiment. 
         FIGS. 3C-1 and 3C-2  are a circuit schematic diagram of the stimulator device of  FIGS. 3A and 3B . 
         FIG. 3D  is a functional block diagram of a stimulator device and a patch device according to an embodiment. 
         FIGS. 3E-1 and 3E-2  are a schematic depiction of the diagram of  FIG. 3D . 
         FIG. 4  is a depiction of a working prototype of a neuromuscular blockage monitoring system according to an embodiment. 
         FIG. 5  is a system block diagram of a neuromuscular blockage monitoring system according to an embodiment. 
         FIG. 6  is a screenshot of a graphical user interface (GUI) of a neuromuscular blockage monitoring system according to an embodiment. 
         FIG. 7  is a software flow diagram of a neuromuscular blockage monitoring system according to an embodiment. 
         FIG. 8  is a flow diagram of a method related to a neuromuscular blockage monitoring system according to an embodiment. 
     
    
    
     While embodiments are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit to be limited to or by the particular embodiments depicted and described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the appended claims. 
     DETAILED DESCRIPTION 
     Embodiments relate to devices, systems and methods for noninvasive, automated determination of the level of neuromuscular blockade in a patient. In embodiments, a single patch device comprises electrodes and at least one sensor. The patch device can comprise an adhesive or other material for temporarily and selectively coupling the patch device to a peripheral nerve area of a patient, such as proximate the ulnar nerve, facial nerve or tibial nerve. The patch device can be operatively and communicatively coupled to a computing device, such as a computer, laptop, tablet, smartphone, PDA, or other device, which can be used to control the patch device in use. 
     In operation, such as during a surgery or other procedure or setting, an anesthesiologist or other medical professional can, via the computing device, initiate a stimulation routine by the electrodes of the patch device and view a resulting signal from the sensor sensing a response to the stimulation routine. Viewing the resulting signal can include viewing the actual data related to the stimulation, such as a graphical depiction of the muscular response detected by the sensor, as well as viewing an analysis of the test results provided by the computing device (e.g., a calculation of the TOF ratio and/or other metrics). The computing device can record the details of the test and the related results, which can comprise providing information related to the test and results to an electronic medical records (EMR) system. 
     Referring to  FIGS. 1A and 1B , a block diagram of an embodiment of a neuromuscular blockage monitoring system  100  is depicted. System  100  can comprise a patch device  110  (also referred to herein as a “smart electrode”; see  FIG. 1B ), a stimulator device  120  and a computing device  130 . Computing device  130 , or stimulator device  120  and computing device  130  collectively, are also referred to herein as a “control system”; see  FIG. 1B . Patch device  110  can be operatively coupled with stimulator device  120 , which in turn can be operatively coupled with computing device  130 . These couplings can be wired, wireless or a combination of wired and wireless. 
     For example, in one embodiment the connection between patch device  110  and stimulator device  120  is wired, such that power to patch device  110  can be provided by stimulator device  120 . In one particular example depicted in  FIG. 1B , two wires  117   a  and  117   b  couple patch device  110  to stimulator device  120 , with one or more wires sharing functionality (e.g., sensing and stimulation wires can be combined). In other embodiments, more (e.g., three, four or more) or fewer wires can couple patch device  110  to stimulator device  120 . The connection between stimulator device  120  and computing device  130  also can be wired. In other embodiments, one, some or all of the connections can be wireless, such as via WIFI, BLUETOOTH, near-field communication, radio frequency (RF) or some other suitable wireless connection. In embodiments utilizing wireless communications, one, some or all of patch device  110 , stimulator device  120  and computing device  130  can be independently powered, either via one or more batteries, an AC connection (e.g., 120 V, 220 V), or some other suitable power source. 
     While stimulator device  120  and computing device  130  are depicted as two separate devices in  FIG. 1A , in other embodiments they can be integrated in a single unit ( FIG. 1B ) and/or integrated with some other medical device or computing device. For example, computing device  130  can comprise a general computer or a computing device that carries out other tasks, such as monitoring of patient vital signs, administration of drugs or fluids, or some other process. In still other embodiments, stimulator device  120 , one or more patch devices  110 , and optionally one or more cables for operative coupling therewith can be provided as a system or kit, with stimulator device  120  coupleable with virtually any computer, tablet, smartphone or other computing device  130  owned or obtained separately by a user or medical facility. Such a system or kit can further comprise hardcopy or digital operating instructions. Patch device  110 , stimulator device  120  and computing device  130  are discussed in more detail below. 
