fig1 and tables 1 and 2 describe the ventilation therapy of the present invention in contrast to conventional therapies . in a main embodiment of the invention a ventilation method is described in which a patient &# 39 ; s respiration is augmented by certain ventilation - oxygen delivery parameters , delivered directly into the trachea with an indwelling percutaneous transtracheal catheter coupled to a highly compact light weight portable ventilation apparatus worn or carried by the patient , subsequently referred to as transtracheal inspiratory - synchronized jet - augmented ventilation ( tijv ). jet pulses of gas are delivered into the trachea in synchrony with the patient &# 39 ; s inspiratory phase . fig1 f and 1 g describe tijv and for comparison fig1 a - 1 e describe the conventional therapies . in fig1 a , hfjv is shown , indicating the patient breathing flow curve 2 at around 20 breaths per minute . the jet ventilator flow curve 1 is asynchronous with the patient &# 39 ; s breath cycle and cycling at a rate of around 60 cycles per minute . fig1 b describes high flow oxygen therapy ( hfot ). hfot gas source flow is applied to the patient continuously as seen by the hfot flow curve 10 . fig1 c describes transtracheal oxygen therapy ( ttot ) and pulse demand oxygen delivery ( dod ) therapy and the respective flow curves 14 and 16 . ttot applies continuous flow 14 to the patient , typically 1 - 6 lpm and dod delivers a low flow pulse oxygen flow 16 during inspiratory phase i . fig1 d describes transtracheal open ventilation ( tov ) in which a mechanical breath 18 is delivered from a conventional intensive care ventilator when a patient breath effort 20 is detected . fig1 e describes continuous positive airway pressure ( cpap ) ventilation in which the lung pressure p of the patient is elevated to the cpap pressure setting 24 . now referring to fig1 f and 1 g , the tijv flow curve 21 is shown to be in synchrony with the patient &# 39 ; s inspiratory phase i and more pronounced than dod . as can be seen by the change in lung pressure due to tijv 25 , the therapy increases the lung pressure in the patient , thus helping the patient &# 39 ; s respiratory muscles and showing that tijv ventilation gas is penetrating deep in the lung . the gas is delivered at a frequency that matches the patient &# 39 ; s breath frequency , typically 12 - 30 cycles per minute , thus at a relatively low frequency compared to hfjv which is typically 60 cycles per minute . a low minute volume of gas is delivered relative to cpap , hfjv and hfot , typically 25 ml - 150 ml per breath , or typically 10 - 25 % of the patient &# 39 ; s tidal volume requirement . the gas source supply flow rate is relatively low compared to cpap , hfjv and hfot , typically 4 - 8 lpm , and the incoming pressure requirement for the ventilator is relatively low relative to cpap , hfjv and hfot , typically 10 - 30 psi . the gas can typically be delivered to the patient without adding artificial humidification as opposed to cpap , hfjv and hfot which requires heated humidification . the gas delivery velocity , typically 25 - 400 meters / second , is fast relative to ltot and dod which are typically around 10 meters / second . the jet effect allows for better penetration of oxygen into the lungs . the relatively fast gas exit velocity also causes a venturi effect at the catheter gas exit point which entrains and pulls into the lung gas volume from above the catheter which is typically 5 - 100 % of the volume delivered by the catheter . this entrained gas is naturally humidified and has a beneficial effect of adding to the mechanically delivered gas to extend the benefit of the therapy but without risking drying the lower airways and without risking inadvertent aspiration of saliva from the mouth or gastric contents from the esophagus into the airway due to the relatively low frequency compared to hfjv . in hfjv therapy , 50 - 75 % gas volume ( as a percentage of the delivered gas ) is entrained from the upper airway but at 60 cycles per minute risking aspiration and compromising speech . hfjv is only useful in acute critical situations . the gas source supply in tijv is typically either a liquid oxygen source ( lox ), a compressed oxygen source , or an oxygen generation source . the system is an ultra compact portable system , lasting typically 2 - 8 hours depending on the size of the gas source , to maximize the mobility of the patient . with the unique tijv parameters therefore , the pulsed gas delivery is designed to augment the patient &# 39 ; s bulk ventilatory gas exchange , assist the respiratory muscles in breathing but without making them lazy , as well as to improve oxygen delivery , thus positively effecting both ventilation and diffusion . in dod therapy , gas is always delivered in slow low volume pulses (& lt ; 6 lpm ) into the airway typically through the nasal route , thus effecting diffusion but not ventilation . thus the invention herein is different from dod therapy in that the gas pulses are delivered in a faster and higher volume pulse and at 12 - 30 lpm volumetric flow rate compared to 1 - 6 lpm volumetric flow rate in dod , and therefore provides both ventilation and diffusion improvement , rather than just diffusion improvement as in dod . it should be noted that conventional volume controlled or pressure controlled icu - type ventilators have the ability to deliver assisted breaths upon sensing inspiration from the patient as described by gregoretti in transtracheal open ventilation ( tov ). however , in tov , the ventilator delivers a full or substantially full mechanical breath to the patient and dominates the patient &# 39 ; s breathing mechanics rather than truly assisting the patient . although not yet described in the medical community , these ventilators could be set to deliver the same pressure or volume as in tijv . however , these types of mechanical ventilators are designed for the patient to both receive mechanical breaths and exhale that breath volume back through the large bore breathing circuit attached to the ventilator . in tijv , there is no exhalation by the patient out through the jet catheter to the ventilator , rather all the exhale gas exits the natural breath routes . if using a conventional ventilator which by design expects to detect exhaled gas exiting the breathing circuit , the ventilator would suspect a leak in the system since there would be no exhaled gas detected and a fault condition would be triggered and the ventilator function interrupted . therefore , conventional ventilators can not be used to deliver tijv therapy . in fact , there would be numerous alarms and ventilator inoperative conditions triggered if attempting to use a conventional icu ventilator to deliver the therapeutic parameters through a small bore ventilation catheter . it is neither clear or obvious how these traditional ventilators could be modified to perform tijv , and as such , a whole new ventilator design is required to perform tijv . further , due to their design , conventional ventilators are inherently heavy , non - compact and not suitable for ambulatory tijv therapy . a key to tijv is that its light weight and small size makes it conducive to ambulatory therapy . ideally , a tijv ventilator , including gas source and battery should be less than 5 . 