Remotely powered remotely adjustable gastric band system

Abstract

A remotely adjustable remotely power gastric band system may include a control device, an implant electronic device, and an implantable gastric band. The control device may telemetrically power and communicate with the implant electronic device, which may be used for adjusting the diameter of the implantable gastric band. The implant electronic device may store the gastric band adjustment history records of a patient and regulate the power received from the control device. To improve transmission efficiency, the implant electronic device may adopt a double modulation scheme for communicating with the control device. Furthermore, the implant electronic device may detect and resolve motor blockage issues related to the implantable gastric band.

1 . A power system for use in conjunction with a gastric band coupled with an implantable antenna for receiving a telemetric signal from a remote control device, the power system comprising:
 a rectifying device coupled to the implantable antenna, and configured to rectify the received telemetric signal to form a DC input voltage at a DC input node;   a power sensing device configured to receive the DC input voltage and generate a regulation signal when the DC input voltage exceeds a predetermined threshold;   a regulation device coupled to the power sensing device, and configured to generate a regulation voltage based on the regulation signal; and   a switching device coupled to the regulation device, and configured to generate a feedback signal having a frequency based on the regulation voltage.   
     
     
         2 . The power system of  claim 1 , wherein the switching device includes:
 a frequency modulation device coupled to the regulation device, and configured to generate a frequency modulation signal with a modulated frequency representing the regulation voltage,   wherein the feedback signal includes the frequency modulation signal.   
     
     
         3 . The power system of  claim 2 , wherein the switching device includes:
 a switch coupled to the frequency modulation device, and configured to generate, at the implement antenna, a modulated amplitude for the feedback signal based on the modulated frequency of the frequency modulation signal.   
     
     
         4 . The power system of  claim 3 , wherein:
 the switching device includes a pull down device coupled to the switch, and   the switch periodically connects the DC input voltage node to the pull down device based on the modulated frequency of the frequency modulation signal.   
     
     
         5 . The power system of  claim 1 , wherein:
 the regulation voltage is substantially the same as a local voltage before the regulation signal is generated,   a margin between the local voltage and the regulation voltage is controlled by a voltage level of the regulation signal, and   the frequency of the feedback signal is based on a margin between the regulation voltage and a local voltage.   
     
     
         6 . The power system of  claim 1 , wherein the regulation device includes:
 a voltage regulator configured to receive the DC input voltage and generate a local voltage less than the DC input voltage and the predefined threshold, and   a transistor coupled with the voltage regulator, and configured to create a potential difference between the local voltage and the regulation voltage, the potential difference based on an amplified margin between the DC input voltage and the predefined threshold.   
     
     
         7 . The power system of  claim 6 , wherein the frequency of the feedback signal is based on the potential difference between the local voltage and the regulation voltage. 
     
     
         8 . The power system of  claim 1 , wherein the regulation device includes:
 a transistor configured to draw a regulation current based on a voltage level of the regulation signal,   a first resistor configured to conduct the regulation current from a first node to a second node, thereby building a potential difference between the first node and the second node, and   a second resistor configured to conduct the regulation current from the second node to the transistor, thereby building the regulation voltage at the second node, and   wherein the frequency of the feedback signal is based on the potential difference between the first node and the second node.   
     
     
         9 . The power system of  claim 1 , wherein the power sensing device includes:
 a Zener diode having a breakdown voltage substantially equal to the predetermined threshold, and configured to draw a breakdown current when the DC input voltage exceeds the breakdown voltage, and   a pull down resistor coupled to the Zener diode, and configured to generate the regulation signal based on the breakdown current.   
     
     
         10 . A communication system for use in conjunction with a gastric band coupled with an implantable antenna for receiving a telemetric signal from a remote control device, the communication system comprising:
 a regulation device configured to generate a regulation voltage at a first node, the regulation voltage based on a margin between a DC input voltage and a predetermined threshold;   a data path arranged in parallel with the regulation device, and configured to adjust the regulation voltage to a set voltage at a second node, the set voltage based partially on an output data sequence; and   a frequency modulation device coupled to the second node, and configured to generate a frequency modulation signal having a modulated frequency corresponding to the set voltage.   
     
     
         11 . The communication system of  claim 10 , further comprising:
 a switch coupled to the frequency modulation device, and configured to generate, at the implement antenna, a modulated amplitude based on the modulated frequency of the frequency modulation signal.   
     
