Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
  • A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
  • A61N1/328—Applying electric currents by contact electrodes alternating or intermittent currents for improving the appearance of the skin, e.g. facial toning or wrinkle treatment
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
  • A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
  • A61N1/36014—External stimulators, e.g. with patch electrodes
  • A61N1/3603—Control systems
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
  • A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
  • A61N1/3605—Implantable neurostimulators for stimulating central or peripheral nerve system
  • A61N1/3606—Implantable neurostimulators for stimulating central or peripheral nerve system adapted for a particular treatment
  • A61N1/36071—Pain

Definitions

• This invention relates generally to a device for providing an electrical signal to a patient. More particularly, this invention relates to a device for producing accurate, reproducible, program-controlled voltage waveforms, particularly complex intermittent waveforms-. Still more particularly, this invention relates to an apparatus of the type which comprises means for delivering a programmed prescriptive electrical sig ⁇ nal to a patient by direct application of the prescribed signal via electrodes placed on selected elements of the ear or the astoid process or, in the alternative, by radio transmission of a controlling signal to enable a radio receiver located at the point of application to receive the prescribed signal.
• Means are provided for monitoring the signal applied to the patient and comparing it with the pire- scribed characteristics for noting discrepancies and correcting the applied signal. The differences noted are used to correct the original output of the delivery device.
• Stored data representative of the application of a signal to the patient are analyzed and used to improve subsequent programs for application to that patient.
• the signals are applied to the Shen Men or similar low impedance acupoint to optimize the impedance match between the system output and the patient as a conductive medium.
• the waveform is analyzed with respect to frequencies, positive and negative voltage ampli ⁇ tudes, zero net charge, the duration of each particular pulse, the number of pulses in each packet, the time between adjacent packets of pulses, the number of packets in each train, the time between adjacent packets of pulses, the time between trains of packets of pulses, and the number of trains of pulses in a prescription.
• Such synthesized pulse trains eliminate, to the extent pos ⁇ sible, depolarization or hyperpolarization and demyeli- nation of the nerve sheath, conditioning the patient, and provide the maximum opportunity for accurate simulation of the communication protocols of the brain.
• transcutaneous electrical nerve stimulation has been used for applying a signal voltage to a patient by electrodes placed at the site of local pain.
• TENS transcutaneous electrical nerve stimulation
• the resulting afferent sensory signals compete with the pain signals produced by the human, resulting in analgesia.
• PINS percutaneous induced neurostimulation
• Still another analgesic technique involves the use of implanted deep brain probes (DBP) wherein elec- trodes are inserted directly into the brain so that when voltage is applied, analgesia results.
• DBP deep brain probes
• the TENS and PINS processes induce es ⁇ sentially the same mechanism within the human organism. It is known that pain induces electrical signals which are transmitted to the brain through the spinal cord by a combination of electrical conduction and chemical diffusion where the pain signals are interpreted at the brain because of the activities they induce in certain cells. In the TENS and PINS applications, the pain signals are effectively diluted because of the compe- tition induced with the afferent sensor signals produced by the TENS and PINS processes. The dilution of the pain signals effectively relieves the extremity of the pain interpreted by the brain.
• the DBP process is completely different.
• the electrical signals applied directly to the peri-aqueductal grey space within the brain induce additional secretion of beta-endorphins which act to inhibit the reception of the pain signal at the inter ⁇ pretive end (the Raphe nuclear cells).
• the pain signal is blocked from reaching a destination within the brain where it is normally interpreted and analgesia results.
• the DBP processes are unsatisfac ⁇ tory because they require invasive techniques and are generally limited to terminal patients with extraordi ⁇ nary intractable pain. It is desirable to utilize the pain relieving mechanism of the DBP process without the disadvantages of its invasive application.
• Dr. Ifor D. Capel which shows generally that for a set of unique frequencies, the transcranial voltage induces the secretion of beta-endorphins in the brain and leads to the same kind of analgesia as DBP processes.
• Dr. Capel has also shown that a different set of frequencies is effective for treating the pain associated with with ⁇ drawal, as well as treating the physiological symptoms associated with withdrawal.
• Such efforts are the subject of copending United States Patent Application Serial No. 626,335, filed June 29, 1984, the disclosure of which is incorporated by reference.
• Dr. Capel has explored the effect of electrical signals on the mechanisms for neuro-trans- mission within the brain.
• the effect of habituating drugs on brain chemistry and cellular activity is such that both stimulants and depressents cause debilitating effects on such neuro activity which lead to long-lasting physical change and ultimately to deterioration of the cell affected.
