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Artificial “Lungs”
1938
PUBLIC HEALTH
Such a manufacturer of bedding should, however, be permitted to rely upon a warranty that his filling material has been so treated by the manufacturer of the material before being received by him, provided that he himself has not exposed the material to dirty conditions. The manufacturer of any filling material should be required to supply a warranty of effective treatment with any consignment of material delivered, and the warranty should be accompanied by a statement of the composition of the material and its source or origin. (12) Manufacturers of filling material should be registered with the Local Authority of the area in which their works are situated. They should be subject to regular inspection by the Local Authority of the area, the inspectors having power to inspect all the processes and material of the works and to take samples. (13) Bedding, upholstery, etc., manufacturers, should similarly be registered with the Local Authority and subject to similar inspection. (14) All registrations should be renewed annually, but there should lie with the Local Authority power to withdraw registration on proof of non-compliance with the Act or Regulations. (15) Where a County Council are satisfied that a Local Authority in their administrative area is failing to exercise the powers referred to in the preceding three paragraphs, the County Council should have power to exercise these powers in the area of the Local ~uthority at the expense of the Local Authority. (16) Large quantities of seriously and dangerously soiled rags are imported daily into this country. We are of opinion that consignments should be so controlled that imported rags should be cleansed and sterilised before use in manufacture, and that where filling material is imported the responsibility for immediate cleansing and sterilisation of the material should be placed on the importer. (17) We do not advocate that a power should be given to open up and to sample the filling in articles of furniture, bedding, etc., manufactured in this country, but such a power should in our opinion be possessed by port sanitary authorities so that the importation of any furniture, bedding, etc., in which the filling did not comply with the British requirements should be prevented.
resulted in more convenient and safe operation of the mechanism, added comfort and increased effectiveness. The Drinker Respirator consists of a steel chamber, or cabinet, which is large enough to accommodate a person over 6 feet in height, and yet can be used for a small child. The interior of the chamber is equipped with a bed and mattress set on a trolley and attached at one end to a sloping lid. The bed and lid of the chamber are supported on an upright frame fitted with castors. The patient lies on the bed with the whole of the body, except the head and neck, enclosed in the chamber, the head and neck extending through a soft rubber collar in the lid and resting on a platform outside the chamber. The rubber collars on the lid are detachable and are made with apertures of different sizes to ensure an air-tight seal about the patient's neck. The lid closes against a rubber gasket and is held fast by means of hand clamps which render the respirator air-tight. By loosening these clamps, the lid with the attached bed can be pulled out with ease for purposes of nursing and to permit the occasional examination of the patient. On either side of the chamber are working portholes, through which the nurses's arms are inserted when tending to the patient. These working ports are fitted with small rubber collars which fit closely round the arms of the nurse and prevent any disturbance of the mechanism when the respirator is in use. An extra large porthole allows a bed pan to be inserted and removed without opening the respirator. Large observation ports situated at the top and sides of the respirator allow the patient to be observed easily and clearly and facilitate the use of the arm ports. The chamber is illuminated by means of a roof light, which also helps to keep an even temperature in the interior, and a thermometer records this temperature. A leak valve is fitted on the respirator in order to regulate the negative pressure and consequently the depth of the respirations. The depth and rate of respirations are registered by means of a U-tube manometer filled with coloured water and connected to the chamber. The apparatus is, as already stated, mounted on a frame set on castors and can be wheeled about the ward. There is a special fitting device so that the end of the chamber can be raised or lowered to the desired angle. An electric k h.p. motor drives a cylindrical bellows connected to the chamber by means of a flexible pipe. This