Abstract:
A medical device includes a control interface for operating the medical device in a hands-free mode. To control the medical device in a hands-free mode, the control interface includes multiple proximity sensors, each sensor associated with a level of adjustment. For example, a sensor located on a top portion of the medical device is used to increase the level of adjustment. And similarly, a sensor located on a bottom portion of the medical device is used to decrease the level of adjustment. The magnitude of the level of adjustment applied to a parameter of the medical device is controlled based at least in part on the length of time an object remains in proximity to a respective sensor. In one embodiment, the longer the object is held over a respective sensor the more adjustment the control interface will make to the parameter.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is related to concurrently filed, co-pending, and commonly assigned U.S. application Ser. No. 12/553,846, entitled “SYSTEMS AND METHODS FOR ENHANCEMENT OF MEDICAL DEVICE TRACKING,” which filed on Sep. 3, 2009, is incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     This disclosure is related to medical device controls and more specifically to systems and methods for controlling electronic medical devices in a sterile environment. 
     BACKGROUND OF THE INVENTION 
     The use of electronic medical devices of all types is now routine. Often these devices are used in environments where adjustments must be made during the course of a medical procedure. In many situations, these adjustments need to be made to a control, or set of controls that may be preferably remotely located from the operator. 
     By way of example, a sonographic procedure is performed by a sonographer holding a scan-head probe against a patient&#39;s body and moving the probe along the body&#39;s contours in order to facilitate obtaining the desired image. While the sonographer is moving the probe with one hand it is often necessary to make one or more adjustments with respect to controls located on a control panel located separately from the probe. Typically, the sonographer must stretch spread-eagle style to reach both the control panel and the patient at the same time. 
     In some situations, remote control buttons can be placed on the probe to avoid requiring the operator to reach one hand for controls mounted behind or off to the side of the location where the probe is being used. However, in the case of a sterile environment the operator must not touch any non-sterile controls. This then presents a problem when any adjustments must be made during the course of the procedure. 
     BRIEF SUMMARY OF THE INVENTION 
     If simple control of a key parameter is needed, by incorporating a presence detector at the top of a control unit and one at the bottom of the control unit, the operator need only waive a hand near one or the other of the embedded detectors to control an up or down setting of a medical device. In one embodiment, the longer the hand is held over a detector the more adjustment the system will make. In another embodiment, safety mechanisms protect against false readings, for example, by not reacting when both detectors concurrently sense a presence. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention, reference is made to the following descriptions taken in conjunction with the accompanying drawing, in which: 
         FIG. 1  shows one embodiment of a medical device employing the concepts of the invention; 
         FIG. 2  illustrates one embodiment of a control system for using proximity detectors for controlling a medical device; and 
         FIGS. 3 and 4  show embodiments of flow charts for controlling methods for utilization of proximity detectors. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows one embodiment of medical device  10  having control interface  11  and controlled system  100  employing the concepts of the invention. In the embodiment shown, the system is turned on by the operator pushing button  12  of control interface  11 . Control interface  11  is connected, usually by a cable, such as cable  101  or possibly via RF link, such as Bluetooth™, to a controlled system, such as system  100 . The control interface  11  may be attached to the controlled system  100  or physically separated therefrom as shown. Control interface  11  can be a remote control of a device or embedded in the device itself. Controlled system  100 , when used for sonographic procedures could be as shown in the &#39;363 patent or any other sonographic control system. Note that these are only examples and the inventive concepts can be used with any type of system that requires an operator to change parameters without making physical contact with a control circuit. 
     By way of example; to control the level of some parameter, up or down, such as a light on the end of a catheter, auxiliary control button  13  can be used to turn on/off the light (or turn on/off other equipment). In such a situation the power (or other parameter) of the light (or other equipment) can be controlled by increase or decrease buttons  14  and  15 , respectively. If the operator desires to work in the hands-free mode then that mode is entered, for example, by operating both buttons  14  and  15  simultaneously. 
     Note that if the hand-free mode needed to be enabled without physically touching on/off switch  12  then proximity detectors  16  and  17  could be used, for example by moving an object, such as a hand or a sterile cloth, simultaneously or in some sequence into proximity with both of them for a period of time. 
     Once the hands-free mode is entered, the operator simply moves an object, such as a hand, into proximity with top sensor  17  when power is to be increased or into proximity with lower sensor  16  when power is to be decreased. Because the sensors are located top and bottom the direction of power change is intuitive for the operator. The length of time the object is maintained in proximity to the respective sensor determines the magnitude of the change. Alternatively, a wave of the hand could be used to signal the controller that a new incremental step up or down was requested. 
     In the embodiment illustrated, the actual sensors are within the housing of control interface  11  (as will be discussed with respect to  FIG. 2 ) and their respective signals are presented to the operator via holes (labeled T and R in  FIG. 1 ). 
     In order to prevent false readings, control logic verifies that both sensors  16  and  17  are not receiving presence signals simultaneously (except perhaps prior to hands-free operation when simultaneous reception for a certain length of time could equate to a turn on signal). Holes T and R are designed in this embodiment to have a relatively narrow “field of view” so that they will only sense within a defined area. The volume of the presence sensing space (cone of acceptance) is a combination of hole placement, hole opening size, signal power and distance the actual sensor is placed behind the aperture. If desired, one or more of these variables can be operator controllable. For example, one or both of the T, R apertures can be made variable so that the operator can change the shape of the cone of acceptance to adjust distance/sensitivity as desired. The sensors can be made to be selectively sensitive to only a narrow spectrum such as infrared. The apertures would advantageously have covers on them that are transparent to the infrared region of light. The covers could also be filters to prevent other signal sources from interfering in the operation. The light source T can also be modulated such that sensor R is selective to only that modulation thereby making the detector especially resistant to false readings. 