5 lbs in order for it to be successfully embraced by users . table 1 describes the output of tijv ventilation compared to oxygen therapy devices , indicating the fundamental differences in outputs . in the main embodiment of the present invention , the breathing pattern is sensed for the purpose of timing and controlling the delivery of the tijv augmentation volume delivery pulse . fig2 describes an embodiment of using breath sensors which compensate for drift and artifacts . various sections of the breathing curve are distinguished by analyzing the information from the breath sensors . for example , by taking the derivative of the breathing curve , different sections of the breathing curve can be discerned . for example , the change in sign would indicate the point in inspiration when the inspired flow stops increasing and starts decreasing . or , different points between the start of inspiration and the end of inspiration could be discerned . these different characteristic points can then be used to trigger and time the delivery of the augmentation pulse . fig2 a describes the patient breath flow curve 2 , and a primary breath sensor signal 30 which lags the patient breath flow curve , and a dampened breath sensor signal 32 which lags the primary sensor signal . in fig2 b , the signal delta 34 between the primary and dampened sensor signals is plotted . the delta curve 34 therefore compensates for drift 38 or artifacts 34 that can be present in a typical breath sensing systems as shown in the prior art pressure or flow sensor signal 36 shown in fig2 c which is derived from the typical pressure or flow sensors that are commonly used . fig2 d shows the curve of the first order differential 42 of the signal delta curve 34 . in fig3 conventional ltot is described again , indicating the patient volume curve 43 and the ltot volume curve 44 . fig4 describes again dod showing the patient volume curve 43 and the dod volume curve . dod systems deliver the oxygen to the patient when the breath sensor senses inspiration has started . other than the response time in the system , typically 100 - 200 msec ., the oxygen is delivered as soon as the start of inspiration has been detected . fig4 describes how the present invention is different from the existing systems in that the augmentation volume pulse 50 pulse is more pronounced and can be delivered at any strategic time within the inspiratory phase i . for example , the augmentation pulse can be delivered in the later half of inspiration after the respiratory muscles have produced their work or most of their work which occurs in the initial “ increasing flow rate ” section of the inspiratory curve . when persons are ventilated while the respiratory muscles are working , it is known that these persons can neuromuscularly become lazy and will , over time , let the ventilator do more and more of the inspiratory work , thus weakening the persons inspiratory muscles which is undesirable . the present invention can avoid this problem by delivering the oxygen later in the inspiratory phase when the inspiratory muscles are not working or doing less work . or , alternatively , the augmentation pulse can be delivered early in inspiration . for example , if the patient is under exertion , inspiratory flow is steep at the beginning of inspiration and hence a very early augmentation trigger may be more comfortable , or if the patient is at rest , when the inspiratory flow curve is slow at the beginning of inspiration , a slight delay in the augmentation trigger time might be more comfortable . further , in the present invention the start point of the augmented pulse delivery can be adjusted backwards and forwards in the inspiratory phase as desired , by manual adjustment or by automatic adjustment for example by a feedback from a respiratory parameter . the delivery time is typically 0 . 1 to 0 . 8 seconds , depending on the length of the person &# 39 ; s inspiratory phase and i : e ratio . further , in the main embodiment of the present invention , breath sensors are included on the catheter to directly measure inspiratory and expiratory air flow within the trachea , as opposed to all other prior art systems which if measuring the breathing curve measure air flow or air pressure in the catheter or breathing circuit lumen . both flow directionality and flow amplitude are measured to discern both the phase of respiration and the depth of respiration throughout the entire breathing pattern . prior art systems are only good at measuring the start of inspiration and no other portions of the breathing curve . also , in the present invention , multiple pulses can be delivered within inspiration , the pulse amplitude can be adjusted 52 , the pulse can be moved earlier in inspiration 54 or moved later in inspiration 56 . in addition a secondary lower volume augmentation pulse 58 can be delivered adjunctively to the augmentation volume pulse 50 , or a secondary ventilation gas flow 60 can be delivered adjunctively to the augmentation volume pulse 50 . further in the main embodiment of the present invention , fig5 - 19 describe unique pneumatic drive systems to provide the pressure and flow required for tijv . first , in fig5 a unique lox system is described to provide the pressure and flow required for tijv , including a ventilator 100 , lox unit 110 , lox 112 , lox unit vacuum chamber 114 , lox outlet tube 116 , heat exchanger 124 , heater 120 , check valve 122 , oxygen gas reservoir 128 , reservoir pressure regulator 126 , gas outlet on / off valve 130 , outlet to patient pt and incoming breath signal s . typical lox systems include a liquid phase oxygen compartment and an oxygen gas phase compartment which is continually filled by the boiling of the liquid oxygen . the phase change is catalyzed by a heat exchanger unit . these systems maintain the gas phase compartment at about 23 psi by bleeding gas to atmosphere to avoid pressurization beyond 23 psi . typical medical lox systems have been designed specifically to conserve oxygen and as such their output is relatively weak compared to the requirements of tijv . the compact lox systems which are designed for portability are engineered to deliver gas at very low flow rates (& lt ; 3 lpm ) and low pressures ( below 5 psi ). the larger less portable lox units are engineered for greater flow output however are not realistically suited for active ambulatory patients because of their larger size . the typical systems are capable of delivering oxygen gas at a continuous flow rate of below 4 liters per minute at a pressure well below 23 psi since the pressure in the gas phase compartment drops within fractions of a second when the system is opened to the patient . the gas phase compartment contains typically less than 50 ml of gas and the rate of gas creation by boiling is limited to below 4 liters per minute due to the design and construction of the heat exchanger which is typically less than 20 square inches surface area . gas flow output to the patient is also limited by the size of the orifice in the outlet valve , typically less than 0 . 