US 5,429,123 AGranted

Process control and apparatus for ventilation procedures with helium and oxygen mixtures

AssigneeTemple University of the Commonwealth System of Higher Education

InventorsThomas H. Shaffer, Marla R. Wolfson

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Abstract

A process is provided for controlling a ventilation procedure wherein a heliox ventilation system passes a breathing medium through at least a portion of a patient's pulmonary pathways. In this process, desired ranges for certain process parameters associated with the heliox ventilation system are established. These desired ranges are input into a signal processor. Initial settings for the heliox ventilation system are then made such that the actual conditions which will initially occur during the heliox ventilation procedure fall within their respective desired ranges. Thereafter, the heliox ventilation procedure is commenced. During the heliox ventilation procedure, conditions which relate to the established ranges are continually monitored by appropriate sensors. The monitored information is also input into the signal processor. The signal processor is designed to compare the actually-occurring monitored conditions to their respective desired ranges and determine if there is a difference therebetween. If there is a difference, the signal processor generates signals which are designed to correct the discrepancy. These signals can be designed to trigger alarms which instruct an operator to make the appropriate adjustments and/or to activate a servo-controlled valving network. By practicing this invention, it is possible to maintain proper oxygenation levels in a patient ventilated with a heliox ventilation system while minimizing lung compliance and lung resistance levels.

Claims12

Dependent claims

A process for guiding, monitoring and regulating a heliox ventilation system wherein said ventilation system is designed to circulate a breathing medium comprising gaseous helium and gaseous oxygen through at least a portion of a patient's pulmonary pathways, and wherein said heliox ventilation system includes a gas mechanics circuit component, a gas concentration circuit component and a temperature/humidification circuit component, said process comprising the steps of:

(a) establishing a set of desired ranges for process parameters associated with the gas mechanics circuit, the gas concentration circuit and the temperature/humidification circuit components of said heliox ventilation system, said set of established desired ranges are represented by a first set of signals;
(b) inputting the first set of signals in to a signal processor,
(c) making initial adjustments to the gas mechanics circuit, the gas concentration circuit and the temperature/humidification circuit components of said heliox ventilation system, said initial adjustments are such that actual conditions of said heliox ventilation system's gas mechanics circuit, gas concentration circuit and temperature/humidification circuit components, which occur while a breathing medium circulates through at least a portion of the patient's pulmonary pathways, fall within the purview of their corresponding established desired ranges, said initial adjustments establish the patient's initial ventilatory profile;
(d) preparing a breathing medium comprising gaseous helium and gaseous oxygen;
(e) circulating the breathing medium through at least a portion of the patient's pulmonary pathways in accordance with said initial adjustments made to the gas mechanics circuit, the gas concentration circuit and the temperature/humidification circuit components of said heliox ventilation system;
(f) monitoring a set of actual conditions of said heliox ventilation system's gas mechanics circuit, gas concentration circuit and temperature/humidification circuit components which occur while said breathing medium is circulating through at least a portion of the patient's pulmonary pathways, said monitored set of actual conditions correspond with said set of established desired ranges, and said set of monitored actual conditions being represented by a second set of signals;
(g) inputting the second set of signals into said processor;
(h) implementing said signal processor to determine whether said second set of signals fall within the purview of their corresponding ranges represented by said first set of signals, instances wherein said second set of signals fall outside of said first set of signals are represented by a third set of signals;
and
(i) implementing said third set of signals to manipulate said initial adjustments such that said second set of signals fall within the purview of their corresponding ranges represented by said first set of signals.

7 more elements

A ventilator system for blending a mixture of at least gaseous helium and gaseous oxygen to form a helium-oxygen blend and for automatically controlling the administration of the helium-oxygen blend into at least a portion of a patient's pulmonary air pathways such that physiological homeostasis is maintained, at reduced lung pressures and resistances, within the patient with respect to helium-oxygen blend gas flows, gas volumes and gas pressures, with respect to helium and oxygen concentrations in the helium-oxygen blend, with respect to heat exchange and humidification means between the helium-oxygen blend and the patient, and with respect to the patient's body temperature during ventilation, said ventilation system comprising:

(a) gaseous helium pressure control means for providing a pressure regulated source of gaseous helium;
(b) gaseous oxygen pressure control means for providing a pressure regulated source of gaseous oxygen;
(c) blending means designed to blend gaseous helium and gaseous oxygen together to form a gaseous helium-oxygen blend;
(d) helium flow control means for controlling the rate at which gaseous helium flows into said blending means, said helium flow control means being in gaseous communication with said helium source and said blending means;
(e) oxygen flow control means for controlling the rate at which gaseous oxygen flows into said blending means, said oxygen flow control means being in gaseous communication with said oxygen source and said blending means;
(f) respiration receptacle in gaseous communication with said blending means and at least a portion of a patient's pulmonary air pathways;
(g) temperature adjusting means for controlling the temperature level of the helium-oxygen blend within said respiration receptacle;
(h) humidification adjusting means for controlling the humidity level of the helium-oxygen blend within said respiration receptacle;
(i) helium-oxygen blend flow control means for controlling the rate at which the helium-oxygen blend flows into said respiration receptacle;
(j) inspiration volume control means for controlling the volume of said helium-oxygen blend inspired during the inspiratory portion of a patient's breathing cycle;
(k) expiration volume control means for controlling the volume of gas expired during the expiratory portion of a patient's breathing cycle;
(l) first means for selecting a desired concentration of gaseous helium in said helium-oxygen blend as said helium-oxygen blend is in said respiration receptacle and generating a first signal having a value indicative of said desired helium concentration in said helium-oxygen blend;
(m) second means for selecting a desired concentration of gaseous oxygen in said helium-oxygen blend as said helium-oxygen blend is in said respiration receptacle and generating a second signal having a value indicative of said desired oxygen concentration in said helium-oxygen blend;
(n) third means for selecting a desired helium-oxygen blend flow rate from said respiration receptacle into at least a portion of the patient's pulmonary pathways and generating a third signal having a value indicative of said helium-oxygen blend desired flow rate;
(o) forth means for selecting a desired temperature level of said helium-oxygen blend prior to said helium-oxygen blend being inspired by the patient and a fifth means for selecting a desired temperature level of said gas being expired by the patient, said forth means generates a forth signal having a value indicative of said helium-oxygen blend desired temperature level and said fifth means generates a fifth signal having a value indicative of said expired gas desired temperature level;
(p) sixth means for selecting a desired humidification level of said helium-oxygen blend prior to said helium-oxygen blend being inspired by the patient, said sixth means generates a sixth signal having a value indicative of said helium-oxygen blend desired humidification level;
(q) seventh means for selecting a desired temperature level of at least a portion of a patient's pulmonary pathways as the patient is being ventilated with said helium-oxygen blend and generating a seventh signal having a value indicative of the patient's pulmonary pathways desired temperature level;
(r) eighth means for selecting a desired pressure level of said helium-oxygen blend as said helium-oxygen blend is passing from said respiration receptacle to the patient's pulmonary pathways and a ninth means for selecting a desired pressure level of said gas being expired by the patient, said eighth means generates an eighth signal having a value indicative of said helium-oxygen blend desired pressure level and said ninth means generates a ninth signal having a value indicative of said expired gas desired pressure level;
(s) tenth means for selecting a desired volume of said helium-oxygen blend to be inspired by the patient and an eleventh means for selecting a desired volume of said gas being expired by the patient, said tenth means generates a tenth signal having a value indicative of said helium-oxygen blend desired volume and said eleventh means generates an eleventh signal having a value indicative of said expired gas desired volume;
(t) twelfth means for selecting a desired concentration of gaseous oxygen in said expired gas and generating a twelfth signal having a value indicative of said desired oxygen concentration in said expired gas;
(u) thirteenth means for selecting a desired concentration of oxygen in a preselected portion of the patient's circulatory system while the patient is ventilated with said helium-oxygen blend and generating a thirteenth signal having a value indicative of said desired oxygen concentration in the patient;
(v) fourteenth means for detecting the actual concentration of gaseous helium in said helium-oxygen blend as said helium-oxygen blend is in said respiration receptacle and generating a fourteenth signal having a value indicative of said actual helium concentration in said helium-oxygen blend;
