Improvements in and in connection with Apparatus for Administering Anæsthetics and for similar purposes.
Year: 1897

page_text: Date of Application, 1st Dec., 1897-Accepted, 15th Jan., 1898
COMPLETE SPECIFICATION.
Improvements in and in connection with Apparatus for Administering
Anæsthetics and for similar purposes.
I, CILARLES WILLIAM KROHINE, of 8, Duke Street, Manchester Square, London, W.,
Manufacturer of Surgical Instruments and Appliances, do hereby declare the
nature of this invention, and in what manner the same is to be performed, to be
particularly described) and ascertained in and by the following statement: —
When using chloroform, methylene, ether, and the like for producing anaesthesia
in the performance of surgical operations, it is very necessary that the absorption of
the desired quantity of the anaesthetic used should be effected so as to ensure com-
plete anesthesia, within a definite time varying according to the age and con-
stitution of the patient, and to accomplish. this safely, it is necessary that the
administration should be commenced in every case, with the anaesthetic very much
diluted. There should then be a gradual and systematic increase to the largest
percentage of vapour, which the patient is able to inhale comfortably, with normal
and regular inspiration, until anesthesia of the required degree is reduced. In
ordinary apparatus an air-ball is held in the hand of the operator and compressed
so as to pump air through the apparatus for the purpose of evaporating the chloro-
form or other anaesthetic and carrying it to the mask over the mouth and nostrils
of the patient, and the variation in quantity and strength of each inspiration is
controlled by the degree of compression given to the air-ball.
This invention relates to means whereby the amount of compression given to
the air-ball is known and can be regulated to a known degree and by which the
gradual increase in quantity and strength at each inspiration is readily effected.
According to this invention the air-ball is constructed of such shape that the
amount of air displaced by a full compression between the fingers of the operator,
gradually increases as the operator acts upon a different part of its surface. This
is preferably, though not necessarily, effected in a regular manner, and suitable
indicating marks are placed on the outside of the ball so that the amount of air
displacement is known. It will thus be seen that by gradually proceeding from
the smaller to the greater, the gradual increase in strength and quantity required
is effected in a regular and known manner.
Referring to the accompanying sheet of illustration drawings Fig. 1 is an
elevation and Fig. 2 a section of sufficient of the apparatus to show the invention.
The air ball is provided with a suitable non-return valve band at c is con-
nected by a suitable outlet with the upper ball d surrounded by restraining
netting c. The ball a is shaped so that according to which of the parallel zones
indicated by the marking bands f, f f f³, f, the operator compresses so the
amount of air displaced, vanes and such variations is preferably arranged in the
ratio of, and 1 or other predetermined ratio. It will be seen that by first
acting upon the zone 1 and gradually passing to 2, 3 and 4 the amount of air dis-
placed and consequently the amount of anaesthetic administered can be gradually
increased in a regular and known manner.
13
4'
The ball a is preferably shaped so that the bands f, f' are at substantially equal
distances apart but this is not absolutely necessary.

page_text: This invention is also applicable in all cases where air-balls are used in a
similar manner.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
(1) In apparatus for administering anaesthetics and for similar purposes con-
structing the air ball of such shape that the amount of air displaced and con-
sequently the quantity and strength of anesthetic administered, is regulated
according to the portion of the air-ball upon which the hand of the operator acts,
substantially as described."
(2). In apparatus for administering, anaesthetics and for similar purposes,..con-
structing the air-ball of such shape that by changing the portion of its surface
acted upon by the hand of the operator, the amount of air displaced and conse-
quently the quantity and strength of anesthetic administered can be gradually
increased in a regular and known manner substantially as described.
(3) In apparatus for administering anaesthetics and for similar purposes the
construction of the air-hall a provided with non-return-inlet valve band outlet c,
the air-ball being so shaped that the amount of air displaced and consequently
the quantity and strength of anaesthetic administration depends upon which
portion of the ball is acted upon by the hand of the operator, the degree of com-
pression being indicated by the marking bands.f, f', f³, f³, f substantially as
described with reference to the accompanying drawings.
Dated this 1st day of December 1897.
.:
GEO. H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.
GEO. H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.