Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
  • A61M16/021—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes operated by electrical means
  • A61M16/022—Control means therefor
  • A61M16/024—Control means therefor including calculation means, e.g. using a processor
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
  • A61B5/0205—Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M2230/00—Measuring parameters of the user
  • A61M2230/04—Heartbeat characteristics, e.g. ECG, blood pressure modulation

Definitions

• Such respirators drive a positive pressure breath into the lungs which are already at atmospheric pressure.
• the pressure in the lungs is increased above atmospheric pressure, contrary to normal occurrence, which inhibits the heart's ability to pump blood.
• negative thoracic pressure is developed upon inspiration of air, which aids in filling the heart with blood.
• the resultant pressure gradient (the relatively positive pressure in the periphery and
• PEEP Positive-End-Expiratory Pressure
• a low level of positive pressure is maintained in the airway between positive pressure breaths.
• PEEP uses a standard switch.
• a pressure signal applied to the valve controls the high or low pressure states of the valve.
• the low PEEP state is generated when the valve is fully open.
• a partial closing of the valve creates high intrathoracic pressure between breaths, as some air from the tedal volume is not allowed to escape.
• cardiac output drops significantly.
• Intravenous fluids are used to increase intravascular volume in an effort to minimize this fall in cardiac output. The patient may already have compromised cardiac function, minimizing or negating the advantages of the intravascular volume increase. Additionally, patients
• respirators typically lack adequate kidney function and cannot process the added fluids. If too much intravenous fluid is used, relative to the patient's ability (aided or not) to process the fluid, the fluid may enter the patient's lungs.
• Positive inotropic agents are used to increase the squeeze of the heart to punp more blood. Obviously, the heart works harder than normal resulting in possible heart attacks or arrhythmias. Often, physicians will prescribe a combination of increased intravenous fluids and positive inotropic agents with PEEP.
• the invention concerns a computer-gated.
• the output of a cardiogram machine is amplified and squared, or an LED of a cardiogram machine is optically monitored, to determine an R- a e, or the beginning of electrical systole.
• a signal is fed to a multiplier where the R-R wave signal (period) is multiplied representing the duration of the R-R wave with a variable interval set by a physician.
• the resultant produce (R-R wave times variable interval) is used to trigger a solenoid operated 3-way valve.
• the 3-way valve is normally closed to pass a positive pressure to a standard PEEP valve which functions normally. When triggered, the 3-way valve opens to allow a relatively low pressure to pass to the PEEP valve such that the PEEP valve creates a low pressure to the patient.
• PEEP is removed for a variable time ratio immediately before a next heart beat.
• the PEEP valve is controlled by computer gating a 3-way valve to create pressure drops, allowing the heart to fill. Once the heart fills, PEEP is resumed without any detrimental effects. Respiration of the patient is coordinated with the patient's heart beat to maximize cardiac output. Additionally pressure can be replaced immediately after drop out in an effort to improve emptying of the heart.
• Figure 1 is a schematic of the present invention in its environment.
• Figure 2 is a block diagram of the Figure 1 microcomputer contents, as connected to a 3-way valve.
• Figure 3 reveals a second embodiment for detecting a heart beat interval.
• the computer-gated, positive expiratory pressure system is shown in Figure 1 in its environment, connected to a therapeutic device such as a PEEP system.
• a patient 10 is shown using a respirator or ventilator 12 via a standard expiratory (PEEP) valve 14.
• PEEP standard expiratory
• the PEEP valve 14 opens and closes to allow low and high pressures to the patient 10.
• the patient 10 is also connected to a cardiogram machine (EKG) 16. Successive heart beats are detected by the EKG 16 and a signal representing each beat is output to a microcomputer 18, the details of which are discussed regarding Figures 2 and 3.
• EKG cardiogram machine
• variable interval is generated by generator 20 as a
• the microcom uter 18 combines the variable interval signal from 20 and a value representing the period between successive heart beats from EKG 16 and generates a controlling output to a solenoid 22 of a 3-way valve 24.
• the 3-way valve 24 is connected by a first end to a positive pressure source 26.
• a second valve end is pneumatically connected to a low relative pressure 28, while a third end is connected to the PEEP valve 14 via which the patient 10 received the positive pressure breaths.
• the PEEP valve 14 Under normal operation of the ventilator 12, the PEEP valve 14 is operated to allow alternate low and high positive pressure breaths (approximately .4 psi) from the ventilator 12 to pass directly to the patient 10. However, in response to the output of microcomputer 18, the solenoid 22 is energized to yield at output 30, a negative pressure from the low relative pressure source 28. The negative pressure output at 30 opens the PEEP valve 14. Because the PEEP valve 14 is fully opened, a low pressure is received by the patient 10 from the ventilator 12. The resultant low pressure, in accordance with the present invention, occurs just prior to a predicted heart beat to insure the heart, when filling, does not work against high pressures. ? ⁇ ? systems per se too often generate high pressures -.- en the heart beats, inhibiting heart filling and deereasing cardiac output.
• microcomputer 18 The output of EKG 16 is run through an operational amplifier 32 to a timer 34 which squares the amplified EKG signal to develop a series of electrical pulses corresponding to s-uccessive heart beats.
• the electrical pulses of timer 34 are received by memor /calculator 36 which determines a period representing the interval between successive heart beats. This period is used to predict a next heart beat so a low pressure is delivered to the patient slightly before and during this next heart beat.
• the variable interval generator 20 is set by the attending physician between 15 and 400 microseconds, for instance, by typical anolog controls.
• the variable interval signal from 20 and the period signal from calculator 36 are used to generate a produce in multiplier 38.
• the resultant product is used as a signal to energize the solenoid 32, to control 3-way ⁇ valve 24.
• the 3-way valve 24 now opens output 30 to the vacuum 28. Accordingly, a resultant negative pressure fully opens the PEEP valve 14 and a low pressure reaches the patient. Should the heart rate vary, the difference between predicted and actual heart beats will be detected and pulse timing corrected. The time duration of the pulse to the solenoid is controlled by a second timer (not shown) .
• FIG. 3 reveals a second embodiment for determining or sensing heart beats.
• a photodetector 40 is used to detect the blinking LED 42 which is typically part of a cardiogram machine.
• the photodetector 40 turning on and off with the flash of the LED 42, requires no timer or wave squarer, and thus is input directly to the amplifier 32 for subsequent processing in the manner of the Figure 2 embodiment.
• a microprocessor e.g. C 64 Commadore Computer
• a microprocessor may be adapted and software developed to monitor and determine beat period, with a programmable variable interval for use by the physician.