• the debilita- ting effect can be reversed to counteract the effect of drugs at the cellular level.
• the application of the' teachings of Dr. Capel are both beneficial and thera ⁇ Panic as an aid to recovery from addiction, from the standpoint of both relief of pain and attention to the physiological changes associated with withdrawal from the use of addictive drugs.
• it is another general object of this inven ⁇ tion to provide a device with the capability of providing prescriptive therapeutic voltage signals of duration, amplitude, frequency, modulation, and intermittency ac- cording to the teachings of Dr. Capel.
• analogue devices for producing wave ⁇ forms suitable for the application of the TENS and PINS processes are known. In general, these devices rely mainly on the use of resonant tank analogue circuitry. However, such devices do not produce signals which are sufficiently reproducible, controlled, and accurate to merchandize as a reliable medical device.
• a method and apparatus comprises means for developing and generating a reliable, reproducible, program-controlled, prescriptive electrical waveform, having a desired therapeutic and analgesic effect.
• the system according to the apparatus comprises a develop- ment station and a control unit for developing and storing a prescriptive waveform of the type described, available for insertion into a personal delivery instru ⁇ ment (PDI).
• PDI personal delivery instru ⁇ ment
• the personal delivery instrument comprises means for receiving and storing the developed prescriptive waveform from the control unit for delivery of an accurately-controlled waveform to the patient.
• the PDI includes a central processing unit, having a ROM and a RAM for programming a voltage source powered by a battery, to provide the desired waveform transcranially to the head of a patient.
• Means are provided for monitoring the signal applied to the patient and comparing it with the prescribed signal characteristics stored according to the prescription from the control unit and by noting discrepancies, cor- recting the applied signals.
• the signal actually applied to the patient and any differences from the prescription are thus recorded for transmission to the control unit for storing data actually representative of the appli ⁇ cation of a prescriptive signal to the patient for subsequent use in analyzing and improving subsequent prescriptive programs for application to that patient or others.
• the PDI includes components for accurately con ⁇ trolling each of the parameters of a train of pulses and for adjusting the signals so that the net voltage charge applied to the patient is zero.
• a set of pulses is referred to as a packet and a train is a set of packets.
• the definition of the waveform includes: (1) the pulse frequency or frequencies f j _, since the prescription may include pulses delivered at more than one frequency, where fj_ is the frequency of the pulses in the _ith packet;
• the prescription may include packets and pulses at dif ⁇ ferent frequencies, where the packets may have different amplitudes and pulse widths.
• the method according to the invention is also dis ⁇ closed discussing a number of internal tests and veri ⁇ fications for security and monitoring.
• Means ' are provided for delivering the signals from the PDI to the patient by leads from a machine attached to the pinnae, ear lobe, mastoid process, or to the Shen Men or other acupoint.
• An alternative means for signal delivery are provided by using radio transmis ⁇ sion of the signal from a separate computerized con- troller-transmitter, containing the patient's program for a particular prescriptive waveform, with reception means worn by the patient. The patient receiver will decode the signal and output the prescribed waveform.
• Fig. 2 is a generalized waveform for illustrating the parameters controlled by the device for achieving an accurate signal prescription for transmission to a pa ⁇ tient and for analysis, where Fig. 2A is a generalized waveform showing a typical wave packet _i of pulses, Fig. 2B is a generalized waveform of a typical train of packets j; Fig. 2C shows a typical prescription of trains J; and Fig. 2D is a chart of the parameters of the prescription delivered by the instrument;
• Fig. 3 is a more complex waveform of the type heretofore applied to a patient capable of being analyzed by the system according to the invention
• Fig. 4 is a drawing similar to Fig. 3 showing the use of the device in analyzing the waveform of the type of Fig. 3;
• Fig. 5 is an exemplary program sequence " for in- putting the prescriptive waveform from the control unit to the PDI;
• Fig. 6 is an exemplary program sequence for moni ⁇ toring the prescriptive waveform delivered from the PDI to a patient;
• Fig. 7 is a " representative drawing showing the application of the prescriptive waveform to the Shen Men acupoint of a patient
• Figs. 8A-8C are block diagrams showing several modes of transmitting the prescriptive waveform to a patient;
• Fig. 9 is a more detailed functional block diagram of the personal delivery instrument of the type shown in Fig. 1; and
• Fig. 10 is a more detailed functional block dia ⁇ gram of a controlled signal generator unit of the PDI. Detailed Description of the Preferred Embodiment
• a transcranial electrical nerve stimu ⁇ lator device and system is generally referred to by the reference numeral 15, for developing and generating a reliable, reproducible program-controlled prescriptive electrical waveform having a therapeutic effect for the amelioration of pain or assistance in ameliorating stress or anxiety related disorders and relieving drug habituation diseases by the transcranial application of the prescriptive electrical waveform to a patient.