     
         12 . The communication system of  claim 10 , further comprising:
 a third node coupled by the regulation device and the data path; and   a voltage regulator configured to generate a local voltage at the third node, the local voltage less than the DC input voltage and the predetermined threshold.   
     
     
         13 . The communication system of  claim 12 , wherein:
 the regulation device includes a first resistor configured to build a potential difference between the third node and the first node based on the margin between a DC input voltage and a predetermined threshold, and   the data path includes:
 a second resistor coupled to the second node, and 
 a data switch configured to selectively connect the second resistor to the third node based on the output data sequence. 
   
     
     
         14 . The communication system of  claim 12 , wherein the modulated frequency of the frequency modulated signal is based on a potential difference between the local voltage and the set voltage. 
     
     
         15 . A remotely powered and remotely adjustable gastric band system, comprising:
 a remote control device configured to transmit a telemetric signal having an amplitude and a carrier frequency;   an implantable power device telemetrically coupled to the remote control device, and configured to extract power from the telemetric signal and generate a feedback signal having a message frequency based on the extracted power; and   a gastric band for forming a ventral ring surface around a stomach of a patient, the gastric band coupled to the implantable power device, and configured to receive the extracted power from the implantable power device and adjust the ventral ring surface in response to the telemetric signal.   
     
     
         16 . The gastric band system of  claim 15 , wherein the implantable power device includes:
 an implantable antenna for receiving the telemetric signal from the remote control device,   a rectifying device coupled to the implantable antenna, and configured to rectify the received telemetric signal to form the DC input voltage at a DC input node,   a power sensing device configured to receive a DC input voltage and generate a regulation signal when the DC input voltage exceeds a predetermined threshold,   a regulation device coupled to the power sensing device, and configured to generate a regulation voltage based on the regulation signal, and   a frequency modulation device coupled to the regulation device, and configured to generate a frequency modulation signal with a modulated frequency representing the regulation voltage,   wherein the message frequency of the feedback signal tracks the modulated frequency of the frequency modulation signal.   
     
     
         17 . The gastric band system of  claim 16 , wherein the implantable power device includes:
 a switch coupled to the frequency modulation device, and configured to perform an amplitude modulation at the implement antenna, the amplitude modulation adjust the amplitude of the telemetric signal based on the frequency modulation signal.   
     
     
         18 . The gastric band system of  claim 15 , wherein the remote control device includes:
 an external antenna configured to transmit the telemetric signal and receive the feedback signal,   a sensing device coupled to the external antenna, and configured to sense the feedback signal,   a demodulation device coupled to the sensing device, and configured to extract the message frequency from the sensed feedback signal and generate a voltage control signal based on the message frequency, and   a modulation device coupled to the demodulation device and the external antenna, and configured to adjust the amplitude of the telemetric signal based on the voltage control signal and transmit the adjusted telemetric signal to the external antenna.   
     
     
         19 . The gastric band system of  claim 15 , wherein the sensing device includes a directional coupler configured to separate the feedback signal from the telemetric signal. 
     
     
         20 . A method for detecting motor blockage of a motor for use in conjunction with an implantable gastric band, the motor including a motor coil for conducting a motor coil current and a plurality of gears for adjusting an inner ring surface of the implantable gastric band in response to the motor coil current, the method comprising the steps of:
 applying a voltage pulse across the motor coil;   measuring a plurality of transient motor coil currents;   measuring a maximum motor coil current; and   detecting the motor blockage based on the plurality of transient motor coil currents and the maximum motor coil current.   
     
     
         21 . The method of  claim 20 , wherein the detecting includes the steps of:
 calculating a sum of the plurality of transient motor coil currents,   comparing the sum of the plurality of transient motor coil current with the maximum motor coil current,   determining an occurrence of motor blockage if the sum of the plurality of transient motor coil current is greater than the maximum motor coil current, and   determining an absence of motor blockage if the sum of the plurality of transient motor coil current is less than the maximum motor coil current.   
     
     
         22 . The method of  claim 20 , further comprising the step of:
 increasing an output torque of the motor if the motor blockage is detected.   
     
     
         23 . The method of  claim 20 , further comprising the step of:
 reducing a pulse width of the voltage pulse if the motor blockage is detected.   
     
     
         24 . The method of  claim 20 , further comprising the step of:
 increasing a speed of the motor if the motor blockage is not detected.   
     
