Patent Description:
Myotonic dystrophy is the most common genetically inherited muscle disease in adults. Myotonic dystrophy is a genetic disorder that causes progressive muscle weakness. One primary symptom of myotonic dystrophy is handgrip myotonia, which is characterized by the inability or delayed relaxation of muscles following vigorous effort. Current methods for identifying biomarkers with respect to myotonic dystrophy generally involve measuring grip strength with a handheld dynamometer that requires a specific position. These handheld dynamometers are not capable of measuring full grip force and cannot measure continuous force during relaxation. Additionally, these devices are costly, obtrusive, and are not suitable for weaker muscles and/or mild cases of myotonia.

According to the invention, the problem posed is solved by the handgrip device of claim <NUM>, handgrip system of claim <NUM> and the method of handgrip monitoring of claim <NUM>. A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description that sets forth illustrative examples, in which the principles of the disclosure are utilized, and the accompanying drawings of which:.

Examples and various features and advantageous details thereof are explained more fully with reference to the exemplary, and therefore non-limiting, examples illustrated in the accompanying drawings and detailed in the following description. Descriptions of known starting materials and processes can be omitted so as not to unnecessarily obscure the disclosure in detail.

The present disclosure is drawn to handgrip myotonia devices and related systems operable to measure, track, and/or display both muscle contraction (e.g. grip force) and/or muscle relaxation following muscle contraction. The handgrip myotonia system can include an electronic device communicatively coupled with a handgrip myotonia device. The electronic device can be a computer, including but not limited to, a laptop having a processor operable to implement a software suite installed in memory. The electronic device can generate a cue to request a user to contract their finger muscles (e.g. grip force) on a handgrip myotonia device followed by a second cue to relax their finger muscles. The software can receive force measurements from the handgrip myotonia device and/or generate a display having the received force measurements over time correlated with the cue requesting contraction and relaxation of the finger muscles. The generated display can be a digital display of the electronic device, a print out, and/or display on a secondary electronic device. In at least one instance, the software suite can be a graphical user interface (GUI) based software suite.

The electronic device can be wired and/or wirelessly communicatively coupled with the handgrip myotonia device, thereby allowing receipt of one or more force measurements from the handgrip myotonia device.

The handgrip myotonia device can be operable to measure both muscle contraction and muscle relaxation over time and/or communicate with the electronic device and the software suite installed thereon. The handgrip myotonia device can include one or more force transducers operable to receive and/or measure substantially continuously a grip force provided by a user upon receiving the cue. After the second cue, the one or more force transducers can receive and measure substantially continuous a relaxation force provided by the user.

The grip force and the relaxation force can be tracked and/or plotted by the software suite over time, allowing an operator to determine the ability of the user to generate a grip force and the user's muscles ability to relax following generation of the grip force. Tracking the grip force and the relaxation force with respect to time can provide an operator and/or a medical professional critical information regarding whether the user may or may not have symptoms of myotonic dystrophy.

The handgrip myotonia device can be operable to isolate specific muscle movements of the hand, specifically the fingers, while also being operably arranged to minimize wrist, elbow, and shoulder muscle interaction with the measurements. The isolation of finger muscles can provide a more detailed measurement of a user's grip force and ability to relax muscles following contraction. The identification of myotonic dystrophy can include characterizing, measuring, and/or quantifying myotonia in assessing therapeutic response in one or more clinical trials.

In at least one instance, the handgrip myotonia device can be a hand clasp relaxometer. The handgrip myotonia device can include a palm rest operable to have a user's palm adjacently engaged and a grip bar operable to adjacently engage with a user's fingers. One or more load cells can be disposed between the palm rest and/or the grip bar. The one or more load cells can be operable to measure a compression force as a user's finger muscles contract (e.g. grip strength) and compress the grip bar toward the palm rest, thereby compressing the one or more load cells. During muscle relaxation, the one or more load cells can measure a relaxation force as the grip bar returns to a nominal position. In user's experiencing myotonic dystrophy, an inability to relax the hand muscles will be noticeable based on the one or more load cells detection of the grip bar returning to the nominal position. Alternatively, the grip bar may remain static or stationary as the one or more load cells measure the grip force and/or relaxation force as the user releases the grip bar.

In another instance, the handgrip myotonia device can be a myotonia relaxation actuator having a frame and a palm device mounted thereto. The palm device can be movably coupled with the frame, thereby allowing vertical and/or horizontal position adjustments of the palm device along the frame. In at least one instance, the frame and the palm device can have a tongue and groove arrangement to allow infinite positioning options, and thus micro-adjustment, of the palm device relative to the frame.

