Taser University of Nebraska Medical Center Safety Technical Eval of the Model Xr5000 Stun Gun
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SECTION IV: p. 1 University of Nebraska Medical Center "'" \ . ," , SAPEn" TECHNICAL EVALUATION OF !'liE BODEL U I. ~2nd and Dewey Avenuf Omah., NE 68105 , 5000 ELECTROHIC -STUll cur IIIlTRODOCTIOR: During the fall of 1984, the Douglas County Nebraska Sheriff's Office sought to gain an independent evaluation of a new electronic defensive weapon known as the Stun Gun. Al though this dev ice is being marketed widely witbout significant restrictions, those responsible for the decision whether or not to incorporate it into the Sheriff's inventory desired answers to certain safety questions about the device which had not been addressed heretofore in manUfacturer's promOtional materials or in other pUblished reports about the device. In addition there are questions which would logically be raised by the public 'if s uch devices were to come into general use by. law enforcement. . Accordingly, the evaluation team set about to find consultative resources with knowledge and experience both in the field of electrical safety and the medical aspects of the interaction of electrical stimuli with biological systems, '- especially human subjects. This report constitutes tbe result of these eval uations. . . : I n ** Please Note: The Electronic cicuitry of the NOVA XR-5000 is identical to that of the TASER system, and is produced under patent license to John H. Cover. This safety study therefore applies directly to the TASER device as well as the NOVA XR5000. , ! i ~t'I"Ls ... W8IiIIIill' ....; I ..... SECTION IV: p. 2 II. LITEJlA'l'ORE REVIEW: A systematic review of the ~e~ical literature vas un~ertaken utilizing the National Library of Me~icine computer search service ~. In a~dition various authors known to b' active in the field of electrical safety and electrical injury vere cross reference~·through the UNMC library's Citation In~ex. Overall approximately 500 articles published between 1975 and the present vere reviewed by title, author or by abstract. Approsimately 20 of these were reviewed in depth. ~e computer search criteiia~we~e adjusted to determine the effect on yield of pertinent articles. When strict criteria were employed, i.e., the combination of ·electric injury·, ·electronic weapons·, and various near modification of these descriptors nQt ~ pertinent article vas recovered. This discovery suggested that there has not been significant reported vork in the specific area covered by this report over the past 10 years. Significant confidence that the search was adequately sensitive was gained when such neighboring topics such as electric therapy, electronic torture and electric eroticism pro~uced numerous. reports. If this new control concept in law enforcement becomes as popular generally as it appears to be regionally, reports of this kind should be welcomed into the .e~ical literature. ~ It should be noted that articles on electrical hazards and electrical safety do not always appear in medical journals. One likely location for such articles would be in professional engineering journals. Author cross referencing appears to have picked up most of these and it is doubtful that there are many of significance which were missed. The particular citations to the literature listed in the sections on and are referenced in the appendis. • SECTION IV: p. 3 ftBORl or OPBRA~IORI ~he stated mechanism for effectiveness of the Stun Gun is related to the interaction of the electrical impulses produced by the device with the nervous and muscular systems. The term "temporary incapacity· is used to describe the effect of the Stun Gun on persons in whom control of their aggressive actions is a primary police objective. Nerve and muscle tissue, although differing rather substantially in certain specific characteristics of electrical stimula are in fact quite similar in the major category of "excitability." 