10 ″ diameter , thus restricting airflow . in the present invention the heat exchanger unit 54 is designed with greater surface area , typically greater than 30 square inches , to produce gas at the rate of 6 - 10 liters per minute and the outlet orifice allows that flow rate output as well , typically greater than 0 . 15 ″ diameter . a heater 56 may be added to increase the rate of production of gaseous 02 . the gas volume of the gas phase compartment is typically above 80 ml and can be 250 ml , which typically includes a pressure regulator 60 , a reservoir 58 , check valve 66 , on / off valve 62 and incoming breath signal 64 . this unique design provides an oxygen gas output flowrate of above 6 lpm at above 20 psi continuously , thus meet the demands of the ventilation parameters required in tijv . the unique lox system includes a catheter and all the requisite sensing components and timing functions described earlier in order to deliver the required volume of gas at the correct pressure and at the correct time of the breathing curve . in fig6 an additional embodiment is shown comprising a , lox system with two pressure settings . one low pressure regulator 126 with a setting of 23 psi to be used when the patient requires less powerful therapy or needs to conserve the lox , and a higher pressure regulator 127 with a setting of for example 30 - 50 psi for increasing the output of the unit when needed or when conserving the lox is not a concern . for example , when traveling on an airplane , the lox system can be - set at the low 23 psi setting , and reset to the high setting after the flight or when arriving to the destination where there is a refill station . the two pressure regulators are configured in a manifold 131 which can be operated by a switch 129 to switch between settings . during flight , the patient can still receive the tijv therapy but at a lower level of augmentation corresponding the to 23 psi setting , but after the flight and when the patient becomes more active again , the augmentation level can be increased because the pressure is set to the higher output setting . two pressure settings are exemplary and it can be any number of pressure settings or even a continuous adjustment of the pressure setting between a minimum and maximum value . fig7 describes an alternate embodiment in which a compressed oxygen gas source is combined with the tijv ventilator features to create an integrated ventilator and gas source unit . the output regulator of the oxygen cylinder has a larger orifice than in a traditional oxygen therapy gas flow regulator , typically 0 . 1 - 0 . 2 inches in diameter , such that the flow output can be boosted to & gt ; 6 lpm and meet the demands of tijv . in fig8 an alternate embodiment to the present invention is shown comprising a unique oxygen generating device which can be used to provide the requisite ventilation parameters . an oxygen generator unit 160 is integrated into a ventilator 100 which includes a pump 162 , a pressure amplifier 164 , a gas reservoir / accumulator 168 , a reservoir inlet regulator 166 , and a reservoir outlet on / off valve 130 . typical oxygen generating devices produce a relatively weak output of oxygen (& lt ; 2 lpm at & lt ; 5 psi ). by increasing the storage capacity and optionally including a pneumatic pressure amplifier , the output can be boosted to 4 - 10 lpm and 10 - 30 psi ., thus powerful enough to meet the pressure and volume needs of tijv . this unique oxygen generator system includes a catheter and all the requisite sensing components and timing functions described earlier in order to deliver the required volume of gas at the correct pressure and at the correct time of the breathing curve as required with tijv therapy . fig9 : in another main embodiment of the present invention , tijv therapy can be accomplished by using a conventional gas source 170 , such as a lox systems , compressed gas tanks , or oxygen generator systems , but with a unique volume accumulator 168 and inlet valve 132 placed in between the gas source and the patient . the accumulator acts as a capacitor and stores a pressurized volume of gas close to the patient . the outlet of the accumulator is relatively unrestricted so that a relatively high flow rate can be delivered to the patient during the augmentation time and therefore meeting the requisite volume and pressure requirements . during the augmentation delivery period , the accumulator is depressurized to the patient through a valve which is switched open and during the non - augmentation time the accumulator is re - pressurized from the gas source by closing the patient valve and opening a valve between the accumulator and the gas source . because the augmentation : non - augmentation time ratio is typically 1 : 2 - 1 : 3 , the accumulator is able to be sufficiently re - pressurized in between augmentation pulses . without the accumulator , the conventional gas supply systems do not have enough flow rate output and / or pressure output to meet the ventilation parameters of tijv . a further benefit to this embodiment is safety ; because of the valve configurations , if a valve where to fail open , only the cylinder volume could be delivered to the patient . this unique accumulator system is accompanied by all the requisite sensing components and timing functions described earlier in order to deliver the required volume of gas at the correct pressure and at the correct time of the breathing curve . fig1 : in another main embodiment of the present invention , tijv therapy can be accomplished by using conventional gas sources ( lox systems , compressed gas or o2 concentrators ), but with a unique cylinder and piston placed in between the gas source and the patient . flow from the gas source 170 flows through an inlet valve 132 into a cylinder 180 , moving a piston 182 while an outlet valve 130 is open to the patient pt and closed to the gas source 170 . a valve ball 183 or similar valve feature prevents the gas source from being directly connected to the patient . the cylinder stores a pressurized volume of gas similar to