Landscapes

• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Heart & Thoracic Surgery (AREA)
• Public Health (AREA)
• Pulmonology (AREA)
• Animal Behavior & Ethology (AREA)
• Veterinary Medicine (AREA)
• Biomedical Technology (AREA)
• Anesthesiology (AREA)
• Hematology (AREA)
• Emergency Medicine (AREA)
• Physiology (AREA)
• Cardiology (AREA)
• Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
• Medical Informatics (AREA)
• Biophysics (AREA)
• Surgery (AREA)
• Molecular Biology (AREA)
• Pathology (AREA)
• Physics & Mathematics (AREA)
• Percussion Or Vibration Massage (AREA)
• Respiratory Apparatuses And Protective Means (AREA)
• Measuring And Recording Apparatus For Diagnosis (AREA)
• External Artificial Organs (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=25296488

Family Applications (1)

Country Status (11)

Families Citing this family (34)

Citations (3)

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• 1987
  • 1987-03-27 JP JP62502279A patent/JPS63503207A/ja active Pending
  • 1987-03-27 DE DE19873790137 patent/DE3790137T1/de not_active Ceased
  • 1987-03-27 CH CH4700/87A patent/CH672991A5/fr not_active IP Right Cessation
  • 1987-03-27 GB GB8722069A patent/GB2194892B/en not_active Expired - Lifetime
  • 1987-03-27 EP EP19870902943 patent/EP0273041A4/de not_active Withdrawn
  • 1987-03-27 WO PCT/US1987/000644 patent/WO1987006040A1/en not_active Application Discontinuation
  • 1987-03-27 NL NL8720165A patent/NL8720165A/nl not_active Application Discontinuation
  • 1987-03-27 AU AU72316/87A patent/AU598255B2/en not_active Ceased
  • 1987-03-31 CA CA000533497A patent/CA1302505C/en not_active Expired - Fee Related
  • 1987-09-25 DK DK504687A patent/DK162257C/da not_active IP Right Cessation
  • 1987-09-28 SE SE8703727A patent/SE459214B/sv not_active IP Right Cessation
• 1991
  • 1991-07-26 JP JP1991066000U patent/JPH06125Y2/ja not_active Expired - Lifetime

Patent Citations (3)

Non-Patent Citations (1)

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