1ion, , which is of primary importance here. Precise differentiation of which of these two types of tissue is stimulated preferentially by the electrical stimulus is made somewhat more difficult in gross laboratory evaluation by the fact that nerves normally activate muscles, therefore a particular muscle contraction in response to a Stun Gun stimulUS, for example, might have been caused indirectly by activation of the motor nerve feeding that particular muscle .and not directly by the muscle itself. It <is a well known principal of physiology dating back to the 1700's and the classical work of Galvani that nerve and muscle ~including heart muscle - can be stimulated to react, each in its own "!Jcharacteristic way, by the application of electrical stimuli of the ~ kind. From this knowledge one can postulate that some electrical stimuli may well be improper and hence ineffective in causing excitation of nerve and muscle. It is reasonable to assume that there is a spectrum of electrical stimuli wbich are in an intermediate zone between very effective and ineffective. Such stimuli may be called "marginally effective" and it is in this category that the output from the Stun Gun generator probably belongs. Electrical energy in small amounts may stimulate tissue to respond normally. Higher energies may stimulate as well as daffiage tissue. ~his damage or injury effect is primarily, although not exclusively, related to the heating effect of electrical current passing through tissue. Specifically, heat production in watts is related to the current in amps squared. Each kind of excitable tissue, nerve, muscle, heart etc., is most efficiently excited by electrical stimuli of quite precise characteristics of intensity (voltage or current) and timing (pulse shape and duration). Deviation from the optimum characteristics in either direction means generally that more electrical energy ~ust be injected to cause the same reaction thereby reducing the efficiency and tending toward thermal injury. 3 SECTION IV: p, 4 Nerves favor brief duration stimuli while heart muscle requires much longer duration impulses to become activated. This is due to the ~uch higher electrical capacitance of heart tissue than of nerve tissue. Since the Stun Gun generates extremely short duration i~pulses measuying only a few ~illionths of a second, one ~ight expect it to be totally ineffective in stimulating heart muscle no ~atter bow intense the stimulus. This is indeed the case. These ultra'short duration impulses ere only slightly effecti ve in stimulating nerves even though the intensity, as measured in terms of peak voltage, may be thousands of times greater than the minimum amount necessary if the stimulus were longer in duration. The extreme brevity of the stimulus pul6e as produced by the electronic timing circuit in the Stun Gun accounts for the fact that even though the pu lses may be of such enOIlIlOUS vol tage so as to cause ionization of the air the production of Ozone and the formation of discharge arcs, the duration of these pulses is so short that only a fe,,' nerves in the close vicinity of the pulse generator ere actually stimulated. Cardiac tissue, normally far removed geographically from the Stun Gun in its customary mode of application, would not and could not be stimulated even if it were in direct contact with the Gun due to the unique characteristic of heart tissue requiring relatively prolonged stimulating pulses for effective sti~ulation. ~ The physiologic principal governing these observations is known as . a -tissue chronaxie-. The principal relates stimulus intensity to stimulus duration and, as noted above, is not constant but varies widely from one tissue type to another. .It may vary from one moment to the next in the same tissue depending on physical and chemical surroundings. The shorter duration an electrical impulse is, the higher its intrinsic frequency components. In the case of the stun Gun the major energy component of the shock pulses are actually in the radio frequency spectrum rather than the audible sound spectrum where most functional nerve and muscle stimuli are located. This welt known and predictable phenomenon results in the so-called skin effect wherein high frequency electrical currents crowd to the surface of an electrical conductor such as the human body and does not penetrate to the nerves and muscles beneath. It is well known, for example, that one may touch a radio transmitter antenna possessing thousands of volts of electrical potential and experience no sensation or muscle contraction at all. The Stun Gun produces some sensation but not of the 6everity as would be expected if its pulses were of longer duration. The relationship between the frequency of stimulation a~d the gross effect on muscle contraction was determined by Dalziel. Although his experiments relate the so called -let go- current to the frequency of stimulation, a somewhat different physiologic situation, the results have the advantage of having been obtained in human subjects. I ~ Ii As pointed out above, very short duration pulses are only marginally effective in stimulating excitable tissue. This is a desired circumstance in the design of the Stun Gun since the region of the body effected by the discharge of the.