The palm device can include a palm rest and a finger grip lever. The finger grip level can be pivotally coupled with the palm rest, thereby allowing the software suite to measure a grip force and a relaxation force. A user can pivot the finger grip lever upon muscle contraction, and the finger grip lever can return to a nominal position upon muscle relaxation. In at least one instance, the palm device can include a servomotor received therein and be operable to detect the impedance and/or torque profile of the user's muscle grip and muscle relaxation. User muscle relaxation can generate a muscle relaxation profile measured as servomotor torque output. The servomotor can be operable to minimize interaction force with a user's grip force and/or relaxation force, via the closed loop feedback control.

The handgrip myotonia device and system can be operable to measure a user's muscle contraction and relaxation in any number of positions and/or orientations while simultaneously being cost effective and mobile. The handgrip myotonia device can allow a user's to measure grip strength and/or muscle relaxation in a position most comfortable for the user, thereby providing more accurate results.

<FIG> illustrates a handgrip myotonia system according to at least one instance of the present disclosure. The handgrip myotonia system <NUM> can include an electronic device <NUM> and a handgrip myotonia device <NUM> The handgrip myotonia device <NUM> can be communicatively coupled with the electronic device <NUM> via wired and/or wireless communications. The handgrip myotonia device <NUM> can be operable to engage with a user <NUM> to measure muscle contraction force and/or relaxation force of a user's hand. The measured muscle contraction and/or relaxation data can be communicated to the electronic device <NUM> and a software suite <NUM> installed therein.

The software suite <NUM> can be installed on one or more memory devices <NUM> and executed by one or more processors <NUM> of the electronic device <NUM> The software suite <NUM> can generate a cue requesting a user <NUM> contract muscles and generate a second cue requesting a user relax muscles, while simultaneously receiving force data feedback from the handgrip myotonia device <NUM>. The software suite <NUM> can generate a display of force generated and relaxation force over time and synchronized with the generated cues.

In at least one instance, the cue and second cue can be audio signals generated by the electronic device <NUM>. The electronic device and/or software suite <NUM> can be operable to generate a display overlaying the audio signals with the measured contraction force and relaxation force.

The software suite <NUM> can generate a display <NUM> of the measured data for use with any medium including, but not limited to, digital displays (local displays and remote displays), and/or printed displays. In at least one instance, the display <NUM> can be a local display of the electronic device <NUM>. In other instances, the display <NUM> can be a remote display located some distance away from the electronic device <NUM>. The remote display can be a display within the same room, or a remote location. The remote display can allow an operator to measure the grip force and/or relaxation while communicating the results to one or more medical professionals.

<FIG> illustrates an isometric view of a handgrip myotonia device according to a comparative example. The handgrip myotonia device <NUM> can be operable to measure both a muscle contraction (e.g. grip force) and a muscle relaxation of a user, thereby providing useful information regarding potential symptoms of myotonic dystrophy.

The handgrip myotonia device <NUM> can include a palm rest <NUM> and a grip bar <NUM>. The palm rest <NUM> can be operable to adjacently engage with a user's palm during operation while the grip bar <NUM> can be operable to engage with fingers of a user during operation. The palm rest <NUM> can be in sliding engagement with the grip bar <NUM>, and the grip bar <NUM> can be operable to slide relative to the palm rest <NUM>. The palm rest <NUM> and the grip bar <NUM> can have one or more force transducers <NUM> disposed therebetween.

In at least one instance, the grip bar <NUM> can be statically coupled with the palm rest <NUM>, but formed of a material capable of deformation relative to the palm rest <NUM>. The grip bar <NUM> can have a strain gauge coupled therewith operable to allow a deformation measurement, and thus a grip strength measurement to be determined.

The one or more force transducers <NUM> can be operable to measure compression force when a user's muscle contraction pushes the grip bar <NUM> toward the palm rest <NUM>. The one or more force transducers <NUM> can further be operable to measure relaxation force as the grip bar <NUM> returns to a nominal position relative to the palm rest <NUM> as a user's muscles relax following contraction.

The one or more force transducers <NUM> can be any known force measurement device operable to be disposed between the palm rest <NUM> and the grip bar <NUM>. In at least one instance, the one or more force transducers <NUM> can be one or more load cells. The handgrip myotonia device <NUM> can be modularly arranged, thereby allowing addition and/or removal of force transducers <NUM> based on the necessary arrangement. An increased quantity of force transducers <NUM> can be implemented to more precisely measure weak muscle contraction and/or very strong muscle contractions.