the accumulator system described previously in order to boost the flow rate to the patient to meet the tijv requirements . in addition however the piston in the cylinder compresses the volume in the cylinder as the gas is being delivered to the patient , therefore reducing the pressure and flow rate decay occurring in the cylinder ( due to the compression ) and therefore boosting the volume delivered to the patient in a given period of time and maintaining peak pressure of the delivered gas for a longer period of time . a further benefit to this embodiment is safety ; because of the valve configurations , if a valve where to fail open , only the cylinder volume could be delivered to the patient . this unique accumulator / piston system is accompanied by all the requisite sensing components and timing functions described earlier in order to deliver the required volume of gas at the correct pressure and at the correct time of the breathing curve . comparison of fig1 b which represents a cylinder 180 with no piston and fig1 c which represents a cylinder 180 with a piston 182 , shows the increase in mean pressure output and volume caused by using the piston . fig1 describes in more detail the jet effect of the invention . a unique catheter 500 is described to deliver the gas to the patient in the appropriate manner . the delivery catheter may include a nozzle 506 or diameter restriction at its distal tip ( the patient end ) located above the carina c in the lumen l of the trachea t . the nozzle is dimensioned so that the exit velocity of the gas is increased creating a venturi effect in the local area around the catheter tip . the venturi entrains air from the upper airway above the catheter and pulls that entrained air 400 into the left lung ll and right lung rl with the augmentation jet flow 21 . thus , the total amount of therapeutic gas provided to the patient is the tijv augmented volume ( va ) 50 being delivered from the ventilator , plus the entrained volume ( ve ) 400 , thus adding to the ventilatory support provided by the va alone . since the ve is pulled from the upper airway , it is naturally humidified and in this manner , tijv can be successful for longer periods of time without adding artificial humidification . further , the exit velocity can be designed such that there is for example 50 % entrainment , so that only half of the therapeutic volume comes from the ventilator , thus doubling the length of use of the portable oxygen supply being used . the jet can be tailored to provide 5 %- 100 % entrainment , and if desired can even cause & gt ; 100 % entrainment . for comparison , the effects of tijv are compared to dod indicating tijv increases entrained volume and reduces patient respiratory rate because the patient &# 39 ; s breathing becomes less strenuous , whereas dod does not effect these parameters . alternatively , as shown in fig1 the nozzle dimensions at the tip of the catheter can be automatically and / or remotely adjustable , for example by moving an inner element or by inflating or deflating a element near the tip id . for example a nozzle restrictor element 510 can be deflated 512 to produce a low jet output and can be inflated 514 to produce a high jet output . or a nozzle restrictor slide 520 can be moved from less restricted nozzle position 522 to a more restricted position 524 to increase the jet effect . in this embodiment the nozzle would be adjusted to alter the percentage of entrained airflow , for example if the patient sensed dryness in the nasal cavity or sensed saliva being aspirated into the trachea , the amount of jet velocity could be reduced without removing the catheter in order to reduce the amount of entrained gas from above the catheter . or if the patient needed more mechanical support then the jet could be increased . the jet adjustment could optionally be done automatically by use of physiological feedback signals . fig1 : in a further embodiment of the present invention , ambient air can be mixed in with the oxygen gas being delivered with a low or no electrical power consuming mixing device . for example , ambient air can be mixed in with the pressurized oxygen by sucking the air in by creating a venturi effect with the pressurized flowing oxygen gas , or air can be added by the appropriate valving , or can be added by check valves in a mixing chamber , or can be added to mixing chamber with a small , low - power consumption pump . for example in fig1 a , a venturi air mixing unit 220 is shown receiving oxygen rich gas 222 from a gas source , a venturi port 225 with check valve 226 for sucking in ambient air 224 . also for example in fig1 b a piston system is shown comprising a piston 182 with check valves 230 such that when the piston strokes 250 to deliver volume to the patient the check valves are closed , and when the piston performs a refill stroke , air enters the chamber through the check valves . air 224 is brought into the cylinder 180 through an inlet valve 132 and oxygen rich ventilation gas 222 is brought into the cylinder through the outlet valve 130 . oxygen rich ventilation gas mixed with air is then released to the patient through the outlet valve . the addition of air into the oxygen gas extends the duration of use of the compact portable system . for example a system using a 1 liter cylinder of compressed oxygen can last 2 hours if the ventilator is delivering augmentation pulses of 100 % oxygen , however if ambient air is mixed in so that the augmentation pulses are 50 % oxygen and 50 % nitrogen , then the 1 liter cylinder can last approximately 5 hours . fig1 : in another embodiment of the present invention a pressure amplification device is used to boost the pressure output of the system to the patient . the ventilator 100 includes a gas source 170 , a pressure amplifier unit 530 , a reservoir / accumulator 168 , on on / off valve 130 , flow to the patient pt and an incoming breath signal s . the pressure amplifier unit includes an inlet stage 540 receiving a drive air pressure 542 and an outlet stage 544 emitting a amplified air pressure 546 . schematically the amplifier includes a gas supply 548 , a filter 550 , a regulator 552 , a gas drive inlet 554 , and a gas supply outlet 558 . incoming pressures from the gas supply can be as low as 1 psi and amplified to 10 - 30 psi ., thus providing adequate pressure and flow to accomplish tijv . alternately , the output of the pressure amplifier can be stored in an accumulator which will boost the volume that can be delivered during depressurization of the accumulator during an augmentation pulse as described previously . the pressure amplifier will allow a relatively weak gas supply such as a small lox system , an oxygen concentrator system , or a low powered electrical air pump to be used for the gas source . the pressure amplifier unit can