·puI6es i6 quite l1miteCl and the effect SECTION IV: p. 5 A oproduces n the body no .atter how long the Gun i6 applied h brief. ~he device a brief period of incapacitation and no significant residual effect sucb as burning or damage to ti8sue appears to be possible. The heart is not directly stimulated at all and potentially bazardous subtle or gross rhythm abnormalities of tbe kind associated with accidental electrocution (from a faulty electrical appliance, for example,) is not possible. Furtbermore, tbe energy requirement ~rom tbe Stun Gun supply battery 18 low if tbe sbock pulses are of sbort duration and p'toduced at a low repetition rate. The Stun Gun produces pUlses of sucb brief duration tba~.tbe electrical energy contained in each pulse is only about 0.001 watt-second (Joules). At a pulse repetition rate of 20 pUlses per second wbich is av~ra.ge for the. Stun Gun, tbe amount of energy delivered in a one second·dhcharge to a buman subject (and the amount of energy drawn from the battery which should be roughly equal) would be about 2lwaU-seconds (Joules). A fully charged 8.4 volt NICAD transistor radio battery such as is used in the Stun Gun will effectively deliver about 120 Joules. Tbis would mean the gun can operate for about 2 minutes continuously or can produce about 30 shock bursts of four seconds each. , I ~ .' These performance specifications will vary from day to day and from unit tO,unit depending for the most part on the condition of the battery. The battery, in turn, is dependent on temperature as well as its usage history and its state of charge. The physical and electrical design of the unit is quite straight forward with perhaps one exception, that being the purposeful placement of metal studs transversely across the output terminals. The configuration and spacing of these terminals promotes air breakdown and arc formation when the device is not under a dissipative load. The pulse is generated from a -fly back- type transformer similar to that used in television sets to generate the high electron accelerating voltage for the picture tube. The Stun Gun employs a much slower repetition rate ( 20 pulses per second) than a TV (15,000 pulses per second) and no high voltage rectifier is needed, thereby eliminating several critical and expensive components required of a TV. Furthermore TV set designers go to great lengths to prevent arcing and corona formation into surrounding air - processes which dissipate energy needlessly and create radio frequency interference in the vicinity. The Stun Gun on the other hand promotes arcing by the positioning of the sharp laterally positioned meta~ probes across the output in such a way that an audible and highly visible air discharge occurs for each pulse not dissipated into a subject through the forward facing probes. This -default discharge- is actually necessary for optimum operation of the device since it stabilizes the output between load and no load conditions. question frequently asked is -how is the Stun Gun different from a cattle prod-. These devices are designed to repel animals through the means of electrical shocks. The cattle prod differs in several very important ways other than physical appearance. (See appendix). First the cattle prod is capable of causing tissue injury since its internal or source impedance is much lower than the Stun Gun (so is a fence ~ 5 SECTION IV: p. 6 ~harger as well as is an electronic automobile ignition) and it can ~ause greater amounts of electric current to flow through the body 1n a given tillle than can the Stun Gun even though the Stun Gun's voltage lIIay actually be considerably higher. It is the deep penetration of electric current into tissue which not