     In a preferred embodiment a narrow cone of acceptance is desired. Also, we contemplate that the timing for power increase will be a level change for each second of detected presence, but again that is controllable. Power level display  19  can be used to show the operator the current level by progressively changing the lighted ones of the dots or, if desired, a digital numerical display could be used. 
     Note that the system as illustrated is designed for binary operation such that the object (hand) is either being sensed or not sensed and the time of presence determines the magnitude of the change. However, the system could also be designed such that the magnitude of the parameter to change is a function of the closeness of the hand to the sensor. In that instance, only one sensor might be necessarily employed. 
       FIG. 2  illustrates one embodiment  20  of a control system for using proximity detectors for controlling the medical device shown in  FIG. 1 . Sensors  16  and  17  can have analog or digital outputs. Analog output sensor would be used, for example, if closeness to the sensor is to be used in the calculation. If closeness to the sensor were to be used to determine a magnitude change, having a second sensor, is especially helpful to help prevent a false reading from persons moving in proximity to the control interface. False readings are also minimized by a narrowly focused cone of acceptance (as discussed above) by controller  22 . In the case of analog operation, the output is a numerical representation of the distance of the detected hand to the control interface. In the case of “digital”, the output is binary, i.e., detected or not detected. Thus, in the case of a digital detector, the output from sensors  16  and  17  would be either a “1” or a “0”. 
     Sensors  16  and  17  each send out a transmit signal which is preferably a modulated RF signal for more accurate presence detection. In the embodiment, the RF signal is transmitted using an infrared LED. When an object comes into the cone of acceptance, the modulated signal is reflected back to the respective R aperture (which need not be the same size as the transmit aperture) and sensor  16  or  17 . The returning reflected signal is detected by an infrared detector and demodulated to determine if an object is within the zone of acceptance or not. In the case of a digital detector, if a threshold is exceeded, it provides a digital signal, usually a “1” to controller  22 . 
     In one embodiment, sensors  16  and  17  can be GP2Y0A21YK (Analog type) or GP2Y0D21YK (Digital judgment type) obtained from Sharp Electronics Corporation. Note that the sensors can be any type of presence sensor, electromagnetic, ultrasound, unmodulated light, etc. Also note that while sensors  16  an  17  are paired on a single unit, there can be several different sensors and several different sensor types each controlling different functions or working in combination with each other to perform a single function with more accuracy. 
     As noted above, while the discussion centers on up/down control of a laser light, the system could also control up and down sensitivity or power or any other parameter of any type of medical device, including a power level (or formed beam direction control) of the probe itself. 
     The difference between analog and digital outputs from the sensor is that with digital the system need only detect presence or absence (1 or 0) and then make a decision about what one or the other means. In the case of the digital output, it is possible to set a detection threshold. Some sensors allow an iteratively adjustment and other devices are pre-set. Generally, close detection for a medical instrument is desired. For analog sensors the controller would interpret the actual voltage level in order to make the appropriate decisions. 
       FIG. 3  shows one embodiment  30  of a method for controlling the on/off of the hands-free operation for utilization of proximity detectors. The method illustrated in  FIGS. 3 and 4  can be run on a processor, such as processor  22 - 1 , ( FIG. 2 ) in conjunction with memory  22 - 2  or it can be performed in hardware or in a combination of hardware and processor control. 
     Process  301 , working in conjunction with wait timer  306 , determines if the control interface is in the hand-free mode. If not, then the interface will not respond to the detection of presence at either sensor until the hand-free mode is activated. Activation can be by operation of a switch (such as switch  12 ,  FIG. 1 ) or as shown by process  302  if desired where simultaneous presence detection from the “up” and “down” sensors is determined. If process  301  had determined the system had already been in the hands-free mode, then upon process  304  determining that both detectors or both up and down switches are activated, the system would leave the hands-free mode via process  305 . 
       FIG. 4  shows one embodiment  40  of a method for controlling the up/down function of a controlled system by hands-free operation. Process  401  determines if the system is in the hands-free mode. If not, timer  407  waits for a period of time. When process  401  determines the system to be in the hands-free mode, process  402  determines if both sensors  16  and  17  are sending detection signals. If both detectors are doing so at the same time then this condition prevents both the up and down signals from being sent and timer  407  delays operation for a period of time, for example, two seconds. 
     Assuming now that an “up” presences has been detected alone, then process  403 , in conjunction with process  404  sends an output control signal indicating that power should be raised (or indicating that some other function should be increased). 
     Following a wait period determined by timer  408  (for example, one second), the process repeats. If the up presence is still being detected, another up control signal is sent. This continues until process  403  no longer detects a presence at the up presence detector. 
     The down presence detector works similar to the up detector only using processes  403 ,  405  and  406 . 
     Note that if desired the operator can have an input to change the up and down times ( 408 ,  406 , respectively). Note also that wait timer  407  and the up and down times need not be the same time intervals. 
     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.