be pneumatically powered or electro - pneumatically powered . fig1 : in another embodiment of the present invention , multiple accumulators or pistons are used to store and deliver the augmentation volume . the ventilator 100 includes a gas source 170 , an array of accumulators 570 and 572 , with outlet valves 574 and 576 and a main outlet valve 130 to the patient pt . the accumulators or pistons can alternate such that for example a first accumulator or piston depressurizes to the patient for a first augmentation pulse and a second accumulator or piston depressurizes to the patient in the next augmentation pulse . in this manner , each accumulator or piston has a longer re - pressurization time ( twice as long compared to a system with one accumulator or piston ), therefore able to deliver sufficient volume during the augmentation pulse because of starting to depressurize from a higher pressure . this embodiment is particularly useful in fast breath rate situations for example greater than 30 breaths per minute . fig1 : in another embodiment of the present invention , a unique system is described to provide independent control of augmentation volume and augmentation time for delivering tijv , but without using a pressure or volume feedback loop . fig1 a describes the conventional approach of a flow control valve with a needle , 593 , a variable orifice 592 , a valve body 591 , a valve inlet 590 and outlet 594 , a pressure or flow sensor 596 and a feedback adjustment signal 598 . in the invention shown in fig1 b , an array of accumulators 602 , 604 and 606 with check valves 600 and an array of orifices 616 , 618 , and 620 of different sizes are arranged with a valving system 608 , 610 , and 612 and manifold 614 such that any reasonably desired augmentation time and augmentation volume can be delivered by activating the correct combination of accumulator ( s ) and using the correct orifice size . this embodiment allows for independent selection of augmentation volume delivery time and augmentation volume . for example , 100 ml can be delivered in 0 . 2 seconds or can be delivered in 0 . 4 seconds , depending on what is desired . fig1 : in another embodiment of the present invention a piston with a spring is used to amplify volume delivered to the patient . the reservoir / accumulator 168 includes a cylinder 180 , a moving piston 182 , an outlet valve 130 to the patient pt , a pressurization and depressurization outlet chamber 640 , and a spring 232 . the piston strokes in one direction by the cylinder depressurizing through a valve 130 to the patient . a compressed spring 232 on the opposite side of the piston adds speed to the moving piston , thus increasing the cylinder outlet flow rate to the patient . the cylinder then re - pressurizes through the valve 130 and compresses the spring 232 and repeats the cycle for the next augmentation delivery . fig1 : in another embodiment of the present invention , an adjustable volume cylinder is used to modify volume delivery . in this embodiment shown , the piston in the cylinder stokes from side to side and each stroke sends volume to the patient while to opposite side of the chamber on the other side of the piston is re - pressurizing from the gas supply in preparation for the next stroke to the patient . the cylinder 180 includes a moveable piston 182 , inlet and outlet valves on both ends of the cylinder 130 and 132 , a moveable end cap 650 , a thread system 652 used to move the end cap , an adjustment knob and screw 654 , optionally an adjustment drive belt 656 or other drive system , optionally a knob and screw rotational position sensor 658 , and optionally an end cap axial position sensor 660 . the adjustment can be manual , for example by use of the knob and screw to move one end cap of the cylinder inward or outward . the changed volume will affect the volume delivered during the cylinder depressurization because of the changed capacitance of the accumulator . alternatively , the adjustment can be electronically controlled and optionally the adjustment position can be sensed for display or control loop function by use of sensors , 660 or 658 . also , alternatively the same adjustment mechanisms can be applied to the piston embodiments described previously . fig2 : in another embodiment of the present invention , the augmentation pulse can be shaped in a desired waveform . this is accomplished for example by control of the piston stroke speed which can be controlled with a variable orifice on the outlet of the cylinder , or gas source pressure or stoke speed . for example as shown in the graphs the tijv volume 50 can be a sine wave , square wave , descending wave or ascending wave . fig2 : in another embodiment of the present invention exhalation counter - flow is described which will have the effect of reducing collapse of the diseased , collapsible distal airways by giving those airways a back pressure . an increase in exhaled flow 722 and more volume is then able to be exhaled by the patient during exhalation . the exhalation counter - flow can be delivered in a variety of pressure or flow profiles , such as a square exhalation counter - flow flow curve 720 , a short pulse 728 , multiple pulses 732 , ascending or descending profiles 730 and 734 , oscillation 724 , sign wave 726 , or at the beginning or end of exhalation and at high , medium or low amplitudes . the exhalation counter - flow can be delivered by the piston described previously while the piston is stroking in the opposite direction of an augmentation stroke , or it can be delivered by a simple valve between the patient and the gas supply , or by a second cylinder or piston independent of the augmentation delivery mechanism . a catheter 500 is shown in the lumen l of the trachea t . the exhalation counterflow gas exit from the catheter can be non - diffuse 762 to cause a non - uniform velocity profile 760 , or can be diffuse 766 to create a more uniform velocity profile 764 . the gas exit dynamics are adjusted by the gas exit ports on the catheter , a signal port is useful for non - diffuse gas exit and several small side ports are useful for diffuse gas exit . the velocity profile is selected based on the collapsibility of the patients &# 39 ; airways ; for example a more uniform profile is used for higher degrees of collapsibility . the counterflow amplitude can also be adjusted manually or automatically based on a physiological signal such as co2 , exhaled flow , volume change . fig1 : in another embodiment of the present invention tracheal gas insufflation flow 210 can be delivered to create a higher oxygen gas concentration in the upper airway , adjunctively to the tijv augmentation flow 21 . the catheter 50 includes an augmentation flow exit port 502 and an insufflation flow exit port 504 . the insufflation can be delivered at a strategic