only stimulates but is potentially hazardous due to the thermal effects .entioned earlier. In addition the duration of the cattle prod's pulses are over 10 times longer than the Stun Gun's and the repetition rate is 10 tillles faster .aking it a very effective tissue stimulator as contrasted to the Stun Gun which, as noted above, is only marginally effective. Purtherlllore tbe longer duration of the cattle prod pulses bring tbelll into tbe range of being able to stimulate the beart directly. Indeed the cattle prod pulse cbaracteristics render if poteqtiallY ~azardous to heart rhythm. However, because of the close electrode spacing (about 1 inch) and the great distance between the prod electrodes and the beart, tbe current flow pattern in the region of tbe beart is very limited in conventional usage. lIIucb larger battery packs required of cattle prods ( 2 amperebour as cOlllpared to tbe Stun Gun's .08 ampere-bour) attest to the major difference between these devices. ~he • 6 SECTION IV: p. 7 '('\.oteDtlal lIecUcal Banrasl ~he Stun Gun is not a medical device. ~he manufacturer makes no claim of diagnostic or therapeutic efficacy about the device. Since no such claim is made tbe device does not fall under tbe jurisdiction of the Device Amendments to tbe Pood and Drug Act - 1976 whicb laws prescribe detailed testing ~f new medical devices before manufacture. Also the PDA imposes strict regulations for quality assurance in the manufacturing process of medical devices. No detailed performance specifications were provided with tbe instrument so tbere is no sillple way short of returning the device to the factory to insure that its~op~rating eb~~~cteristics are being maintained. This presents a potential hazard from the standpoint of a possible performance failure. Although unlikely,.a malfunction might cause a change in the electrical characteristics and result in the output becoming substantially more injurious even though the device appeared to function normally. As pointed out in the preceding section, the Stun Gun's output when operating normally and when used in the prescribed manner is not a significant hazard to normal adults. Impulses delivered to the sUbject's face and especially near the eyes could affect vision and possibly cause eye damage. This possibility was not specifically tested ~n this protocol. I, i Electrically sensitive subjects, those whose heart rhythms are unstable because of being on certain drugs, or on pacemakers, Qr who have recently had chest surgery, or possibly a recent heart attack are a special class of individuals in whom lower than normal electrical currents or possibly even the fright of being shocked with the device could conceivably induce medical problems. Some of these possibilities were tested by creating an electrically unstable circumstance in an /' anesthetized animal and delivering the full output of the Stun Gun directly to the heart muscle by means of an intracardiac st_~X9de _ ~ . Recordings of these trials are included in the appen~i'x. The .. ~ed nO effect on cardiac rln'thm or pumping and only ami Id and transient effect on blood pressure with direct stimulation to the inside of the heart. Surprisingly the surface electro cardiogram only showed a minor shift in baseline during the application of the shocks and a . prompt return to normal when the shocks were discontinued. Increased electrical susceptibility was created in the animals by injection of 1 mg of 1:1000 epinephrine intravenously. A characteristically rapid heart rate and blood pressure rise ensued but the Stun Gun was still ineffective in creating heart rhythm disturbances under tbese conditions of augmented sensitivity. Ordinary pacemaker pulses' delivered under ~ tbese circumstances caused immediate ventricular fibrilation. P/ Another type of enhanced electrical susceptibility that could ~oncieVablY be encountered is in the SUbject with an implanted cardiac , pacemaker. Pacemakers themselves have been reported to be susceptible to certain kinds of electromagnetic interference and even now patients with pacers are warned about the •potential hazards of close proximity to , I !, SECTION IV: p. 8 microwave ovens, mobile radio transmitters and tbe like. Several reports bave described interaction between ignition systems of automobiles and even power lawn