US 12,263,321 B2
Method for ascertaining the vertical distance between a patient (level of surgical intervention) and a fluid delivery pump
Thomas Christmann, Berlin (DE); Jan Hendrik Carstens, Berlin (DE); and Hans-Joachim Cappius, Berlin (DE)
Assigned to W.O.M. WORLD OF MEDICINE GMBH, Berlin (DE)
Appl. No. 17/052,299
Filed by W.O.M. WORLD OF MEDICINE GMBH, Berlin (DE)
PCT Filed May 2, 2019, PCT No. PCT/DE2019/000118
§ 371(c)(1), (2) Date Nov. 2, 2020,
PCT Pub. No. WO2019/210894, PCT Pub. Date Nov. 7, 2019.
Claims priority of application No. 10 2018 003 519.1 (DE), filed on May 2, 2018.
Prior Publication US 2021/0236711 A1, Aug. 5, 2021
Int. Cl. A61M 3/02 (2006.01)
CPC A61M 3/0216 (2014.02) [A61M 3/0258 (2013.01); A61M 3/0202 (2021.05); A61M 2205/3327 (2013.01); A61M 2205/3344 (2013.01); A61M 2205/6054 (2013.01); A61M 2205/6072 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for determining a difference in height level hpat between a patient (10) and a fluid feed pump (5) with a current sensor (12) and with a bidirectional pressure sensor (6) in a second tube section (7) between fluid feed pump (5) and connection to a connector (8) or an instrument (9),
comprising a reservoir (1) of a medical device arranged above the fluid feed pump (5), fluidic connection paths that are initially unfilled, and a volume of the fluidic connection paths being known, characterized by the following steps:
a) fluid feeding by the fluid feed pump (5) with a transport roller wheel (4) through a through-going fluidic connection of the reservoir (1),
b) stop fluid feeding as soon as the bidirectional pressure sensor (6) detects a change in pressure, which is caused by a fed water column,
c) backward rotation of the transport roller wheel (4) while measuring, by the current sensor (12), a motor current required for feeding from a first tube section (3) to the reservoir (1),
d) calculation of a pressure value Pwat of a water column before the fluid feed pump from the required motor current,
e) continuation of fluid feeding until the second tube section (7) is completely filled,
f) detection of the fluid exiting from an open end of the second tube section (7) or the instrument (9) by evaluation of the pressure values at the bidirectional pressure sensor (6),
g) termination of fluid feeding,
h) evaluation of a pressure value Phyd of the bidirectional pressure sensor (6),
i) use of the pressure value Phyd for the determination of the difference in height level hpat between the fluid feed pump and the patient (10),
wherein when the pressure value Phyd is positive, this indicates that the fluid feed pump (5) is below the height level of the patient (10),
when the pressure value Phyd is negative, this indicates that the fluid feed pump (5) is above the height level of the patient (10),
when the pressure value Phyd is 0 (zero), this indicates that the fluid feed pump (5) is at a height level of the patient (10).