     Referring also to  FIGS. 2A and 2B , patch device  110  can comprise a patch body  112 , at least one electrode  114  and at least one sensor  116 . Patch device  110  comprises all of the elements needed to quantify the amount of neuromuscular block in a patient and therefore is very versatile, able to be placed on many motor points of muscles. Instead of stimulating a large nerve bundle and measuring the reaction at another location as in conventional devices, patch device  110  can comprise a smart electrode to stimulate the nerves that are proximal to the innervated muscle and measure the muscle reaction at the same place. Co-locating the electrodes  114  and sensor  116  in this way provides many advantages, including a simple, easy to use system that is efficient to apply. The automation features discussed later herein provide additional advantages. 
     The embodiments of  FIGS. 2A and 2B  comprise a wired connection between patch device  110  and stimulator device  120 , via cable  118  in  FIG. 2A  and wires  117   a  and  117   b  in  FIG. 2B , though cable  118  or wires  117   a  and  117   b  can be omitted in other embodiments. Cable  118 , or wires  117   a  and  117   b , can provide power to patch device  110  and also communicate signals between patch device  110  and at least one of stimulator device  120  and computing device  130 . Cable  118  can comprise a single cable as in  FIG. 2A , or multiple cables or wires  117   a  and  117   b  as in  FIG. 2B  and in other embodiments. 
     Patch body  112  can be flexible or semi-flexible in embodiments, such that patch body  112  can easily conform to the shape of an area of a patient&#39;s body to which patch device  110  is applied. While patch body  112  is depicted as being generally rectangular, a variety of other shapes can be implemented in other embodiments, including square, round, oval, oblong, and butterfly, among others. Patch body  112  can be made available in various shapes to more easily conform to particular areas of the body (e.g., a circular patch body may be suited for the facial nerve area, while a rectangular patch body may be suited for the ulner nerve area) as well as in various sizes to be easily used for any of neonatal, pediatric and adult applications. 
     Additionally, while patch body  112  is depicted in  FIGS. 2A and 2B  as a single unitary piece, patch body  112  can comprise a plurality of portions in other embodiments. For example, in one embodiment patch body  112  comprises three portions, one for each of two electrodes  114  and sensor  116 , with the three portions coupled together by cable  118 . The plurality of portions can be provided as a unitary body that is selectively separable (e.g., by tearing along perforations provided between the portions) or partially separable (e.g., coupled by one or more elastic portions) for flexibility in positioning in application to a patient. Such configurations may enable more precise placement of the various components relative to a patient&#39;s particular anatomy, or provide other advantages. 
     In still other embodiments, a single configuration of patch device  110  can be provided, suitable for use with any of the ulnar, facial or tibial nerves, an advantage of such an embodiment being provision of a single device suitable for multiple anatomical applications. 
     In embodiments, patch body  112  can comprise a plurality of layers. As depicted in  FIG. 2B , patch body  112  can comprise an adhesive layer or area to temporarily and selectively couple patch device  110  to the surface of a patient&#39;s skin on the reverse or under-side of patch body  112 . Removing a protective backing layer  113  can expose the adhesive for application to the surface of a patient&#39;s skin. In other embodiments, backing layer  113  can be incorporated into an overall packaging for patch device  110 , such that opening and removing the packaging around patch device  110  also exposes the adhesive layer. Instead of or in addition to an adhesive layer, other devices and methodologies can be used to secure patch body  110  to a patient, such as adhesive tape applied over patch body  112  and/or cable  118  or wires  117   a  and  117   b , an elastic band or cuff, a VELCRO strip or band, adhesive tabs coupled with patch body  112 , a wearable device (e.g., a bracelet, band, glove, sleeve, hat, etc.), or some other suitable securing device or mechanism. 