mowers with cardiac pacers. In order to test tbe possibility of interference of pacer function Clue to Stun Gun operation an anestbetized anima! was paced with a programmable external pacer using body surface sensing electrodes (see appendix for details). In the ·asynchronous· mode ( no sensing employed) the pacer was immune to Stun Gun shocks virtually anywhere on the animals body. Only wben tbe sbocks were delivered directly to tbe pacer itself did erratic pacing function occur. ~be erratic pacing caused extra randomly placed pacer pulses to'be emitted. For the most part, these were only effective in causing extra heart beats limited to tbe duration of application of the sbock. Following termination of the shocks the rhythm returned promptly to the preshock regularity. Neitber the pacer nor tbe heart appeared to suffer any carryover effects at the conclusion of numerous repetitions of this test sequence. In the inhibited mode (sensing required) aberrent pacer function was noted with stimulation sites virtually anywbere on the animal's body. Altbough this mode of pacer operation is tbe most commonly employed in practice. the degree of susceptibility noted is unlikely to cause serious clinical problems because tbe pacer is most likely to be temporarily ~inhibited and therefore produce few if any pulses of its own during this " . 'I' time. I. time of application of the Stun Gun is usually only a fe" seconds, the cardiac effect of which would probably be unnoticed by the patient and unimportant to the heart rhythm. Furthermore, the sensing electrodes for inhibited type pacers are positioned in the heart, (usually they are the pacer electrodes themselves) not on the body surface in close proximity to the Stun Gun as was the case in this test. Normally implanted pacers should be considerably less susceptible to this form of interference than was exhibited by this test. Finally the chance of encountering a person with a functioning demand pacer among the population of individuals likely to be recipients of Stun Gun discharges is probably less than 1 in 10,000 based on the prevalance of pacers in the popUlation. The likelihood that a serious medical problem would arise in a subject even if be bad a pacer and if the Stun Gun were employed in the prescribed way is probably less than I in 100, making the overall probability of serious consequences less than I in a million, hardly a practical concern when weighing the potential benefit of such effective devices in tbe hands of law enforcement. ~he ~ "Il . One hazard of significance which was observed with the frequent use of the Stun Gun in testing was the phenomenon of operator shock. Under a variety of common circumstances some small fraction of the Stun Gun's output is fed back either through the device internally or across the plastic case externally to the operator's finger on the control switch. This problem was worse in high humidity or when the operator's hands were damp as with sweat. It is much worse if the plastic case becomes contaminated with partially conductive materials, such as salt solutions and the like. SECTION IV: p. 9 n 'the baudl h not one of operator incapacity as would be the case wIth the sUbject but a Wstartle Weffect whIch could cause the operator to lOBe control of the device and pOBlllbly drop i t at a critical time • • 'the problem was solved in the laboratory by simply wearing a surgeon's glove on the operating band. A more practical solution would appear to relate to the basic construction of the device with a moisture barrier over the switch and other cracks and crevices to prevent their becoming an electrical pathway back to the operator's hand. 'the sparks generated by the device are quite capable of igniting certain flammable materials, such as gasoline vapor. Caution should be . ... exercised if such vapors are thought, to, be present. .. ~ 'the device appears to be relatively immune to direct physical abuse withstanding numerous edge drops on concrete from a height of 3 feet. 