bellows has an external flap valve, so that its action is really that of a sucker, alternately extracting ARTIFICIAL "LUNGS" the air from the chamber to give a negative pressure The Lo'hdon County Council has recently arranged and allowing air at atmospheric pressure to enter on an interesting demonstration of the various types of the return stroke. The rate of the motor is governed mechanical respirators which are now in use in its by a rheostat, and the rate, as well as the depth of hospitals. respirations can be easily controlled. The respirator The L.C.C. first used mechanical respirators in is so constructed that, in case of power failure or for 1934 and now has 16 of the various types in use--at any other reason, it can be operated by hand. least one of which is at each of the acute infectious Recently another respirator* has been made and supdiseases hospitals. plied to one of the Council's hospitals. In principle, The first type of respirator used was the Drinker this machine is identical with the Drinker respirator. " Iron Lung." This apparatus is now well-known, but since the original Drinker respirator was designed by *This is the Both type of respirator, which Lord Nuffie[d Dr. Phillip Drinker, of Harvard University, a number has munificently offered to manufacture and to present to of refinements and accessories have been added by the hospitals (both voluntary and rate-aided) on application to medical and technical staff of the L.C.C., which have the Nuffield Institute of Medical Research, Oxford. 69
PUBLIC HEALTH The chamber is made of laminated wood and mounted on a tripod stand with a worm and sector tilting device. This respirator is much cheaper, much lighter in construction, more readily transportable, and has certain features and modifications which simplify the mechanical operation and the nursing. The motor is a constant speed motor with triple step belt-drive cones to drive the bellows at rates of 18, 22 and 28 respirations per minute. This makes the motor much quieter in running and less disturbing to the patient. All the working parts are enclosed in a sheet steel cylinder which protects from dust and eliminates noise. ]acket Respirators.--Another apparatus for maintaining artificial respiration is the jacket respirator, originally designed by Dr. A. F. Burstall, Professor of Engineering, University of Melbourne, which consists of a one-piece aluminium cuirass to enclose the trunk of the patient from the neck to the waistline. The openings at the waist, neck and arms have beaded edges over which is stretched soft sheet rubber diaphragms with central openings of varying sizes, to fit the waist, neck or arms, which form an air-tight seal about the part of the patient enclosed. This cuirass is designed to operate from any cabinet type of respirator by means of a flexible hose connected to the cabinet or the bellows. It is of such small capacity that a number of cuirasses can be operated from one cabinet respirator. Three sizes provide for patients ranging from children of the age of three years to medium sized adults. A new jacket respirator has been designed for use in the Council's hospitals and this model is believed to be a distinct improvement on Professor Burstall's respirator. Although it is exactly the same in principle, this apparatus is so constructed as to overcome many of the disadvantages of the original Burstall cuirass. It consists of an aluminium jacket, shaped to the thorax and made in two halves, back and front. These halves join at the sides by thumb screw nuts on an air-tight joint and the apparatus can be applied with much greater ease than the one-piece cuirass and without the slightest discomfort to the patient. Its improved design and simplicity of application also enable it to provide for a greater range of sizes of patients. The alteration of the shape of the armholes to provide greater freedom of movement of the arms, the altered design of the rubber diaphragms and an escape valve to regulate the depth of the respirations are further improvements on the Burstall cuirass. In addition, a separate mechanical unit has been designed to operate this respirator so that the apparatus is, in itself, complete, and not dependent on any cabinet respirator. This unit consists of a ~ h.p. rotor (A.C. 210 to 240 volts) designed to drive a small suction bellows at a fixed speed of 20 double strokes per minute and a maximum operating suction of 25 cms. of water. The bellows, which is connected to the cuirass by means of a flexible hose, is fitted with an excess pressure valve and a regulating valve for adjusting the suction pressure. The respirator can be operated by hand in case of power failure. Motor mechanism and bellows are completely enclosed in a plywood casing and carried on ball-bearing castors.