(w) fifteenth means for detecting the actual concentration of gaseous oxygen in said helium-oxygen blend as said helium-oxygen blend is in said respiration receptacle and generating a fifteenth signal having a value indicative of said actual oxygen concentration in said helium-oxygen blend;
(x) sixteenth means for detecting the actual rate at which said helium-oxygen flows from said respiration receptacle into at least a portion of the patient's pulmonary pathways and generating a sixteenth signal having a value indicative of said helium-oxygen blend actual flow rate;
(y) seventeenth means for detecting the actual temperature of said helium-oxygen blend prior to said helium-oxygen blend being inspired by the patient and an eighteenth means for detecting the actual temperature of said gas being expired by the patient, said seventeenth means generates a seventeenth signal having a value indicative of said helium-oxygen blend actual temperature and said eighteenth means generates an eighteenth signal having a value indicative of said expired gas actual temperature;
(z) nineteenth means for detecting the actual humidity of said helium-oxygen blend prior to said helium-oxygen blend being inspired by the patient and generating a nineteenth signal having a value indicative of said helium-oxygen blend actual humidity;
(aa) twentieth means for detecting the actual temperature of at least a portion of a patient's pulmonary pathways as the patient is being ventilated with said helium-oxygen blend and generating a twentieth signal having a value indicative of the patient's pulmonary pathways actual temperature;
(bb) twenty-first means for detecting the actual pressure of said helium-oxygen blend as said helium-oxygen blend is passing from said respiration receptacle to the patient's pulmonary pathways and a twenty-second means for detecting the actual pressure of said gas being expired by the patient, said twenty-first means generates a twenty-first signal having a value indicative of said helium-oxygen blend actual pressure and said twenty-second means generates a twenty-second signal having a value indicative of said expired gas actual pressure;
(cc) twenty-third means for detecting the actual volume of said helium-oxygen blend being inspired by the patient and a twenty-forth means for detecting the actual volume of said gas being expired by the patient, said twenty-third means generates a twenty-third signal having a value indicative of said helium-oxygen blend actual volume and said twenty-forth means generates a twenty-forth signal having a value indicative of said expired gas actual volume;
(dd) twenty-fifth means for detecting the actual concentration of gaseous oxygen in said expired gas and generating a twenty-fifth signal having a value indicative of said actual oxygen concentration in said expired gas;
(ee) twenty-sixth means for detecting the actual concentration of oxygen in a preselected portion of the patient's circulatory system while the patient is ventilated with said helium-oxygen blend and generating a twenty-sixth signal having a value indicative of said actual oxygen concentration in the patient;
(ff) twenty-seventh means for comparing the first signal to the fourteenth signal and generating a twenty-seventh signal having a value indicative of the difference therebetween;
(gg) twenty-eighth means for comparing the second signal to the fifteenth signal and generating a twenty-eighth signal having a value indicative of the difference therebetween;
(hh) twenty-ninth means for comparing the third signal to the sixteenth signal and generating a twenty-ninth signal having a value indicative of the difference therebetween;
(ii) thirtieth means for comparing the forth signal to the seventeenth signal and generating a thirtieth signal having a value indicative of the difference therebetween;
(jj) thirty-first means for comparing the fifth signal to the eighteenth signal and generating a thirty-first signal having a value indicative of the difference therebetween;
(kk) thirty-second means for comparing the sixth signal to the nineteenth signal and generating a thirty-second signal having a value indicative of the difference therebetween;
(ll) thirty-third means for comparing the seventh signal to the twentieth signal and generating a thirty-third signal having a value indicative of the difference therebetween;
(mm) thirty-forth means for comparing the eighth signal to the twenty-first signal and generating a thirty-forth signal having a value indicative of the difference therebetween;
(nn) thirty-fifth means for comparing the ninth signal to the twenty-second signal and generating a thirty-fifth signal having a value indicative of the difference therebetween;
(oo) thirty-sixth means for comparing the tenth signal to the twenty-third signal and generating a thirty-sixth signal having a value indicative of the difference therebetween;
(pp) thirty-seventh means for comparing the eleventh signal to the twenty-forth signal and generating a thirty-seventh signal having a value indicative of the difference therebetween;
(qq) thirty-eighth means for comparing the twelfth signal to the twenty-fifth signal and generating a thirty-eighth signal having a value indicative of the difference therebetween;
(rr) thirty-ninth means for comparing the thirteenth signal to the twenty-sixth signal and generating a thirty-ninth signal having a value indicative of the difference therebetween;