'the device operate'd at once on removal from a freezer chest where it had been stored for 24 hours. Battery depletion slows the rate of repetitive discharge. This suggests a handy way to determine quickly the residual battery charge. It should be emphasized that conventional transistor batteries are virtually worthless as a power source since their internal impedance is too high to provide the high current necessary to properly operate the device. Proper battery conditioning with the charger according to instructions is imperative. Finally the device was discharged into the mucous membranes of the tongue of an anesthetized animal to ascertain the effects on mucous membranes. Muscle twitching did occur but no visible damage to the membranes was noted. Again, the effect directly on the eye was not tested. Until this is more thoroughly evaluated one should be cautious about the use of this device in the face area. , 9 SECTION IV: p. 10 ~t:O'RICAL , CBARAO'IRIS'l'ICSI following .easurements were aade using e ~echtronic aodel 468 Digital oscilliscope in ASsociation with aodel P 6105 Ilul UpHes Probe's. A specially constructed attenuator with a 1000 aultiplier was employed to record open circuit potentials. ~he a) Pulse wave form 1. No load (arcing) lIIoderately damped sinusoid- '. . , ' Peak to peak voltage approziaetely 1~0,000 V Period between pUlses, 50 milliseconds Pulse decay constant. 2. 0.6 Microseconds Loaded (20,000 Ohms), no arcing Heavily damped sinusoid. " approxi.ately 50,000 V Peak to Peak Voltage Period - between pulses, 50 milliseconds (' Pulse decay constant .. micro seconds• Instantaneous peak current, 20 amperes, each pulse • b) Repetition rate 1. c) Broad spectrum centered about 2 Megahertz on Collins All Band Receiver Average over 1 second,1.2 watts Power consumption from battery 1. f) and unloaded Power production in pulses 1. e) pU1lfes~e~second-b6tn-loaded Electro magnetic radiation 1. d) 20 average over 1 second 3 watts Failure modes 1. Discharged battery to terminal voltage of 6.5 volts or less results in cessation of pulse generation 2. Output shorted - no output, little effect on internal operation 3. Internal spark gap shor~ed 1.0 - no measurable output SECTION IV: p. 11 BOMAR! The SK 5000 Stun Gun was extensively evaluated from the standpoint of electrical safety by subjecting a stock model of the device to various physical and biological testing procedures. The output of the device has been cbaracterized and found to belong to a class of pulse generators known as relaxation oscU latou. Tbe design 1& straigbt forward and famU hr. It takes advantage of some miniaturization tecbniques for tbe size reduction needed for a band held instrument. The output energy is very low even though the measured potential under load is in excess of 50,000 volts. Electrical -skin effect- and certain physiologic cbaracteristics Qf excita~~e tissues make tbe device more effective in stimulating. auperficial nerves tban muscles. Cardiac muscle appears to be completely insensitive to its effects. This finding greatly reduces tbe concern that the use of such a device in a wide variety of unknown subjects may result in untoward cardiac reactions of the kind seen in persons being shocked from faulty household or industrial appliances. In addition to tbe lack of significant electrical bazards, tbe device appears also to be incapable of causing thermal effects such as burns to the skin or otber tissues. The exceedingly sensitive tissue of tbe eyes were not tested bowever and remain as a continuing caution in tbe wide spread use of tbe device. Certain potential hazards sucb as in igniting flammable substances and sbock hazard to the operator were pointed out and discussed. The entire subject of efficacy, the suitability of the device for its intended purpose, was not discussed. These and related subjects are for the most part, psychological and law enforcement matters and are not appropriate in this study. I hope the information presented herein is useful in decisions relating to the acceptance of devices of this kind into law enforcement and in the educational process wbich will maximize effectiveness in the deployment of such devices if tbey are accepted. Robert A. Stratbucker, M.D., Ph.D. SECTION IV: p. 12 APPDDIll INTERNAL CONSTROCTION or STON COil •• I • I . ,i . , ,. ! • - • . , I ! I, ... _. --_ ...