     In general, the adhesive or other securing device is easily applied, sufficiently secure to provide good contact between electrodes  114  and the patient&#39;s skin, nonirritating, and sufficiently easy to remove after use. Medical grade adhesives are suitable in example embodiments. Interior or intermediate layers of patch body  112  can comprise a substrate, traces, wires and other components configured to operatively and electrically couple cable  118  with electrodes  114 , sensor  116  and other elements and circuits of patch device  110 . A top layer can cover patch body  112  and, in embodiments, form a housing or enclosure along with a bottom layer. In some embodiments, a top or other layer of patch body  112  can comprise an antenna, such as in embodiments in which wireless communications are used, or other circuitry or components. 
     Electrodes  114  are at least partially exposed from patch body  112  for coupling with a patient&#39;s skin in a manner sufficient to enable electrical pulses to be delivered in use. In embodiments, electrodes  114  can comprise silver (Ag) electrodes, silver chloride (AgCl) electrodes, or some other suitable material composition. In the embodiment of  FIGS. 2A and 2B , patch device  110  comprises two electrodes  114  on opposite ends or sides of patch body  112 , but other configurations can be used in other embodiments. For example, patch device  110  can comprise more or fewer electrodes in other embodiments, and at least one of the electrodes  114  can be differently shaped, arranged more or less proximate a perimeter of patch body  110 , or spaced apart from the other electrode(s) or sensor  116  by a greater or lesser distance. In still other embodiments, the relative arrangement of electrodes  114  and cable  118  can be altered, such that cable  118  is coupled to patch body  112  on an adjacent side to the one depicted in  FIG. 2A , intermediate electrodes  112  and more proximate sensor  116  as in the embodiment of  FIG. 2B . Such a configuration could reduce a length of cable  118  or other wiring or circuitry used to provide contact with each of electrodes  114  and sensor  116 . 
     Sensor  116  comprises at least one sensing element in embodiments, such as a piezoelectric sensing element, accelerometer, stretch sensor or other sensing element suitable for sensing a muscle response to electrical stimulation. In one embodiment, a piezoelectric sensor can be used, at least in part because of its favorable signal to noise ratio (SNR), small package, inexpensiveness, and the fact that it is a passive sensor. In operation, a piezoelectric sensor can transduce a mechanical muscle reaction to electrical nerve stimulation provided by electrodes  114  and provide an output signal related to an occurrence or degree of muscle reaction. The output signal typically will be an analog output signal, which can be converted to a digital signal by analog-to-digital converter (ADC) in stimulator device  120  or elsewhere in system  100 . 
     Sensor  116  is depicted as being embedded or sandwiched within patch body  112  in the embodiments of  FIGS. 2A and 2B , while in other embodiments, sensor  116  can be otherwise arranged on or within patch body  112  and/or can comprise external contacts for coupling with a patient&#39;s skin. In  FIGS. 2A and 2B , sensor  116  is arranged between electrodes  114 , but other relative arrangements of sensor  116  and one or more electrodes  114  can be implemented in other embodiments, such as to accommodate a patch body  112  design or arrangement, or to be customized for a particular anatomical area. 
     Referring again to  FIGS. 1A and 1B  and also to  FIGS. 3A and 3B , a prototype of stimulator device  120  is depicted in  FIGS. 3A and 3B . Stimulator device  120  can be coupled with patch device  110  via cable  118  or wires  117   a  and  117   b , wirelessly, or via some other device or methodology. Stimulator device  120  comprises a housing  122 , an on/off switch  124 , a port  126  for operative coupling with patch device  110 , and a port  128  for operatively coupling with computing device  130 . Ports  126  and  128  can comprise a variety of different types of ports for coupling with a variety of different cables and technologies. In one embodiment, port  126  comprises a mini-DIN port, and port  128  comprises a USB port. Ports  126  and  128 , or other or additional ports of stimulator device  120 , can also comprise different ports for interfacing with different cables or technologies in other embodiments, such as mini-jacks, firewire, coaxial, HDMI, mini-B, pinned, or virtually any other kind of port or cable. One or both of ports  126  and  128  can be omitted in embodiments in which wireless or a combination of wired and wireless communications are used. 