The palm rest <NUM> and the grip bar <NUM> can be in sliding engagement with one another. The palm rest <NUM> and the grip bar <NUM> can be coupled via linear bearings <NUM>, thereby allowing sliding engagement. The linear bearings <NUM> can be operable to transfer grip force from the user's fingers to the one or more force transducers <NUM>. The linear bearings <NUM> can include a tongue and groove arrangement with at least a portion of the palm rest <NUM> and/or the grip bar <NUM> received with other. In other instances, the palm rest <NUM> and the grip bar <NUM> can be coupled via linear actuators, or any other mechanism allowing linear movement between the palm rest <NUM> and the grip bar <NUM>.

In some instances, the linear bearings <NUM> can be biasing elements (e.g. springs) operable to bias the grip bar <NUM> towards a nominal position. In these instances, the biasing element is calibrated to insure the biasing force (return force) is less than the relaxation force of a user's hand. In other instances, the biasing elements may be placed in parallel or alternatively, in series with the bearings <NUM> and the force transducers <NUM>. The calibration of the biasing element is essential to prevent the biasing element from assisting muscle relaxation of a user's hand.

The handgrip myotonia device <NUM> can be coupled with a force processing circuit <NUM>. The force processing circuit <NUM> can be operable to process data received from the one or more force transducers <NUM> to a format appropriate for the software suite. The handgrip myotonia device <NUM> can further include a data connection <NUM> operable to communicate the processed data to the electronic device and/or software suite.

In at least one instance, the data connection <NUM> can be a universal serial bus (USB) connection. In other instances, the data connection <NUM> can be a network connection (e.g. RJ-<NUM>), wireless connection (WiFi, Bluetooth, etc.), or any other data connection.

The handgrip myotonia device <NUM> can include a plurality of force transducers <NUM> as illustrated with respect to <FIG>. The plurality of force transducers <NUM> can be substantially equally spaced along the longitudinal length <NUM> of the hand myotonia device <NUM>. In some instances, the plurality of force transducers <NUM> can be substantially equally spaced apart relative to a centerline of the longitudinal length <NUM>. In other instances, the plurality of force transducers <NUM> can be substantially equally spaced relative to a proximal end <NUM> and a distal end <NUM>, respectively.

As can be appreciated in <FIG>, the handgrip myotonia device <NUM> can incorporate two force transducers <NUM> substantially evenly spaced long the longitudinal length <NUM> of the handgrip myotonia device <NUM>. The two force transducers <NUM> can be operable to prevent rotation of palm rest <NUM> relative to the grip bar <NUM> during muscle contraction and/or relaxation by a user. The inhibiting of rotation between the palm rest <NUM> and grip bar <NUM> can prevent distortion of force assessments, thereby providing accurate assessments of grip force for each user.

While <FIG> and <FIG> illustrates a handgrip myotonia device <NUM> having one force transducer <NUM> and two force transducers <NUM>, respectively disposed therein, they may include any number force transducers as necessary to measure appropriate muscle contraction and/or relaxation along the palm rest <NUM> and/or the grip bar <NUM>.

<FIG> illustrates a handgrip myotonia system including a handgrip myotonia device in operably engaged with a user. The handgrip myotonia system <NUM> can include an electronic device <NUM> having a software suite <NUM> installed thereon. A handgrip myotonia device <NUM> can be communicatively coupled with the electronic device <NUM>.

The handgrip myotonia device <NUM> can have a user' s hand <NUM> operably engaged therewith. The handgrip myotonia device <NUM> can have a palm rest <NUM> adjacently engaged with the palm of the user's hand <NUM> and a grip bar <NUM> adjacently engaged with the fingers of the user's hand <NUM>.

During operation, the software suite <NUM> can generate a cue (e.g. audio, visual, and/or haptic) to the user requesting the user contract the finger muscles in the hand <NUM>, thereby requesting the compression of the one or more force transducers <NUM>. As user contracts finger muscles (e.g. grip strength) the grip bar <NUM> can be linearly displaced toward the palm rest <NUM>, thereby compressing the one or more force transducers <NUM>. The compression of the one or more force transducers <NUM> can produce a force measurement received, recorded, and/or displayed by the software suite <NUM> on the electronic device <NUM>.