70
DECEMBER The principle of all these methods of respiration is that, when negative pressure is applied to the chamber or jacket, by suction from the bellows, air at atmospheric pressure enters through the mouth and nose and the chest expands. Vqhen the negative pressure within the respirator returns to normal by means of air getting through the flap valve on the return stroke of the bellows, the elastic recoil of the chest produces expiration. Although the jacket respirator is not designed to replace the cabinet respirator (which may be essential for the treatment of certain cases), it has many general advantages over the latter. The whole apparatus is very simple to use and cheap to construct as compared with the Drinker respirator. It has advantages, for instance, in facilitating the carrying out of the essential nursing care of the patient, which is a complicated and difficult procedure in the Drinker respirator. The patient lies on an ordinary bed and has a greater freedom of movement and range of vision. He has full range of voluntary movements of his hands and arms and can comfortably feed himself if his arms are not paralysed. Full movements of the legs are of course possible. Paralysed limbs can be much more easily treated than in a chamber respirator. The Bragg-Paul Pulsator.--Another apparatus for prolonged artificial respiration, on a different principle from that of the Drinker respirator or its modifications, is the Bragg-Paui Pulsator, designed by R. W. Paul, M.I.E.E., F.INST.P., at the suggestion of Sir William Bragg, F.a.s. This apparatus consists of a distensible rubber bag applied around the patient's chest in the form of a belt, this belt being rhythmically inflated with, and emptied of, air from a bellows which is operated electrically. Several sizes of air-belts are available to suit different sizes of patients. The bellows is driven by a small motor which normally can be operated on any electric supply circuit, and may be connected to a lamp socket. The speed of the pulsator can be adjusted to suit the respiratory rate required and the pressure in the chest belt can be controlled by an escape-valve fixed to the bellows. A gauge indicates the amount of pressure applied to the chest and the rate of the compressions. Where electricity is not available, models are made to operate from accumulators or from the water supply. I n case of power failure all the models can be worked by hand. The principle of this method of artificial respiration is that each rhythmic inflation of the rubber chest belt compresses the patient's chest and forces expiration. When the belt is deflated, the elastic recoil of the chest wall produces inspiration. One of the objects of the recent exhibition of these types of apparatus was to encourage authorities in other parts of the country to acquire respirators for use in their own hospitals. The L.C.C. has received many applications for the loan of their respirators, but it has been sometimes difficult to comply with such requests. Now that the cheaper and effective types of respirator have been evolved the cost is no longer a barrier to their acquisition and it may be hoped that the respirators on the " Iron L u n g " principle will be available in every hospital or for home treatment.
PUBLIC HEALTH
Such a manufacturer of bedding should, however, be permitted to rely upon a warranty that his filling material has been so treated by the manufacturer of the material before being received by him, provided that he himself has not exposed the material to dirty conditions. The manufacturer of any filling material should be required to supply a warranty of effective treatment with any consignment of material delivered, and the warranty should be accompanied by a statement of the composition of the material and its source or origin. (12) Manufacturers of filling material should be registered with the Local Authority of the area in which their works are situated. They should be subject to regular inspection by the Local Authority of the area, the inspectors having power to inspect all the processes and material of the works and to take samples. (13) Bedding, upholstery, etc., manufacturers, should similarly be registered with the Local Authority and subject to similar inspection. (14) All registrations should be renewed annually, but there should lie with the Local Authority power to withdraw registration on proof of non-compliance with the Act or Regulations. (15) Where a County Council are satisfied that a Local Authority in their administrative area is failing to exercise the powers referred to in the preceding three paragraphs, the County Council should have power to exercise these powers in the area of the Local ~uthority at the expense of the Local Authority. (16) Large quantities of seriously and dangerously soiled rags are imported daily into this country. We are of opinion that consignments should be so controlled that imported rags should be cleansed and sterilised before use in manufacture, and that where filling material is imported the responsibility for immediate cleansing and sterilisation of the material should be placed on the importer. (17) We do not advocate that a power should be given to open up and to sample the filling in articles of furniture, bedding, etc., manufactured in this country, but such a power should in our opinion be possessed by port sanitary authorities so that the importation of any furniture, bedding, etc., in which the filling did not comply with the British requirements should be prevented.