     
         25 . The method of  claim 20 , further comprising the step of:
 increasing a pulse duration of the voltage pulse if the motor blockage is not detected.   
     
     
         26 . The method of  claim 20 , wherein the:
 the plurality transient motor coil currents are measured during a middle period after an initial period, and   the maximum motor coil current is measured during an ending period after the middle period.   
     
     
         27 . The method of  claim 26 , wherein the voltage pulse includes a first constant voltage pulse applied during the initial period,
 a second constant voltage pulse applied during the initial period and after the first constant voltage pulse,   a third constant voltage pulse applied during the middle period, and   a fourth constant voltage pulse applied during the ending period.   
     
     
         28 . A tangible computer medium for storing instructions, upon being executed by a processor, that cause the processor to perform a method comprising the steps of:
 receiving measurements of a plurality of transient motor coil currents conducted by a motor coil of a motor for use in conjunction with an implantable gastric band;   receiving a measurement of a maximum motor coil current conducted by the motor coil; and   detecting a blockage of the motor based on the measurements of the plurality of transient motor coil currents and the measurement of the maximum motor coil current.   
     
     
         29 . The tangible computer medium of  claim 28 , wherein the detecting includes the steps of:
 calculating a sum of the measurements of the plurality of transient motor coil currents,   comparing the sum of the measurements of the plurality of transient motor coil current with the measurement of the maximum motor coil current,   determining an occurrence of motor blockage if the sum of the plurality of transient motor coil current is greater than the maximum motor coil current, and   determining an absence of motor blockage if the sum of the plurality of transient motor coil current is less than the maximum motor coil current.   
     
     
         30 . The tangible computer medium of  claim 28 , further comprising instructions for executing the step of:
 generating a signal for increasing an output torque of the motor if the motor blockage is detected.   
     
     
         31 . The tangible computer medium of  claim 28 , further comprising instructions for executing the step of:
 generating a signal for reducing a pulse width of the voltage pulse if the motor blockage is detected.   
     
     
         32 . The tangible computer medium of  claim 28 , further comprising instructions for executing the step of:
 generating a signal for increasing a speed of the motor if the motor blockage is not detected.   
     
     
         33 . The tangible computer medium of  claim 28 , further comprising instructions for executing the step of:
 generating a signal for increasing a pulse duration of the voltage pulse if the motor blockage is not detected.   
     
     
         34 . The tangible computer medium of  claim 28 , further comprising instructions for executing the step of:
 generating a signal for applying a voltage pulse across the motor coil during an initial period.   
     
     
         35 . The tangible computer medium of  claim 34 , wherein:
 the measurements of the plurality transient motor coil currents are taken during a middle period after the initial period, and   the measurement of the maximum motor coil current is taken during an ending period after the middle period.   
     
     
         36 . The tangible computer medium of  claim 34 , wherein the voltage pulse includes
 a first constant voltage pulse applied during the initial period,   a second constant voltage pulse applied during the initial period and after the first constant voltage pulse,   a third constant voltage pulse applied during the middle period, and   a fourth constant voltage pulse applied during the ending period.   
     
     
         37 . A motorized gastric band system, comprising:
 an implantable gastric band for forming a loop having a ventral surface for contacting a stomach of a patient;   a motor coupled to the implantable gastric band, and including:
 a motor coil for conducting a motor coil current, and 
 a gear responsive to the motor coil current, and for adjusting the ventral surface of the implantable gastric band; and 
   a processor coupled to the motor, and configured to:
 receive measurements of a plurality of transient motor coil currents conducted by the motor coil, 
 receive a measurement of a maximum motor coil current conducted by the motor coil, and 
 detect a blockage of the motor based on the measurements of the plurality of transient motor coil currents and the measurement of the maximum motor coil current. 
   
     
     
         38 . The motorized gastric band of  claim 37 , further comprising:
 a resistor connecting in series with the motor coil, and configured to conduct the plurality of transient motor coil currents and the maximum motor coil current.   
     
     
         39 . The motorized gastric band of  claim 38 , wherein:
 the resistor has a first resistance,   the motor coil has a second resistance, and   the second resistance is about 167 times of the first resistance.   
     