     In  FIG. 3B , an interior of a prototype of stimulator device  120  is depicted according to an embodiment. Stimulator device  120  comprises a printed circuit board (PCB)  132 , on which are mounted a switch mechanism  134  of switch  124 , a mini-DIN adapter  136  coupled with port  126 , and a USB adapter  138  coupled with port  128 . A microcontroller  140 , power source  142 , transformer  144 , voltage regulator  146 , MOSFET (metal-oxide-semiconductor field-effect transistor)  148 , and operational amplifier  150  are also mounted on PCB  132 . The particular arrangement and elements of  FIG. 3B  (and  FIG. 3C ) are but an example embodiment of stimulator device  120 , and the operation and features of stimulator device  120  can be implemented in many other ways, with more or fewer circuits and components, in other embodiments without departing from the spirit or scope of the claims. 
     Switch  124  and switch mechanism  134  control the power on or off status of stimulator device  120 . Adapters  136  and  138  couple ports  126  and  128 , respectively, with microcontroller  140  and other elements of stimulator device  120  and/or system  100 . Power source  142  can comprise one or more batteries, such as a 9V battery in the embodiment of  FIG. 3B , coupled with voltage regulator  146 , which can be a 5V regulator in one embodiment. In still other embodiments, power source  142  can instead or in addition comprise an external connection to a 120 V, 220 V or other power source. 
     Referring also to  FIG. 3C , op amp  146 , MOSFET  148  and other circuitry can form a constant current circuit  152 , coupled between transformer  144  (which is in turn coupled with adapter  136 ) and microcontroller  140 . Constant current circuit  152  and transformer  144  are utilized to send electrical pulses to the nerve(s) of the patient through electrodes  114  of patch device  110 . Whenever a digital high signal is sent by microcontroller  140  to the input of constant current circuit  152 , electrodes  114  will provide a surge of power that will activate the nearest nerves. Microcontroller  140 , with computing device  130 , controls the timing of the stimulation and the strength by using pulse width modulation (PWM) on the input to constant current circuit  146 . Using constant current can be advantageous in embodiments because a nerve is activated depending on the amount of current it sees. Since the resistance of the electrode-skin interface can be variable from one person to the next, it can be important that the same amount of current is sent through electrodes  114  to cause the same amount of nerve activation in each patient, a muscle response to which can be sensed by sensor  116 . 
     The resulting output sensed by sensor  116  can be amplified by a 100-times gain circuit  154 . Microcontroller  140  can use a 10-bit ADC to measure the sensor, but only immediately after the stimulation of the muscle has occurred in one embodiment. Microcontroller  140  can find the maximum sensor readings of each electrical pulse. As previously mentioned, sensor  116  can be piezoelectric, a passive sensor comprising two different materials that create a voltage proportional to the amount of mechanical deflection sensed. To improve the sensor signal, a capacitor  156  can be used in between the input and output of sensor  116  to reduce the oscillating noise amplitude, and a pull down resistor  158  can be used to reduce or remove any direct current offset sensor  116  might experience. 
       FIGS. 3D and 3E  are additional depictions of an embodiment of patch device  110  and stimulator device  120 . Couplings and connections shown in  FIG. 3D  can be actual physical connections, functional connections or both, such as those depicted in  FIG. 3E . For example, while four connections are shown between stimulator device  120  and patch device  110  in  FIG. 3D , only two wires may physically couple stimulator device  120  and patch device  110  to accomplish the four connections depicted. In that way, the connections can comprise functions or abilities to communicate between different devices and components, and those functions or communications can take place via shared or the same physical couplings, such as via wires or wirelessly. 
     Additionally, what is depicted in  FIGS. 3D and 3E  is but one example embodiment, and the components, couplings and/or connections can vary in other embodiments. 
     In an embodiment, stimulator device  120  comprises microcontroller  140 , such as a PIC16F1825 14-pin microchip available from MICROCHIP TECHNOLOGY or another comparable or suitable microcontroller device. Microcontroller  140  comprises inputs for programming, such as via computing device  130  or some other device or methodology. 
     Stimulator device  120  also comprises power source  142 , such as a battery (e.g., 9 V), external power connection (e.g., to 120 V or 220 V) or some other power source. Power source  142  is coupled with patch device  142  in embodiments to provide power for stimulation via electrodes  114  and, optionally, sensing via sensor  116 . In other embodiments, sensor  116  and circuitry  115  can be powered via a USB connection or other source. If power source  142  comprises a battery, microcontroller  140  can be coupled to the battery to monitor the status of the battery and provide an output related thereto (e.g., an LED that indicates that suitable power is available or that lights when power is below some threshold programmed into microcontroller  140 ). In embodiments, microcontroller  140  can be powered via the battery, or via a USB, AC or other connected power source, rather than power source  142  when power source  142  comprises a battery, to reserve battery power for stimulation. 