resulted in more convenient and safe operation of the mechanism, added comfort and increased effectiveness. The Drinker Respirator consists of a steel chamber, or cabinet, which is large enough to accommodate a person over 6 feet in height, and yet can be used for a small child. The interior of the chamber is equipped with a bed and mattress set on a trolley and attached at one end to a sloping lid. The bed and lid of the chamber are supported on an upright frame fitted with castors. The patient lies on the bed with the whole of the body, except the head and neck, enclosed in the chamber, the head and neck extending through a soft rubber collar in the lid and resting on a platform outside the chamber. The rubber collars on the lid are detachable and are made with apertures of different sizes to ensure an air-tight seal about the patient's neck. The lid closes against a rubber gasket and is held fast by means of hand clamps which render the respirator air-tight. By loosening these clamps, the lid with the attached bed can be pulled out with ease for purposes of nursing and to permit the occasional examination of the patient. On either side of the chamber are working portholes, through which the nurses's arms are inserted when tending to the patient. These working ports are fitted with small rubber collars which fit closely round the arms of the nurse and prevent any disturbance of the mechanism when the respirator is in use. An extra large porthole allows a bed pan to be inserted and removed without opening the respirator. Large observation ports situated at the top and sides of the respirator allow the patient to be observed easily and clearly and facilitate the use of the arm ports. The chamber is illuminated by means of a roof light, which also helps to keep an even temperature in the interior, and a thermometer records this temperature. A leak valve is fitted on the respirator in order to regulate the negative pressure and consequently the depth of the respirations. The depth and rate of respirations are registered by means of a U-tube manometer filled with coloured water and connected to the chamber. The apparatus is, as already stated, mounted on a frame set on castors and can be wheeled about the ward. There is a special fitting device so that the end of the chamber can be raised or lowered to the desired angle. An electric k h.p. motor drives a cylindrical bellows connected to the chamber by means of a flexible pipe. This bellows has an external flap valve, so that its action is really that of a sucker, alternately extracting ARTIFICIAL "LUNGS" the air from the chamber to give a negative pressure The Lo'hdon County Council has recently arranged and allowing air at atmospheric pressure to enter on an interesting demonstration of the various types of the return stroke. The rate of the motor is governed mechanical respirators which are now in use in its by a rheostat, and the rate, as well as the depth of hospitals. respirations can be easily controlled. The respirator The L.C.C. first used mechanical respirators in is so constructed that, in case of power failure or for 1934 and now has 16 of the various types in use--at any other reason, it can be operated by hand. least one of which is at each of the acute infectious Recently another respirator* has been made and supdiseases hospitals. plied to one of the Council's hospitals. In principle, The first type of respirator used was the Drinker this machine is identical with the Drinker respirator. " Iron Lung." This apparatus is now well-known, but since the original Drinker respirator was designed by *This is the Both type of respirator, which Lord Nuffie[d Dr. Phillip Drinker, of Harvard University, a number has munificently offered to manufacture and to present to of refinements and accessories have been added by the hospitals (both voluntary and rate-aided) on application to medical and technical staff of the L.C.C., which have the Nuffield Institute of Medical Research, Oxford. 69
PUBLIC HEALTH The chamber is made of laminated wood and mounted on a tripod stand with a worm and sector tilting device. This respirator is much cheaper, much lighter in construction, more readily transportable, and has certain features and modifications which simplify the mechanical operation and the nursing. The motor is a constant speed motor with triple step belt-drive cones to drive the bellows at rates of 18, 22 and 28 respirations per minute. This makes the motor much quieter in running and less disturbing to the patient. All the working parts are enclosed in a sheet steel cylinder which protects from dust and eliminates noise. ]acket Respirators.