time during the patient &# 39 ; s inspiratory phase or can be delivered at a strategic time during the patient &# 39 ; s expiratory phase . for example , if insufflation is delivered during the 250 msec of inspiration that precedes the augmentation pulse , then the entrained air sucked into the lung by the augmentation jet will be higher in o2 content . or , if insufflation is delivered during exhalation it can have the effect desired plus also provide exhalation counterflow described previously . the amplitude of the insufflation flow can be adjustable , manually or automatically . fig2 : in another embodiment of the present invention tracheal gas evacuation is used to lower the co2 content in the trachea , which will cause a lower co2 content in the distal compartments of the lung due to mixing and diffusion that will occur because of the concentration gradient . the evacuation flow 780 can be applied during inspiration , exhalation or both and the evacuation profile can be constant , oscillatory , synchronized , sinusoidal , etc ., or can be applied intermittently at a rate and amplitude as determined by biofeedback such as by monitoring co2 levels in the trachea . fig2 : in another embodiment of the present invention , the ventilator can include a non - cylindrical gas accumulators or gas supply reservoir in order to optimize the overall shape of the compact ventilator , since an optimally small ventilator may not accommodate the conventional shape of a gas cylinder . for example the shape can be concave 800 , or an interconnected series of cylinders 802 , or a conduit system 806 . or the ventilator enclosure 804 itself can comprise the gas reservoir or gas supply by having a bilayer casing 805 . in the case shown the ventilator enclosure cross section is bone - shaped , however it could be of any reasonable shape . unorthodox shaped reservoirs are capable of handling the typical working pressure of the invention which is below 50 psi . in another embodiment of the present invention , the ventilator is electrically powered by a manual hand - cranked charging generator unit , either internal to the ventilator or externally connected to the ventilator , ( not shown ). in another embodiment of the present invention the ventilator can receive gas flow and pressure by a manual pneumatic pump system actuated by the user , ( not shown ). in other embodiments of the present invention shown in fig2 - 33 , catheter designs are described which will space the catheter tip in the center of the trachea , so that the tip is not poking , irritating or traumatizing the wall of the trachea , a problem described with other transtracheal catheters . also , stabilizing the catheter tip in the center of the tracheal lumen so that the tip does not whip during the jet pulse is important . whipping , a problem with other catheters , can cause tracheal wall trauma . further , the tip should be directed generally in the direction of the carina c and not towards a tracheal wall w , in order for the augmentation pulse to effectively reach the lower portions of the left lung ll and right lung rl . fig2 : in one embodiment of the invention , a looped catheter with approximately a 360 degree curve 809 , is described which is inserted through a stomal sleeve 808 and contacts the anterior wall aw , spaces it from the posterior wall pw , and spaces the catheter gas exit port 811 in the center of the tracheal lumen l . the catheter lumen beyond the exit port is occluded so the gas can exit out of a the port 811 , or the loop can extend so that the catheter tip points downward toward the carina . the catheter loop is biased so that the anterior section of the loop is always touching the anterior tracheal wall thus assuring that the catheter exit port will be somewhere in the middle of the tracheal lumen . alternatively as shown in fig2 , the catheter can comprise approximately a 450 - 540 degree loop 810 so that the distal tip is directed down toward the carina . in this embodiment it may be more advantageous for the catheter bend to be biased such that there is contract with either or both of the anterior and posterior tracheal wall . this embodiment will also apply a gentle tension on the tracheal wall to help keep it in position , however when the trachea collapses with coughing , the curved catheter will compress with the trachea . fig2 : in another embodiment of the invention a dual cannula design is described with an ostomy or stomal sleeve 808 . the outer guiding cannula 820 removably attaches to the sleeve so that the guiding cannula can be removed and reinserted conveniently . the guiding cannula is especially thin wall , for example 0 . 010 ″- 0 . 030 ″ and is typically made of a braid or coil reinforced elastomer or thermoplastic to resist kinking . the guiding cannula , although semi - rigid , is short compared to the front - to - back width of the trachea and therefore is atraumatic . the inner cannula is the tijv catheter and is dimensioned to fit the id of the guiding cannula snuggly . the tip of the tijv catheter extends beyond the tip of the guiding cannula . the guiding cannula semi - rigidity provides a predetermined known track for the tijv catheter to follow and therefore positions the tijv catheter tip somewhere in the tracheal lumen and not touching the tracheal wall . fig2 : in another embodiment of the invention a shaped catheter design is described which is intended to remain close to the anterior wall of the trachea , thus when the patient &# 39 ; s trachea collapses during coughing or bronchospasm , the posterior wall is not irritated . near the tip of the catheter the catheter makes a gentle anterior bend 842 and posterior bend 843 such that the tip is directed away from the tracheal anterior wall . the stomal sleeve inner flange 922 provides a spacing of the catheter away from the anterior wall in that location . the catheter includes an flange 844 that can be adjustable . alternatively the catheter tip can include an atraumatic spacer that pushes it away from the anterior tracheal wall . fig2 : in another embodiment of the invention a catheter design is described which is comprised of extremely soft material , for example 30 - 60 shore a so that it does not irritate the tracheal wall when it comes in contact with it . the shape of the soft highly flexible catheter is maintained by a rigid filament stiffening member 830 imbedded into the catheter construction , for example a thin stainless steel , thermoplastic or shape memory wire shaped - set into the required and desired shape . fig2 : in another embodiment a catheter is described which is connected to the male connector of a standard tracheal tube such as a short tracheostomy tube 860 or a laryngectomy tube and which includes a protruding or extending sensor 900 which extends through the length of the