     
         40 . The motorized gastric band of  claim 38 , further comprising:
 an analog amplifier arranged in parallel with the resistor, configured to measure and amplify the plurality of transient motor coil currents and the maximum motor coil current; and   an analog-to-digital convertor (ADC) coupled to the analog amplifier, and configure to:
 digitize the amplified measurements of a plurality of transient motor coil currents and the amplified measurement of the maximum motor coil current, and 
 deliver the digitized measurements of a plurality of transient motor coil currents and the digitized measurement of the maximum motor coil current to the processor. 
   
     
     
         41 . The motorized gastric band of  claim 37 , wherein the processor is configured to:
 calculate a sum of the measurements of the plurality of transient motor coil currents,   compare the sum of the measurements of the plurality of transient motor coil current with the measurement of the maximum motor coil current,   determine an occurrence of motor blockage if the sum of the plurality of transient motor coil current is greater than the maximum motor coil current, and   determine an absence of motor blockage if the sum of the plurality of transient motor coil current is less than the maximum motor coil current.   
     
     
         42 . The motorized gastric band of  claim 37 , wherein the processor is configured to generate a signal for increasing an output torque of the motor if the motor blockage is detected. 
     
     
         43 . The motorized gastric band of  claim 37 , wherein the processor is configured to generate a signal for reducing a pulse width of the voltage pulse if the motor blockage is detected. 
     
     
         44 . The motorized gastric band of  claim 37 , wherein the processor is configured to generate a signal for increasing a speed of the motor if the motor blockage is not detected. 
     
     
         45 . The motorized gastric band of  claim 37 , wherein the processor is configured to generate a signal for increasing a pulse duration of the voltage pulse if the motor blockage is not detected. 
     
     
         46 . The motorized gastric band of  claim 37 , wherein the processor is configured to generate a signal for applying a voltage pulse across the motor coil during an initial period. 
     
     
         47 . The motorized gastric band of  claim 46 , wherein:
 the measurements of the plurality transient motor coil currents are taken during a middle period after the initial period, and   the measurement of the maximum motor coil current is taken during an ending period after the middle period.   
     
     
         48 . The motorized gastric band of  claim 46 , wherein the voltage pulse includes:
 a first constant voltage pulse applied during the initial period,   a second constant voltage pulse applied during the initial period and after the first constant voltage pulse,   a third constant voltage pulse applied during the middle period, and   a fourth constant voltage pulse applied during the ending period.   
     
     
         49 . A retractable antenna device for a remotely adjustable and remotely powered an implantable gastric band, comprising:
 a housing having a top wall and a bottom wall;   a winding drum disposed within the housing and along the axle, the winding drum having a neck and a base, the winding drum is configured to rotate about an axis between a first position and a second position;   an antenna disposed between the base of the winding drum and the bottom wall of the housing;   a cable configured to coil around the neck of the winding drum when the winding drum is at the first position, and configured to uncoil and substantially extend outside of the housing when the winding drum is at the second position; and   a locking device configured to lock the winding drum when the winding drum rotates from the first position to reach the second position, so that the winding drum remains stationary at the second position.   
     
     
         50 . The retractable antenna device of  claim 49 , further comprising:
 an axle engaging the top wall and the bottom wall along the axis about which the winding drum rotates.   
     
     
         51 . The retractable antenna device of  claim 49 , wherein the locking device is configured to produce a sound when the winding drum is locked. 
     
     
         52 . The retractable antenna device of  claim 49 , wherein a substantial portion of the cable is disposed within the housing when the winding drum is at a first position. 
     
     
         53 . A remote control device for use in conjunction with a remotely adjustable and remotely powered implantable gastric band, comprising:
 a handle;   a display screen having a proximal side and a distal side, the proximal side positioned between the handle and the distal side;   a sensing device configured to determine an orientation of the remote control device by sensing the relative position of the distal side and the proximal side of the display screen; and   a processing device coupled to the sensing device, configured to transmit a display signal to the display screen for displaying an image on the display screen with a first image orientation or a second image orientation depending on the orientation of the remote control device, and configured to adjust the implantable gastric band.   
     
     
         54 . The remote control device of  claim 53 , further comprising:
 a left button; and   a right button,   wherein the processor configured to activate the left button and deactivate the right button when the image is displayed with the first image orientation, and the processor configured to activate the right button and deactivate the left button when the image is displayed with the second image orientation.   
     