--Another apparatus for maintaining artificial respiration is the jacket respirator, originally designed by Dr. A. F. Burstall, Professor of Engineering, University of Melbourne, which consists of a one-piece aluminium cuirass to enclose the trunk of the patient from the neck to the waistline. The openings at the waist, neck and arms have beaded edges over which is stretched soft sheet rubber diaphragms with central openings of varying sizes, to fit the waist, neck or arms, which form an air-tight seal about the part of the patient enclosed. This cuirass is designed to operate from any cabinet type of respirator by means of a flexible hose connected to the cabinet or the bellows. It is of such small capacity that a number of cuirasses can be operated from one cabinet respirator. Three sizes provide for patients ranging from children of the age of three years to medium sized adults. A new jacket respirator has been designed for use in the Council's hospitals and this model is believed to be a distinct improvement on Professor Burstall's respirator. Although it is exactly the same in principle, this apparatus is so constructed as to overcome many of the disadvantages of the original Burstall cuirass. It consists of an aluminium jacket, shaped to the thorax and made in two halves, back and front. These halves join at the sides by thumb screw nuts on an air-tight joint and the apparatus can be applied with much greater ease than the one-piece cuirass and without the slightest discomfort to the patient. Its improved design and simplicity of application also enable it to provide for a greater range of sizes of patients. The alteration of the shape of the armholes to provide greater freedom of movement of the arms, the altered design of the rubber diaphragms and an escape valve to regulate the depth of the respirations are further improvements on the Burstall cuirass. In addition, a separate mechanical unit has been designed to operate this respirator so that the apparatus is, in itself, complete, and not dependent on any cabinet respirator. This unit consists of a ~ h.p. rotor (A.C. 210 to 240 volts) designed to drive a small suction bellows at a fixed speed of 20 double strokes per minute and a maximum operating suction of 25 cms. of water. The bellows, which is connected to the cuirass by means of a flexible hose, is fitted with an excess pressure valve and a regulating valve for adjusting the suction pressure. The respirator can be operated by hand in case of power failure. Motor mechanism and bellows are completely enclosed in a plywood casing and carried on ball-bearing castors.
70
DECEMBER The principle of all these methods of respiration is that, when negative pressure is applied to the chamber or jacket, by suction from the bellows, air at atmospheric pressure enters through the mouth and nose and the chest expands. Vqhen the negative pressure within the respirator returns to normal by means of air getting through the flap valve on the return stroke of the bellows, the elastic recoil of the chest produces expiration. Although the jacket respirator is not designed to replace the cabinet respirator (which may be essential for the treatment of certain cases), it has many general advantages over the latter. The whole apparatus is very simple to use and cheap to construct as compared with the Drinker respirator. It has advantages, for instance, in facilitating the carrying out of the essential nursing care of the patient, which is a complicated and difficult procedure in the Drinker respirator. The patient lies on an ordinary bed and has a greater freedom of movement and range of vision. He has full range of voluntary movements of his hands and arms and can comfortably feed himself if his arms are not paralysed. Full movements of the legs are of course possible. Paralysed limbs can be much more easily treated than in a chamber respirator. The Bragg-Paul Pulsator.--Another apparatus for prolonged artificial respiration, on a different principle from that of the Drinker respirator or its modifications, is the Bragg-Paui Pulsator, designed by R. W. Paul, M.I.E.E., F.INST.P., at the suggestion of Sir William Bragg, F.a.s. This apparatus consists of a distensible rubber bag applied around the patient's chest in the form of a belt, this belt being rhythmically inflated with, and emptied of, air from a bellows which is operated electrically. Several sizes of air-belts are available to suit different sizes of patients. The bellows is driven by a small motor which normally can be operated on any electric supply circuit, and may be connected to a lamp socket. The speed of the pulsator can be adjusted to suit the respiratory rate required and the pressure in the chest belt can be controlled by an escape-valve fixed to the bellows. A gauge indicates the amount of pressure applied to the chest and the rate of the compressions. Where electricity is not available, models are made to operate from accumulators or from the water supply. I n case of power failure all the models can be worked by hand. The principle of this method of artificial respiration is that each rhythmic inflation of the rubber chest belt compresses the patient's chest and forces expiration. When the belt is deflated, the elastic recoil of the chest wall produces inspiration. One of the objects of the recent exhibition of these types of apparatus was to encourage authorities in other parts of the country to acquire respirators for use in their own hospitals. The L.C.C. has received many applications for the loan of their respirators, but it has been sometimes difficult to comply with such requests. Now that the cheaper and effective types of respirator have been evolved the cost is no longer a barrier to their acquisition and it may be hoped that the respirators on the " Iron L u n g " principle will be available in every hospital or for home treatment.