Surgery: light – thermal – and electrical application – Light – thermal – and electrical application – Electrical therapeutic systems
Reexamination Certificate
1999-07-15
2001-02-13
Schaetzle, Kennedy (Department: 3762)
Surgery: light, thermal, and electrical application
Light, thermal, and electrical application
Electrical therapeutic systems
Reexamination Certificate
active
06188929
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates, to device for providing electrical stimulation to tissue, muscles, bones and nerves for producing a therapeutic effect.
BACKGROUND OF THE INVENTION
Electrical devices and methods are known for providing electric stimulation to tissue and cells for desired therapeutic effects such as the type described in Hansjurgens, U.S. Pat. No. 5,573,552 the disclosure of which is hereby incorporated by reference. Generally these prior devices and methods are adapted to stimulate tissue and bone cells to promote healing and the like, to stimulate muscle contractions to provide a therapeutic effect thereto and to stimulate or block the transmission of signals by nerves to, for example, decrease or block pain. Also if heating is desired, the current applied to the tissue can be increased to induce heating of the cells also to produce a therapeutic effect or to destroy cells such as tumors or the like.
A drawback of the devices and methods suggested by Hansjurgens Pat. No. 5,573,552 (the '552 patent) is that their operation is premised upon using a constant amplitude while varying the frequency of the potential applied to the cell or nerve in a predetermined, ramping fashion. As described in the '552 patent, corner frequencies are selected, a lower comer frequency and a higher, upper corner frequency. These comer frequencies are selected to span the frequency (at the constant amplitude) which triggers the desired stimulus response (e.g. muscle contraction) in the tissue or nerve. Thus in most instances the upper corner frequency exceeds the frequency necessary to trigger the desired response. With a constant amplitude, the frequencies are modulated in a linear, ramping, sweeping, fashion between the lower and upper corner frequencies crossing, during their traversal up and down between these frequencies, exceeding the action potential frequency eliciting the stimulus response such as a muscle contraction which may be at, for example, 1500 Hz. It has been found that once a stimulus response has been elicited, that amplitude must be increased or frequency reduced to elicit another response. This phenomena is believed to be based upon the target such as a muscle, becomes conditioned not to respond to the same magnitude of stimulus. Thus the ramping approach described above has worked with a constant amplitude since frequency is varied during the ramping sweep of frequencies to trigger the stimulus response during the sweep and the upper corner frequencies have been selected to far exceed the value necessary to trigger the response. Thus even though the tissue becomes conditioned, the increasing values will ultimately elicit the response.
With reference to
FIG. 1
, there is shown the relationship between tissue impedance A, current delivered B, power C versus frequency. As can been seen the tissue impedance Z has an inverse relationship to frequency, i.e. decreases as frequency increases. Power P and current I have a direct, non-linear, relationship to frequency. For current I, if the voltage remains constant, the reduction in impedance Z with the increase in frequency, increases the current I delivered. Similarly, since power P is the product of voltage and current I, if voltage is held constant the power P will increase proportionately with the current I. Another relationship that is important to understand is that energy is the product of power and the length of time the power is delivered.
FIG. 2
shows the relationship between energy and time for various frequencies. Line D represents, for example, a frequency of 20,000 Hz, line E for a frequency of 10,000 Hz, line F for a frequency of 5000 Hz and line G for a frequency of 2500 Hz.
Because the amplitude of the prior art system as described in the above patent is held constant (frequency is varied), there is no means to control the amount of energy (heat) which would be delivered without altering the lower and upper corner frequencies, i.e. starting points of the ramping sweep, or frequency step (the increase in frequency), frequency sequence or dwell time, i.e. how long the power is delivered at that frequency. Thus, one cannot alter one desired parameter such as energy without adjusting one or more of the other parameters. For example, one could not reduce the amount of energy delivered to consume less power, without, for example, lowering the corner frequencies and thus not, perhaps, obtaining the stimulus threshold required for stimulation of the tissue or nerve.
Furthermore these prior devices do not permit the operator to select a delivery protocol such as one to deliver multiple signals to elicit a stimulus response during a sweep cycle while minimizing the power required. Thus one could not heretofore select during a sweep period that a first stimulus response by induced during a first portion of the sweep, again near the middle of the sweep and again near the end of the sweep while the intervening intervals during the sweep are selected to minimize the power required.
There is a need for a device and method which overcomes the aforementioned drawbacks, which enables the selection of one or more events, such as a stimulation response, to occur during a sweep period and which otherwise selects parameters for the sweep corresponding to a desired, overall, protocol be it conservation of power, heating or the like.
SUMMARY OF THE INVENTION
There is, therefore, provided according to the present invention a multi-parameter bio-electric device for electro-stimulation which includes a data structure storing data at discrete addresses which corresponds to a current frequency and amplitude to be applied for a predetermined period of time, hereinafter referred to as a dwell period. Means are provided for selecting a therapy protocol to be delivered during a sweep cycle. One protocol may be to conserve power. Another may be to deliver heat. The selection means may be embodied as a computer processor at which the user may select between different protocols by using an input device such as a keyboard, switch, dial, mouse or other input device. Means are also provided for selecting at least one of the parameters of frequency and amplitude to be delivered during the sweep cycle. As but an example, the user may select frequencies and amplitudes to elicit two stimulation responses during a sweep period and may select the location and dwell period for the responses over the sweep cycle. A processor is programmed to, in response to the selection of the parameters and protocol to store at addresses in the data structure the frequencies, amplitudes and dwell times. As but an example where the user has selected a power conservation protocol and has selected to deliver signals to elicit two stimulation responses during each sweep, the processor would select and assign to two addresses at the data structure data corresponding to a frequency, amplitude and dwell time sufficient to elicit the desired stimulation response for the desired interval. For time intervals during the sweep between the stimulating parameters, the processor would select frequencies, amplitudes and dwell times to conserve power. During a sweep cycle the processor reads the data stored at the addresses in the data structure and generates signals corresponding thereto. These signals are provided to a frequency and amplitude generator which converts the processor signals into electric current of the corresponding amplitudes and frequencies for the designated dwell periods. Means such as electrodes are provided to deliver the electric current to the tissue to elicit the desired response. According to the preferred embodiment, the sweep data is stored sequentially at the data structure and during each sweep cycle sequentially retrieves the data from the addresses in order and supplies the data to the generator.
The frequency, amplitude and dwell periods for intervals between selected parameters may be randomly selected or preferably are selected to correspond to pre-determined sweep period wave-forms dictated by the predetermine
Anderson Philip J.
Anderson & Morishita, LLC
Schaetzle Kennedy
LandOfFree
Sequentially generated multi-parameter bio-electric delivery... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sequentially generated multi-parameter bio-electric delivery..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sequentially generated multi-parameter bio-electric delivery... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2607885