The software suite can then generate a second cue (e.g. audio, visual, and/or haptic) to the user requesting the relaxation of finger muscles in the hand <NUM>, thereby allowing the grip bar <NUM> to return to a nominal position relative to the palm rest <NUM> in embodiments having a dynamic grip bar. The one or more force transducers <NUM> can track the relaxation of the muscles and communicate the measurements to the software suite <NUM> for recording and/or display. The software suite <NUM> can overlay and/or time synchronize the cue, second cue, compression force and/or the relaxation force on a single plot.

The cue and second cue generated by the software suite <NUM> and/or the electronic device <NUM> can be an audio signal, visual signal, haptic signal, and/or any other signal operable to request or signal the user to contract and/or relax finger muscles in the hand <NUM>. The cue and/or the second cue can be synchronized (e.g. by the software suite) with handgrip myotonia device measurement, such that the cue and/or the second cue can be recorded as a time series with substantially the same sampling rate as any other measurements from the handgrip myotonia device.

As can be appreciated in <FIG>, the user's hand <NUM> can be restrained against a rigid surface in an effort to isolate finger muscle contraction and relaxation while eliminating and/or minimizing adjacent muscle groups, such as wrist, forearm, elbow and/or shoulder.

While <FIG> illustrates the user's hand <NUM> in a substantially palm up arrangement, the handgrip myotonia device(s) and/or system(s) of the present disclosure can be implemented in any arrangement comfortable for the user. Further, while <FIG> illustrates the user's hand <NUM> right- hand, the handgrip myotonia device(s) and/or system(s) are operably arranged to be ambidextrous to be implemented with a user's right-hand or left hand.

<FIG> illustrates a force chart generated by the handgrip myotonia system as described. The force chart <NUM> displays two data sets recorded by the handgrip myotonia device, along with the cues (e.g. cue and second cue) generated by the software suite of the handgrip myotonia system.

The force chart <NUM> can be a plot of generate force (e.g. grip strength) over time. The cue <NUM> can be overlaid on the force chart <NUM>, thereby allowing representation of reaction time of both the user and/or the user's muscles. The measured force <NUM>, <NUM> can be plotted as independent trials representative of multiple operations of the handgrip myotonia device. The measured force <NUM>, <NUM> can show the user's generated force in both a muscle contraction and a muscle relaxation situation by overlayment of the cue. The force chart <NUM> can detail the user's ability to contract muscles upon receipt of the cue and similarly the ability of the user's muscles to relax upon receipt of the second cue after contraction. Thus, a delayed muscle relaxation can be identified within the force chart <NUM> and/or the handgrip myotonia system, thereby allowing medical professionals to potentially identify myotonic dystrophy. The identification of myotonic dystrophy can include characterizing, measuring, and/or quantifying myotonia in assessing therapeutic response in one or more clinical trials.

<FIG> illustrates a handgrip myotonia device being a myotonia relaxation actuator, according to the present disclosure. The handgrip myotonia device <NUM> can include a myotonia relaxation actuator. The handgrip myotonia device <NUM> can include a frame <NUM> and a palm device <NUM>. The palm device <NUM> can be in sliding engagement with the frame <NUM>, thereby allowing the palm device to be positioned at any desired position on the frame <NUM>. Further, the frame <NUM> can have a vertical frame <NUM> and a horizontal frame <NUM>. The horizontal frame <NUM> can be in sliding engagement with the vertical frame <NUM>, thereby allowing the vertical position of the horizontal frame <NUM> to be independently adjusted. While <FIG> illustrates the palm device <NUM> moveably coupled with the horizontal frame <NUM>, it is within the scope of this disclosure to implement the palm device <NUM> with the horizontal frame <NUM>, the vertical frame <NUM>, and/or a frame member disposed at any angle between horizontal and vertical, thereby allowing the handgrip myotonia device <NUM> to be positioned at the most comfortable position for a user.

The handgrip myotonia device <NUM> can be communicatively coupled with an electronic device (as described in <FIG>) by data connection <NUM> and have a force processing circuit <NUM>.

<FIG> illustrates a side isometric view of the handgrip myotonia device of <FIG>. The palm device <NUM> can include a palm rest <NUM> and a finger grip lever <NUM>. The finger grip lever <NUM> can be pivotally coupled with the palm rest <NUM> and operable to pivot as a user's finger muscles contract. The palm device <NUM> can have an actuator <NUM> disposed between the palm rest <NUM> and the finger grip lever <NUM>. The actuator <NUM> may further include a sensor or force transducer to detect and/or measure force applied to pivot the finger grip lever <NUM> relative to the palm rest <NUM>. In at least one instance, the actuator <NUM> can be a servomotor.