     In embodiments, stimulator device  120  comprises USB adapter  138 , such as a DLP-USB232R mini USB-UART adapter available from DLP DESIGN or another comparable or suitable USB adapter or adapter for another communication technology. USB adapter  138  can couple stimulator device  120  with patch device  110  (and sensor circuitry  115  in particular) and/or computing device  130  to provide, receive and/or exchange stimulation, sensing and other operational data before, during or after operation, as well as power (e.g., 5 V) for stimulator device  120  itself in embodiments. 
     Stimulator device  120  can comprise a switch  143  in embodiments. In one embodiment, switch  143  can comprise a MAX323 single-supply, SPST analog switch available from MAXIM or another comparable or suitable switch or switching device. In embodiments, switch  143  is coupled between microcontroller  140  and the stimulation circuitry  113  and electrodes  114  of patch device  110 . In this way, in operation, when microcontroller sends a “PULSE” signal to switch  143 , switch  143  in turn provides a “STIM” signal to stimulation circuitry  113  of patch device  110 . Circuitry  113  can comprise amplifiers, a transformer, capacitors, resistors, transistors, diodes and other circuitry arranged to transform the “STIM” signal from switch  143  to stimulation pulse(s) via electrodes  114 . In one embodiment, the transformer can comprise a 42TM013 transformer available from XICON or another comparable or suitable transformer or circuitry. The transformer can provide positive and negative stimulation pulses to electrodes  114  (e.g., a positive stimulation pulse to a first one of electrodes  114  and a negative stimulation pulse to the other of electrodes  114 , in an embodiment). 
     In embodiments, microcontroller  140  can be coupled with sensing circuitry  115  of patch device  110  to send signals to and/or receive signals and data from sensor  116 . In embodiments, this can be a direct coupling (e.g., via a wire  117   a  or  117   b ), coupling via USB adapter  138  (which also can be via wire  117   a  and/or  117   b  in some embodiments, or some other way in other embodiments), both a direct coupling and a coupling via USB adapter  138 , or some other arrangement or configuration. 
     Referring to  FIGS. 4 and 5 , stimulator device  120  can communicate with computing device  130  via a cable  160 , which in one embodiment comprises a USB cable with suitable connectors for interfacing with each stimulator device  120  (e.g., a mini B male connector for interfacing with port  128 ) and computing device  130  (e.g., a male USB connector). Stimulator device  120  can communicate with computing device  130  over asynchronous serial communication. Data can be sent two bytes at a time, with one sending 8-bit data and another sending an 8-bit command, in one embodiment. Data can be placed in a buffer that can be checked continuously, and if data exists on the buffer it can be read and cleared. In embodiments, cable  160  also can provide power to stimulator device  120 , such as 5V via USB. 
     Referring also to  FIGS. 6 and 7 , computing device  130  can comprise a suitable program, such as an application (or “app”) using visual basic or other software or programming, providing a graphical user interface (GUI)  170  on a display  162  to enable a user to operate and interact with system  100  via computing device  130 . One example GUI  170  is depicted in  FIG. 6 . GUI  170  can be designed to mimic the button layout of a traditional PNS that a user may be accustomed to, while at the same time providing additional intuitive displays and features to provide information previously obtained only manually. For example, GUI  170  includes a TOF and baseline data display  172  of the muscle twitch readings for the current TOF measurement as well as the average strength of the initial TOF measurement or baseline. A metrics display  174  can include a response indicator of how many of the four stimulations of the TOF test resulted in a sensed muscular response as well as a result of a calculation of the TOF ratio. Stimulation buttons  176  can be provided to select and initiate one or more different stimulation routines. As depicted in  FIG. 6 , a TOF test has been selected, but GUI  170  can enable a user to select other test methodologies, such as double burst stimulation (DBS), post tetanic count (PTC), single twitch, and others. A strength control and display portion  178  can enable a user to adjust stimulation strength, while also displaying the currently selected strength. An exit button  180  also can be provided to close the app and/or save data, such as to a .csv or other file. In still other embodiments, button  180  or another feature can cause the program or app to automatically save and/or send data to an EMR, medical server or network, or other device, in conjunction with exiting GUI  170  or separately, such as midway through a procedure, in which case GUI can further comprise a “save” button in addition to exit button  180 . In still other embodiments, GUI  170  can be configured to automatically save and/or transfer data after each test, periodically or according to some other timing. 