(ss) fortieth means responsive to said twenty-seventh signal, said fortieth means being designed to manipulate the helium flow control means until there is no significant difference between the first signal and the fourteenth signal;
(tt) forty-first means responsive to said twenty-eighth signal, said forty-first means being designed to manipulate the oxygen flow control means until there is no significant difference between the second signal and the fifteenth signal;
(uu) forty-second means responsive to said twenty-ninth signal, said forty-second means being designed to manipulate the helium-oxygen blend flow control means until there is no significant difference between the third signal and the sixteenth signal;
(vv) forty-third means responsive to said thirtieth signal, said forty-third means being designed to manipulate the temperature adjusting means until there is no significant difference between the forth signal and the seventeenth signal;
(ww) forty-forth means responsive to said thirty-first signal, said forty-forth means being designed to manipulate the temperature adjusting means until there is no significant difference between the fifth signal and the eighteenth signal;
(xx) forty-fifth means responsive to said thirty-second signal, said forty-fifth means being designed to manipulate the humidification adjusting means until there is no significant difference between the sixth signal and the nineteenth signal;
(yy) forty-sixth means responsive to said thirty-third signal, said forty-sixth means being designed to manipulate the temperature adjusting means until there is no significant difference between the seventh signal and the twentieth signal;
(zz) forty-seventh means responsive to said thirty-forth signal, said forty-third means designed to manipulate at least one of the following:
gaseous helium pressure control means, gaseous oxygen pressure control means, oxygen flow control means, helium flow control means, helium-oxygen blend flow control means, inspiratory gas volume control means and expiratory gas volume control means until there is no significant difference between the eighth signal and the twenty-first signal;
(aaa) forty-eighth means responsive to said thirty-fifth signal, said forty-eighth means designed to manipulate at least one of the following:
gaseous helium pressure control means, gaseous oxygen pressure control means, oxygen flow control means, helium flow control means, helium-oxygen blend flow control means, inspiratory gas volume control means and expiratory gas volume control means until there is no significant difference between the ninth signal and the twenty-second signal;
(bbb) forty-ninth means responsive to said thirty-sixth signal, said forty-ninth means being designed to manipulate at least one of the following:
gaseous helium pressure control means, gaseous oxygen pressure control means, oxygen flow control means, helium flow control means, helium-oxygen blend flow control means, inspiratory gas volume control means and expiratory gas volume control means until there is no significant difference between the tenth signal and the twenty-third signal;
(ccc) fiftieth means responsive to said thirty-seventh signal, said fiftieth means being designed to manipulate at least one of the following:
gaseous helium pressure control means, gaseous oxygen pressure control means, oxygen flow control means, helium flow control means, helium-oxygen blend flow control means, inspiratory gas volume control means and expiratory gas volume control means until there is no significant difference between the eleventh signal and the twenty-fourth signal;
(ddd) fifty-first means responsive to said thirty-eighth signal, said fifty-first means being designed to manipulate at least one of the following:
gaseous helium pressure control means, gaseous oxygen pressure control means, oxygen flow control means, helium flow control means, helium-oxygen blend flow control means, inspiratory gas volume control means and expiratory gas volume control means until there is no significant difference between the twelfth signal and the twenty-fifth signal;
and
(eee) fifty-second means responsive to said thirty-ninth signal, said fifty-second means being designed to manipulate at least one of the following:
gaseous helium pressure control means, gaseous oxygen pressure control means, oxygen flow control means, helium flow control means, helium-oxygen blend flow control means, inspiratory gas volume control means and expiratory gas volume control means until there is no significant difference between the thirteenth signal and the twenty-sixth signal.

61 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/167,680Filed 15 Dec 1993
Granted: 4 Jul 1995
Term ends: Not estimatedThe source records don’t support an estimate.

Classification17 codes

A61M 16/161
Devices to humidify the respiration air: with means for measuring the humidity
A61M 16/0051
Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators ; Tracheal tubes: with alarm devices
A61M 16/024
Control means therefor: including calculation means, e.g. using a processor
A61M 16/0627
Means for improving the adaptation of the mask to the patient: with sealing means on a part of the body other than the face, e.g. helmets, hoods…