tracheal tube and into the tracheal airway where the sensor can sense airflow . fig3 : in another embodiment of the invention a catheter design is described that has an anchoring basket 850 to center the catheter in the tracheal lumen . the basket is highly forgiving such that partial or full collapse of the tracheal diameter ( during coughing or spasms ) is not impeded by the basket and any contract is atraumatic . the basket material must be lubricious and rounded so that it does not encourage granulation tissue growth and become attached to the tracheal wall . the basket is typically releasable from a sleeve for easy insertion and removal but can also be easily inserted and removed through the ostomy due to its compliant nature . alternatively , the basket can be an inflatable fenestrated cuff . fig3 : in another embodiment of the invention a catheter design is described which includes a spacer 840 that spaces it from the anterior wall of the trachea . the spacer can be a soft material or a shape memory foam encapsulated in a highly compliant membrane . or , the spacer can be an inflatable cuff . the cuff can be a normally deflated cuff that requires inflation by the user , or can be a normally inflated and self inflating cuff which requires deflation for insertion and removal . the spacer can be a protrusion of the stomal sleeve 808 or the catheter 50 . fig3 : in another embodiment of the invention a shaped catheter design is described which is intended to distend in the tracheal lumen minimally , by being shaped in a right angle or approximately a right angle 864 . this shape allows the tip of the catheter to be directed downward toward the carina , but with a very short catheter length . this shape may be advantageous when the trachea is moving and elongating since the body of the catheter will not be contacting the tracheal walls , unless the trachea is collapsed . the catheter also includes an adjustable flange 860 to set the required depth of insertion of the catheter . fig3 : in another embodiment a catheter is described comprising a compliant and / or inflatable sealing sleeve 870 for sealing and securing the catheter shaft transcutaneously to the ostomy site . the sleeve can be a self deflating or inflating or a manually deflating or inflating design , for example a memory foam encapsulated by a compliant elastomeric membrane with a deflation bleed port . fig3 : in another embodiment a smart catheter is described in which there is a proximal external catheter section 900 and distal internal catheter section 902 which connect to each other . each section contains a miniature device that produces an electrical signature wherein the distal section signature tag 908 is recognized by the proximal section recognition tag 910 . in this manner , different catheter designs for different therapeutic modes can be attached to the ventilator unit , and the ventilator unit will detect which catheter and therefore which mode should be used . for example , a non - jet catheter 904 can be attached and the ventilator can switch to non - jet mode , and a jet catheter 906 can be attached and the ventilator switches to a jet mode . or the electrical signature can track usage time and alert the user when the catheter needs to be replaced or cleaned . or the signature can be patient specific or distinguish between adults and pediatric patients , or to report on therapy compliance . fig3 : in another embodiment a transtracheal catheter sleeve 808 is described for placement in the trachea transcutaneous ostomy site . the sleeve comprises a proximal flange 920 and a distal flange 922 for the purpose of positioning the distal end of the sleeve just barely inside the tracheal lumen and preventing inadvertent decannulation of the sleeve . the distal flange is retractable into the main lumen of the sleeve so that when the sleeve is being inserted into the ostomy the retracted flange 924 is not protruding and the sleeve can assume a low profile for easy and atraumatic insertion . then , when inserted into the trachea , the flange can be deployed by pushing a trocar against the retracted flange or by releasing a release cord 930 which was keeping the flange in the retracted state . fig3 : a sensor arrangement is described which combines negative thermal coefficient ntc and positive thermal coefficient ptc thermistors to detect cooling and heating for the purpose of determining breath flow directionality . the ntc thermistor is especially effective in detecting inspiration ; as the thermistor is cooled by the cooler inspired air , the start of inspiration is detected . the ptc thermistor is especially effective in detecting exhalation ; as the thermistor is heated by the warmer exhaled air the start of exhalation is detected . an external reference thermistor is used to measure ambient temperature . if the ambient temperature is cooler than body temperature which will normally be the case , the arrangement described is used , however if ambient temperature is warmer than body temperature , then the operation of the ntc and ptc thermistors is reversed . each thermistor is paired with a reference thermistor ntcr and ptcr and the signals from each pair of sensing thermistor and its reference thermistor are processed through an electronic comparator , such as a wheatstone bridge 960 with resistors r to complete the bridge , to yield a dampened output signal 952 and 954 that dampens artifacts in the respiratory pattern and drifts that occur because of surrounding conditions . alternatively , the thermistor sensors can be heated by applying a voltage to them such that their resting temperature and resistance is kept at a known constant value . therefore , heating and cooling from inspiration and exhalation is highly predicable when ambient temperature is known . for example , the thermistors can be warmed to a temperature of 120 degrees f . exhalation cools the thermistor less than inspiration and therefore the breath phase can be determined . the thermistors can be arranged on the catheter such that the positive coefficient thermistors are located on the side of the catheter facing exhaled flow , and the negative coefficient thermistors are located on the side of the catheter facing inspired flow , 962 . or alternatively , the thermistors can be spacially arranged in some other strategic orientation such as placing the sensing thermistors such that they are fully exposed to airflow and the reference thermistors such that they less exposed to airflow 964 . in another aspect of the present invention , sensors are included to provide biofeedback for a variety of purposes . for example , the presence of coughing or wheezing or dyspnea is monitored by comparing the measured breathing curve to algorithms in the software . if an exacerbation is detected , a medicant can be delivered , such