The actuator <NUM> can be coupled with an impedance feedback control loop allowing the actuator <NUM> to detect the force applied by a user's muscle contraction and match the measured torque to a net zero torque.

The palm device <NUM> can also include a position sensor <NUM> coupled with the palm rest <NUM> and the finger grip lever <NUM> and operable to determine a position of the finger grip lever <NUM> relative to the palm device <NUM>. The position sensor <NUM> can provide additional information about a user's range of motion, while simultaneously allowing the software suite to correlate the overall movement of a user's hand with the muscle contraction force relative to position.

In at least one instance, the actuator <NUM> can track the motion of the finger grip lever <NUM> via the position sensor <NUM> and match the interaction force via a closed loop, impedance based control. The closed loop, impedance based control can allow the actuator <NUM> produce a net zero torque, thereby preventing the device from assisting the user with muscle contraction and/or muscle relaxation while still providing dynamic force measurement.

The handgrip myotonia device <NUM> can detect rotation/pivoting of the finger grip lever <NUM> and measure the impedance while minimizing interaction force. The handgrip myotonia system (as described in <FIG>) can measure the muscle relaxation profile by output the torque output of the actuator <NUM>.

The palm rest <NUM> can be operable to engage with a user's palm during operation while the finger grip lever <NUM> can be operable to engage with a user's fingers during operation.

<FIG> illustrates a handgrip myotonia device of <FIG> during operation. The handgrip myotonia device <NUM> can operably receive a user's hand <NUM> by adjacent engagement between the user's palm and the palm rest <NUM> and the user's fingers and the finger grip lever <NUM>.

As described above with respect to <FIG> and <FIG>, the handgrip myotonia system can generate a cue requesting contraction user's finger muscles. Contraction of the user's finger muscles can rotate and/or pivot the finger grip lever <NUM> relative to the palm rest <NUM>, and providing the actuator <NUM> a force measurement (e.g. grip strength). The handgrip myotonia system can subsequently generate a second cue requesting relaxation of user's finger muscles, and allowing the actuator <NUM> to measure a relaxation profile. In at least one instance, the actuator <NUM> can detect the relaxation profile as torque output of a servomotor.

In another instance, the position sensor <NUM> can be set to a predetermined angle of the finger grip lever <NUM> relative to the palm rest <NUM>. The actuator <NUM> can be operably engaged to maintain the predetermined angle by generating net torque on the finger grip lever <NUM> substantially equal to the torque applied by a user's muscle contraction. The net zero torque can allow the finger grip lever <NUM> to maintain a substantially static position during muscle contraction, while still providing accurate force measurement of muscle contraction.

In yet other instances, during muscle relaxation as a user's finger muscles relax, the actuator <NUM> can maintain a net zero torque by applying a torque substantially equal to the user's muscle relaxation. Maintaining a net zero torque allows the actuator <NUM> to track a user's muscle relaxation and/or position without applying a torque to the user's hand to artificial assist muscle relaxation.

While <FIG> illustrate the handgrip myotonia device <NUM> in a substantially palm up orientation, it is within the scope of this disclosure to arrange the handgrip myotonia device <NUM> in any orientation depending on a user's comfort and/or preference.

<FIG> illustrates a force chart of the handgrip myotonia device of <FIG>, according to at least one instance of the present disclosure. The force chart <NUM> can provide data sets recorded by the handgrip myotonia device <NUM> including position and torque, along with the cues generated by the software suite of the handgrip myotonia system.

The force chart <NUM> can be a plot of torque (e.g. grip strength), position, and cue over time. The cue <NUM> can be overlaid on the force chart <NUM>, thereby allowing representation of reaction time of both the user and/or muscles. The measured torque <NUM> can be plotted as operation of the handgrip myotonia device <NUM>. The measured torque <NUM> can show the user's generated force in both a muscle contraction and a muscle relaxation situation by overlayment of the cue. The force chart <NUM> can detail the user's ability to contract muscles upon receipt of the cue and similarly the ability of the user's muscles to relax upon receipt of the second cue after contraction. Thus, delayed muscle relaxation can be identified by the force chart <NUM> and/or the handgrip myotonia system, thereby allowing medical professionals to potentially identify, characterize, and classify the severity of myotonic dystrophy for further assessing therapeutic response in clinical trials.