• - . _. .. __ . LABELS REFER TO SCHEMATIC DIAGRAM The device is electronically a relaxation oscillator producing approximately 20 pulses per second. Tbe pulses are delivered to a subject from tbe secondary winding of transformer T 2• An internal spark gap G1 is an important part of tbe c Lr cu I try accomplisbing much toe same function as the ingi t.ion points of an automobile distributor. Tbe output pulses are exceedingly narrow and contain much less energy than lI'ost familiar types of spark phenomena including automobile ignitions, fence chargers and the like. I i iLL !iii! ~ SECTION IV: p. 13 APPDDIX TYPICAL CATTLE PROD ------------------- In this model the handle assembly is nearly all taken up with battery storage. The battery capacity is nearly 10 times that of the Stun Gun. Although the prod end has nearly the same dimensions as that of the Stun Gun the output voltage is much lower and no arc develops. The character of the pulses and the lower source impedance of the output result in a much greater and more penetrating current flow pattern than is available from the Stun Gun. l- ; ! Iil. . .....J SECTION IV: p. 14 8CB1KA~IC CIICOI~ . . . - ". '- eo, 20MA.-- 4:7k· c~ ~II P"'St' 6w,tt"! SA VolTS DESCRIPTION '1'he basic circuit is that of a non-linear relaxation oscillator consisting of transitor 01' diodes CRl,-4 and tbe dual primary windings of the oscillator transforller '1'1" Pulses produced in the secondary of '1'~ are applied across a small spark gap inside tbe unit (see pJioto.) When tbe charge across CI capac tor reaches the arc potential of the intenal spark gap, the developing lIIagnetic field in '1'1 collapses suddenly creating a brief bigh voltage pulse across ~be output terminals of ~2. Onder unloaded conditions the high output voltage from the secondary of stepup trans~orller '1'2 causes a spark discharge across the" inner probes of the Stun Gun's output terminals. When in contact with a subject's body the output is sufficiently loaded that the arc potential is not reached although tbe internal spark gap continues to spark and an effective output voltage continues 0 be delivered. '1'his latter pulsatile voltage is the effective -incapacitating output- of the device. " Gl Gl' ( A '1'be circuit appears optimized for maximulll voltage output. It is difficult to imagine any component failures wbich would result in output parameter changes whicb would cause the unit to suddenly become electrically dangerous. Most failure 1II0des which were simulated resulted in the unit failing to function at all. '1'he inherent battery capacity. being as low as it is effectively limits dangerous emissions frolll the Stun Cun under 1II0st component failure seenar Ioe, . 1 SECTION IV: p.15 -, • i • • i • • ,I • • I • . ~_.. ._-_. -... .. Typical external pacemaker used in these experiments. In this series 1 mg of epinephrine solution 1:1000 was injected intravenously and the tracings were done within a minute or so afterward. The purpose oj the study was to investigate the possibility of increased. susceptibility of the heart to Stun Gun impulses in a situation dJ heightened rhythm instability and lowered VF threshold. laMa J Li i 2 22 SECTION IV: p. 16 PHYSIOLOGIC UPElUllEHTS ~he first series of experiments were designed to determine the effect if any of cutaneous stimulation, of an anima~ in the cbest region using the Stun Gun. __ _.~..J ._._ - .. _._ ... _._- .. _." ---_. - - - _ J • . -. _.. - .. , •• • •• • _ . . • • • ~ • . - . -~ -r : . . --- -... _... _.. __... --- ----=...--,--'--_._.. --_..-_.- ..-. . .-- -----. _" .--_ _.- .. -_._ .....--:-_.- --"' - ---' . ...... ..... ..... -. . .. -_. Siur-.; - . -. - " ." " - ' .... . ..- .. '.'-"" _- - .. .- . _ ....... .. - ' $W - ._. . ...... --_ .....••. - " . _.-.- .•.. - -_ - ._-- _.-. .. ~"-" _- ---_ .. _... _.....- .. ' I t-.l~ ~VN A~PLIE'D TO LE"FT 1"'0(.11'1" one notes a regul ar sinus rhythm whicb is encumbered by a small baseline artifact when the Stun Gun is applied to the left chest using electrode paste. Note that the QRS rhythm remains unaltered. SECTION IV: p. 17 , [' (n , • I ~he second series of experiDents involved the use of a paceDaker pulse generator delivering pulses to the right ventricle by ~eans of a bipolar catheter in the right ventricle. ••• • •• .. .-- -_ _-- - . ••••• • , J.. _ _• . -. .. _ ---_..- -- ._---...,-...,-_._--- -. .. -._... ..... . ... ....._.. _- .... _... .- .. • ..._.__0----' ....__ .....• --"--' .._._._._._...--.- ... __...., I :J.-' .. II.-_ ·j~ • •• _. . • • • ----: . -, " " _,_ .. ) • lLa .. _---_ _._. , :t - .- ....•- _-_ -.