     In yet another embodiment, GUI  170 , the underlying app or software, or some other feature of computing device  130  and/or system  100  can further comprise at least one input device, such as a physical keyboard or a graphical keyboard operable via a touchscreen feature of computer device  130 , a mouse, a touchscreen feature, a barcode or QR code reader, a scanner, an audio or video feature like a camera, or some other input device. Such an input device can enable a user to enter relevant patient or procedural data or otherwise interact with system  100  to match data obtained by system  100  with an EMR or other document or system. 
     Referring also to  FIG. 8 , in use stimulator device  120  and computer device  130  are communicatively coupled with one another, such as via cable  160  or wirelessly, at  202 . At  204 , patch device  110  is coupled to a patient, such as by removing a backing layer of patch device  110  to expose an adhesive layer, and affixing the adhesive layer to a patient&#39;s skin proximate any convenient motor point. At  206 , stimulator device  120  is turned on, such as via switch  124 , and at  208  the app and GUI  170  are run on computing device  130 . At  210 , patch device  110  and stimulator device  120  are operatively coupled with one another, such as via cable  118 . At  212 , at least one neuromuscular blockage test, such as a TOF test, is initiated via GUI  170 , and this may be repeated one or more times throughout a surgical or other procedure. Once complete, data can be saved and GUI  170  exited at  214 , at which point patch device  110  can be removed from the patient and disposed of, while stimulator device  120  and computing device  130  can be powered off. 
     The order of the tasks or events in  FIG. 8  can be changed in other embodiments, and other tasks and events can be added before, within or after those shown in  FIG. 8 . For example, the order of  202  and  204  can be reversed, or data can be saved as part of or after  212  but before  214 . After  214 , a report or other documentation can be run and/or a summary screen presented via GUI  170  to summarized some of all of the stimulation or sensor events that occurred during a particular time or procedure. 
     In embodiments, GUI  170  can also provide access to diagnostic or troubleshooting information, such as to calibrate sensor  116 , stimulator device  120  or some other component of system  100 . GUI  170  can also provide a user guide, instructions, help screens, diagnostics, self-test and contact information and functionality that can be useful to a user before, during or after a procedure. In still other embodiments, GUI  170  can be programmed to remind a user using an audio and/or visual cue to initiate a neuromuscular blockage test periodically, such as every fifteen minutes or according to a frequency associated with a surgical procedure, patient characteristic, a facility or other best practice, or some other characteristic. 
     In embodiments, the app, software or program underlying GUI  170  can be obtained via the internet, such as via an app store or a website. In one embodiment, a kit comprising at least one patch device and the stimulator device further comprises instructions or an access code for obtaining the app, software or program. For example, the kit can comprise a code that a user can enter in an app store or on a website to initiate a free download of the app, software or program. In still other embodiments, the app, software or program can be provided via a computer-readable medium, such as a CD, disk, USB drive or other fixed tangible media. 
     While embodiments discussed herein relate to patient neuromuscular blockage monitoring, such as during surgical procedures, other embodiments can be used beyond such monitoring and/or outside of surgical settings and procedures, such as for relative assessment of various muscle forces in an ICU patient, among others. This could provide insights into drug levels, loss of contractions due to edema or other causes, etc., by performing motor point stimulation of various muscle groups. Various other uses and applications are also possible, in these and other embodiments. Other uses contemplated include veterinary uses. 
     In embodiments, computing device  130 , microprocessors and other computer or computing devices discussed herein can be any programmable device that accepts digital data as input, is configured to process the input according to instructions or algorithms, and provides results as outputs. In an embodiment, computing device  130  and other such devices discussed herein can be, comprise, contain or be coupled to a central processing unit (CPU) configured to carry out the instructions of a computer program. Computing device  130  and other such devices discussed herein are therefore configured to perform basic arithmetical, logical, and input/output operations. 
