Improvements in Sphygmo-manometers.
Year: 1897

page_text: Date of Application, 11th May, 1897
Complete Specification Left. 9th Feb. 1898-Accepted. 26th Mar., 1898
PROVISIONAL SPECIFICATION.
Improvements in Sphygmo-manometers.
We, LEONARD ERSKINE HILL, of Jasmine Cottage, Frognal, Hampstead, Lecturer
on Physiology, HAROLD LESLIE BARNARD, of 36, Hamilton Road, Highbury, Fellow
of the Royal College of Surgeons, and JAMES JOSEPH HICKS, of 8, Hatton Garden,
Meteorological Instrument Maker, all in the County of London, do hereby declare
the nature of this invention to be as follows:-
The invention has for its object improvements in sphygmo-manometers whereby
not only the blood pressure but also the pulsations are clearly indicated on a scale,
the blood pressure being indicated in our improved instrument by the maximum of
such pulsations.
According to our invention we employ a spring clasp preferably of steel, lined
with a flaccid rubber bag and made to partially or entirely encircle the arm or other
part of the body. We connect this rubber bag by a tube with an air pump and a
manometer the latter consisting of a chamber like that of an aneroid barometer
but not exhausted; such chamber has pressing on its outer side a spring which is
compressed by the pressure of air within the chamber and acts to return the side of
said chamber to its normal position when the pressure is relieved. This chamber
operates a hand or pointer by similar mechanism to that used in an ordinary
anercid barometer and said hand or pointer moves over a suitably divided scale.
The tube attached to the pump is provided with a valve whereby the air pressure
can be gradually relieved when desired until the maximum pulsation of the hand
or pointer is obtained and it is also provided with an ordinary non-return valve to
prevent loss of pressure except when the relief valve is operated.
The mode of using the apparatus is as follows:-The spring clasp is placed, say
around the arm, pressure is then applied by means of the pump until the rubber
bag within the clasp applies sufficient pressure on the arteries to give the maximum
pulsation of the hand or pointer and also to give the pressures at which the
pulsation appears and disappears as the pressure is raised.
Dated this 11th day of May 1897.
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.
Improvements in Sphygmo-manometers.
We, LEONARD ERSKINE HILL, of Jasmine Cottage, Frognal, Hampstead, Lecturer
on Physiology, HAROLD LESLIE BARNARD, of 36, Hamilton Road, Highbury, Fellow
of the Royal College of Surgeons, and JAMES JOSEPH HICKS, of 8, Hatton Garden,
Meteorological Instrument Maker, all in the County of London, 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:-
The invention has for its object improvements in sphygmo-manometers whereby

page_text: not only the blood pressure in the arteries of man or animal, but also the pulsations
of the arteries are clearly indicated on a scale, the mean arterial blood pressure being
indicated in our improved instrument by the maximum of such pulsations.
Our invention is illustrated in the accompanying drawings, in which :-
Fig. 1 is a view of the apparatus complete.
Fig. 2 is a side elevation and Fig. 3 is a plan of the manometer, and
Fig. 4 is a section of part of the clasp or armlet separately.
According to our invention we employ a clasp or armlet a preferably of steel
covered with india rubber, but it may be of other suitable material, and lined with a
flaccid rubber bag 6 and made to partially or entirely encircle the arm or other part
of the body.
We connect this rubber bag b, by a tube c, with an air pump d and with the
tube el of a manometer having a chamber e like that of an aneroid barometer, but
not exhausted; such chamber has pressing on its outer side a spring f, which is
. compressed by the pressure of air within the chamber e and acts to return the side
of said chamber to its normal position when the pressure is relieved.
This chamber operates a hand or pointer by similar mechanism to that used in
an ordinary aneroid barometer, as hereinafter described, and said hand or pointer g
moves over a suitably divided scale h.
The chamber is fixed to the foundation plate j and it has fixed to its upper
side an arm k connected by link with a small adjustable lever m¹ fixed on the
pivoted shaft m, to which latter is also fixed a longer lever m². This lever m² is
connected by link n and chain n¹ with a pulley on the spindle g¹ of the hand.
or pointer g, and to such spindle g¹ is attached one end of a spiral spring o, the other
end of which is connected to one of the pillars of a frame p carried by the fixed
arm extending over the chamber e.
The tube attached to the pump is provided with a valve i similar to that
used with pneumatic tyres, whereby the air pressure can be gradually relieved
when desired by slightly rotating the part until the maximum pulsation of the
hand or pointer g is obtained, and it is also provided with an ordinary non-return
valve to prevent loss of pressure except when the relief valve is operated.
The mode of using the apparatus is as follows:-The clasp or armlet a is lightly
fixed, say around the arm, pressure is then applied by means of the pump d until
the rubber bag.b on the inside of the clasp or armlet applies sufficient pressure on
the arteries to give the maximum pulsation of the hand or pointer g and also to
give the pressures at which the pulsation appears and disappears as the pressure is
raised.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:-
A sphygmo-manometer comprising, in combination, a clasp or armlet, a flexible
air bag on the inside of such clasp, an air pump, a tube connecting such flexible bag
with the air pump and a manometer comprising a flexible chamber connected to
said flexible bag, a pointer mechanically connected to the flexible chamber of the
manometer so as to be moved thereby in response to the pressure and pulsation of
pressure on the flexible rubber bag, and a scale over which the pointer moves to
indicate the mean arterial blood pressure and pulsations, substantially as herein
set forth and represented in the drawings.
1000
HARRIS & MILLS..
23; Southampton Buildings, London, W.C., Agents.