Servo lung simulator and related control method

Boots – shoes – and leggings

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

G09B 2328

Patent

active

059757485

DESCRIPTION:

BRIEF SUMMARY
I. BACKGROUND OF INVENTION

A. Technical Field
This invention relates to the field of mechanical devices, including computer-controlled mechanical devices, which simulate the action of human breathing. One use of such devices is to test the operation of mechanical ventilators. In the preferred embodiment, the invention is a servo-controlled mechanical piston which simulates the mechanical properties of the human lung, chest wall and diaphragm. The invention includes the control method for the servo lung simulator which is implemented on a digital computer through software which provides the simulation and control signals for the mechanical piston.
B. Background Art
In the prior art, there were published standards for the minimum performance of mechanical ventilators. These published standards include ANSI Standard Z79.7, ISO Standard 5469.:1987, and ASTM Standard 1100. Testing of ventilators to determine whether these standards are met may be part of new prototype product evaluation, quality assurance during the manufacturing process, calibration in the field or as part of a routine service program. Ideally, any testing device for medical devices should meet or exceed the minimum performance standards. However, there are a few existing test lungs that exceed these published standards. The TTL, training and test lung manufactured by Michigan Instruments (Grand Rapids, Mich.) is probably one of the best known. This device uses two spring loaded bellows to create a two compartment mechanical lung simulation. A few discrete resistances can be modeled using fixed resistive elements that are added in the tubing of the test lung. Compliance is adjusted by changing the spring loaded force on the upper plate of the bellows. Lung pressure is measured using traditional pressure gauges on the front panel. Lung volume is measured by observing the displacement of the upper bellows plate. Michigan instruments sells a PC board and software that will collect data from the pressure transducers and using the compliance setting, which must be keyed in by the user, calculate volumes. This system is specified to have an accuracy of 5%. The system does provide a crude mechanism for providing triggering events; however, the ability to simulate a two compartment lung is lost if triggering is used. The lung simulator does not provide a reasonable method for simulating spontaneous respiration. There are other systems such as the Biotek system that include a pneumotach and are somewhat more sophisticated; however, in general they all have similar problems. Essentially there are not tools that can be used to reliably test mechanical ventilators throughout the spectrum of their capabilities.


II. DISCLOSURE OF THE INVENTION

The invented servo lung simulator uses a computer controlled piston to accurately reproduce the behavior of a one or two compartment lung model, including the chest wall activity necessary for modeling spontaneous breathing and triggering events. This system uses a model reference servo control algorithm to simulate the lung. "Lung" volume is calculated from piston diameter and piston position, which is measured by a shaft encoder on the motor that drives the piston. Volume can be measured to a resolution of 50 .mu.L. This provides volume accuracy of better than 1% from pediatric to adult lung sizes. Since the model is mathematical and implemented in software, an infinite variety of resistance and compliance values can be chosen by the user. A variety of different active chest wall functions can be used that simulate simple triggering events and more complex spontaneous breathing. The system also provides integrated data acquisition, management and display.
The following is a brief list of the advantages of the invention over the prior art: pediatric and adult simulations. The invented servo lung simulator will provide a two compartment lung simulation of pediatric and adult patients, without the need for equipment changes. or spontaneous respiration, because the two compartment system of the prior art is entirely