__._ ' . - . ' .. _.ON _ _ \_~.E... __._._ ._0_' STU cU ~"N--f1~t D T t-f ~O() Q • t4 R'~HT VEN"TR\CLr: IN • ,A: :l This trace shows the pulse generator artifact on the baseline at the left. The intensity was adjusted to determine VF threshold and at the arrow VF was produced. Pulse generator was set at approximately 50 pulses per second• •.. ,- , - _._-. . .. .... ... ..... .. . _.. _-.......... • . · ' .. .... _. ",' '," ·l·.··:.~. , r~',l · ... '~-~-;-~.-'''''- :, ~ 4' . , \ , I ' . .... , I . _ -- .- .. _. . •\ i··----···· "11 &IIt - _. .. "'-t~, ,,' "'-'- _.. ---_._--- ----- .- - - -_ .. _-..,....-- .. -_ .. . ._-- - - --_._. ..---- ,.~., • t. • • "'1 ' ·~~I.:.ltrE-.\t'!.'t::.1 \.".: i: ,'. I ' i~1... ':';:":''';;;'1... ~~;.: i. i~ :i-;-lS"r i 1 i 1.t:::;ri : :\~!. r.,.';7; 7: I, hTf'.-f/:'-{'V-'U'--I!lM . ~ '. ,'. ~-~ --""'---"'.a: .•..•.. .\ ••... a •• ,"' .l:~'ll . . I' •, .. ...... -' 11 " . i; ·:t" . -.. <t" ·_-t·:··· .. ' 1 i·. ""~<~:."~': \ ..N.6.".l.t.Qt"-__ . . " _ ._-_....~ <Tlt i i. 1• .'.--~- . :~ PACfR. ON + STUtU ~JN (s~ e.TI-\R£"~o-...\l) ~ ~ ::j.._~.~.~: --.-;- _·-·-c--- _.-. __ _- _..• :-~·~-:t{f;';t.; ..... .• _ - l.,... l\i\-¥1' .• - ~". :~-=-~~=-=-_.~~-=. ----.- .•. ,,_.__ _ ,-.. _. _._.. -- ..__ ' ...' V'-_" _...t-=. -=- SECTION IV: p. 18 ~he trace below ahow. the blood pre•• ure r ••ponse to the oft.et of ventricular fibrillation 8. produced by the pacer. ARTERIAL BLooD PRFSSU1(E" T VF p,2.00uc.c 0 -------- -----------_. _.- _.,.,.• _------ .. _--_ .. In this sequence the stimulator is increased in amplitude until VP is produced at the arrow in ~raceA. Defibrillation is accomplished with externa 1 paddles and 100 Joules at the point· indicaetd in Trace B. In Trace C the post recovery unstable rhyt\lm is superimposed with Stun Gun activity delivered to the left chest without significant change in rhythm. (nfRACf ( A .. .. ..- - . .. - • .-_. -- ... A'. - --- . _.... _._. - - ----_..... -- •.. - ~ . " 5ve.TA \ I\J 1:0 V. r=:. TRACE" • B "• • • • •• • •• _. .' . . . ... .... ... • • .-.. ) - -- ....__ .... •• I - • • ...,.,.. I .- -.- ... _. -. . .. . -.- I • •• . • . ~ • --_.-_ ..... . .• • . • ., - SECTION IV: p. 19 " 'J'hb ezperbent attempta to demonstrate the lack of effect of Stun Gun Itimulation luperimposed on an unltable rhythm 1••ediately following defibrillation. 'J'he aequence is uninterrupted in time. , i I In trace A a complex rhythm i. hoted Which resulted directly from tbe epinephrine injection. A profound tacbycardia and bypertensive response ensued. 'J'he StUD Gun delivered PUlses to tbe left thorax at the time indicated and no additional rhythm abnormalities developed. T~~_C£_I:\ . .I.. :._ ---- ... -.'.~~.'. _ I .... -'---.-_ ..... -._, ' .... : ..I -- I f.- • ..' .~ ·..I~'11'1'11'..'j""T.,1 ~-"i'I"'''''''I'', /._ ,', 1, r. ,. .-I _ _ . ... ' ._" _. . _._ . . _ . __ .!,_l}"\A'\~.'.l,,. "' .. 1 1.'~'J'.1'.I~" .. ii. UJ';.\':3rl -It I;~ .'to ••I.""i-.'. v" .. _. __ .__ . ..~;,.,." , , . i- : l'v....:.:,lA:v j, J Ju1'Jnr/'.---NO. --, .....,·-·:---,t. --' -. !--~. ·~-4·· ~"'-i'" ': 'r"jJ~ :\.J. ._ r: ,__ ............ _"'. r- 'I I:, · ":\? . .... - ...~, 'V " . -;,. ...!.. ,", . .'y"" ...... --.--.-... __.__, .v V·.lJ' · -- - ._. - -_. ... ... .... _ _ .•. _. _ .. __ . __ _. ; ------.-. _.- ...- ._..... .-... ,.. _... -. --_.. .. . .- ..._ ....._- ._-_.- ·_-_._-'-'-_0_.;---,,- ..._- -- . ..... - _._-_ ...---:----- . - - - -.. o . ----...,..,--,-------,------" ._._-........ __ . .. • 1 . - • . . 1 \ ' \ ' \ . ' • •,\• • • • •\ .. . .0 •• _ • . • _ _ ••• _ ' • • • _ •• _ . ~ I ~.o_·· ~- '" -~,---_._--- (l'fOST E:PI N£p HR I Ne ... RtlYTkH --4,-,'-'-.. . ON " ..-:::r--- --. ---- ----- __ In Trace B the pacer vas adjusted to produce bigemini with the epinephrine effect still veIl in place. This added degree of instability vas not affected by the Stun Gun applied as in 'J'race A• • TRACE" _. • - , 1 . ~ .• , - . . 'V :- . j"I .- o.•_.__ . .. , _ _. . • __ - ~_.o. __ •.. _ _ .. . . • w • 0 I SECTION IV: p. 20 APPBRDII 1. of Medical PhY8iology Sixth Edition 1984 w. B. Saunders' Co., Philadelphia- ~extbook - - 2. Dalziel, C. F. Study of the Hazard8 of Iapulse Currents. ~ran8actions of American Institute of Electrical Engineers Vol. 72 1953 3. Dalziel, C. F. Electric S£ock Hazard IEEE Spectrum, Feb. 1972 ,-0 , ) , ( ' , - '- 4.1...... ..J