Further, the force chart <NUM> can include measured position <NUM> over time. The measured position <NUM> can detail the position of the finger grip lever <NUM> relative to the palm rest <NUM>. Thus, delayed muscle relaxation can be identified by the force chart <NUM> and/or the handgrip myotonia system, thereby allowing medical professionals to potentially identify myotonic dystrophy.

Referring to <FIG>, a flowchart is presented in accordance with an example method. The example method <NUM> is provided by way of example, as there is a variety of ways to carry out the method <NUM>. Each block shown in <FIG> can represent one or more processes, methods, or subroutines carried out in the example method <NUM>. Furthermore, the illustrated order of blocks is illustrative only and the order of the blocks can change according to the present disclosure. Additional blocks may be added or fewer blocks can be utilized, without deviating from the present disclosure. The example method <NUM> can begin at block <NUM>.

At block <NUM>, a handgrip myotonia system can be operably arranged to engage a user's hand. The operable arrangement and/or engagement with the user can include adjusting the vertical and/or horizontal positioning of a hand myotonia device relative to the user to ensure comfort and proper alignment for measurement purposes. The method <NUM> can proceed to block <NUM>.

At block <NUM>, a software suite can be initiated to measure one or more elements of a user's muscles via the handgrip myotonia device. The method <NUM> can proceed to block <NUM>.

At block <NUM>, the software suite can generate a cue operable to request the user to contract the desired muscle group (e.g. fingers). The cue can be audible, visual, haptic, and/or any other signal operable to communicate to the user the request. The cue can be synchronized as a digital time series with substantially the same sampling rate as other measurements from the handgrip myotonia device, including muscle contraction (block <NUM>) and/or muscle relaxation (block <NUM>) The method <NUM> can proceed to block <NUM>.

At block <NUM>, the software suite can receive measurements, from one or more force transducers, as the user contracts the desired muscle group (e.g. fingers), thereby compressing one or more force transducers coupled with the handgrip myotonia device. The software suite can synchronize a received muscle contraction measurement with a digital time series in view of the cue. The method <NUM> can proceed to block <NUM>.

At block <NUM>, the software suite can generate a second cue operable to request the user to relax the desired muscle group (e.g. fingers). The second cue can be audible, visual, haptic, and/or any other signal operable to communicate to the user the request. The method <NUM> can proceed to block <NUM>.

At block <NUM>, the software suite can receive measurements, from one or more force transducers, as the user relaxes the desired muscle group (e.g. fingers), thereby allowing the one or more force transducers coupled with the handgrip myotonia device to return to a nominal position. The software suite can synchronize a received muscle relaxation measurement with a digital time series in view of the second cue. The method <NUM> can proceed to block <NUM>.

At block <NUM>, the software suite can generate a display of the measurements for muscle contraction, muscle relaxation in view of time and the cue and the second cue. The software suite can synchronize the cue, muscle contraction, the second cue, and/or the muscle relaxation can be synchronized as a digital time series with substantially the same sampling rate. The display can be a physical print-out, a visual display (e.g. computer screen), and/or combinations thereof. The method <NUM> can proceed to block <NUM>.

At block <NUM>, the software suite can store the contraction measurements and/or the relaxation measures for each user to a server. The server can be a local hard disk drive (HDD) including a solid state drive (SSD), remote storage, cloud storage, and/or any other data storage medium including combinations thereof.

Claim 1:
A handgrip device (<NUM>), comprising:
a palm rest (<NUM>) operable to engage with a palm of a user;
a grip bar (<NUM>) pivotally coupled with the palm rest (<NUM>), the grip bar (<NUM>) operable to engage with one or more fingers of a user;
one or more force transducers (<NUM>) disposed between the palm rest (<NUM>) and the grip bar (<NUM>), the one or more force transducers (<NUM>) operable to measure a compression rate and the return rate of the grip bar (<NUM>) relative to the palm rest (<NUM>) in response to the grip bar (<NUM>) rotating relative to the palm rest (<NUM>);
a position sensor (<NUM>) coupled with the palm rest (<NUM>) and the grip bar (<NUM>), the position sensor (<NUM>) operable to determine a position of the grip bar (<NUM>) relative to the palm rest (<NUM>); and
a data connection (<NUM>) operable to communicate the compression rate, the return rate and the position of the grip bar (<NUM>) relative to the palm rest (<NUM>).