Abstract: Apparatus for rupturing muscle fibres in a lower oesophageal sphincter comprises a balloon catheter. A multi-electrode impedance planimetry measuring system comprising a pair of stimulating electrodes and sensing electrodes is located on the catheter within the balloon for monitoring the diameter of the balloon when the balloon is inflated with a liquid saline solution from a reservoir through a flowmeter under the control of a microprocessor. The microprocessor computes the minimum diameter value from signals read from the sensing electrodes each time the cumulative volume of the liquid saline solution in the balloon increases by a predefined unit volume. The microprocessor computes a curve of a plot of the minimum diameter values against the corresponding cumulative volume values and determines the slope at each computed minimum diameter value. Rupture of the muscle fibres of the sphincter is determined at the point of inflection of the curve.

Abstract: A method and apparatus for a balloon catheter can be provided. The balloon catheter includes a catheter and a balloon, a plurality of measuring electrodes formed on a primary substrate extend around the catheter within the balloon. The primary substrate and secondary substrate is formed by a portion of a flexible resilient membrane. The membrane is coiled to form a roll, and a primary substrate is also coiled around a rolled secondary substrate. The coiled primary and secondary substrates is urged through a second lumen in the catheter from the proximal end thereof to a radial slot in the catheter communicating with the second lumen. The primary substrate is urged through the radial slot and wrapped around and bonded to the catheter to form the measuring electrodes as band electrodes.

Abstract: A balloon catheter comprises a catheter and a balloon located on the distal end of the catheter. A pair of stimulating electrodes for receiving a constant current stimulating signal when the balloon is inflated with an electrically conductive medium and a plurality of sensing electrodes for producing voltage response signals are located on the catheter. The voltage response signals are indicative of the values of the transverse cross-sectional area of the balloon adjacent the sensing electrodes. A first lumen accommodates the inflating medium to and from the balloon, and a second lumen accommodates electrically conductive wires to the stimulating and sensing electrodes. A pressure sensing element is located in a protective housing in the second lumen, and communicates through a communicating opening in the protective housing and through a communicating port in the catheter with a hollow interior region of the balloon.

Abstract: In a system (2) having a balloon catheter (1) with a balloon (7) and an elongated catheter (3), a planimetry measuring system (19) in the balloon, and a linear distance measuring element (23) slideable along the elongated catheter from a proximal end (4) thereof to the datum location (8) when the balloon catheter has been inserted through the arterial system with the balloon located in the valve orifice (17), a plurality of secondary optically detectable elements (30) are equi-spaced longitudinally along the catheter and an optical encoder (32) in the linear distance measuring element counts the detectable elements as the linear distance measuring element is moved from a reset position to the datum location. A signal processor (20) reads signals from the linear distance measuring element and from the planimetry measuring system for determining the distance of the valve orifice of the aortic valve (9) from the datum location.

Abstract: A balloon catheter (60) comprises an elongated catheter member (63) and an inflatable balloon (65) located adjacent a distal end (5) of the catheter member (63). Band type measuring electrodes (7) located on the catheter member (63) within the balloon (65) comprise a pair of outer stimulating electrodes (8) and sensing electrodes (9) for measuring the cross-sectional area and volume of the balloon (65) by impedance planimetry measuring. A light emitting diode (20) is located on each measuring electrode (7) for emitting light so that the location of the balloon catheter, and in particular, the measuring electrodes (7) can be detected in a vessel (91) with a translucent wall within the body of a human subject.

Abstract: A balloon catheter comprising a catheter (3) and a balloon (7) located at a distal end (5) of the catheter (3). A plurality of measuring electrodes (12) formed on a primary substrate (17) extend around the catheter (3) within the balloon (7). The primary substrate (17) is formed by a portion of a flexible resilient membrane (25) which also forms a secondary substrate (19). The measuring electrodes (12) are formed on the primary substrate (17) by first electrically conductive tracks (27) and second electrically conductive tracks (28) which are electrically connected to the first electrically conductive tracks (27) are simultaneously formed on the secondary substrate (19). The membrane (25) is coiled to form a roll, and the primary substrate (17) is also coiled around the rolled secondary substrate (19).