• the system comprises a personal delivery instrument (PDI) 16, a control unit 18, and a development station 20.
• the PDI 16 when programmed with the prescriptive electrical waveform, is used to provide current signals trans ⁇ cranially to the head 21 of a patient either by direct connection 22, as shown in Fig.
• the control unit 18 is usable by medical personnel to program the required prescriptive signals in the PDI 16.
• the development station 20 is used to generate compatible data to the control unit 18 and to analyze the results from the control unit 18 and the PDI 16.
• the prescriptive waveforms having the extended therapeutic effects are disclosed in detail in the above-mentioned pending patent application of Ifor D. Capel, while other signal prescriptions have been known to investigators for research on patients or animals in developing acceptable prescriptions. It is contemplated that the device according to the invention is capable of delivering any of such prescriptive waveforms to a pa ⁇ tient, upon identification of the parameters of the waveform, including their sequence.
• the program for that programmed waveform is provided by connection between the PDI 16 and the' control unit 18 through an interfacing connection 17.
• the PDI 16 in ⁇ cludes a delivery control unit 24 having a central processing unit 25, a ROM 26, and a RAM 27 for precisely programming the operation of a pulse electrical source 28 connected to a power source 28a to provide the desired waveform on an output lead 22 connected to the head 21 of the patient.
• Monitoring means 29 are provided for monitoring the signal applied to the patient and comparing it in the delivery control unit 24 with the prescribed charac ⁇ teristics stored therein from the control unit 18 for noting discrepancies and correcting the applied signals. The differences noted are used to correct the original signal output of the personal delivery instrument (PDI) 16 for storing data accurately representative of the actual application of a signal to the patient for analy ⁇ sis, to develop subsequent prescriptive programs, and to improve existing prescriptive programs for application either to that patient or others by returning the stored data on an output 30 to the control unit 18 for inter- facing on lead 31 with the development station 20.
• a developed or modified prescriptive program prepared at the development station 20 may be transferred by the interface 19 to the control unit 18, or to a plurality of such control units located at a number of locations, such as hospitals.
• the control unit 18 also operates with respect to the PDI 16 to perform a number of additional functions.
• the control unit 18 thus may reset the PDI 16 to prepare it for reception of a new prescriptive program, inter ⁇ rogate for current operational conditions and errors, perform appropriate internal verifications, communicate selected applications to the PDI in simple or encrypted format, verify the correct- receipt of the prescriptive program by the PDI 16, communicate a current time, and request statistics from the PDI 16.
• the PDI 16 after communication of a series of instructions from the control unit 18, outputs an electrical signal, the basic component of which is a pulse having a frequency, shape, duration, amplitude, and number, each of which is programmable. It is a feature of the PDI to provide an output where the time average of the current passing between the two output electrodes is zero.
• the PDI 16 may also be programmed to provide either a low frequency or a high frequency sequence wave modulation to the output pulse, acting to turn on or off the output pulse so that the output pulse becomes a modulation envelope for the HF modulation.
• the presence and frequency of modulation are also programmed into the device 16, as is the time to traverse from zero to nominal amplitude (i.e. ramp time) .
• the system 15 has the advantage of using currently available devices. For example, for the PDI, a 146805
• CMOS microcomputer may comprise the CPU 25, interacting (acting as a signal source) with a byte wide CMOS RAM 27 and EPROM 26, a programmable D/A converter with low power operational amplifiers to generate the output signal, and CMOS LSI logic.
• the control unit 18, for compati ⁇ bility, may utilize a 16 bit computer with floppy discs to store the program sequence parameters to insure media compatibility with the development station 20.
• the development station may comprise a personal computer compatible with accompanying accessories for utilizing stock software readily available for laboratory analysis and report generation.
• a significant feature of the invention resides in its precise control of each of the particular parameters of a wave train applied to a patient according to the prescription.
• Fig. 2 is a generalized depiction of an electrical waveform for analyzing a train of pulses comprising a plurality of irregularly spaced packets of pulses wherein the pulses in each packet are also controlled.