REFERENCES:
patent: Re29317 (1977-07-01), Mosley et al.
patent: 3049812 (1962-08-01), Bovard
patent: 3420225 (1969-01-01), Holden et al.
patent: 3589190 (1971-06-01), Jones
patent: 3808706 (1974-05-01), Mosley et al.
patent: 4001700 (1977-01-01), Cook et al.
patent: 4036221 (1977-07-01), Hillsman et al.
patent: 4167070 (1979-09-01), Orden
patent: 4324127 (1982-04-01), Gazzara et al.
patent: 4407152 (1983-10-01), Guth
patent: 4430893 (1984-02-01), Barkalow
patent: 4878388 (1989-11-01), Loughlin et al.
patent: 4996980 (1991-03-01), Frankenberger et al.
patent: 5076093 (1991-12-01), Jones, Jr. et al.
patent: 5277176 (1994-01-01), Habashi et al.
patent: 5277196 (1994-01-01), Hankinson et al.
patent: 5327774 (1994-07-01), Nguyen et al.
patent: 5403192 (1995-04-01), Kleinwaks et al.
patent: 5473954 (1995-12-01), Hoyt et al.
patent: 5584701 (1996-12-01), Lampotang et al.
Gardner, RM, Hankinson, JL, and West, BJ, "Evaluating Commercially Available Spirometers" American Review of Respiratory Disease vol. 121, pp. 73-82 (1980).
Gardner, RM, Hankison, JL, and West, BJ, "Testing Spirometers--ATS Standards" ATS News pp. 24-25.
Hankinson, JL, Gardner, RM, "Standard Waveforms for Spirometer Testing" Am. Rev. Resp. Dis. (1982), vol. 126, pp. 362-364.
Hankinson, JL and Gardner, RM, "Standardization of Spirometery" Am. Rev. Resp. Dis. (1982), vol. 126, pp. 493-495.
Hankinson, JL and Gardner RM, "Standardization of Spirometry--1987 ATS Update", Letters to the Editor, Journal of Occupational Medicine. vol. 30, No. 3 (Mar. 1988) pp. 272-273.
"Report of Snowbird Workshop on Standardization of Spirometry" ATS News Thornton, MJ ed., (Summer 1977) vol. 3, No. 3, pp. 20-24.
Renzetti, Jr., AD, "Standardization of Spirometry--Statement American Thoracic Society", American Lung Association vol. 119 No. 5 (May 1979) pp. 1-11.
Yeh, MP, Gardner, RM, Adams, TD and Yanowitz, FG, "Computerized Determination of Pneumotachometer Characteristics Using a Calibrated Syringe", Special Communications, The American Physiological Society (1982) pp. 280-285.
Crapo, RO, Morris, AH and Garnder, RM, "Reference Spirometric Values Using Techniques and Equipment that Meet ATS Recommendations", Am. Rev. Resp. Dis. (1981) vol. 123, pp. 659-664.
Gardner, RM, Glindmeyer III, HW, Hankinson, JL, "Standardization of Spirometry with Special Emphais in Field Testing" Occupational Lung Diseases Research Approaches and Methods, Marcel Decker, Inc. NY (1981) pp. 61-85.
Ostler, DV, Gardner, RM and Crapo, RO, "A Computer System for Analysis and Transmission of Spirometry Waveforms Using Volume Sampling", Computers and Biomedical Research, (1984) 17 pp. 229-240.
Crapo, RO, Morris, AH and Gardner, RM, Am. Rev. Resp. Dis. (Sep. 9, 1981) 124:764.
Sweeney, JT (May 19, 1980), Glindmeyer, H (Feb. 14, 1980) and Putterman, K (Mar. 5 1980), Gardner, RM, Hankinson, JI, and West, BJ (Mar. 31, 1980) "Evaluating Commercially Available Spirometers" Am. J. Resp. Dis., (1980) pp. 171-175.
Gardner, RM, "How to Evaluate Commercially Available Spirometers", Lecture Series 1981 American Association for Respiratory Therapy, pp. 145-154.
Weiss et al., "American Thoracic Society--Device Standards--Apr. 1975" ATS News, 21-25.
Gardner, RM and Clemmer, TP, "Selection and Standardization of Respiratory Monitoring Equipment", Respiratory Care (Jul. 1985) vol. 30 No. 7, pp. 560-571.
Branson, RD, Hess, DR and Chatburn, RL, "Humidification: Humidifiers and Nebulizers" Respiratory Care Equipment, J.B. Lippincott Co., (1995) pp 87-101, 331-333, 425-449.
Glindmeyer III, HW, "An Experimental Investigation of the Errors of Spirometry" Thesis, Tulane University, (Nov. 1976) pp. 1-84.
West, BJ, "Dynamic Response Testing of Spirometers" Thesis, Univ. of Utah (Aug. 1977) pp. 1-37.
Nelson, SB, "Commercially Available Spirometers: A Performance Evaluation" Thesis, Univ. of Utah (Mar. 1987) pp. 1-46.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Servo lung simulator and related control method does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Servo lung simulator and related control method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Servo lung simulator and related control method will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2126271

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.