     Computing device  130  and other devices discussed herein can include memory. Memory can comprise volatile or non-volatile memory as required by the coupled computing device  130  or processor to not only provide space to execute the instructions or algorithms, but to provide the space to store the instructions themselves. In embodiments, volatile memory can include random access memory (RAM), dynamic random access memory (DRAM), or static random access memory (SRAM), for example. In embodiments, non-volatile memory can include read-only memory, flash memory, ferroelectric RAM, hard disk, floppy disk, magnetic tape, or optical disc storage, for example. The foregoing lists in no way limit the type of memory that can be used, as these embodiments are given only by way of example and are not intended to limit the scope of the invention. 
     In embodiments, the system or components thereof (e.g., computing device  130 , stimulation device  120  or other devices or components) can comprise or include various engines, each of which is constructed, programmed, configured, or otherwise adapted, to autonomously carry out a function or set of functions. The term “engine” as used herein is defined as a real-world device, component, or arrangement of components implemented using hardware, such as by an application specific integrated circuit (ASIC) or field-programmable gate array (FPGA), for example, or as a combination of hardware and software, such as by a microprocessor system and a set of program instructions that adapt the engine to implement the particular functionality, which (while being executed) transform the microprocessor system into a special-purpose device. An engine can also be implemented as a combination of the two, with certain functions facilitated by hardware alone, and other functions facilitated by a combination of hardware and software. In certain implementations, at least a portion, and in some cases, all, of an engine can be executed on the processor(s) of one or more computing platforms that are made up of hardware (e.g., one or more processors, data storage devices such as memory or drive storage, input/output facilities such as network interface devices, video devices, keyboard, mouse or touchscreen devices, etc.) that execute an operating system, system programs, and application programs, while also implementing the engine using multitasking, multithreading, distributed (e.g., cluster, peer-peer, cloud, etc.) processing where appropriate, or other such techniques. Accordingly, each engine can be realized in a variety of physically realizable configurations, and should generally not be limited to any particular implementation exemplified herein, unless such limitations are expressly called out. In addition, an engine can itself be composed of more than one sub-engines, each of which can be regarded as an engine in its own right. Moreover, in the embodiments described herein, each of the various engines corresponds to a defined autonomous functionality; however, it should be understood that in other contemplated embodiments, each functionality can be distributed to more than one engine. Likewise, in other contemplated embodiments, multiple defined functionalities may be implemented by a single engine that performs those multiple functions, possibly alongside other functions, or distributed differently among a set of engines than specifically illustrated in the examples herein. 
     Various embodiments of systems, devices and methods have been described herein. These embodiments are given only by way of example and are not intended to limit the scope of the invention. It should be appreciated, moreover, that the various features of the embodiments that have been described may be combined in various ways to produce numerous additional embodiments. Moreover, while various materials, dimensions, shapes, configurations and locations, etc. have been described for use with disclosed embodiments, others besides those disclosed may be utilized without exceeding the scope of the invention. 
     Persons of ordinary skill in the relevant arts will recognize that the invention may comprise fewer features than illustrated in any individual embodiment described above. The embodiments described herein are not meant to be an exhaustive presentation of the ways in which the various features of the invention may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the invention can comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art. Moreover, elements described with respect to one embodiment can be implemented in other embodiments even when not described in such embodiments unless otherwise noted. Although a dependent claim may refer in the claims to a specific combination with one or more other claims, other embodiments can also include a combination of the dependent claim with the subject matter of each other dependent claim or a combination of one or more features with other dependent or independent claims. Such combinations are proposed herein unless it is stated that a specific combination is not intended. Furthermore, it is intended also to include features of a claim in any other independent claim even if this claim is not directly made dependent to the independent claim. 
     Any incorporation by reference of documents above is limited such that no subject matter is incorporated that is contrary to the explicit disclosure herein. Any incorporation by reference of documents above is further limited such that no claims included in the documents are incorporated by reference herein. Any incorporation by reference of documents above is yet further limited such that any definitions provided in the documents are not incorporated by reference herein unless expressly included herein. 
     For purposes of interpreting the claims for the present invention, it is expressly intended that the provisions of Section 112, sixth paragraph of 35 U.S.C. are not to be invoked unless the specific terms “means for” or “step for” are recited in a claim.