• the PDI 16 includes a pulse profile controller which produces a waveform, the com- ponents of which are shown respectively in 2A, 2B, and 2C.
• a typical wave packet i of pulses at a frequency £__ are shown having a positive amplitude Ap, a negative amplitude A n , a positive pulse duration Sp, and a negative pulse duration S n , for a representative example of a packet _i, where the number n of pulses is three.
• the pulse frequency f __ may vary either within a packet _i or between adjacent packets so that the prescriptive waveform in ⁇ cludes a specification of the pulse frequency or fre- quencies fj_, where fj_ is the frequency of the pulses in' the i_ packet.
• the PDI 16 delivers a pulse having a positive pulse amplitude A p . for each pulse in each packet of each train forming the prescription. While Fig. 2A shows positive and negative pulses A p , A n , of approximately the same respective amplitudes, the amplitudes may vary between adjacent positive or negative pulses if the prescription so re ⁇ quires. Similarly, the PDI 16 produces a waveform which includes a specification of the positive pulse duration Sp. for each pulse in each packet of each train forming the prescription, and the negative pulse duration S n .
• the PDI 16 also delivers a train j of packets i_ of pulses of the type shown in Fig. 2A.
• the PDI 16 thus also controls the respective times between the delivery of adjacent packets where the time between the first packet and the second packet, for example, is noted by ]_t2 so that for a generalized case, the instrument delivers packets at the time ( j_ _ i ) t__ for packet _i.
• the instrument 16 also delivers a prescription of trains J of packets i_where the time between adjacent trains is controlled according to the generalized expression (j _i ) Tj, where the time be ⁇ tween respective adjacent trains during the prescription by vary.
• the entire prescription includes M trains and N packets in the prescriptive train j.
• the instrument 16 is capable of de ⁇ livering a prescriptive program waveform defined by the parameters shown in Fig. 2D under the conditions wherein the product A p S p is equal to A n S n to deliver zero net charge.
• Fig. 3 is a more complex waveform which may also be analyzed according to the application of the tech ⁇ niques of the invention. Because the prior art devices for applying TENS signals to patients tended to output a signal like that shown in Fig. 3, this particular wave ⁇ form is of special interest to investigators.
• Such a waveform 33 can be analyzed by the instru ⁇ ment of the invention by inputting it or a reproduction of the waveform to the monitoring means 29 to produce a program for determining by approximation its constitu ⁇ ents as shown in Fig. 4.
• the investigator has a common basis for comparison of new prescriptions with former applications.
• Fig. 5 is a program for transferring the signal prescription from the control unit 18 to the PDI 16.
• the patient identification such as name and code number
• a brief description and other identifying data concerning the patient profile are input in steps 36 and 37.
• the patient code is checked for accuracy against a user identifi ⁇ cation for security in step 39 and, if incorrect, the prescription will not be loaded from the control unit 18 into the PDI 16 and the program returns to the input step 36.
• the treatment code is input in sequence 38 ' containing the prescription for a precise wave train to be applied to the patient. As will be seen, more than one prescription may be applied to a patient.
• the prescription is provided by sequentially inputting the frequency, the amplitude A p , of the posi ⁇ tive pulse, the sequency S p . of the positive pulse, the amplitude A n . of the negative pulse, and the duration S n . of the negative pulse in steps 40, 41, 42, 43, and 44.
• steps 45 the product of Ap.S p . is calcu ⁇ lated and the product A n .S n . is calculated, the calcu- lated products are compared to provide a net zero cur ⁇ rent, and a correction signal is input in step 45a.
• An appropriate final check may be made at step 52 to insure complete delivery of all prescriptive com- ponents, if desired.
• Fig. 6 is a block diagram of a representative se ⁇ quence for checking and correcting the prescription delivery.
• the system is commanded in step 57 to perform a sequence of internal delivery service checks of the battery in sequence 58, of the RAM in sequence 59, of any other appropriate components 59a, and of the circuit by monitoring the circuit using test voltages in step 60.
• Step 55 may include checks on whether the electrodes are open, loose, or closed, sta ⁇ tion power delivery is appropriate, and other prelimi ⁇ nary confirmation tests.
• a correction signal is given and the zero level reset (for zero net charge) is also periodically provided, preferably after each pulse, especially for low frequency transmission. If the signals are within accepted norms, the delivered data to the patient are then recorded for subsequent transfer to the control unit 18 and for use at the development station 20 for analysis.