Abstract: A device (1) for monitoring the transverse cross-section of a gastric sleeve (3) as the gastric sleeve (3) is being formed in a stomach (4) during a sleeve gastrectomy procedure comprises a catheter (15) with a primary balloon (19) located thereon towards a distal end (17). The primary balloon (19) is located in the stomach, and the portion of the stomach which is to form the gastric sleeve (3) is stretched around the primary balloon (19) when the primary balloon (19) has been inflated to a diameter approximating to the diameter to which the sleeve (3) is to be formed. As the stomach (4) is being sutured to form the sleeve (3) the pressure within the primary balloon (19) is monitored to avoid excessive stretching of the stomach around the primary balloon (19). The diameter of the primary balloon (19) is also monitored to avoid necking of the sleeve (3) during suturing of the stomach (4).

Abstract: A device (1) comprises a sheath (9) for protecting a balloon catheter (2) from contamination with bodily fluids and other matter during the carrying out of a procedure or investigation at a remote site in a human or animal body. The sheath (9) defines a catheter accommodating portion (14) and a balloon accommodating portion (15) for accommodating a catheter (4) and a balloon (8) of the balloon catheter (2) therein. The sheath (9) is of a flexible material having a closed distal end (11) and a proximal opening (13) at a proximal end (10) thereof to a hollow interior region (12) within which the balloon catheter (2) is accommodated. A guide wire engaging distal portion (19) engages and locates a guide wire (7) within the sheath (9). The balloon accommodating portion (15) permits inflating of the balloon (8) to a predefined volume.

Abstract: A balloon catheter (1) comprises a catheter (2) and a balloon (6) located on the distal end of the catheter. A pair of stimulating electrodes (15) for receiving a constant current stimulating signal when the balloon (6) is inflated with an electrically conductive medium and a plurality of sensing electrodes (16) for producing voltage response signals are located on the catheter (2). The voltage response signals are indicative of the values of the transverse cross-sectional area of the balloon (6) adjacent the sensing electrodes (16). A first lumen <9) accommodates the inflating medium to and from the balloon (6), and a second lumen (19) accommodates electrically conductive wires (18) to the stimulating and sensing electrodes (15,16).

Abstract: A system for inflating a balloon (8) of a balloon catheter (4) with a liquid inflating medium which removes air during inflation of the balloon (8) comprises a vertically mounted syringe (36) containing the liquid inflating medium for inflating the balloon (8). Air in the system is displaced into a return lumen (30) and a return line (46). Air drawn into the syringe (36) with the liquid inflating medium is trapped between a piston (39) of the syringe and a top surface of the liquid inflating medium in the syringe, and thereby separated from the liquid inflating medium. Re-inflating and deflating of the balloon continues until the level of air in the balloon, the flow and return lumens and the flow and return lines (44,45) has been reduced to a predefined level. Then, an accurate determination of the inflation pressure can be read from first and second pressure sensors (50,51; 52,53) on the return and flow lines, respectively.

Abstract: Apparatus for determining the volume of a vessel (2,3) or a part thereof comprises a balloon catheter (5) having a catheter (6) and an inflatable balloon (10) located at a distal end (8) thereof which when inflated defines with the catheter (6) an annular hollow interior region (12). A pair of spaced apart stimulating electrodes (14) are located on the catheter (6) within the balloon (10) and a plurality of spaced apart sensing electrodes (15) are located on the catheter (6) between the stimulating electrodes (14). The balloon (10) is inflated by an electrically conductive saline solution to define the interior of the vessel (2,3). A stimulus signal of constant current is applied to the stimulating electrodes (14), resulting voltages on the sensing electrodes (15) are read for determining the transverse cross-sectional area of the balloon adjacent the respective sensing electrodes (15).

Abstract: A system (1) for dilating an occlusion (3) in an oesophagus (4) comprises a device (5) having a catheter (8) extending from a proximal end (9) to a distal end (10). An inflatable balloon (12) defining a hollow interior region (14) is located on the catheter (8) adjacent the distal end (10) thereof for dilating the occlusion (3). The balloon (12) is inflated with a saline solution by a pump (34) through an axial communicating bore (20) and radial communicating bores (21) in the catheter (8). A pair of stimulating electrodes (25) on the catheter (8) within the balloon (12) adjacent axially opposite ends (18,19) thereof receive stimulating voltage signals from a signal generator (43).