     
         55 . A system for rapidly charging a remote control device for remotely adjusting and powering an implantable gastric band via a telemetric coupling, comprising:
 a battery for providing power to the remote control device, and having a battery voltage; and   a charging station for charging the battery, the charging station configured to monitor the battery voltage of the battery, deliver a constant charging current to the battery until the battery voltage reaches a predefined threshold, and deliver a constant charging voltage to the remote control device thereafter to maintain the battery voltage.   
     
     
         56 . A system for remotely adjusting and powering an implantable gastric band configured to be installed around a stomach of a patient, comprising:
 an implantable memory configured to be disposed inside the patient and to store a patient record relatable to the patient and an adjustment record relatable to an adjustment history of the implantable gastric band; and   a processor coupled to the memory, and configured to:
 retrieve the adjustment history upon receiving a telemetric data retrieval signal from a remote control device, 
 generate a signal for adjusting the implantable gastric band upon receiving a telemetric band adjustment signal from the remote control device, and 
 update the adjustment record based on the telemetric band adjustment signal. 
   
     
     
         57 . An implantable gastric band, comprising:
 a tubular member having a first end and a second end, the second end defining an opening, the first end having a flange configured to engage the second end of the tubular member, thereby forming a tubular ring having an adjustable ventral ring surface and a substantially rigid dorsal ring surface;   a skeleton disposed between the adjustable ventral ring surface and the substantially rigid dorsal ring surface of the tubular ring, the skeleton having a distal end pushing against the first end of the tubular member and a proximal end pushing against the second end of the tubular member, the skeleton configured to support the substantially rigid dorsal ring surface of the tubular ring;   a flexible screw slid between the skeleton and the adjustable ventral ring surface, the flexible screw having a hook anchoring the distal end of the skeleton and a crimped end extending beyond the opening of the tubular member, the flexible screw having an outer portion disposed outside of the tubular ring and an inner portion disposed inside of the tubular ring, the inner portion of the flexible screw defining a circumference of the adjustable ventral ring surface;   a motor anchoring the proximal end of the skeleton and engaging the flexible screw, and configured to increase or decrease the inner portion of the flexible screw, thereby adjusting the circumference of the adjustable ventral ring surface;   a processor for receiving an telemetric signal and for controlling the motor; and   a cable having a processor end coupled to the processor and a motor end coupled to the motor.   
     
     
         58 . The implantable gastric band of  claim 57 , further comprising:
 a sheath for encapsulating the processor end of the cable and stabilizing the coupling between the cable and the processor.   
     
     
         59 . The implantable gastric band of  claim 57 , wherein the motor includes a protective sleeve configured to seal the motor and stabilize the coupling between the cable and the motor. 
     
     
         60 . The implantable gastric band of  claim 57 , wherein the flange includes:
 an inner striated surface for engaging the second end of the tubular member; and   a tongue for clipping onto and securing the second end of the tubular member.   
     
     
         61 . The implantable gastric band of  claim 57 , wherein the second end of the tubular element has a marking device visible when the second end of the tubular element is engaged by the flange of the first end. 
     
     
         62 . The implantable gastric band of  claim 57 , wherein the tubular element includes:
 a dorsal arch having a groove configured to align the skeleton element; and   a stretchable sleeve configured to encapsulate a substantial portion of the dorsal arch.   
     
     
         63 . The implantable gastric band of  claim 57 , further comprising a manipulation handle having:
 a base end configured to be coupled with the processor;   a tapered end, the tapered end is substantially narrower than the base end;   a helicoidal body connecting the base end and the tapered end, and having a first thickness adjacent to the base end and a second thickness adjacent to the tapered end, the first thickness is greater than the second thickness; and   a plurality of arrow markers disposed serially along the helicoidal body and pointing towards the tapered end, the plurality of arrow markers.   
     
     
         64 . The implantable gastric band of  claim 57 , wherein the cable includes:
 a plurality of motor wire pairs, each connecting the processor to the motor and including a nominal motor wire and a redundant motor wire; and   a central ground wire surrounded by the plurality of motor wire pairs.   
     
     
         65 . The implantable gastric band of  claim 57 , further comprising a plurality of cushion members positioned along the adjustable ventral ring surface of the tubular ring, each of the plurality of cushion members having:
 a front portion having a convex surface engraved with a plurality of grooves selected from a group consisting of straight lines, curvy lines, and combinations thereof, and   a back portion facing the adjustable ventral ring surface, the front portion.