• Fig. 7 shows a portion of the ear of a patient illustrating application of the electrodes 22 to the Shen Men acupoint on the ear of a patient.
• electrical signals of other processes were delivered to a patient by direct application of the prescribed voltage through electrodes placed on selected elements of the ear or the mastoid process.
• the precisely con ⁇ trolled prescriptive electrical signals according to the invention are applied to the Shen Men or other acupoint of the ear. It is believed that the application of the prescriptive signals at this point will optimize the impedance match between the output of the system 15 and the patient as a conductive medium.
• FIG. 8A contemplates a delivery control unit 24' miniaturized to be worn by the patient or further minia- turized to become a part of a non-invasive application appearing similar to a hearing aid or eyeglasses with enlarged ear lobes.
• the control unit 18' similar to the control unit 18, is connected to a RF transmitter 102 for transmitting all of the signals for loading and applying the prescriptive waveforms to the unit for reception by an RF receiver 104 connected to the delivery control unit 24'.
• the delivery control unit 24' may be loaded and the prescriptive electrical signal delivered at the patient.
• Such radio transmission may require additional security coding to prevent erasing a preloaded delivery control unit 24'.
• the delivery control unit 24' may comprise a cassette or cartridge preloaded with the prescriptive electrical signal from a control unit 18' to be activated by a secured RF transmitted signal. Either of the foregoing embodiments permits a patient significant increase in freedom of movement while undergoing treatment.
• Fi x . 8B is representative of an embodiment where- in a control unit 18' and a delivery control unit 24' operate as described in connection with Fig. 1 but where the prescriptive waveform is transmitted by an RF trans ⁇ mitter 102" to be received by an RF receiver 104' at the patient in a suitable patient device 105, such an ear piece or radio receiver.
• the RF transmitter/receiver pair may com ⁇ prise a pair of transceivers suitably secured for two-way communication of the transmitted and monitored data.
• Fig. 8C is similar to Fig. 8B wherein the patient device is an implant 105a to illustrate an embodiment wherein the prescriptive waveform is radio transmitted to an implanted receiver at the patient to achieve the desired therapeutic effects.
• Fig. 9 is a functional block diagram of the PDI 16 according to its presently preferred embodiment for incorporation in a portable desk top unit.
• the principles of the invention may be embodied in a device sized to be portable with the patient as in Fig. 8 while receiving the applied signal characteristics, such as discussed in connection with Fig. 8.
• the embodiment.of Fig. 9 is designed to provide the electrical signal characteristics of the type des- cribed, the power requirements, memory requirements, display, key board, connectors and operational require- ments to achieve the intended purposes of the invention.
• the output current pulse characteristics provided by the unit include a zero cumulative current with a positive 35 milliamp peak output current programmable throughout the range of zero to maximum current with limitations on the maximum output current for patient safety.
• the fre ⁇ quencies of the pulses are provided in a range of 0.5 hz to 500 hz with a one percent deviation or less from optimum throughout the range of primary interest in implementing the waveform prescription according to the aforementioned identified patent application.
• the fre ⁇ quency range and pulse shape are programmable and pro ⁇ vided with a 100 microsecond sampling interval, for example.
• the modulating wave may be provided in a suitable range, for example, 5.0 Khz to 100 Khz for high frequency modulation, whereas low frequency modulation of the output current pulse is selectable in predetermined time increments, such as 0.1 minutes, up to 20 minutes, on an on/off basis.
• the ramp time exhibited by the wave pulses i.e. the time lapse necessary to change from zero to the programmed output current
• the unit exhibits load characteristics approxi- mating 10000 ohms in parallel with a 0.05 microfarad capacitance.
• the unit is preferably powered by an internal dual power supply having both a battery and a backup to insure data retention in the case of power failure. A data retention feature is also provided as will be discussed.
• the internal clock is accurate to 0.1 percent.
• the display is preferably a one digit LED display capable of generating numbers zero to nine while the keyboard is preferably a one button unit.
• the speaker for emitting audible warning signals, may generate audio signals as desired, for example, from two seconds to five minute increments.
• Connections of the PDI 16 to the patient are provided by conventional plugs and jacks and, as described, the unit is capable of a self-test sequence, a main line sequence, and data moni ⁇ toring storage sequencing. As described, the unit is capable of generating current pulses of defined ampli ⁇ tude and duration, with high frequency and low frequency modulation ranging from .05 hz to 500 hz according to the program stored therein according to the waveform pre ⁇ scription discussed in connection with Figs. 1, 2, and 5. The self-diagnostic sequence for the unit has been dis ⁇ cussed in connection with Fig. 6.