as a bronchodilator . or , tracheal humidity can be monitored for the purpose of increasing or decreasing the delivered volume so that the lung does not become dry , or alternatively the jet venturi can be increased or decreased to increase or decrease upper airway entrainment , in order to maintain the correct lung humidity or correct ventilation volume . or , patient activity level can be monitored with an actigraphy sensor and the ventilation parameters can be adjusted accordingly to match the activity level of the patient . or the patient &# 39 ; s venous oxygen saturation can be measured in the percutaneous ostomy by a pulse oxymetry sensor placed in the ostomy sleeve or in the catheter and the ventilation parameters adjusted accordingly . or the patient &# 39 ; s tracheal co2 level can be measured with a co2 sensor and the ventilation parameters adjusted accordingly . all these prospective measured parameters can be transmitted by telemetry or by internet to a clinician for external remote monitoring of the patient &# 39 ; s status . fig3 : another potential problem of new minimally invasive ventilation and oxygen therapy modalities is the patient acceptance and tolerance to the new therapy , and the acclimation of the body to the intervention such as a minitracheotomy . for example patients may not want to have an intervention performed unless they can experience what the effect of the therapy will be . or for example , the body may be initially irritated by the intervention , and if the therapy is started immediately after the intervention , the benefit may be spoiled by other physiological reactions . therefore in another aspect of the present invention a novel medical procedural sequence is described , to allow the patient to experience the therapy and to acclimate the patient to the intervention before the therapy is started . the patient is subjected to a tolerance test by using a non - invasive patient interface such as a mask or nasal gastric tube or a laryngeal mask or oropharyngeal airway ( ngt , lma or opa ). in the case of using the ngt the patient &# 39 ; s nasal cavity can be anesthetized to allow the patient to tolerate the ngt easily . tijv is then applied to the patient in this manner for an acute period of time to determine how well the patient tolerates the therapy . also , information can be extracted from the tolerance test to extrapolate what the therapeutic ventilation parameters should be for that patient . after the tolerance test , a mini - otomy procedure is performed and an acclimation sleeve and / or acclimation catheter is introduced into the airway . after a subchronic acclimation period with the temporary sleeve / catheter , for example one week , the therapeutic catheter and / or ostomy sleeve is inserted into the patient and the therapy is commenced , or alternatively another brief acclimation period will take place before commencing the ventilation therapy . if the patient was a previous tracheotomy patient , for example having been weaned from mechanical ventilation , then the tolerance test can be applied directly to the trachea through the tracheotomy . if the patient was a previous ttot patient , for example with a 3 mm transtracheal catheter , in the event the mature ostomy tract is too small for the tijv catheter , then the tolerance test can be administered from the nasal mask , ngt , lma or opa as described previously , or alternatively the tolerance test is performed using a smaller than normal tijv catheter that can fit in the existing ostomy . or alternatively the tolerance test is delivered directly through the ostomy pre - existing from the transtracheal catheter using the same or similar transtracheal catheter , or a transtracheal catheter with the required sensors . then if needed , a larger acclimation catheter and or sleeve is placed in the ostomy to dilate it and after the correct acclimation period the therapy is commenced . fig3 : in another embodiment of the present invention a special catheter is described with a stepped or tapered dilatation section . the catheter can be used to dilate the otomy to the appropriate amount during an acclimation period or during the therapeutic period by inserting to the appropriate depth , or can be used to successively dilate the otomy to larger and larger diameters . the catheter tapered section can be fixed or inflatable . length and diameter markings are provided so that the proper diameter is used . fig3 describes the overall invention , showing a wear - able ventilator 100 being worn by a patient pt , which includes an integral gas supply 170 , battery 101 , volume reservoir / accumulator 168 , on / off outlet valve 130 , transtracheal catheter 500 , a tracheal airflow breath sensor 101 and signal s , as well as an optional exhalation counterflow unit 980 , gas evacuation unit 982 and medicant delivery unit 984 and respective flow output or input 988 , and a biofeedback signal 986 . it should be noted that the different embodiments described above can be combined in a variety of ways to deliver a unique therapy to a patient and while the invention has been described in detail with reference to the preferred embodiments thereof , it will be apparent to one skilled in the art that various changes and combinations can be made without departing for the present invention . also , while the invention has been described as a means for mobile respiratory support for a patient , it can be appreciated that still within the scope of this invention , the embodiments can be appropriately scaled such that the therapy can provide higher levels of support for more seriously impaired and perhaps non - ambulatory patients or can provide complete or almost complete ventilatory support for non - breathing or critically compromised patients , or can provide support in an emergency , field or transport situation . also , while the invention has been described as being administered via a transtracheal catheter it should be noted that the ventilation parameters can be administered with a variety of other airway interface devices such as et tubes , tracheostomy tubes , laryngectomy tubes , cricothyrotomy tubes , endobronchial catheters , laryngeal mask airways , oropharyngeal airways , nasal masks , nasal cannula , nasal - gastric tubes , full face masks , etc . and while the ventilation parameters disclosed in the embodiments have been specified to be compatible with adult respiratory augmentation , it should be noted that with the proper scaling the therapy can be applied to pediatric and neonatal patients .
modes , methods , systems and devices are described for providing assisted ventilation to a patient , including wearable ventilation systems with integral gas supplies , special gas supply features , ventilation catheters and access devices , and breath sensing techniques .