• the unit is intended for operation over a five hour period so that current pulses on the order of or less than 10 milliamps provided to a 10 K ohms load require a 0.1 watt signal permitting selection of a battery source to meet the operating parameters.
• the PDI 16 comprises a plurality of functional modules.
• the controller 80 provides for the timing and control of all ' of the units and acts as an interface between any two modules.
• the display numeric module 81 is used as a status indicator, while the keyboard module 82 is used to command data input to establish the program sequence described in connec ⁇ tion with Fig. 5.
• the alarm module 83 may be actuated as described in connection with Fig. 6 to obtain operator attention, as described in connection with step 61.
• the alarm module not only functions as an alarm, but also monitors the time between activities and the start ⁇ ing and stopping time to associate the data generation with the status of the patient.
• the program storage module 84 and the data storage module 85 respectively store the electrical signal prescription and self-test schedule in the program storage module 84 as well as the results of the tests and signal schedule in the data storage module 85.
• the battery indicator module 86 monitors the conditions of the battery source in the system to provide an indication when the battery needs changing, while the 10 port module 87 outputs the gathered data and receives the inputs of the new program sequences.
• the signal generator module 87 generates the electrical signal prescription with the signal duration and waveform cre ⁇ ated according to the discussions of Figs. 1 and 3 by the program sequence.
• the PDI 16 as shown in Fig. 9 is capable of performing program scheduling, signal genera ⁇ tion, self-testing, data output, and battery charging or changing. Each of those modes has been described in connection with Figs. 1-8 " above.
• the controller 80 may control an 8 bit CMOS microcomputer of a single chip design to permit signal generation at random time intervals and to inter ⁇ face between different modules.
• the controller 80 may include the CPU, ROM, and RAM capabilities discussed in connection with Fig. 1.
• the display module 81 preferably comprises an LCD character generator driven by a 4 bit word from the micro ⁇ processor in the controller 80. That signal is converted to proper format and multiplexed to drive the LCD, as is known in the art.
• a 32 Khz clock is used to drive the generator.
• the clock chip preferably contains an on-chip oscillator to generate the multilevel waveforms.
• the signal generator module 87 is shown in greater detail in Fig. 10.
• the signal generator comprises an 8 bit D to A converter 90 to obtain the needed voltage levels, connected to operational amplifiers 91.
• the microprocessor in the controller 80 will program the D to A unit 90 to provide current at the desired levels.
• the output levels from the D to A converters is thus fed into the two operational amplifiers to generate a electrical differential at the output.
• a bipolar signal from the operational amplifiers can generate current flowing in either direc ⁇ tion through the electrodes 22, connected to terminals El and E2.
• the binary numbers are selected to generate the pulse or inverse current signal with an 8 bit resolution.
• the microprocessor control unit selects the binary number determined by the software.
• the 10 module 87 controls all of the input and output activity of the PDI.
• the output comprises a plurality of signal channels for output of status information and input of programming sequencing, two of which are dedicated to the use of electrodes and another of which is for recharging-, if a recharge cable battery is selected.
• the invention may be embodied in other specific forms without departing from its spirit or essential characteristics.
• the present embodiments are, there ⁇ fore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the claims rather than by the foregoing description and all changes which come within the meaning and range of the equivalents of the claims are therefore intended to be embraced therein.

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• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• Veterinary Medicine (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Radiology & Medical Imaging (AREA)
• Public Health (AREA)
• General Health & Medical Sciences (AREA)
• Biophysics (AREA)
• Heart & Thoracic Surgery (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Plastic & Reconstructive Surgery (AREA)
• Pain & Pain Management (AREA)
• Neurology (AREA)
• Neurosurgery (AREA)
• Measurement And Recording Of Electrical Phenomena And Electrical Characteristics Of The Living Body (AREA)
• Electrotherapy Devices (AREA)

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• 1985
  • 1985-10-18 WO PCT/US1985/002045 patent/WO1986002567A1/en not_active Application Discontinuation
  • 1985-10-18 AU AU50623/85A patent/AU5062385A/en not_active Abandoned
  • 1985-10-18 EP EP19850905463 patent/EP0202258A4/de not_active Ceased
  • 1985-10-18 JP JP60504824A patent/JPS62501192A/ja active Pending
• 1986
  • 1986-06-24 KR KR1019860700382A patent/KR870700375A/ko not_active Application Discontinuation

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